BG1.1 | The Role of Fire in the Earth System: Understanding Interactions with the Land, Atmosphere, and Society
EDI
The Role of Fire in the Earth System: Understanding Interactions with the Land, Atmosphere, and Society
Co-organized by AS3/CL2/NH7
Convener: Fang Li | Co-conveners: Antonio Girona-GarcíaECSECS, Angelica Feurdean, Renata Libonati, Rebecca ScholtenECSECS, Sander Veraverbeke
Orals
| Mon, 15 Apr, 08:30–12:30 (CEST), 14:00–15:45 (CEST)
 
Room C
Posters on site
| Attendance Tue, 16 Apr, 10:45–12:30 (CEST) | Display Tue, 16 Apr, 08:30–12:30
 
Hall X1
Posters virtual
| Attendance Tue, 16 Apr, 14:00–15:45 (CEST) | Display Tue, 16 Apr, 08:30–18:00
 
vHall X1
Orals |
Mon, 08:30
Tue, 10:45
Tue, 14:00
Fire is the primary terrestrial ecosystem disturbance globally and a critical Earth system process. Fire-related research is rapidly expanding across disciplines and sectors, reflecting the pressing need to deepen our understanding of fire phenomena. This need will likely grow as future fire activity increases. This session invites contributions that investigate the role of fire within the Earth system across any temporal and spatial scale, using statistical (including AI) and process-based models, field and laboratory observations, proxy records, remote sensing, and data-model fusion techniques. We strongly encourage abstracts that deepen our comprehension of fire's interactions with: (1) weather, climate, atmospheric chemistry, and circulation, (2) land physical properties, (3) vegetation composition and structure and biogeochemical cycle, (4) cryosphere elements and processes (such as permafrost, sea ice), and (5) human health, land management, conservation, and livelihoods. Moreover, we welcome submissions that address: (6) spatial and temporal changes in fire in the past, present, and future, 7) fire products and models, and their validation, error/bias assessment and correction, as well as (8) analytical tools designed to enhance situational awareness for fire practitioners and to improve fire early warning systems.

Session assets

Orals: Mon, 15 Apr | Room C

Chairpersons: Fang Li, Sander Veraverbeke, Angelica Feurdean
08:30–08:35
Fire observations and reanalyses
08:35–08:45
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EGU24-10947
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solicited
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Highlight
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On-site presentation
Guido van der Werf, James Randerson, Dave van Wees, Yang Chen, Roland Vernooij, Louis Giglio, Joanne Hall, Douglas Morton, Kelley Barsanti, and Bob Yokelson

Quantifying burned area and associated fire emissions is paramount to understand how changing fire patterns affect radiative forcing and air quality. It is now well established that many fires are too small to be detected by coarse resolution satellite burned area products on which the Global Fire Emissions Database (GFED) relied. In the fifth version of GFED (GFED5) we therefore combine burned area derived from mapped coarse-resolution burned area from the MODIS sensor -which excels in detecting larger fires- with small-fire burned area. The latter is derived from MODIS active fire detections scaled to burned area using ratios constrained by higher-resolution burned area datasets from Landsat and Sentinel-2 for selected regions. Burned area in cropland regions was based on the Global Cropland Area Burned (GloCAB) dataset. Total global burned area is 61% higher than in GFED4s. We converted burned area to emissions using a simplified version of the CASA model used in previous GFED versions, but which now runs at a 500 m spatial resolution. This allows for better constrained modeled fuel loads based on field measurements. Although GFED5 emissions are aggregated to a 0.25 degree grid due to the statistical nature of deriving our burned area, we can now account for heterogeneity in fire processes within these large pixels. Emissions (3 Pg carbon per year) are roughly 50% higher than in GFED4 and we show how diverging trends in grassland versus forest ecosystems impact trends in total emissions. Finally, we show how converting fire carbon losses to trace gas and aerosol emissions is now better constrained due to the addition of several new emission factor measurement campaigns. In the savanna biome we now account for spatial and temporal variability in emission factors.

How to cite: van der Werf, G., Randerson, J., van Wees, D., Chen, Y., Vernooij, R., Giglio, L., Hall, J., Morton, D., Barsanti, K., and Yokelson, B.: Burned area and fire emissions according to the fifth version of the Global Fire Emissions Database (GFED), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10947, https://doi.org/10.5194/egusphere-egu24-10947, 2024.

08:45–08:55
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EGU24-19330
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On-site presentation
Marc Padilla, Ruben Ramo, Sergio Sierra, Bernardo Mota, Roselyne Lacaze, and Kevin Tansey

Current global burned area products are available at coarse spatial resolutions (300-500 m), what leads to large amounts of errors, hindering an accurate understanding of fire-related processes. This study proposes a global calibration method for a sensor-independent burned area algorithm, previously used with 300 m Sentinel-3 Synergy data, and here implemented with 20 m Sentinel-2 MSI imagery. A binomial model that combines reflectance-based burned area predictions constrained by spatio-temporal densities derived from VIIRS active fires is calibrated using a reference dataset generated from Landsat imagery at a sample of 34 units across the globe. Preliminary leave-one-out cross-validation analyses show promisingly high accuracies (Dice of coefficient of 84.8%, commission error ratio of 13.2%, omission error ratio of 17.1% and relative bias of -4.5%), especially taking into account the mismatch of acquisition dates between reference and algorithm input data, what introduces apparent errors on the validation results.

How to cite: Padilla, M., Ramo, R., Sierra, S., Mota, B., Lacaze, R., and Tansey, K.: Burned Area Mapping with Sentinel-2 based on reflectance modelling and deep learning – preliminary global calibration and validation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19330, https://doi.org/10.5194/egusphere-egu24-19330, 2024.

08:55–09:05
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EGU24-12529
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ECS
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Highlight
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On-site presentation
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Alice Hsu, Jane Thurgood, Adam Smith, Liana Anderson, Hamish Clarke, Stefan Doerr, Paulo Fernandes, Crystal Kolden, Cristina Santín, Tercia Strydom, and Matthew Jones and the GlobalRx Consortium

Prescribed (Rx) and controlled fires are an important land management tool used globally for a variety of reasons, including the reduction of hazardous fuel loads, ecological conservation, agriculture, and natural resource management. Its use has important implications for wildfire risk, biodiversity, and carbon storage. However, the use of Rx and controlled fires is highly dependent upon weather conditions, requiring a weather window during which a careful balance of temperature, moisture, and wind ensure that the burns achieve their objectives while minimizing ecological damage or risk to human lives or assets. The planning and execution of Rx burns must also consider how these weather conditions interact with the local vegetation and ecology. As fire weather is projected to grow more extreme under the impacts of climate change, there is a growing need to monitor this effect on the ability to carry out Rx burning.

Here, we introduce a new dataset, GlobalRx, which includes around 140,000 records of Rx and other controlled fires from 16 countries, encompassing 207 ecoregions and 13 biomes around the world. For each record, we have geolocated values of various metrics of fire weather and fire danger (e.g. fire weather indices, vapour pressure deficit) from the ERA5 meteorological reanalysis, as well as the biome, ecoregion, fuelbed type, and protected area status from global thematic layers. We demonstrate the usefulness of this dataset for analyzing viable meteorological windows under which Rx fires may be conducted across diverse environmental settings in the present climate, as well as how these Rx burning windows may shift under the threats of climate change. This dataset has potential to shed light on how Rx burning windows may shift under future climate change, as well as opportunities to understand other drivers and effects of Rx burning.

This project has been supported by valuable contributions from non-public data from a consortium of data providers: Parks Canada, South Africa National Parks, Brazilian Institute of the Environment and Renewable Natural Resources, East-Pyrenees Prescribed Burning Team, Institute for Nature Conservation and Forests (Portugal), Regional Forest Fire Service (Italy), Russian Federal Forestry Agency, H2020 LifeTaiga Project, Government of the Principality of Asturias, Council of Andalucía, Council of Galicia, Forestry England, National Forestry Commission of Mexico, ZEBRIS Geo-IT GmbH, Hokkaido University, Pau Costa Foundation, Asian Forest Cooperation Organization.

How to cite: Hsu, A., Thurgood, J., Smith, A., Anderson, L., Clarke, H., Doerr, S., Fernandes, P., Kolden, C., Santín, C., Strydom, T., and Jones, M. and the GlobalRx Consortium: GlobalRx: A global assemblage of regional prescribed fire records for use in assessments of climate change impacts, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12529, https://doi.org/10.5194/egusphere-egu24-12529, 2024.

09:05–09:15
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EGU24-1756
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ECS
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On-site presentation
Will Maslanka and Martin Wooster

Landscape fires are a widespread natural phenomenon that directly influences carbon cycling through the combustion of organic material. Space-based remote sensing, including Active Fire (AF), remains the only way to estimate wildfire activity accurately on the regional-to-global scale. Fire emission inventories generally fall into two categories. “Bottom-up” methodologies rely on observations of AF counts, Fire Radiative Power (FRP), or burned area to estimate the amount of biomass burned, or “Top-down” methodologies, which directly relate observations of FRP to landscape fire emission estimates. Bottom-up methods tend to have a reliance on uncertain parameters, such as pre-fire fuel load and combustion completeness, or a conversion factor between FRP and fuel consumption rate. The Fire Radiative Energy Emission (or FREM) approach is one such top-down methodology that has removed such a reliance, by directly relating FRP to observed rates of emissions, such as CO or aerosols, but has so far been used with geostationary FRP data only. Whilst very effective at lower latitudes, due to the poor spatial resolution and extreme viewing geometry of geostationary data at higher latitudes, the approach is not applicable for fires in this region in its current format. However, by using polar orbiting FRP data and making use of the high latitude orbital convergence, this study looks to adapt the FREM approach to deliver direct estimation of carbon emissions for high latitude (>60°N) landscape fires. We use direct observations of FRP, from Suomi-NPP, NOAA-20 and MODIS, along with observations of Total Column Carbon Monoxide from TROPOMI onboard Sentinel-5P. A series of cloud-free plumes and associated FRP data were identified in Deciduous and Evergreen Needleleaf biomes in North America and Russia in the summers of 2019 – 2023. The resulting emission coefficients and emission totals were compared to pre-existing top-down and bottom-up emission coefficients and totals from the FEER, GFAS, and GFED inventories for high latitude fires between 2018-2023. This adapted FREM approach is shown to provide direct emission estimates without recourse to significant assumptions and can do so in real time – opening up a new avenue for real-time fire emission estimation at high latitudes.

How to cite: Maslanka, W. and Wooster, M.: Direct Estimation of Carbon Emissions from High Latitude Fires: The Adapted FREM Approach, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1756, https://doi.org/10.5194/egusphere-egu24-1756, 2024.

09:15–09:25
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EGU24-6077
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ECS
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On-site presentation
Ailish M Graham, James B McQuaid, Thomas E L Smith, Hanun Nurrahmawati, Devina Ayona, Hasyim Mulawarman, Chaidir Adam, Dominick V Spracklen, Richard Rigby, and Shofwan A B Choiruzzad

Air pollutant emissions from wildfires on Indonesian peatlands lead to poor regional air quality across south-east Asia. Fine particulate matter (PM2.5) emissions are particularly high for peat fires leading to substantial population exposure to PM2.5. Despite this, air quality monitoring is limited in regions close to peat fires meaning the impacts of peatland fires on air quality is poorly understood and it is difficult to evaluate predictions from atmospheric chemistry models. To address this, we deployed a network of low-cost (Purple Air) PM2.5 sensors at 8 locations across Central Kalimantan, where peat fires are frequent. The sensors measured indoor and outdoor PM2.5 concentrations during August to December 2023. During the haze season (September 1st to October 31st), daily mean outdoor concentrations were 120 mg m-3 but peaked at >400 mg m-3. Indoor PM2.5 concentrations were only ~10% lower (mean 110 mg m-3), indicating that is difficult for the population to reduce their exposure to PM2.5 from fires. The reduction in mean PM2.5 concentrations between outdoor and indoor environments was larger in urban locations (-11%) compared with rural locations (-3%), suggesting urban housing may provide better protection from outdoor air pollution. To generate an updated assessment for the population’s exposure to peatland fire PM2.5 we combine the information from monitoring both indoor and outdoor PM2.5 concentrations with modelled ambient (outdoor) PM2.5 concentrations from the WRF-Chem atmospheric chemistry transport model. Our updated exposure assessment accounts for the population’s personal exposure to peatland fire PM2.5 for the first time.

How to cite: Graham, A. M., McQuaid, J. B., Smith, T. E. L., Nurrahmawati, H., Ayona, D., Mulawarman, H., Adam, C., Spracklen, D. V., Rigby, R., and Choiruzzad, S. A. B.: Updated Exposure Estimate for Indonesian Peatland Fire Smoke using Network of Low-cost Purple Air PM2.5 sensors, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6077, https://doi.org/10.5194/egusphere-egu24-6077, 2024.

09:25–09:35
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EGU24-18941
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On-site presentation
Johannes Kaiser, Kerstin Stebel, Philipp Schneider, and Vincent Huijnen

Exceptional wildfire activity occurred in the Arctic during the last years due to pronounced heat episodes. The Arctic has an abundance of peat and soils with organic content. When peat is burnt, the carbon flux into the atmosphere is virtually irreversible and this process may become of global significance for Arctic fires. Furthermore, smoke from smoldering fires (below-ground, peat) has a different chemical composition than smoke from flaming fires. It is therefore important to distinguish peat fires and above-ground, potentially flaming fires in fire emission estimation.

The operational Copernicus Atmosphere Monitoring Service (CAMS) is tracking global fire activity and emissions with its Global Fire Assimilation System (GFAS) as a near-real time service. GFAS uses satellite-based observations of fire radiative power (FRP), which links observed thermal radiation directly to the biomass combustion rate, i.e. amount of biomass burnt and corresponding emission of carbon into the atmosphere, based on satellite retrievals from MODIS and VIIRS. 

Here, we present a partitioning of the Arctic fire activity represented in GFAS into smoldering below-ground and potentially flaming above-ground fires using two approaches: (1) masking the fire activity maps with published peat maps and (2) analysing the observed diurnal cycles of the fire activity at all locations. We subsequently apply adapted emission factors and compare the resulting emission estimates to the standard values produced by CAMS for carbon, carbon monoxide, nitrogen dioxide and aerosols.

Furthermore, we may confront the fire emission estimates with independent atmospheric smoke observations by feeding them into IFS-COMPO, which is used to generate hindcasts of atmospheric composition, including tropospheric columns of CO and NO2. This allows an evaluation of the estimated trace gas emissions, by comparing the model simulations to satellite retrievals of carbon monoxide and nitrogen dioxide. It thus provides an independent assessment of the estimated fire emissions, and, in turn, carbon flux.

How to cite: Kaiser, J., Stebel, K., Schneider, P., and Huijnen, V.: Arctic peat fire emissions estimated from satellite observations of fire radiative power, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18941, https://doi.org/10.5194/egusphere-egu24-18941, 2024.

09:35–09:45
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EGU24-17593
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On-site presentation
Ville Vakkari, Angela Buchholz, Liqing Hao, Mika Ihalainen, Kerneels Jaars, Kajar Köster, Viet Le, Pasi Miettinen, Arya Mukherjee, Saara Peltokorpi, Iida Pullinen, Stefan J. Siebert, Olli Sippula, Markus Somero, Lejish Vettikkat, Annele Virtanen, Pasi Yli-Pirilä, Arttu Ylisirniö, and Pieter G. van Zyl

Fire is an integral part of savanna and grassland biomes and globally approximately half of landscape fire emissions originate from savannas and grasslands. Emissions of trace gases and aerosol particles from landscape fires are characterised by emission factors (EFs), which denote the amount of emitted substance per mass of combusted biomass. EFs vary depending on both the biomass that is consumed in the fire and the combustion characteristics of the fire, i.e. the ratio of flaming to smouldering combustion. However, emission inventories tend to use only one average EF for each biome.

Here, we use a set of 27 laboratory experiments to characterise the effect of combustion characteristics on submicron aerosol EFs from savanna and grassland biomass acquired from South Africa as well as boreal forest floor samples from Finland. Combustion experiments were carried out at the ILMARI facility in Kuopio, Finland from May to June 2022 under an open stack mimicking natural burning and dilution. Sample was injected into a 29 m3 environmental chamber for ageing studies. Chemical and physical properties of both fresh and aged smoke were observed with a host of instruments including e.g. AMS, FIGAERO-CIMS, VOCUS, SP2 and SMPS. The ratio of flaming to smouldering combustion was characterised by modified combustion efficiency (MCE), i.e. CO2/(CO2+CO).

The increase of organic aerosol EF with increasing smouldering fraction (i.e. decreasing MCE) was very similar for both the grassland and savanna combustion experiments. Surprisingly, also the boreal forest floor EFs closely follow the same trend, where smouldering-dominated combustion EFs are more than 10 times higher than EFs for flaming combustion. We observed also that the submicron aerosol particle size distribution shifts towards larger sized particles with increasing smouldering fraction. Furthermore, both the number and the mass of the size distribution cannot be fully characterised with a single log-normal size distribution, which needs to be considered when converting mass emissions into number size distribution in simulations.

How to cite: Vakkari, V., Buchholz, A., Hao, L., Ihalainen, M., Jaars, K., Köster, K., Le, V., Miettinen, P., Mukherjee, A., Peltokorpi, S., Pullinen, I., Siebert, S. J., Sippula, O., Somero, M., Vettikkat, L., Virtanen, A., Yli-Pirilä, P., Ylisirniö, A., and van Zyl, P. G.: Effect of combustion conditions on aerosol particle emissions from savanna and grassland fires, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17593, https://doi.org/10.5194/egusphere-egu24-17593, 2024.

09:45–09:55
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EGU24-16676
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ECS
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On-site presentation
Victor Bon, Cyril Crevoisier, and Virginie Capelle

Biomass burnings are one of the major sources of greenhouse gases in the atmosphere, impacting air quality, public health, climate, ecosystem dynamics, and land-atmosphere exchanges. In the tropics, South America represents about 10 % of the tropical emissions and present a large diversity of biomes and fire conditions. Over the last two decades, satellite observations have provided crucial information, notably via active fires detection, Fire Radiative Power (FRP) estimates and burned area (BA) measurements from imagers such as Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS). Global inventories (e.g., GFED, GFAS, FEER, QFED, etc.) heavily rely on these satellite-derived indicators to estimate emissions from biomass burnings. However, emissions derived from these various models can significantly differ among them and large uncertainties persist regarding fire emissions, their variability, and their links with several drivers (e.g., type of combustion, vegetation, transport, etc.).

In this context, we propose a novel approach to estimate emissions from biomass burnings by directly using greenhouse gas concentrations in the atmosphere derived from spaceborne observations. Leveraging a decade of observations from the Infrared Atmospheric Sounding Radiometer (IASI) on-board the three Metop satellites, we have access to an unprecedented spatial coverage of global mid-tropospheric CO2 and CH4 concentrations twice a day (9:30 AM/PM LT). From this dataset, we developed the Daily Tropospheric Excess (DTE) method, which is based on the use of the diurnal cycle of biomass burnings and the vertical transport of their emissions to link the observed diurnal variations of the mid-tropospheric CO2 and CH4 concentrations to burnings activities.

We will demonstrate the relevance of the DTE for analyzing CO2 and CH4 emissions from various type of burnings, biomes, and human activities across South America. This will be achieved by comparing DTE with existing indices of fire characteristics such as FRP and BA from MODIS/SUOMI satellite observations, alongside global emissions databases like GFED and GFAS. Globally, we will show that their spatial distribution, seasonal intensity, and interannual variability are consistent with each other, even if some differences have been found and will be discussed. Additionally, geostationary data from GOES-R, MSG, and Himawari-8 satellites will be used to analyze the impact of observation times on the differences observed between the various datasets and the DTE.

How to cite: Bon, V., Crevoisier, C., and Capelle, V.: Study of greenhouse gases emitted by biomass burnings with a decade of infrared observation of CO2 and CH4 by IASI, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16676, https://doi.org/10.5194/egusphere-egu24-16676, 2024.

09:55–10:05
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EGU24-11599
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ECS
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On-site presentation
Dave van Wees, Vincent Huijnen, Matthias Forkel, Jos de Laat, Niels Andela, and Christine Wessollek

Amazon forest conservation is critical for reaching net-zero carbon emissions and protecting regional biodiversity but these efforts are at risk from deforestation, fire and drought. In particular, accurate quantification of carbon losses from forest and deforestation fires are required to understand long-term impacts of fire on the carbon cycle and inform management strategies. Recent developments in the detection of burned area, near-real time tracking of fire patch metrics, and higher-resolution fire emissions models allow for improved estimates of carbon losses from fire. Nevertheless, independent validation of these novel approaches often remains elusive, leading to large disagreement between different emissions inventories.

Here, we compare carbon emissions estimates from several state-of-the-art fire emissions models, including a 500-m resolution GFED version, GFAS, and the Sense4Fire project, in a case-study for the Amazon region. Where necessary, we have updated the models to extend to 2022 and to include the most recent version of model input data from MODIS (Collection 6.1). We analysed the added years of data to elucidate recent trends in fire-related carbon emissions across the Amazon and adjacent biomes. For validation, we ingested the CO emissions from the considered fire emissions models into an atmospheric transfer simulation (IFS-COMPO) and compared those to column CO observations from Sentinel-5P TROPOMI. Finally, we propose an optimization methodology for matching modelled CO concentrations to observations with the objective of constraining regional carbon losses from fire. Results provide novel insights into carbon losses from fire across different fire types and land use practices, and can be extended to global scale for improved estimates of global fire emissions.

How to cite: van Wees, D., Huijnen, V., Forkel, M., de Laat, J., Andela, N., and Wessollek, C.: Comparison and validation of state-of-the-art fire emissions models for the Amazon, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11599, https://doi.org/10.5194/egusphere-egu24-11599, 2024.

10:05–10:15
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EGU24-11962
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On-site presentation
Nicholas Kettridge, Katy Ivison, Alistair Crawford, Gareth Clay, Claire Belcher, Laura Graham, and Kerryn Little

New fire vulnerable communities are emerging in traditionally non-fire prone regions of the world. But these communities are often largely unaware of the developing threat and do not hold the core wildfire knowledge to galvanise collective community-based action to mitigate the risk. Furthermore, we urgently require knowledge of fuel moisture dynamics and flammability of fuels in such regions to provide accurate assessments of fire danger at the national scale. Here we characterise the moisture content and flammability of heather through engaged environmental science, demonstrating the potential of the approach to develop a public consciousness and knowledge of wildfire within communities. Fuel sampling kits were sent to 150 samplers who collected ~1000 vegetation samples across the UK (from Land’s End to John O’Groats) over a period of two days during a single period of high fire danger. The validity of the volunteer approach for collecting high quality fuel moisture data was also assessed from the analysis of a separate ~1500 samples collected by 17 samplers in a single test plot. The approach provides a simple nationally available entry point for residents traditionally unaware of both the wildfire risk and the management of their community for wildfire mitigation. Empowering samplers offers potential future opportunity to create meaningful local datasets, to build communities, and in doing so give a strong voice to residents in regional and national policy discussions.

How to cite: Kettridge, N., Ivison, K., Crawford, A., Clay, G., Belcher, C., Graham, L., and Little, K.: The Great Fuel Moisture Survey: developing fundamental wildfire science and sustainable community owned agency in traditionally non-fire prone societies, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11962, https://doi.org/10.5194/egusphere-egu24-11962, 2024.

Coffee break
Chairpersons: Sander Veraverbeke, Fang Li, Angelica Feurdean
Fire drivers and influence
10:45–10:55
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EGU24-5191
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ECS
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Highlight
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On-site presentation
Tsin Hung Leo Ng, Amos P. K. Tai, Stephen Sitch, Luiz Aragao, and Shixian Zhai

Biomass burning in Amazon Basin has a significant impact on regional climate and deteriorates regional air quality, which poses a threat to human and ecosystem health. The fire-induced pollution worsens during dry season (Jul to Nov) and shows a strong seasonal variation. Past research has demonstrated that the occurrence of wildfires in Amazon is not only influenced by deforestation, but also interannual climate variability, particularly droughts. Here we estimate the impacts of deforestation and droughts on fire emissions and regional air quality between 2010 to 2015 by using Global Fire Emission Database Version 4 (GFED v4) to drive a global 3-D atmospheric chemical transport model GEOS-Chem High Performance (GCHP) and further examine the effect of PM2.5 and O3 on premature mortality across the region. By comparing the “fire-on” and “fire-off” scenarios, we find that biomass burning alone in normal years (2011 and 2013) contributes 5.7 μg m-3 (47.6% of the total concentration) PM2.5, 0.08 ppm (46.3%) CO, 0.03 ppb (85.0%) NOx, and 9.5 ppb (41.2%) O3; and these numbers during drought years (2010, 2012, 2014 and 2015) increase to 19.6 μg m-3 (74.7%) for PM2.5, 0.20 ppm (67.0%) for CO, 0.19 ppb (97.4%) for NOx, and 15.6 ppb (52.0%) for O3. We find that these pollutants from wildfires mainly concentrate in the south-eastern Amazon and then transport southward, thus strongly impacting public health in the downwind regions. We estimate that premature mortality due to long-term exposure to particulate matter and ozone by applying the simulated concentration to the concentration-response functions from the European Environment Agency. We find that ~8,500 and ~10,400 deaths per year are attributable to PM2.5 and O3 exposure for 2010-2015 respectively. During drought years, we discover there are 2.8% and 3.4% more deaths than normal years for PM2.5 and O3 exposure. Our study shows the significance of biomass burning emissions in shaping the air quality in the Amazon region, and highlights the impact of drought events on enhancing biomass emissions, worsening regional air quality and causing public health issues. Therefore, it is important to address the underlying causes of biomass burning in the Amazon, such as deforestation and land use change, and droughts, to protect the region's ecosystems and mitigate the impacts of climate change.

How to cite: Ng, T. H. L., Tai, A. P. K., Sitch, S., Aragao, L., and Zhai, S.: Impacts of land use change and interannual climate variability on biomass burning emissions, air quality and public health in Amazon, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5191, https://doi.org/10.5194/egusphere-egu24-5191, 2024.

10:55–11:05
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EGU24-2099
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ECS
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On-site presentation
Gengke Lai, Jialing Li, Jun Wang, Chaoyang Wu, Yongguang Zhang, Constantin M. Zohner, and Josep Peñuelas

2023 has witnessed a record-breaking extreme wildfire season in Canada from coast to coast, following closely to the unprecedented wildfire outbreaks in 2019/20 Australia and 2021 Siberia, causing far-reaching threats on terrestrial carbon stock, air quality, and human society. The heightened wildfire activity in specific regions prompts us to rethink the underlying factors driving the global wildfire dynamics. Climate change has been recognized as an important factor in amplifying wildfire risk, mainly through increasing temperature and reducing relative humidity. However, the role of vegetation productivity and phenology on wildfire dynamics remains elusive, even though which can exacerbate or mitigate the climate-induced fire risk. Importantly, changes in vegetation phenology can cause biophysical feedback to the climate system and land surface by modulating the exchanges of water and energy between land and the atmosphere. Considering the climate feedback of vegetation phenology, we hypothesize that peak photosynthesis timing (PPT) can contribute to wildfire activity. To explore it, we provide comprehensive analyses using multiple satellite-based photosynthesis observations from solar-induced chlorophyll fluorescence (SIF), and wildfire activity from national fire perimeters and MODIS global burned area records from 2001 to 2018, as well as diverse methodologies and models. In response to changes in various biological and climatic factors, we find PPT has advanced 1.10 ± 0.57 days per decade at a global scale. This earlier PPT acts to expand the extent of wildfires, with an increase in the global average burned fraction by 0.021% (~2.20 Mha) for every additional day of PPT advancement. Satellite observations and the Earth system modeling consistently reveal that this expansion is attributed to the intensified drought conditions during the potential fire season, induced by the earlier PPT that can modulate the global patterns of temperature, precipitation, and surface soil moisture. Furthermore, current fire-vegetation models participating in the FireMIP project underestimate the sensitivity of burned area to PPT, despite reproducing their negative correlation. Our findings highlight the importance of climate-vegetation-fire feedback loops in future prediction of wildfire dynamics and the strategy of climate change adaptation and mitigation.

How to cite: Lai, G., Li, J., Wang, J., Wu, C., Zhang, Y., Zohner, C. M., and Peñuelas, J.: Exploring the effect of vegetation photosynthesis phenology on wildfire dynamics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2099, https://doi.org/10.5194/egusphere-egu24-2099, 2024.

11:05–11:15
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EGU24-20821
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On-site presentation
Peeking into the model. Subgroup discovery for extracting comprehensible interpretations of underlying catalysts for wildfires from a machine learning model
(withdrawn)
Hans Korving and Margreet van Marle
11:15–11:25
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EGU24-6624
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ECS
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On-site presentation
Till Mattes, Irene Marzolff, and Angelica Feurdean

Wildfire is an integral part of temperate ecosystems, but human activities have significantly altered fire regimes, including frequency, size, intensity and seasonality. Romania, located in central-eastern Europe, recently exhibited the highest biomass burning in Europe. However, little is known of the trends and determinants of fire recurrence, apart from the common use of fire to clear crop residues on arable land. This study utilizes satellite-based fire data (FIRMS) from 2001 to 2022 and land cover maps (CORINE) to investigate temporal trends in fire occurrence across ecoregions and land cover types in Romania and identify those most susceptible to fire.

Over 2001-2022, Romania witnessed a total of 0.44 fires/ km² averaging 0.02 fires/km²/yr. Our analysis revealed a declining trend in fire occurrence along an elevation gradient, from plains to hills, plateaus and mountains, aligning with the prevalence of the dominant land cover classes and climatic gradients. Agricultural land cover types demonstrated the highest fire incidence, with arable land exhibiting the highest rate (0.04 fires/km²/yr) and forests the lowest (below 0.01 fires/km²/yr). Following the accession of Romania to the EU in 2007 and the prohibition of agricultural fires, a reduction in burning on arable land (crop residues) can be observed, while the use of fire in other agricultural classes persisted or even increased, indicating a more complex effect of socio-economic developments on fire pattern. Specifically, areas more marginal for agriculture, such as complex agricultural fields interspaced with housing and natural vegetation continued to employ fire as a management tool.

Natural land cover classes, such as wetlands principally occupying the Danube Delta (0.06 fires/km²/yr) and natural grasslands (0.01 fires/km²/yr), also experienced substantial fire occurrences and an intensification in more recent periods. Given the rarity of naturally ignited fires (lightning) in Romania, the intentional use of fire to clear dry reed biomass for land regeneration appears to be prevalent also in moist areas. Remarkably, broadleaved and mixed forests burned more frequently than coniferous forests despite the latter having traits to convey high flammability and burn with high frequency. This feature suggests that fires in broadleaved forests, predominant at low and mid elevations, likely expanded from neighbouring agricultural lands.

Crucially, our analysis highlights that years with elevated fire occurrence coincide with extreme droughts and heatwaves (e.g., 2012, 2015), emphasizing the influence of extreme climate conditions in accelerating fire episodes and the spread of fires initiated in agricultural areas into natural and semi-natural habitats. Given the substantial occurrence of fires in agricultural land but also in natural habitats, such as wetlands and grasslands in Romania, research investigating the risks and vulnerability of these habitats to fire should be prioritized.

How to cite: Mattes, T., Marzolff, I., and Feurdean, A.: Excessive fire occurrence in Romania from 2001 to 2022: Trends and drivers across ecoregions and land cover classes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6624, https://doi.org/10.5194/egusphere-egu24-6624, 2024.

11:25–11:35
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EGU24-8303
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ECS
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Highlight
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On-site presentation
Zhiyi Zhao, Zhongda Lin, and Fang Li

Wildfires pose an increasing threat to boreal forest and tundra ecosystems in boreal North America (Alaska and northwestern Canada), as their frequencies rise under global warming. These fires exhibit strong interannual variability that is influenced by regional atmospheric circulation. However, potential impacts of remote boundary forcings on regional fires and the underlying mechanisms remain unclear. This study provides a comprehensive analysis on the impacts of spring sea surface temperature (SST) and sea ice on interannual variability of burned area in this region during fire season (summer) from 1997 to 2020 using GFED5 burned area, SST and sea ice concentration data from the Met Office Hadley Centre, and ERA5 reanalysis data. Results show that in spring a warmer SST in the East Pacific and reduction of sea ice in the northern Chukchi Sea lead independently to an increase in burned area in boreal North America. The correlation coefficients between the SST and sea ice factors with the burned area in boreal North America are 0.43 and –0.44 respectively. The SST-fire relationships can be explained as follows: A warm SST anomaly in the East Pacific triggers a northeastward-propagated Rossby wave, inducing a high-pressure anomaly over boreal North America in spring. Consequently, this circulation anomaly causes a higher surface temperature and thus vegetation growth or drying. As temperatures rise and lightning activity intensifies in summer, burned area increases. On the other hand, the process of sea ice affecting burned area is different. A reduction in sea ice coverage in the northern Chukchi Sea leads to a decrease in surface albedo, resulting in an increase in heat flux. The heat release persists from spring to summer and causes a high-pressure circulation anomaly in boreal North America in summer, which suppresses regional water vapor convergence and precipitation, reducing soil moisture and surface air humidity and increasing vapor pressure deficit (VPD) thereby promoting fuel flammability.

How to cite: Zhao, Z., Lin, Z., and Li, F.: Impacts of Spring East Pacific SST and Arctic Sea Ice on Interannual Variability of Summer Burned Area in boreal North America, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8303, https://doi.org/10.5194/egusphere-egu24-8303, 2024.

11:35–11:45
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EGU24-9270
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ECS
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On-site presentation
Thomas Janssen and Sander Veraverbeke

In recent years, boreal forests have experienced unprecedented fire activity. These fires have contributed substantially to carbon emissions and posed hazards to human health. In the remote northeast Siberian taiga, the vast majority of fires are ignited by lightning strikes and not by human activity. Furthermore, active fire suppression is largely absent in these remote areas, resulting in uncontrolled fire growth. Here, we present a detailed look at the places and times where these lightning fires do finally stop spreading and aim to identify the causes. We employ various remote sensing and geo-spatial datasets including fire weather as well as landscape variables such as the presence of surface water, road networks, woody fuel load, fire history, elevation and landcover, to pinpoint the limitations to fire growth along fire perimeters recorded between 2012 and 2022 at a 300-meter spatial resolution. We were able to attribute 87% of all fire perimeter locations to a statistically significant (p < 0.01) change in one or more of these fire limitations over either time (fire weather) or space (landscape). The analysis reveals that fire growth is mainly limited by a change in the vegetation (fuel type and fuel load) as well as a change to less favourable weather for fire spread, although there are clear regional differences in the importance of specific limitations. Overall, fire weather seems to be the most important limitation to fire growth in the north of the Siberian taiga where continuous permafrost is present. With a rising frequency of lightning strikes, droughts, and heatwaves in boreal regions, uncontrolled lightning fires have the potential to expand even further in the future, leading to significant implications for vulnerable permafrost landscapes and, consequently, the global carbon cycle.

How to cite: Janssen, T. and Veraverbeke, S.: What limits the growth of lightning fires in the remote northeast Siberian taiga?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9270, https://doi.org/10.5194/egusphere-egu24-9270, 2024.

11:45–11:55
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EGU24-11291
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ECS
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Virtual presentation
Rutuja Kate and Jayanta Bhattacharya

This research delves into the dynamics of forest fires across various Indian regions, particularly during the unique COVID-19 lockdown period. The study's core focus is on the interaction between forest fires, climatic factors, and vegetation indices in a scenario of reduced human activity. It employs a multidimensional methodology, integrating satellite imagery and climatic data from periods before, during, and post-lockdown. The lockdown provides a critical opportunity to assess the impact of decreased human interference on forest fire patterns. Advanced statistical techniques are used to analyze the relationship between vegetation indices, fire occurrences, and meteorological conditions. This approach aims to uncover the underlying mechanisms driving these relationships, moving beyond simple trend identification. The research offers a nuanced perspective by differentiating natural factors from human influences. This distinction is vital in understanding the environmental dynamics during the lockdown. The findings have significant implications, offering insights for policymakers and environmentalists in enhancing forest fire management strategies. Emphasizing the need for a comprehensive understanding of environmental interactions, this study contributes to forming more informed and sustainable approaches to natural disaster management in the face of global challenges like climate change and pandemics.

How to cite: Kate, R. and Bhattacharya, J.: Forest Fires during COVID-19: Assessing Environmental Interactions and Fire Dynamics Amidst Reduced Human Intervention in India, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11291, https://doi.org/10.5194/egusphere-egu24-11291, 2024.

11:55–12:05
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EGU24-106
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ECS
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On-site presentation
Assessment of Wildfire-Induced Changes in Energy Fluxes and Environmental Variables: A Case Study in the Similipal Forest Reserve, Odisha, India
(withdrawn)
Shyam Sunder MS and Bhishma Tyagi
12:05–12:15
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EGU24-9225
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ECS
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Highlight
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On-site presentation
Max van Gerrevink, Sander Veraverbeke, Sol Cooperdock, Stefano Potter, Qirui Zhong, Michael Moubarak, Scott J. Goetz, Michelle C. Mack, James T. Randerson, Merritt R. Turetsky, Guido van der Werf, and Brendan M. Rogers

The Arctic-boreal region is warming rapidly, with consequences for northern ecosystems and global climate. Fires across the Arctic-boreal region are a major natural disturbance mechanism that initiate climate warming (positive) and cooling (negative) feedbacks. Understanding the net forcing effect from boreal fire on climate is crucial in managing and mitigating climate change impacts of boreal fires. Here we report radiative forcing estimates from boreal forest fires across Alaska and Western Canada (Arctic Boreal Vulnerability Experiment-domain). Our results integrate the effect of greenhouse gas emissions (warming) and aerosols emission (net cooling) have through direct combustion, post-fire vegetation recovery sequestering carbon (cooling), fire-induced permafrost degradation emitting CO2 and CH4 (warming), and changes in surface albedo (cooling). Alaskan fires are on average climate warming (1.34±2.95 W/m2 per burned area) – uncertainty given as spatial standard deviation, while Canadian fires show on average a climate cooling (‑2.26±2.48 W/m2 per burned area) effect. The emissions from the combustion of organic soils and post-fire permafrost thaw dominate the positive feedback for Alaskan fires, whereas the cooling effect of post-fire changes in surface albedo because of prolonged spring snow cover dominate for the western Canadian fires. Our work demonstrates large-scale spatial variability in the climate feedbacks from North American boreal forest fires. Such fine-scale spatial information on the warming and cooling influences of forest fires could be useful in designing forest management and fire suppression activities informed by climate impacts.

How to cite: van Gerrevink, M., Veraverbeke, S., Cooperdock, S., Potter, S., Zhong, Q., Moubarak, M., Goetz, S. J., Mack, M. C., Randerson, J. T., Turetsky, M. R., van der Werf, G., and Rogers, B. M.: Warming and cooling influences of North American boreal fires, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9225, https://doi.org/10.5194/egusphere-egu24-9225, 2024.

12:15–12:25
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EGU24-1123
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ECS
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On-site presentation
Nagashree Ge and Ashutosh Sharma

Himalayan forests boast an incredible biodiversity, harboring a wide range of flora and fauna and playing a significant role in regulating water resources. Forest fires are one of the disturbances which constitute a major force influencing, even determining, the structure and functions of ecological components-populations, communities, and ecosystems. The ability to withstand disturbance is defined as resistance whereas resilience is the capacity to recover from disturbance. These two terms define the ecohydrological response to forest fire. This study insights on how remote sensing technique can be utilized for the measurement of ecohydrological response of a large extent of region subjected to forest fire based on resistance-resilience framework and how further implementation of these measures would help to know the changes in the interaction been vegetation and water cycle. Normalized burn ratio (NBR) is used to quantify the response.  The outcome of the study reveals that deciduous needled leaf forests are subjected frequently to forest fires compared to other classes of forests during 2002-2022. The regions considered for study showed moderate to high range of resistance but low resilience, signifying the region has gained and lost vegetations in the post-fire. There was a variation in rainfall and run-off occurred during the post-fire year for different burn severities. The present approach has the potential to quantify the response of ecosystems to the forest fire and related effects on hydrology of the region.

How to cite: Ge, N. and Sharma, A.: Assessment of ecohydrological response of Himalayan Forest ecosystems to  forest fires, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1123, https://doi.org/10.5194/egusphere-egu24-1123, 2024.

12:25–12:30
Lunch break
Chairpersons: Rebecca Scholten, Sander Veraverbeke, Angelica Feurdean
Fire regimes, modeling, future
14:00–14:10
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EGU24-18977
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Highlight
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On-site presentation
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Matthew Kasoar, Cathy Smith, Ol Perkins, James Millington, and Jayalaxshmi Mistry

Landscape fires are increasingly represented in dynamic global vegetation models to understand impacts on carbon emissions and climate. Deliberate human fire use and management influence landscape fire characteristics, varying in space and time depending on social, economic, and ecological factors. For example, fire is used variously in rural livelihoods involving e.g., agriculture, hunting, gathering, and for other cultural practices, often depending on the time of year. Yet existing global fire models typically represent human fire use as a constant function of gridded datasets such as population density or gross domestic product.

Recently, initiatives have begun to draw together available data on global fire use from across multiple disciplines and disparate sources into coherent databases. We draw on information from one of these databases, the Livelihood Fire Database (LIFE), which includes case studies in 587 locations worldwide, to assess the availability of data on seasonality of anthropogenic fires associated with small-scale rural livelihoods. By defining seasonal cycles relative to the local variation of precipitation and evapotranspiration at each case study location, we look for patterns in the spatiotemporal nature of anthropogenic fires associated with different fire-use purposes - such as clearing vegetation for agriculture, maintaining pasture for livestock, or driving game when hunting - and consider the potential for this analysis to inform fire models.

For many fire types, especially those related to hunting, gathering, human wellbeing, and social signalling, there are limited quantitative data available, but it is possible to draw qualitative insights from case studies. Where quantitative data are available, we find some correspondence between fire seasonality and the intended fire-use purpose, suggesting that distinguishing between distinct fire-use purposes could improve the representation of human fire use in fire models, and consequently the seasonal cycle of fire emissions. Case studies demonstrate that environmental and social conditions drive variation in fire use for the same purpose, reiterating that a wide range of factors influence human behaviour and that assumptions of uniform drivers of anthropogenic fire may be misleading. Many of the fires now being revealed in global burned area data by new fine-scale remote sensing products are likely human-set; continued collection, collation, and analyses of data on human fire use globally is important to ensure appropriate anthropogenic representation in fire models.

How to cite: Kasoar, M., Smith, C., Perkins, O., Millington, J., and Mistry, J.: Global seasonality of small-scale livelihood fire, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18977, https://doi.org/10.5194/egusphere-egu24-18977, 2024.

14:10–14:20
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EGU24-16263
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ECS
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On-site presentation
Ramesh Glückler, Elisabeth Dietze, Stefan Kruse, Andrei Andreev, Boris K. Biskaborn, Evgenii S. Zakharov, Izabella Baisheva, Amelie Stieg, Shiro Tsuyuzaki, Kathleen Stoof-Leichsenring, Luidmila A. Pestryakova, and Ulrike Herzschuh

The Republic of Sakha (Yakutia), the coldest permanently inhabited region on Earth, is characterized by unique ecological relationships between larch forest, permafrost, and wildfires. Together, they can stabilize each other, preserving the larch-dominated biome. Abundant lakes have important cultural and subsistence-related functions and are dynamically connected to warming permafrost processes. Recently intensified wildfire seasons, however, raised questions regarding the causes and impacts of long-term (centennial to millennial) fire regime changes. Despite recent progress, eastern Siberia is still sparsely covered by reconstructions of long-term fire history. This also limits any evaluation of fire regime impacts on permafrost lake development and catchment erosion. Past studies have shown the benefit of combining paleoecological fire reconstructions with geochemical data to shed light on fire regime changes and their impacts on lake catchments, as well as traces of potential human land use.

We present nine new records of Late Holocene wildfire activity, based on macroscopic charcoal in lake sediments (including information on charcoal particle sizes, morphologies, and length to width ratios), accompanied by sediment geochemistry data from high-resolution XRF core scanning. The studied lakes are located in the Lena-Amga interfluve of the Central Yakutian Lowlands, the Verkhoyansk Mountains, and the Oymyakon Highlands. The new data cover both thermokarst and glacial lakes, and a range from remote to rural settings and low to high elevations. Charcoal concentration in the lowland lakes is on average three times as high as in the highland lakes. Contrary to our hypothesis, charcoal concentration in most lakes is negatively correlated to many XRF-derived lithogenic elements indicating detrital input from catchment erosion (e.g., Ti, K). Reminiscent of earlier findings [1], multiple lowland sites share a signal of sharply decreasing biomass burning around 1300 CE. This coincides with the initial settlement of the Sakha people and increased catchment erosion. The new fire reconstructions allow for the evaluation of potential human impacts on past fire regime changes in Yakutia, while improving the region’s representation in global synthesis studies.

[1]  Glückler R. et al. (2021): Wildfire history of the boreal forest of south-western Yakutia (Siberia) over the last two millennia documented by a lake-sediment charcoal record. Biogeosciences 18 (13): 4185–4209. https://doi.org/10.5194/bg-18-4185-2021.

How to cite: Glückler, R., Dietze, E., Kruse, S., Andreev, A., Biskaborn, B. K., Zakharov, E. S., Baisheva, I., Stieg, A., Tsuyuzaki, S., Stoof-Leichsenring, K., Pestryakova, L. A., and Herzschuh, U.: Fire, permafrost, and people: Late Holocene fire regimes and their impacts on lake systems in Yakutia, Siberia, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16263, https://doi.org/10.5194/egusphere-egu24-16263, 2024.

14:20–14:30
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EGU24-20564
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ECS
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Highlight
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On-site presentation
Olivia Haas, Colin Prentice, and Sandy P. Harrison

There is growing concern over future trajectories of burning on Earth. One the one hand, some regions have seen the emergence of large and novel wildfires, whilst satellite observations continue to show declining burnt area globally, most notably in the tropics. Quantifying the response of global wildfire regimes to future changes in especially challenging given that wildfires are driven by climate, vegetation, and human activities, and that these different factors may have contrasting and opposing effects.

Using global empirical models of burnt area, fire size and fire intensity we explore the trajectory of future fire regimes under high and low climate change mitigation efforts. The models are driven by lightning ignitions, climate, vegetation properties, topography, and human factors. Making use of a set of sensitivity analysis, we show a global shift in wildfire patterns by the end of the 21st century even with warming kept below 1.5°. Burning will generally be reduced in tropical regions but larger and more intense wildfires will occur in extra-tropical regions. Under low mitigation, increases in burnt area worldwide overwhelm the human-driven decline, with up to a 60% increase in burnt area by the end of the century. However, fire size and intensity will be increasingly limited by dryness and vegetation fragmentation.

These results suggest that even under high climate change mitigation, fire management strategies must urgently be revised as current fire-suppression policies will no longer be effective in much of the world. Regional-level fire management, led by local stakeholders, should be encouraged. Wildfire risk and management must also be incorporated into mitigation scenarios that rely on extending forest area if these mitigation scenarios want to remain realistic.

How to cite: Haas, O., Prentice, C., and Harrison, S. P.: Future global wildfire regimes under high and low climate mitigation efforts , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20564, https://doi.org/10.5194/egusphere-egu24-20564, 2024.

14:30–14:40
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EGU24-14891
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On-site presentation
Marcos Rodrigues, Pere Gelabert, Teresa Lamelas, Raúl Hoffrén, Juan de la Riva, Darío Domingo, Cristina Vega-García, Paloma Ibarra, Aitor Ameztegui, and Lluís Coll

In this work we showcase the in-progress results from the FirePATHS project (PID2020-116556RA-I00). The project aims to assess the evolution of fire danger under different emission and forest management scenarios through the explicit interaction of the climate-vegetation-fire system. For this purpose, a methodological framework combining different simulation models of the elements of this system is proposed. The core of the process lies in the modeling of vegetation dynamics at stand scale according to different trajectories of climatic evolution to characterize the state and typology of fuels and the subsequent simulation of potential fire behavior during the 21st century.

We analyzed a set of 114 Pinus halepensis plots, surveyed in the field during 2017;  68 plots burned during the summer of 1994 and 46 unburned control stands. We used the medfate model to simulate forest functioning and dynamics, which provides the necessary fuel model parameters to be entered into fire behavior models (Fuel Characteristics Classification System, implemented in medfate as well). The combination of these two approaches provides time-varying estimates of fire behavior metrics (e.g., flame length or rate of spread). The simulation was conducted under SSP climate scenarios (SSP 126, 245, 370 and 585) depicting different levels of climate warming, vegetation dynamics and, hence, fire danger. Likewise, we devised a set of forest management prescriptions aimed at reducing climate vulnerability of tree communities and reducing extreme wildfire potentials. A baseline scenario with no management was also assessed.

We observed very contrasting trajectories between burned and control stands, with the first leading to increasing fuel loads, except in SSP 585. Fire potentials depicted a significant increase in surface fire behavior, with adaptive and mitigation management being able to mitigate it to some extent.

How to cite: Rodrigues, M., Gelabert, P., Lamelas, T., Hoffrén, R., de la Riva, J., Domingo, D., Vega-García, C., Ibarra, P., Ameztegui, A., and Coll, L.: Fire hazard trajectories under climate change and management scenarios, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14891, https://doi.org/10.5194/egusphere-egu24-14891, 2024.

14:40–14:50
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EGU24-8506
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On-site presentation
Pere Joan Gelabert Vadillo, Adrian Jiménez Ruano, Fellice Catelo, and Marcos Rodrigues Mimbrero

In recent years, the EU Commission has enacted various firefighting policies to combat and diminish the adverse effects of wildfires. The Mediterranean area has experienced an observable extension of its wildfire season, coupled with rapid shifts in fire-weather dynamics, resulting in exceptionally severe wildfire occurrences. As of 2022, the EU has recorded an approximate total burned area of 792,902 hectares, with forests accounting for 66% of this figure (Rodrigues et al., 2023).

The main objective of this study is to anticipate extreme wildfire conditions by providing a synthetic product depicting the chances of a fire event starting and escaping containment. To do so, we combined empirical models of ignition likelihood and effectiveness of the initial attack stage. We employed machine learning techniques to calibrate binary regression models using historical wildfire ignition data and geospatial layer depicting the main drivers of ignition and containment, namely: accessibility, human pressure on wildlands, fuel moisture and availability. We illustrate our approach along the Mediterranean coastal region of Spain. Our approach enables us to predict wildfire contention capacity under diverse population growth and climate warming scenarios. This strategy aims to improve disaster risk reduction by pointing wildfire management zones and prioritizing intervention in high-risk areas.

Results indicate a high predictive ability to model human-caused wildfire ignition (AUC>0.80) but a modest capability to capture the containment capability (AUC≈0.70). Accessibility by road largely controls the spatial pattern of ignition and containment, with dead fuel moisture content modulating the temporal pattern of probability. We further illustrate the approach by providing insights into future SSP (Shared Socieconomic Pathways) scenarios by synthesizing both products into comprehensive management zones (Rodrigues et al., 2022).

 

References

Rodrigues, M., Camprubí, À.C., Balaguer-Romano, R., Megía, C.J.C., Castañares, F., Ruffault, J., Fernandes, P.M., Dios, V.R. de, 2023. Drivers and implications of the extreme 2022 wildfire season in Southwest Europe. Science of The Total Environment 859, 160320. https://doi.org/10.1016/j.scitotenv.2022.160320

Rodrigues, M., Zúñiga-Antón, M., Alcasena, F., Gelabert, P., Vega-Garcia, C., 2022. Integrating geospatial wildfire models to delineate landscape management zones and inform decision-making in Mediterranean areas. Safety Science 147, 105616. https://doi.org/10.1016/j.ssci.2021.105616

How to cite: Gelabert Vadillo, P. J., Jiménez Ruano, A., Catelo, F., and Rodrigues Mimbrero, M.: Anticipating future extreme wildfire events by coupling ignition and success of initial attack models, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8506, https://doi.org/10.5194/egusphere-egu24-8506, 2024.

14:50–15:00
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EGU24-14762
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On-site presentation
Chaeyeon Park, Kiyoshi Takahashi, Shinichiro Fujimori, Thanapat Jansakoo, Chantelle Burton, Huilin Huang, Sian Kou-Giesbrecht, Christopher Reyer, Matthias Mengel, and Eleanor Burke

Climate change has influenced fire activities, altering the fire risk associated with air pollution and human health. However, the specific contribution of climate change to fire risks on air pollution and health burden has not yet been discovered. In this study, three fire-vegetation models were employed to simulate fire aerosol emissions under two simulations over the past six decades: an observation climate scenario and a counterfactual scenario where the long-term climate change trend is removed. Combining fire aerosol emissions with a chemical transport model and an avoidable mortality risk model, we calculated global fire PM2.5 and its associated mortality. By comparing the results under the two simulations, we demonstrated the climate change has increased the fire PM2.5 and its mortality. The findings indicated an increase in fire mortality over the six decades: 46,401 in the 1960s and 98,748 in the 2010s, with 3-8% attributed to climate change. Clear relationships were observed between the contribution of climate change to fire mortality and relative humidity or air temperature in some regions. This suggests that fire risks in these regions are sensitive to climate change and necessitate the development of adaptation strategies to mitigate risks in the future.  

How to cite: Park, C., Takahashi, K., Fujimori, S., Jansakoo, T., Burton, C., Huang, H., Kou-Giesbrecht, S., Reyer, C., Mengel, M., and Burke, E.: Climate change has increased fire PM2.5 and its associated health burden, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14762, https://doi.org/10.5194/egusphere-egu24-14762, 2024.

15:00–15:10
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EGU24-5494
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ECS
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Highlight
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On-site presentation
Oliver Perkins, Matthew Kasoar, Apostolos Voulgarakis, Tamsin Edwards, and James Millington

Globally, vegetation fires are a key component of many ecosystems and have substantial impacts on carbon emissions. Yet humans also use and manage fires for a huge range of purposes around the world, dependent on numerous social and biophysical factors. Existing representations of anthropogenic fire in dynamic global vegetation models (DGVMs) have been highly simplified, with readily available global variables (e.g. population density) used to estimate numbers of anthropogenic ignitions. Here, we present results from a novel coupled socio-ecological modelling approach to improve understanding of how human and biophysical factors combine to drive the spatio-temporal distribution of global fire regimes. Specifically, we present the integration of two process-based models. The first is the Wildfire Human Agency Model (WHAM!1), which draws on agent-based approaches to represent anthropogenic fire use and management. The second model is JULES-INFERNO2, a fire-enabled DGVM, which takes a physically-grounded approach to the representation of vegetation-fire dynamics.

The new WHAM-INFERNO model ensemble suggests that as much as half of all global burned area is generated by managed anthropogenic fires - typically small fires that are lit and spread according to specific land use objectives (such as crop residue burning). Furthermore, we demonstrate that including representation of managed anthropogenic fires in a coupled socio-ecological simulation can improve understanding of the biophysical drivers of unmanaged wildfires, by allowing clearer recognition of the role of anthropogenic land management in global fire regimes. Hence, WHAM-INFERNO is applied to understand how landscape fragmentation, wider land use change, and changes in human fire management have together led to observed recent declines in global burned area despite the warming climate. Overall, findings presented here have substantial implications for understanding of present and future fire regimes, indicating that changes to socio-economic systems are at least as important a consideration as climate change.  

1. Perkins, O., Kasoar, M., Voulgarakis, A., Smith, C., Mistry, J., and Millington, J. (2023). A global behavioural model of human fire use and management: WHAM! v1.0. EGUsphere, 1–42. 10.5194/egusphere-2023-2162.

2. Mangeon, S., Voulgarakis, A., Gilham, R., Harper, A., Sitch, S., and Folberth, G. (2016). INFERNO: a fire and emissions scheme for the UK Met Office’s Unified Model. Geosci. Model Dev. 9, 2685–2700. 10.5194/gmd-9-2685-2016.

How to cite: Perkins, O., Kasoar, M., Voulgarakis, A., Edwards, T., and Millington, J.: Half of global burned area is due to managed anthropogenic fire: findings from a coupled socio-ecological modelling approach , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5494, https://doi.org/10.5194/egusphere-egu24-5494, 2024.

15:10–15:20
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EGU24-10606
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ECS
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On-site presentation
Rui Wang, Enrico Zorzetto, Sergey Malyshev, and Elena Shevliakova

Lightning ignitions are the dominant causes of wildfires in many regions, responsible for 80% of burned areas at high latitudes and about 70% of fires in the Amazon rainforest. With global wildfire activities and extreme fire events (e.g., intensity, duration, and size) increasing under the changing climate conditions, understanding the interactions between lighting, landscape characteristics, and wildfires is crucial for predicting and mitigating the impacts of climate change. Cloud-to-ground lightning activities are driven by a combination of large- and local-scale factors, e.g., local atmospheric circulations and convection and topography. Furthermore, the number of lightning strikes is predicted to increase by 10 – 30 % per degree warming. Decadal satellite observations have revealed Earth’s lightning hotspots at very high resolution, however, there is a paucity of fine-scale lightning strikes and lightning-ignited wildfires (LIW) in the Earth system and climate models. Currently, many climate and ESM  models do not include fires at all or simulate them with meteorological inputs and grid-average lightning at the scale of atmospheric models (25 to 100 km), introducing large uncertainties of LIW due to the lack of information at the scales relevant to fire dynamics.  Lack of information about lightning trends and variability hinders the prediction and projection of fires and their contribution to carbon and other atmospheric tracers and global warming. For example, in the US National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory (GFDL) ESM4.1 model, the fire model uses a climatology of lightning strikes from preindustrial to 2100.

In this presentation, we will demonstrate the implications of capturing subgrid lightning distributions in the GFDL land model LM4.2 for the global simulations of wildfire dynamics over the available records (1998-2013) and provide insights into future projections. LM4.2 captures sub-grid heterogeneity of land cover and use, soil geomorphology, and topography, facilitating the understanding of LIW distribution across global to regional and sub-grid scales. In this study, we leverage 0.1° × 0.1° lightning observations from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) in the GFDL LM4-HB to characterize fine-scale lightning strike distribution and associated LIW.

How to cite: Wang, R., Zorzetto, E., Malyshev, S., and Shevliakova, E.: Characterizing lightning-ignited wildfire occurrences at sub-grid scales in orography-aware NOAA/GFDL land model LM4.2, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10606, https://doi.org/10.5194/egusphere-egu24-10606, 2024.

15:20–15:30
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EGU24-12320
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ECS
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On-site presentation
Hyun-Woo Jo, Shelby Corning, Pavel Kiparisov, Johanna San Pedro, Andrey Krasovskiy, Florian Kraxner, and Woo-Kyun Lee

Forest fires pose a growing global threat, exacerbated by climate change-induced heat waves. The intricate interplay between changing climate, biophysical, and anthropogenic factors emphasizes the urgent need for sophisticated predictive models. Existing models, whether process-based for interpretability or machine learning-based for automatic feature identification, have distinct strengths and weaknesses. This study addresses these gaps by integrating human domain knowledge, crucial for interpreting forest fire dynamics, into a machine learning framework. We introduce FLAM-Net, a neural network derived from IIASA's wildfire Climate impacts and Adaptation Model (FLAM), melding process-based insights of FLAM with machine learning capabilities. In optimizing FLAM-Net for South Korea, new algorithms interpret national-specific forest fire patterns, and multi-scale applications, facilitated by U-Net-based deep neural networks (DN-FLAM), yield downscaled predictions. Successfully tailored to South Korea's context, FLAM-Net and DN-FLAM reveal spatial concentration near metropolitan areas and the east coastal region, with temporal concentration in spring. Performance evaluation yields Pearson's r values of 0.943, 0.840, and 0.641 for temporal, spatial, and spatio-temporal dimensions. Projections based on Shared Socioeconomic Pathways (SSP) indicate an increasing trend in forest fires until 2050, followed by a decrease due to increased precipitation. During the optimization process of FLAM-Net for Italy, optimal parameters for sub-areas are identified. This involves considering biophysical and anthropogenic factors at each grid, contributing to improved localized projection optimization by utilizing various sets of optimal parameters. There by, this process illuminates the intricate connections between environmental factors and their interpretation in the dynamics of forest fires. This study demonstrates the advantages of hybrid models like FLAM-Net and DN-FLAM, seamlessly combining process-based insights and artificial intelligence for interpretability, accuracy, and efficient optimization. The findings contribute scientific evidence for developing context-specific climate resilience strategies, with global applicability to enhance climate resilience.

How to cite: Jo, H.-W., Corning, S., Kiparisov, P., San Pedro, J., Krasovskiy, A., Kraxner, F., and Lee, W.-K.: Integrating Human Domain Knowledge into Artificial Intelligence for Hybrid Forest Fire Prediction: Case Studies from South Korea and Italy, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12320, https://doi.org/10.5194/egusphere-egu24-12320, 2024.

15:30–15:40
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EGU24-12223
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ECS
|
On-site presentation
Ryan Lagerquist and Christina Kumler

The ignition, spread, and severity of wildfires are driven largely by weather conditions (Jain et al. 2020: https://doi.org/10.1139/er-2020-0019; Liu et al. 2013: https://doi.org/10.1371/journal.pone.0055618).  The main tool for weather prediction across the globe is a set of physical, coupled atmosphere/ocean models, called numerical weather prediction (NWP).  Despite rapid improvements in the last few decades, NWP alone is not sufficient for wildfire prediction, because it does not resolve every process related to wildfire.  One solution is to post-process NWP with statistical models, which correct the NWP model towards better resolving processes related to the phenomenon of interest (here, wildfire).  This post-processing is called model-output statistics (MOS) and typically involves linear regression.  However, recent work has advanced MOS by incorporating more powerful statistical models from deep learning (DL).  We use DL to predict extreme fire weather and behaviour at multi-day lead times throughout the United States.

 

For fire weather, we have trained U-nets -- a type of deep neural network -- to predict at lead times of 3-240 hours over the United States.  The output (target) variables are seven indices from the Canadian Fire Weather Index System (CFWIS), computed from the ECMWF Reanalysis version 5 (ERA5).  These seven indices include the fine-fuel moisture code (FFMC), initial-spread index (ISI), overall fire-weather index (FWI), etc.  Meanwhile, the input (predictor) variables come from five sources.  The first is a forecast time series of atmospheric state variables (height, temperature, humidity, and wind) from the Global Forecast System (GFS) NWP model.  The second is a forecast time series of surface and subsurface moisture (soil moisture, accumulated precipitation, and snow depth) from the GFS.  The third is a set of constant fields (terrain height/slope/aspect, land-sea mask, etc.) describing the underlying terrain.  The fourth is a lagged time series of CFWIS over the past several days, i.e., past target values.  The fifth is a forecast time series of CFWIS indices, computed by applying the CFWIS functions directly to GFS-forecast weather variables.  These are the uncorrected (GFS-only) CFWIS forecasts, to be corrected by the U-net.

 

For fire behaviour, we have trained random forests -- ensembles of decision trees -- to predict fire radiative power (FRP) at lead times of 1-48 hours over the United States.  The labels (correct answers) for FRP are obtained from the Regional ABI and VIIRS Emissions (RAVE) merged satellite product.  Predictors for the random forest include the first three sources listed for the U-net above, plus a lagged time series of FRP over the past 24 hours, i.e., past target values.

 

Both models -- the U-net for fire weather and the random forest for fire behaviour -- are trained with built-in uncertainty quantification.  Thus, at every lead time and grid point, both models provide an expected value and an estimate of their own uncertainty.  We will present objective evaluation results (for both the mean forecast and uncertainty) and explainable artificial intelligence (XAI) to understand what the models have learned, e.g., which spatiotemporal weather patterns in a given area are most conducive to extreme fire weather/behaviour.

How to cite: Lagerquist, R. and Kumler, C.: Using deep learning to improve multi-day forecasts of extreme fire weather and behaviour throughout the United States, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12223, https://doi.org/10.5194/egusphere-egu24-12223, 2024.

15:40–15:45

Posters on site: Tue, 16 Apr, 10:45–12:30 | Hall X1

Display time: Tue, 16 Apr 08:30–Tue, 16 Apr 12:30
Chairpersons: Antonio Girona-García, Rebecca Scholten, Fang Li
Fire observations, simulations, and regimes
X1.1
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EGU24-1183
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ECS
Lightning-ignited fires in Portugal: A Comparison of satellite-derived and in-situ Databases
(withdrawn after no-show)
Lucas S. Menezes, Ana Russo, Alexandre M. Ramos, Ricardo M. Trigo, Célia M. Gouveia, Akli Benali, José M. C. Pereira, Ricardo Deus, Renata Libonati, and Carlos A. Morales Rodriguez
X1.2
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EGU24-763
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ECS
Vinothan Sivapalan and William Hockaday

Paleofire reconstructions are a challenging endeavor primarily due to the numerous factors involved in wildfire frequency, behavior, and regimes. These factors include, but are not limited to fuel composition, moisture, soil types, climate/weather conditions, and topographical features. Therefore, development of robust wildfire proxies requires vigorous experimental testing for multiple variables. Here, we explore the influence of pyrolysis time, moisture, and plant species on a novel proxy for fire intensity—carbon bridgehead fraction of charcoal. Experimentally, we have produced charcoals from three native Texas plants: live oak (Quercus sp.), Ashe juniper (Juniperus ashei), and broomsedge bluestem (Andropogon virginicus) under a range of temperature (300-700°C), moisture (0-100% moisture capacity), and time (0-1 hr) conditions in a tube furnace. Samples were analyzed using solid-state C-13 nuclear magnetic resonance (NMR) spectroscopy with two experiments to calculate carbon bridgehead fraction: cross polarization – magic angle spinning (CP-MAS) to quantify total aromatic carbon and dipolar dephasing (DD) to quantify aromatic bridgehead carbon. Results reveal significant differences between vegetation types, with moisture delaying or slowing the rate of carbon bridgehead formation. Relationship between carbon bridgehead fraction and time are less clear and may be influenced by the formation of pyrolysis byproducts (such as pyroligneous acids and free radicals) and/or signal losses in the cross-polarization spectra. To assess the influence of these factors on carbon bridgehead fraction we plan to conduct additional analyses on our experimental charcoals, including electron paramagnetic resonance (EPR) spectroscopy to quantify the free radicals in samples and C elemental analysis to assess carbon observability by NMR. Future work involves ground truthing the proxy to modern wildfires and subsequently applying it to paleorecords.

How to cite: Sivapalan, V. and Hockaday, W.: The influence of pyrolysis time, moisture, and plant species on carbon bridgehead fraction of charcoal, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-763, https://doi.org/10.5194/egusphere-egu24-763, 2024.

X1.3
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EGU24-5236
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ECS
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Highlight
Cunhui Zhang, Thomas Janssen, Matt Jones, and Sander Veraverbeke

Tropical rainforests have exceptionally high biodiversity and store large amounts of carbon in biomass. However, large and frequent fires across tropical rainforests in the last decades threaten the ecosystem integrity of these ecosystems. The general belief is that fires in the Amazon rainforest are all human-ignited and that lightning fires do not occur in rainforests due to the predominant wet conditions. However, recent research indicates the possibility of lightning fires in tropical rainforests. Here, we aim to investigate the occurrence of lightning-ignited fires in the Amazon rainforest, a topic that has been largely overlooked in the current understanding of fire dynamics in this biome. We collected and analyzed data on lightning strikes, fire occurrences, and weather patterns derived from satellite imagery and climate datasets. The objective is to detect, quantify, and characterize lightning fires in the Brazilian Amazon rainforests, thereby providing new insights into the natural fire regime of this crucial ecosystem.

How to cite: Zhang, C., Janssen, T., Jones, M., and Veraverbeke, S.: Are there lightning Fires in the Amazon Rainforest?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5236, https://doi.org/10.5194/egusphere-egu24-5236, 2024.

X1.4
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EGU24-8017
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ECS
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Raul Hoffren, Juan de la Riva, Darío Domingo, María Teresa Lamelas, Paloma Ibarra, Alberto García-Martín, and Marcos Rodrigues

Mediterranean forests are recurrently affected by wildfires. Fire activity is expected to accelerate in the future due to landscape homogenization, fuel accumulation, and climate warming. A key aspect to prevent and mitigate the negative impacts of wildfires on ecosystems is to understand the factors that govern the recovery of forest communities. This study analyzes the post-fire recovery potential of four representative Mediterranean tree-communities (Pinus halepensis, Pinus nigra, Pinus pinaster, and Quercus ilex) affected by large wildfires (> 500 ha) during the summer of 1994 in Spain. For this purpose, information collected in the field 25 years after the fires in 203 forest plots (131 burned and 72 unburned control plots) was coupled with remote sensing, geospatial, and forest inventory data, to build an empirical model capable of assessing recovery. Remote sensing data provided a proxy for burn severity, through the Composite Burn Index, and allowed modelling the local topography (slope and aspect) of the terrain. The geospatial data included climatic information on temperature and precipitation trends. These data were entered into the model, calibrated using Random Forest, to provide information on the degree of recovery, inferred from the similarity (in terms of vegetation height, aboveground biomass, species diversity) between the burned and unburned control plots. Results showed that only the 25% of the burned plots can be considered as recovered. The burn severity had a significant effect on the recovery albeit strongly modulated by local topography. Overall, the key features of the recovered plots were a low-to-moderate burn severity and a favorable topographical setting, especially the shading effect of steep northwestern slopes. Furthermore, a warmer and more humid climate improved the capacity of recovery. These results constitute a valuable tool for improving forest management and preserving ecosystem services.

How to cite: Hoffren, R., de la Riva, J., Domingo, D., Lamelas, M. T., Ibarra, P., García-Martín, A., and Rodrigues, M.: Combining stand-level and remote sensing data to model post-fire recovery of Mediterranean tree-forest communities – A case study in Spain., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8017, https://doi.org/10.5194/egusphere-egu24-8017, 2024.

X1.5
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EGU24-13426
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ECS
Fire rate-of-spread model inversion: what can be inferred from remote sensing observations of fire behaviour?
(withdrawn)
David Sandoval, Ramesh Ningthoujam, and Iain Colin Prentice
X1.6
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EGU24-6761
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ECS
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Highlight
Houjie Li and Parisa Ariya

Wildfires have become more prevalent in recent years because of climate change. Meanwhile wildfires, as a major type of biomass burning, could emit a large amount of black carbon (BC) and brown carbon (BrC) to the atmosphere. Since BC and BrC play important roles in climate change, air pollution and human health issues, it is necessary to research their physicochemical properties to evaluate their impacts on urban areas. Here we present BC mass concentration and absorption coefficients measured by aethalometer (AE43), combing with the chemical constitutions acquired by GC-MS, during the record-breaking 2023 wildfire season in Canada. The back-trajectory analysis indicated that the smoke mainly came from north Quebec where the wildfires took place. We demonstrated how BC and BrC emitted by wildfires could affect urban regions after long-range transport.

How to cite: Li, H. and Ariya, P.: Measurement of Physicochemical Properties of Black Carbon and Brown Carbon and the Impacts of Canada Record-Breaking Wildfires in Summer 2023 , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6761, https://doi.org/10.5194/egusphere-egu24-6761, 2024.

X1.7
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EGU24-8507
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ECS
Guilherme Mataveli, Matthew W. Jones, Gabriel Pereira, Saulo R. Freitas, Valter Oliveira, Esther Brambleby, and Luiz E.O. C. Aragão

Biomass burning (BB) plays a key role in the biosphere–atmosphere interaction. It is a major source of trace gases and aerosols that alters the atmosphere and the water cycle. Additionally, these emissions are often related to other detrimental impacts including biodiversity loss in fire-sensitive biomes, increase of respiratory diseases, and massive economic losses. BB emissions are used as inputs in models that estimate air quality and the effect of fires on Earth’s climate. Hence, an accurate estimation of BB emissions is paramount. While BB emissions spread over most of the global vegetated areas, the integration of orbital remote sensing and modelling is the most effective approach to estimate them from regional to global scales. BB emission estimation follows the relationship between burned biomass and the emission factor (EF - mass emitted of a given species, for example carbon dioxide, per mass of dry matter burned). The burned biomass can be estimated using two approaches: (i) based on the relationship among burned area, above-ground biomass, and combustion completeness; or (ii) based on fire radiative power (FRP), a quantitative measurement that is directly related to the rate of burned biomass and is estimated to each active fire detected by several orbital sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. EF values, which are Land Use and Land Cover (LULC) based, are required to estimate BB emissions independently on the approach adopted to estimate the burned biomass. Although novel approaches to improve the accuracy of BB emissions have been developed, the impact of EF values on the final estimated emissions remains uncertain. We have evaluated the impact of the EFs on the final estimate of fine particulate matter (PM2.5) emitted from BB in the Brazilian Amazon during a nineteen years’ time series (2002-2020) by running the PREP-CHEM-SRC emissions preprocessor tool under four EF scenarios: the tool original EF values based on the work of Andreae and Merlet (2001), the average EF values recently updated by Andreae (2019), and the minimum and maximum EF values also proposed by this author. The minimum (maximum) EF values were defined as the average EF value for each LULC class minus (plus) one standard deviation. The PM2.5 emissions were estimated at the spatial resolution of 0.1º using the FRP approach implemented on PREP-CHEM-SRC (3BEM_FRP model) having MODIS active fires as input, since this approach requires fewer inputs and the impact of the EFs over the emissions would be more evident. Our results showed that the annual average PM2.5 emission in the Amazon varied by 163% between the four EF scenarios (from1,426 Gg and 3,747 Gg), while the scenario based on the average values was the closest to the one based on PREP-CHEM-SRC original EF values (2,582 Gg and 2,213 Gg, respectively – an increase of 17%). These results contribute to the better understanding of how this single parameter impacts on the estimation of BB emissions.

How to cite: Mataveli, G., W. Jones, M., Pereira, G., R. Freitas, S., Oliveira, V., Brambleby, E., and E.O. C. Aragão, L.: Unravelling Variability: Discrepancies in Amazonian Biomass Burning Emissions Under Different Emission Factor Scenarios , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8507, https://doi.org/10.5194/egusphere-egu24-8507, 2024.

X1.8
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EGU24-10145
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ECS
Patrícia Páscoa, Ana Russo, Andreia Ribeiro, and Célia Gouveia

Large burned areas (BA) in southeastern Australia were regularly registered during hot and dry years, such as the Black Saturday (2009) and the Black Summer (2019-2020) extreme bushfires. These types of extreme climate conditions are expected to become more frequent, leading to an increased risk of large BA in this region.

In this work, the influence of drought conditions and hot events on the BA in southeastern Australia was assessed, using correlation and copula functions. Bivariate copula functions were fitted, and conditional probabilities of large BA given climate extremes were computed. Three classes of drought intensity were studied, namely moderate, severe, and extreme, as well as three thresholds for temperature extremes, namely the 80th, 90th, and 95th percentiles. Monthly BA were computed as the sum of the burned pixels in the fire season (from October to March), using data from the MODIS Burned Area product. The analysis was performed on forests, grasslands, and savannas separately. Drought conditions were assessed with SPEI at several time scales, computed with data from the CRU TS4.07 dataset. Maximum and minimum daily temperature were retrieved from the ERA5 dataset.

Results showed that the correlation between BA and SPEI was high in the current and previous 1 month for all land covers, being highest in savannas and lowest in grasslands. Short time scales of SPEI had the highest correlation on grasslands, and the opposite was observed in forests and savannas. The correlation with maximum temperature increased until 10-15 days before the fire event and surpassed 0.6 over forests. Minimum temperature presented much lower correlations and there was not a pronounced increase in the previous days, as observed with the maximum temperature.

The conditional probability of large BA increased with the intensity of the drought on all land covers, and it reached almost 100% probability of exceeding the 50th percentile of BA under extreme droughts on forests and savannas. For the case of the 80th percentile of BA, the probability was lower, but the difference given drought and non-drought conditions was larger than for the 50th percentile. On savannas and forests, the conditional probability was still high when considering SPEI in the previous 2 and 3 months.

Maximum temperature yielded a higher probability of BA for the two highest percentiles. Savannas presented the lowest probability of BA given hot events, and forests the highest. The probability increased up to 10 days before the fire. Overall, the probabilities obtained given drought conditions are higher than given hot events, particularly for larger fires. Moreover, high probabilities obtained with large time scales and longer lead times are indicative of the importance of drought conditions before the fire season and may help predict the occurrence of large BA.

 

Acknowledgments: This study was partially supported by FCT (Fundação para a Ciência e Tecnologia, Portugal) through national funds (PIDDAC) – UIDB/50019/2020, by project Floresta Limpa (PCIF/MOG/0161/2019), and by project 2021 FirEUrisk, funded by European Union’s Horizon 2020 research and innovation programme under the Grant Agreement no. 101003890). A.R. was supported by FCT through https://doi.org/10.54499/2022.01167.CEECIND/CP1722/CT0006. 

How to cite: Páscoa, P., Russo, A., Ribeiro, A., and Gouveia, C.: Burned area and climate extremes in different land covers in southeastern Australia, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10145, https://doi.org/10.5194/egusphere-egu24-10145, 2024.

X1.9
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EGU24-10793
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ECS
Padraig Flattery, Klara Finkele, Paul Downes, Alan Hally, and Ciaran Nugent

Since 2006 the Canadian Forest Fire Weather Index System (FWI) has been employed operationally at Met Éireann to predict the risk of forest fires in Ireland. Around 11% or 770,000 ha of the total land area of Ireland is afforested, but there are also large areas of open mountain and peatlands covered in grasses, dwarf-shrub and larger woody shrub type vegetation which can provide fuel for spring wildfires under suitable conditions. After winter, vegetation can be dead or have a very low live moisture content, and the flammability of this vegetation can be readily influenced by prevailing weather, especially following prolonged dry periods.

Different decision support tools are available to different sectors, namely:

  • The General Public: who have access to fire weather index meteograms on Met Éireann’s public website.
  • Local Authorities, who have access to the ANYWHERE multi-hazard warning system, which provides multiple sources of information about fire danger and propagation.
  • The Department of Agriculture, Food and Marine (DAFM), who are provided with information and additional support from National and European partners and networks.

DAFM is the Forest Protection authority in Ireland responsible for issuing Forest Fire Danger Notices which improve preparedness for fire responses and are based on a range of factors including information provided by Met Éireann who calculate the FWI and FWI components using observation data at synoptic stations, and the predicted FWI for the next five days ahead based on numerical weather prediction data. This allows fire responders to build resilience and prepare for impending fires.

The FWI is determined based on the types of forest fuel and how quickly they dry out/get rewetted, and components of fire behaviour. The FWI represents the fire intensity as the rate of energy per unit length of fire front (kW/m). The components which provide the most accurate indication of risk under Irish conditions are the Fine Fuel Moisture Code and Initial Spread Index, based on the fuels involved and ignition patterns observed to date. Since 2022 Met Eireann provide the FWI as well as the individual components Fine Fuel Moisture Content and Initial Spread Index via the public website for synoptic stations. These indices are based on observations and a seven-day forecast into the future using ECMWF predictions. This allows all county councils responsible for wildfire preparedness to access this information swiftly and directly.

Met Éireann also use the ANYWHERE multi-hazard warning tool which allows for visualisation of multiple fire-related risk factors and warning indices to be viewed simultaneously. The ANYWHERE system, in combination with our station-based forecast and antecedent conditions, provide fire managers and response teams with excellent information with which to make decisions.

How to cite: Flattery, P., Finkele, K., Downes, P., Hally, A., and Nugent, C.: A Decision Support System for Forest Fire Danger Notices in Ireland , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10793, https://doi.org/10.5194/egusphere-egu24-10793, 2024.

X1.10
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EGU24-10920
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ECS
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Seppe Lampe, Lukas Gudmundsson, Vincent Humphrey, Inne Vanderkelen, Bertrand Le Saux, and Wim Thiery

The temporal coverage (∼2000 to present) of global burned area satellite observations limits many aspects of fire research e.g., long-term trend analysis, disentangling the effect of various drivers on fire behaviour and detection and attribution of changes to climate change. As a result, global fire models are more frequently being called upon to answer questions about past and future fire behaviour. Unfortunately, the limited temporal coverage of the observations also hinders the development and evaluation of these fire models. The current generation of global fire models from ISIMIP are able to simulate well some characteristics of regional fire behaviour such as mean state and seasonality. However, the performance of these models differs greatly from region to region, and aspects such as extreme fire behaviour are not well represented yet. Here, we explore the possibility of using machine learning algorithms to model burned area from the same input parameters that are passed to global climate models. Once trained, this data-driven model can be evaluated against regional proxies for past fire behaviour e.g., tree rings and charcoal records. Hopefully, this data-driven reconstruction can provide valuable insights on the 20th century burned area, and can help improve and evaluate fire models.

How to cite: Lampe, S., Gudmundsson, L., Humphrey, V., Vanderkelen, I., Le Saux, B., and Thiery, W.: Reconstructing 20th century burned area by combining global fire model input, satellite observations and machine learning, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10920, https://doi.org/10.5194/egusphere-egu24-10920, 2024.

X1.11
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EGU24-11432
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ECS
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Highlight
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Dimitra Tarasi, Eirini Boleti, Katie Blackford, Matthew Kasoar, Emmanouil Grillakis, Guillermo Rein, Hafizha Mulyasih, and Apostolos Voulgarakis

Climate warming is occurring most rapidly at high latitudes, heightening the vulnerability of carbon-rich peatlands to fire. Northern peatlands comprise the largest terrestrial carbon store, and exert a net cooling effect on the climate. Warmer and drier conditions due to the anticipated climate change are expected to contribute substantially to increased fire severity and frequency in the northern high latitudes, potentially shifting peatlands from being carbon sinks to being greenhouse gas emission sources. Therefore, peat fires, which are considered the largest and most persistent fires on Earth, can significantly impact the global carbon cycle, atmospheric composition, climate, air quality, and human health. Representing peatland fire feedbacks to climate in Earth system models is essential for accurately predicting the future of the climate system. Here, we present the first steps of an effort to distill lab results on peat burning and emissions into global fire modelling. Since peat moisture content and the depth of burn have been experimentally proved to be critical for the representation of peat fires, we aim to incorporate those mechanisms into a global model functionality. More specifically, we aim to represent the mechanistic understanding of the ignition and spread of peat fires in INFERNO-peat, the peat module of the JULES-INFERNO global fire model. To assess the added value of our updated model, we compare the simulated burnt area and carbon emissions with observation-based products. As boreal regions remain a big mystery for the future of our planet, our improved model representation of peat fires in northern high latitudes contributes to a better understanding of future atmospheric composition, radiative forcing and climate. 

How to cite: Tarasi, D., Boleti, E., Blackford, K., Kasoar, M., Grillakis, E., Rein, G., Mulyasih, H., and Voulgarakis, A.: Northern high latitude peat fires: from lab to modelling , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11432, https://doi.org/10.5194/egusphere-egu24-11432, 2024.

X1.12
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EGU24-15436
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ECS
Maria Paula Velasquez Garcia, Richard Pope, Steven Turnock, and Martyn Chipperfield

Wildfires in South America are a significant concern, causing high emissions and deforestation rates. They affect air quality, radiation balance, and sensitive ecosystems like the Amazon rainforest. Wildfires are expected to intensify with future land use and climate changes, making it crucial to enhance decision-making tools. Models of atmospheric composition, combined with wildfire emissions inventories, support decision-making by simulating events and their impacts on air quality. There are currently a range of wildfire/biomass burning emission inventories, which all use different approaches. This can lead to substantial differences in estimated emissions and thus impacts on atmospheric composition estimation.  This study aims to assess four inventories (2004-2022) in South America: Global Fire Emissions Database (GFED), Fire INventory from NCAR (FINN), Global Fire Assimilation System (GFAS) and Brazilian Biomass Burning Emission Model (3BEM-FRP), focussing on carbon monoxide (CO) given its relatively large emission and complementary satellite missions retrieving atmospheric CO. Our results analyse the temporal consistency in the emission seasonal cycles from the inventories and quantify the spatial agreement/differences between them. We also exploit the Measurements Of Pollution In The Troposphere (MOPITT) retrieved CO to assess the links between emission inventory tendencies with that of the atmospheric temporal evolution. Finally, we use an offline version of the INteractive Fire and Emission algoRithm for Natural envirOnments (INFERNO) model, within the Joint UK Land Environment Simulator (JULES) framework to investigate simulated skill of emissions of CO against the observational constraints above as INFERNO is the fire model of choice in the UK Earth System Model (UKESM).

How to cite: Velasquez Garcia, M. P., Pope, R., Turnock, S., and Chipperfield, M.: Investigation of spatiotemporal variability in South American wildfire emissions and its impacts on CO concentrations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15436, https://doi.org/10.5194/egusphere-egu24-15436, 2024.

X1.13
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EGU24-13237
Rita Durao, Catarina Alonso, Ana Russo, and Célia Gouveia

The intensity of a wildfire can be assessed based on its released energy, obtained through remote measurements of the fire's radiative power. Since the Fire Radiative Power (FRP) is proportional to the amount of burned biomass and therefore to smoke production. Higher FRP values are associated with more severe fires, suggesting higher levels of smoke production and, consequently, higher emissions of particulate matter and other pollutants. The specific composition of smoke emissions can vary depending on factors such as the type of vegetation burned, the temperature of the fire, and the combustion conditions. In general, fire smoke is composed of a variety of air pollutants, including gases (NOx, CO, VOCs, O3, PAHs, etc) and particulate matter (PM). The objective of this work is to evaluate the ability of FRP, to be used as an indicator of fire smoke pollution. Particulate matter (PMx) and carbon monoxide (CO) concentrations emitted during recent wildfires in Portugal are analyzed to assess the link between pollution concentration levels and fire intensity over the affected areas, taking into account the spatial and temporal characteristics of each event. For this purpose, two particularly severe fires with significant impacts on air quality in central and southern Portugal were analyzed namely the ones taking place in October 2017 and August 2018. Concentrations of PMx and CO were evaluated through CAMS data, and the radiative power through the FRP product of the SEVIRI/MSG disseminated by LSA-SAFThe results show that the emitted pollutant concentrations significantly exceeded the established daily target limit values (air quality and public health guidelines). The fire intensity, based on the emitted Radiative Energy (FRE) derived from FRP, aligns with the known severity of these events, consistent with the observed concentrations of air pollutants, being demonstrated that the FRP can be associated with smoke production, especially PMx emissions during a fire. Thus, the proposed methodology using FRP can be a valuable tool for assessing the impact of wildfires on air quality and understanding the potential for smoke dispersion over fire-affected regions. The role of FRP as an indicator of air pollution highlights the potential use of FRP in assisting in management activities, operational planning, and emergency intervention during ongoing fires. 

Acknowledgments: This study is partially supported by the European Union’s Horizon 2020 research project FirEUrisk (Grant Agreement no. 101003890); and by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES on behalf of DHEFEUS -2022.09185.PTDC and the project FAIR- 2022.01660.PTDC).

How to cite: Durao, R., Alonso, C., Russo, A., and Gouveia, C.: The role of fire radiative power to estimate fire-related smoke pollution., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13237, https://doi.org/10.5194/egusphere-egu24-13237, 2024.

X1.14
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EGU24-14202
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Highlight
Fang Li, Xiang Song, Sandy Harrison, and Zhongda Lin

       Fire is the primary form of terrestrial ecosystem disturbance globally and a critical Earth system process. So far, most Earth system models (ESMs) have incorporated fire modeling, with 19 out of them submitted fire simulations to the CMIP6. Transitioning from CMIP5 to CMIP6, much more models submitted fire simulations and the dominant fire scheme has evolved from GlobFIRM to the Li scheme. However, it remains unknown how well CMIP6 ESMs perform in fire simulations. This study provides the first comprehensive evaluation of CMIP6 fire simulations, through comparisons with multiple satellite-based datasets and the Reading Paleofire Database of global charcoal records (RPD).

        Our results show that most CMIP6 models simulate the global amounts of present-day burned area and fire carbon emissions within the range of satellite-based products, and reproduce observed major features of spatial pattern and seasonal cycle as well as the relationships of fires with precipitation and population density, except for models employing the GlobFIRM fire scheme. Additionally, most CMIP6 models can reproduce the response of interannual variability of tropical fires to ENSO, except for some models incorporating the SPITFIRE fire scheme. From 1850 to 2015, CMIP6 models generally agree with RPD, with some discrepancies in southern South America before 1920 and in temperate and eastern boreal North America, Europe, and boreal Asia after 1990. Compared with CMIP5, CMIP6 has solved the serious issues of CMIP5 which simulates the global burned area less than half of observations, fails to capture the high burned area fraction in Africa, and underestimates seasonal variability. CMIP6 fire carbon emissions simulations are also closer to RPD. However, CMIP6 models still fail to capture the present-day significant decline in observed global burned area and fire carbon emissions partly due to underestimation in anthropogenic fire suppression, and fail to reproduce the spring peak in NH mid-latitudes mainly due to an underestimation of crop fires. Based on our findings, we identify potential biases in fire and carbon projection based on CMIP6 models. We also provide suggestions for the fire scheme development, and bias correction methods when generating multi-source merged fire products.

How to cite: Li, F., Song, X., Harrison, S., and Lin, Z.: Evaluation of global fire simulations in CMIP6 Earth system models, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14202, https://doi.org/10.5194/egusphere-egu24-14202, 2024.

X1.15
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EGU24-14446
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ECS
Laurel Sindewald, Shawn Urbanski, Karin Riley, Christopher Eckerson, Alex Dye, and Rachel Houtmann

In 2023, 6,551 wildfires across Canada burned 184,961 km2 of the landscape—about 5% of Canadian forests—emitting nearly 480 megatonnes of carbon, with emissions leading to air quality warnings as far away as Washington DC, USA. In early June, the air quality index in New York City was over 400, and by mid-June, smoke plumes passed above Europe. As wildland fires of increasing severity occur with increasing frequency, driven by global climate change and decades of fire suppression, societies near and far from high-risk ecosystems face increased exposure to wildfire emissions that may have both acute and long-term health impacts. Prescribed fire interventions show promise for reducing the risk of large wildfires in fire-prone ecosystems, but implementing prescribed fire can be difficult, in part due to concerns about the potential health impacts of prescribed fire smoke on nearby communities. To provide decision support for land managers aiming to reduce wildfire risk with prescribed fire treatments, we will produce a geospatial database of daily pollutant emissions and fire intensity from simulations of prescribed and wildland fires over a 20-year period for: 1) a baseline scenario of no management actions, 2) one or more scenarios of prescribed fire locations and timing based on interaction with tribes and Okanogan-Wenatchee National Forest (OWNF) managers, and 3) scenarios of prescribed fire locations and timing based on fire paths, locations of highly valued resources, areas available and suitable for treatment, determined by the research team. We can accomplish this by iterating between FSim, the Large Fire Simulator, which stochastically simulates large wildfire ignition and spread across a LANDFIRE fuels landscape, and FFE-FVS, the Forest Vegetation Simulator with the Fire and Fuels Extension, which simulates post-fire regeneration, forest growth, management actions including prescribed fire, fuel dynamics, and fuel consumption and pollutant emissions from prescribed fires and wildfires. Because FSim takes a Monte Carlo approach, simulating fires over 10,000 or more hypothetical fire seasons comprised of daily weather sequences, we will be able to estimate the probability of each landscape pixel burning in a wildfire and the conditional probability of that pixel burning at different flame lengths, allowing us to provide emissions estimates within a risk-assessment framework for managers. The framework will allow land managers to quantify the likelihood that smoke impacts from near-term prescribed fire treatments will be offset by reductions in severe smoke events from future wildfires. Additionally, the smoke event geospatial datasets may provide input into atmospheric transport models which could be used to simulate regional to national scale smoke impacts. We will pilot the project in Okanogan-Wenatchee National Forest, Washington, USA, working with the forest’s managers to design fuel treatment scenarios that will yield realistic fire occurrence trajectories and emission estimates to inform near-term prescribed fire operations. As a U.S. Federal Bipartisan Infrastructure Law Research & Development “proof of concept” project, the Wildland Fire Smoke and Emissions Tradeoff Decision Support project will inform U.S. Forest Service management policy and strategy around the use of prescribed fire in other National Forests in the U.S.

How to cite: Sindewald, L., Urbanski, S., Riley, K., Eckerson, C., Dye, A., and Houtmann, R.: Wildland Fire Smoke and Emissions Tradeoff Decision Support, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14446, https://doi.org/10.5194/egusphere-egu24-14446, 2024.

X1.16
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EGU24-15518
Valentina Bacciu, José Costa Saura, Grazia Pellizzaro, Bachisio Arca, Pierpaolo Duce, Donatella Spano, and Costantino Sirca

The Mediterranean region, already a climate change hotspot, is experiencing milder winters, hotter and drier summers, and increased extreme weather events, leading to longer fire seasons and increasing fire impacts. The socio-economic consequences of wildfires are significant, including the loss of human lives, infrastructure, and economic activity. Additionally, wildfires contribute significantly to climate change, accounting for up to 20% of global greenhouse gas emissions annually. Climate change is expected to worsen these conditions in the near future.

Given these circumstances, it is necessary to accelerate the transition towards the implementation of integrated and holistic fire management approaches aligned with future hazards. In the framework of The HUT project (The Human-Tech Nexus - Building a Safe Haven to cope with Climate Extremes), financed by the Horizon Europe program, the "Ogliastra-DEM8" case study (located in Sardinia, Italy) is aimed at responding to this necessity.

In particular, the main objective of The HUT is to mitigate the effects of climate-related events, by integrating and leveraging best practices and successful multi-disciplinary experiences and focusing on the prevention and preparedness phases of the disaster risk management cycle. In this context, the specific aim of the "Ogliastra-DEM8" case study is to provide the scientific/knowledge base needed to help policymakers and decision-makers defining adaptation and mitigation strategies that are effective in reducing fire impacts and associated costs in the short to medium-term under a changing climate. Towards this end, innovative tools (e.g., fire simulators, catastrophe insurance products, nature-based solutions) and stakeholder engagement, including participatory methods, will be developed.

This work presents the first phase of the work aimed at evaluating enablers and barriers to multi-hazard/systemic risk reduction by (i) reviewing the literature from other projects based in Sardinia, (ii) mapping and engaging stakeholders during an initial round of workshops, and (iii) debating fire-smart land management and adaptation options. Preliminary results indicate key barriers such as stakeholder conflicts, administrative silos, lack of political will, and funding complexities. All these elements contributed to varying degrees to the lack of a comprehensive approach towards integrated and sustainable management of the entire territory. On the other hand, enablers include stakeholder engagement, evidence of performance and co-benefits, and community awareness.

Further work will integrate stakeholder opinions into fire exposure and risk mapping under climate change conditions, with the goal of selecting and co-designing with them which fire-smart land management and adaptation options can be applied and where to protect the most important and vulnerable communities and ecosystems.

How to cite: Bacciu, V., Costa Saura, J., Pellizzaro, G., Arca, B., Duce, P., Spano, D., and Sirca, C.: Integrating stakeholders’ opinion in land management to build climate resilience in the context of fire risk, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15518, https://doi.org/10.5194/egusphere-egu24-15518, 2024.

X1.17
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EGU24-16165
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ECS
The combustion conversion coefficient for constructing open biomass fire burning emission based on satellite FRE
(withdrawn after no-show)
Jian Wu
Fire drivers and influence
X1.18
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EGU24-18169
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ECS
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Highlight
Rebecca Scholten, Tirtha Banerjee, Yang Chen, Ajinkya Desai, Tianjia Liu, Douglas Morton, Sander Veraverbeke, and James Randerson

Wildfires are an important disturbance in global ecosystems and are a critical driver of trends in the land carbon budget. Fire is an extreme phenomenon, with the largest burned area often occurring during extreme fire seasons generating large fires. Days with fire conditions conducive to fire ignition and spread are increasing in a warming climate in many regions of the world, contributing to increases in fire occurrence and annual burned area. However, the climate, fuel, and weather conditions that lead to extremely large fires in different biomes are poorly understood.

Here, we explore the temporal evolution of extremely large fires in temperate and boreal regions using new satellite-derived fire event tracking datasets optimized to match higher resolution time series of fire progression from aircraft and other sources. We aimed to understand the specific environmental conditions required for the development of a large fire. Our analysis revealed a disproportionate impact of multiple fire ignitions in creating large fires through merging. Our findings suggest that the largest fires in both biomes may be commonly created through multiple fires growing together. We hypothesize that a combination of physical and anthropogenic factors may accelerate merging, making these fires extremely difficult to contain and more robust to environmental controls regulating extinction. In our analysis, we use the Fire Events Database, the Arctic-boreal Fire Atlas, and GOFER, which enable attribution of ignition sources. Our analysis may contribute to an improved understanding of the influence of large-scale lightning storms in creating extremely large and destructive fire events.

How to cite: Scholten, R., Banerjee, T., Chen, Y., Desai, A., Liu, T., Morton, D., Veraverbeke, S., and Randerson, J.: What makes a fire grow extremely large?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18169, https://doi.org/10.5194/egusphere-egu24-18169, 2024.

X1.19
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EGU24-4071
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ECS
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Highlight
Yuquan Qu, Harry Vereecken, Sander Veraverbeke, and Carsten Montzka

Wildfires are known to be controlled by fuels and weather. Climate teleconnections may influence wildfires by altering fuel availability and fire weather. In this study, we used the random forest approach to systematically detect relationships between teleconnection climate indices (CIs) and burned area while accounting for different lag times. Results indicate that burned area is especially modulated by climate teleconnections in Africa and Australia. The Tropical Northern Atlantic (TNA) pattern was the most influential CI for the global burned area, followed by the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and the Pacific–North American (PNA) pattern. To study pathways of how teleconnections affect the burned area, we distinguished two classes of fire drivers: bottom-up fuel availability and top-down weather conditions. Bottom-up fuel drivers showed higher correlation with CIs than top-down weather drivers and served as mediators between teleconnections and wildfires. The mediating effect of top-down weather drivers was only apparent in specific seasons. Our study highlights that in teleconnection-wildfire hotspot regions, knowledge of the relation between CIs and drivers of wildfires could improve long-term wildfire predictability. We recommend that bottom-up fuel drivers should also be integrated into wildfire predictive frameworks as they play an important mediating role in linking teleconnections and wildfires.

How to cite: Qu, Y., Vereecken, H., Veraverbeke, S., and Montzka, C.: The Influence of Climate Teleconnections on Global Burned Area, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4071, https://doi.org/10.5194/egusphere-egu24-4071, 2024.

X1.20
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EGU24-11206
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ECS
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Highlight
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Esther Brambleby, Sander Veraverbeke, Guilherme Mataveli, Manoj Joshi, and Matthew Jones

Lightning is recognised as a crucial wildfire ignition source worldwide, especially in remote regions including boreal and temperate forests where large carbon stocks are held. The societal consequences of these wildfires, as well as their contribution to climate change, can be immense. The occurrence of lightning is projected to increase in these areas under climate change, however robust assessments of lightning contribution to wildfire risk have been restricted to selected regions due to the narrow spatial extent of cloud-to-ground lightning records. Consequently, evaluations of lightning-fire relationships using existing global lightning observational datasets have been limited to considering the total amount of lightning. Only cloud-to-ground lightning can ignite a wildfire, therefore when considering impacts on wildfire risk it is essential to distinguish between lightning types.

Using Vaisala’s unique Global Lightning Dataset (GLD360), which discriminates between cloud lightning and cloud-to-ground lightning strikes, we present our preliminary analyses of the spatial patterns and seasonality of cloud-to-ground lightning. Here, we show the regional variation in the lightning frequency and the cloud-to-ground fraction, as well as the strength (current) and polarity of cloud-to-ground lightning strikes.

By considering cloud-to-ground lightning strikes only, we characterise the spatial and seasonal variation in lightning events with the potential to ignite wildfires. Combining global observations of lightning strikes with observations of individual fires and coincident meteorology will advance our mechanistic understanding of wildfire ignition potential in a range of weather conditions, improve the process representation of the ignition process in global models, and refine projections of changing wildfire risks under climate change.

How to cite: Brambleby, E., Veraverbeke, S., Mataveli, G., Joshi, M., and Jones, M.: Global cloud-to-ground lightning data to inform wildfire ignition patterns, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11206, https://doi.org/10.5194/egusphere-egu24-11206, 2024.

X1.21
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EGU24-8668
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ECS
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Snehitha M. Kommula, Angela Buchholz, Yvette Gramlich, Tero Mielonen, Liqing Hao, Iida Pullinen, Lejish Vettikkat, Jorma Joutsensaari, Siegfried schobesberger, Petri Tiitta, Ari Leskinen, Dominic Heslin Rees, Sophie Haslett, Karolina Siegel, Chris Lunder, Paul Zieger, Radovan Krejci, Sami Romakkaniemi, Claudia Mohr, and Annele Virtanen

Global warming and climate change-induced rise in Earth’s temperature have increased the frequency of forest/wildfires over the past decade. Therefore, understanding the effect of fire emissions on aerosol-cloud interactions is crucial for improving Earth system models.

         We present observations from in-situ measurements of aerosol properties at the Puijo SMEAR IV station in eastern Finland and the Zeppelin Observatory in Ny-Ålesund, High Arctic. Both stations are frequently inside low-level clouds due to their topographic prominence. During the autumn of 2020, fire emissions from the same active fire region in south-eastern (SE) Europe reached both stations after ~2 - 8 days of atmospheric aging. This enabled us to investigate the changes in aerosol and cloud properties for clouds formed under the influence of aged fire emissions (referred to as the ‘fire’ period) and under cleaner conditions with no fire emission influence at these stations (‘non-fire’ period). The aerosol hygroscopicity parameter (κchem) was derived from the chemical composition data obtained from online aerosol mass spectrometers and was used to derive the number concentration of cloud condensation nuclei (NCCN) from the measured particle size distributions.

         At both stations, the aerosol number concentration in the accumulation mode and the cloud condensation nuclei concentration (NCCN) were higher during the fire period than during non-fire times. However, the aerosol hygroscopicity increased at Puijo but decreased a Zeppelin from the non-fire to fire period. At Puijo, in-situ measured cloud droplet number concentration (CDNC) was by a factor of ~7 higher when comparing fire to non-fire periods. This was in good agreement with the satellite observations (MODIS, Terra). At Puijo, the higher CCN concentrations during the fire period cause a depletion of the water vapor available for cloud droplet activation leading to larger observed activation diameters during cloud events despite the higher hygroscopicity of the aerosol particles.

         These observations show the importance of SE European fires for enhancing the CCN activity in Finland and the high Arctic. Results from this study emphasize the complex interplay between particle size and chemical composition, and how fires even from sources far away can have strong impacts in these remote regions.

How to cite: Kommula, S. M., Buchholz, A., Gramlich, Y., Mielonen, T., Hao, L., Pullinen, I., Vettikkat, L., Joutsensaari, J., schobesberger, S., Tiitta, P., Leskinen, A., Rees, D. H., Haslett, S., Siegel, K., Lunder, C., Zieger, P., Krejci, R., Romakkaniemi, S., Mohr, C., and Virtanen, A.: Effect of long-range transported fire emissions on aerosol and cloud properties at high latitudes: In situ measurements and satellite observations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8668, https://doi.org/10.5194/egusphere-egu24-8668, 2024.

X1.22
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EGU24-1471
Wenxuan Fan, Jie Li, Zhiwei Han, and Jian Wu
From March to April, widespread forest fires and agro-residue burning frequently occur in Southeast Asia, which release large amounts of gas species and aerosols and impact air quality over the wide source and downwind regions. In this study, we investigated the impact of biomass burning (BB) over Southeast Asia on particulate matter concentrations and aerosol properties in downwind areas of the low-latitude plateau from 1 March to 30 April 2019, with a focus on a typical pollution event in Kunming (KM), the capital of Yunnan Province, by using a wide variety of observations from the Chenggong ground monitoring station in Yunnan University, an air quality network in China, satellite retrievals and ERA-5 reanalysis data and numerical simulation. A regional pollution event contributed by BB pollutants from Southeast Asia and the India-Myanmar trough occurred in Yunnan Province on 31 March to 1 April 2019, which was the only typical pollution event that pollution transmission ran through central Yunnan Province from south to north since 2013, when the Airborne Pollution Action Plan was unveiled by China government. The daily mean PM2.5, PM1, and black carbon concentrations increased by 73.3 μg m−3 (78%), 70.5 μg m−3 (80%), and 7.7 μg m−3 (83%), respectively, and the scattering and absorbing coefficients increased by 471.6 Mm−1 and 63.5 Mm−1 , respectively, at the Chenggong station. The southwest winds exceeding 2 km vertically thick appeared in front of the India-Myanmar trough over the fire regions, pushing BB plumes northward into Yunnan Province. The model results show that 59.5% of PM2.5 mass produced by BB in Yunnan Province was sourced from the Myanmar-Thailand border, and 29.3% was from western Myanmar at a lower altitude (<4.9 km), which indicated that BB in the Myanmar-Thailand border was the dominant contributor.

How to cite: Fan, W., Li, J., Han, Z., and Wu, J.: Impacts of biomass burning in Southeast Asia on aerosols over the low-latitude plateau in China: an analysis of a typical pollution event, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1471, https://doi.org/10.5194/egusphere-egu24-1471, 2024.

X1.23
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EGU24-15398
Kwon-Ho Lee, Kwanchul Kim, and Dasom Lee

Spatiotemporal patterns and trends of atmospheric aerosols in high latitude region have been analyzed. Aerosol observation data from 2000-2022 acquired from the earth observing satellites including the Moderate Resolution Imaging Spectroradiometer (MODIS), the Ozone Monitoring Instrument (OMI), or geostationary satellites such as the Geostationary Korea Multi-Purpose Satellite-2A (GK-2A) . Results showed that Aerosol Optical Thickness (AOT) over the high latitude region has gradually decreased before 2016. However, AOT has increased significantly over the past 8 years. This increase was clearly shown in North America and North Asia, and was associated with an increase with fire activities. Smoke plumes originated from fire active fires transported eastward with meteorology, but occasionally moved toward the Arctic region. The occurrence of fires and the production and transport of aerosols will be a consequence or factor of the recent rapid climate change.

Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2019R1I1A3A01062804).

 

How to cite: Lee, K.-H., Kim, K., and Lee, D.: Effects of recent increase in anomalous fires and smokes at high latitude regions on regional atmosphere, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15398, https://doi.org/10.5194/egusphere-egu24-15398, 2024.

X1.24
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EGU24-5348
Katarzyna Marcisz, Mariusz Bąk, Mariusz Lamentowicz, Piotr Kołaczek, Thomas Theurer, Paweł Matulewski, and Dmitri Mauquoy

Monoculture forests are now a dominant forest type in Europe. Created for easier management and increased timber production, they are now witnessing many disturbances due to climate change, such as more frequent windthrows, droughts, fires or insect outbreaks. The functioning of forests impacts other elements of the landscape, including peatlands, which also have been affected by various natural and anthropogenic disturbances (e.g., drainage) that make them more vulnerable to drying and burning. We aim to recognize how peatland functioning has changed along with changing forest management strategies. For this we studied a Sphagnum-dominated peatland located in the Tuchola Pinewoods – one of the largest Scots pine (Pinus sylvestris) monoculture forest in Poland. We used high-resolution multi-proxy palaeoecology including pollen, plant macrofossils and testate amoebae, additionally focusing on a wide range of charcoal analyses: charcoal counts, charcoal morphological types, and Raman spectroscopy. Our results show that the studied peatland experienced several critical transitions in vegetation composition and hydrology over the last 600 years when new forest management techniques were introduced. A reduction in fire activity led to a dominance of Sphagnum and increased peat accumulation rates. Establishment of a monoculture forest further impacted the site and stabilized Sphagnum growth and acidity levels. We believe that these results can be helpful for the improvement of conservation planning for peatlands located in forested areas, especially in monoculture forests.

The study is funded by the National Science Centre, Poland (2020/39/D/ST10/00641).

How to cite: Marcisz, K., Bąk, M., Lamentowicz, M., Kołaczek, P., Theurer, T., Matulewski, P., and Mauquoy, D.: Wetlands in monoculture forests – how fire activity and different forest management strategies impact Sphagnum-dominated peatlands, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5348, https://doi.org/10.5194/egusphere-egu24-5348, 2024.

X1.25
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EGU24-7467
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ECS
Jiangshan Mu, Yingnan Zhang, Chenliang Tao, Zhou Liu, Yu Zhao, Lei Zhang, Yuqiang Zhang, and Likun Xue

Nitrogen deposition can exert a significant impact on global ecosystems. The increased occurrence of natural factors such as wildfires are becoming more important in atmospheric deposition especially with the continued decreases of the anthropogenic emissions in developed countries. In this study, we investigate the mechanisms by which the increasingly frequent wildfires affect nitrogen deposition in the United States using comprehensive datasets and multiple linear regression (MLR) methods. We found a downward trend in nitrogen deposition in the U.S. (-0.09 kgN ha yr-1), mainly due to the decreases in oxidative nitrogen deposition (-0.1 kgN ha yr-1). In contrast, reduced nitrogen deposition showed a slight increase (0.02 kgN ha yr-1). Our preliminary results show that wildfires contributed ~10% to the U.S. domestic deposition overall, but the magnitudes and signs of impact vary geographically, depending on the frequency and intensity of wildfires and the dominant deposition types. On average across the U.S., wildfires predominantly negatively contribute to wet deposition, while their contributions to dry deposition is smaller or slightly positive. Specifically, wildfires enhance dry deposition in the western U.S. while inhibiting wet deposition in the southeastern U.S. Wildfires exert a suppressive effect on both oxidized and reduced forms of nitrogen deposition in the southeastern U.S. Our study highlights the significant influence of wildfires on nitrogen deposition, underscoring the need to consider wildfire events in environmental management and policy-making.

How to cite: Mu, J., Zhang, Y., Tao, C., Liu, Z., Zhao, Y., Zhang, L., Zhang, Y., and Xue, L.: The Impact of Wildfires on Atmospheric Nitrogen Deposition in the United States: A Multiple Linear Regression-based Analysis, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7467, https://doi.org/10.5194/egusphere-egu24-7467, 2024.

X1.26
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EGU24-16087
Jonay Neris, Carmen Sánchez-García, Marta Basso, Roger Lew, Anurag Srivastava, Mariana Dobre, Pete Robichaud, Erin Brooks, Cristina Santin, and Stefan Doerr

Soil and ash are key sources of sediment, carbon, nitrogen, and associated pollutant movement following a wildfire. Their transport into freshwater systems can pose severe environmental and socio-economic implications including impacts to water quality and aquatic ecosystems, disruptions to drinking water supply and high remediation costs, as well as the depletion of carbon and nutrients from areas affected by erosion. We assessed the risk of soil erosion, ash and contaminant transport, and water contamination in three burned European catchments in Central Europe (Germany and the Czech Republic), Portugal and Spain using the European Water Erosion Prediction Project cloud interface with the Wildfire Ash Transport and Risk (WEPPcloud-EU WATAR) watershed model. The watersheds varied in size from 100 to 22,000 ha and represent distinct climatic conditions. To our knowledge, this is the first application of this model in European post-fire scenarios. We calibrated and validated the model using catchment runoff data (where available) and nearby streamflow data from both pre- and post-fire periods when runoff data was unavailable. Additionally, we used sediment transport data (where available) along with ash contaminant content data to calibrate and validate erosion and ash transport rates. Model performance was assessed using statistics like Nash-Sutcliffe Efficiency (NSE), coefficient of determination (R2) and percent bias (PBias (%)). Once the model was calibrated and validated, we estimated the post-fire risk of soil erosion, ash transport, and ash pollutant concentrations in the affected areas. The simulations provided the probabilities of occurrence and return periods for severe erosion events, as well as for ash and contaminant transport events. Based on these simulations, we identified hillslopes that were the main sources of runoff, erosion, ash and contaminant transport. This information is important to managers who can prioritize the application of mitigation treatments and prevention plans. Given the projected increase in fire weather in many regions in Europe, our findings suggest that the WEPPcloud-EU WATAR model is an increasingly useful tool in predicting and mitigating soil erosion and water contamination impacts of European burnt catchments.

How to cite: Neris, J., Sánchez-García, C., Basso, M., Lew, R., Srivastava, A., Dobre, M., Robichaud, P., Brooks, E., Santin, C., and Doerr, S.: Assessing post-fire soil erosion and water contamination risk in European fire-affected catchmentswith WEPPcloud-EU WATAR watershed model, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16087, https://doi.org/10.5194/egusphere-egu24-16087, 2024.

X1.27
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EGU24-11965
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ECS
Luigi Marfella, Mark A. Ashby, Georgia Hennessy, Rossana Marzaioli, Flora A. Rutigliano, and Helen C. Glanville

Peatland soil is a valuable component of natural capital by constituting the largest terrestrial carbon sink (~30% of the global soil carbon) and an essential freshwater source. Despite covering only ~3% of the Earth’s surface, peatlands provide crucial ecosystem services i.e. water-quality improvement and climate regulation by storing carbon in peat. However, peat degradation due to anthropogenic activities (e.g. drainage) as well as global climate change exposes this ecosystem to fire risk.
This study assessed the medium-term (~5 years) impacts of the 10 August 2018 wildfire within The Roaches Nature Reserve. This area spans the southeastern sector of the Peak District National Park and Special Area of Conservation (SAC-UK0030280). According to the Staffordshire Wildlife Trust (responsible authority for Reserve management), the human-caused fire broke out in a wooded area and aided by wind, spread to the peatland. Here, we integrated soil analyses and vegetation surveys of a burnt and unburnt area i) to assess possible correlations between soil biogeochemical properties and vegetation cover with ii) remote sensing to collect data on fire severity exploring temporal and spatial wildfire impacts.
Processing of satellite imagery highlighted a high-severity fire impact within the perimeter of the burned area, which predicts alteration of soil characteristics. Preliminary outcomes on the soil indicated deacidification and reduced water content in the burned peat remains 5 years post-fire.
Given that global peatland conservation is an important tool for addressing climate-change, this research appears necessary to develop effective management strategies, including rewetting of peatlands postfire.

How to cite: Marfella, L., Ashby, M. A., Hennessy, G., Marzaioli, R., Rutigliano, F. A., and Glanville, H. C.: Effects of 2018 wildfire on soil properties in a peatland within the Peak District National Park (central England), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11965, https://doi.org/10.5194/egusphere-egu24-11965, 2024.

X1.28
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EGU24-16293
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ECS
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Highlight
Iulian-Alin Rosu, Matt Kasoar, Eirini Boletti, Mark Parrington, and Apostolos Voulgarakis

Wildfires are a central but relatively unexplored component of the Earth system. Severe wildfire events can lead to intense destruction of both nature and property, as was the case during the anomalously intense 2023 Canadian wildfire event. Last year, approximately 5% of the total forest area of Canada burned [1] [2], which is the highest wildfire damage Canada has ever sustained [1].

Conditions pertaining to climate change and modifications in atmospheric conditions are considered to be responsible for this record series of wildfires [3]. Increasing mean temperatures and decreasing humidity in the region has exacerbated wildfire risk. Carbon emissions from the 2023 Canadian wildfires have been the highest on record [4], including large amounts of carbonaceous aerosol which can exert substantial atmospheric radiative forcing. Also, Canadian fire emissions contributed around 20% of global emissions from vegetation fires. Thus, beyond the well-known health risks of wildfire emission compounds, it is important to also study the consequences of these emissions on large-scale atmospheric composition and meteorological behavior.

In this work, the global and regional atmospheric impact of the previously mentioned series of wildfires is investigated using the EC-Earth3 and UKESM1 earth system models. Simulated atmospheric conditions with and without the wildfire emissions, as provided by the Copernicus Atmosphere Monitoring Service (CAMS) Global Fire Assimilation System (GFAS), are compared through atmospheric modelling in the context of the Canadian 2023 fire season. The investigation reveals the connections between the emissions produced by this series of wildfires and atmospheric phenomena of importance, such as large-scale circulation, temperature patterns, and precipitation.

[1] "Fire Statistics". Canadian Interagency Forest Fire Centre. Retrieved January 4, 2024.

[2] The State of Canada’s Forests: Annual Report 2022. Canadian Minister of Natural Resources.

[3] Barnes, Clair, et al. "Climate change more than doubled the likelihood of extreme fire weather conditions in eastern Canada." (2023).

[4] “Copernicus: Emissions from Canadian wildfires the highest on record – smoke plume reaches Europe”. Atmosphere Monitoring Service, Copernicus. Retrieved January 4, 2024.

How to cite: Rosu, I.-A., Kasoar, M., Boletti, E., Parrington, M., and Voulgarakis, A.: Global atmospheric impacts of aerosols emitted from the 2023 Canadian wildfires, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16293, https://doi.org/10.5194/egusphere-egu24-16293, 2024.

X1.29
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EGU24-16592
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ECS
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Highlight
Antonio Girona-García, Diana Vieira, Stefan Doerr, and Cristina Santín

Wildfires release approximately 2.1 Pg C to the atmosphere each year. The impact of wildfires on the carbon cycle, however, extends well beyond direct emissions, involving complex interactions among various source and sink processes. One such process, the enhanced post-fire soil organic carbon (SOC) erosion, remains unquantified as a potential C sink mechanism. Post-fire SOC erosion functions as a C sink when the subsequent burial and stabilization of eroded C offsite, coupled with the recovery of net primary production and SOC content onsite, outweigh the C losses to the atmosphere during post-fire transport of SOC. In this work, we synthesize published data on post-fire SOC erosion and evaluate its overall potential to act as C sink. In addition, we estimate its magnitude at continental scale following the 2017 wildfire season in Europe, showing that SOC erosion can indeed play a quantitatively significant role in the overall C balance of wildfires. 

How to cite: Girona-García, A., Vieira, D., Doerr, S., and Santín, C.: Exploring the role of post-fire erosion as a carbon sink mechanism, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16592, https://doi.org/10.5194/egusphere-egu24-16592, 2024.

X1.30
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EGU24-11809
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ECS
Luis Filipe Lopes, Erika S. Santos, Leónia Nunes, Paulo M. Fernandes, and Vanda Acácio

Forests play a substantial role in generating externalities and supporting services essential for maintaining key ecosystem functions and processes. Fire has long been a natural element of forest dynamics, contributing to model the structure, composition, and diversity of vegetation. However, changes in fire regimes in recent decades in Europe (e.g., more frequent and severe fires) have led to negative ecological, social, and economic impacts, particularly marked by a decline in the provision of ecosystem services. Mediterranean Europe, being a region highly prone to wildfires and currently experiencing a change in fire regimes, exemplifies this situation.

In this study, we aim to understand the effects of postfire oak afforestation on the provision of ecosystem services (ES). We analysed 15 afforestation projects with the deciduous Pyrenean oak (Quercus pyrenaica) carried out in 1994-2006 in similar soil type (Cambisols) in the North and Center of Portugal, including seven pure and eight mixed oak stands. For each project area, we identified an adjacent control area affected by the same fire event but without oak afforestation or evident management. In 2021-2022, for each project and control areas, we collected field data on: site conditions, stand characteristics, forest biometry, understory vegetation (height and cover), floristic richness and diversity, oak natural regeneration and litter. At the moment of data collection, the majority of projects (10) were 12 to 17 years old, with the remaining projects (5) having been implemented 21 to 25 years ago. Collected data was used to quantify provisioning ecosystem services (wood volume) and regulation and maintenance services (forest and litter carbon, fire protection, maintenance of nursery populations, habitats, and seed dispersal).

Afforested areas supplied more provisioning services (higher wood volume), as a consequence of a higher tree density when compared to non-afforested areas. Total carbon content and litter carbon were not significantly different between afforested and control areas. Nevertheless, afforested and control areas exhibited distinct patterns concerning carbon in the different forest layers: carbon in the tree layer was significantly higher in afforested areas, while carbon in the understory layer was significantly higher in control areas. Afforested areas also showed a significantly higher fire protection service, as a consequence of lower fuel load from regular understory shrub management. Lastly, we found no significant differences in services related to maintenance of nursery populations and habitats (estimated with floristic species and diversity), and seed dispersal (estimated with oak natural regeneration), although afforested areas presented a higher number of oak seedlings.

Our study shows that postfire afforestation in oak forests may have a positive, null or negative impact on ES, depending on the service under analysis, highlighting the existence of trade-offs among multiple ES. We emphasize the importance of a comprehensive understanding of the impacts of postfire afforestation on ES to guide postfire management, aiming to enhance forest resilience in the face of predicted climate change.

How to cite: Lopes, L. F., Santos, E. S., Nunes, L., Fernandes, P. M., and Acácio, V.: Analysing the effects of postfire oak afforestation on the provision of ecosystem services, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11809, https://doi.org/10.5194/egusphere-egu24-11809, 2024.

X1.31
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EGU24-19716
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ECS
Manoela Machado, Wesley da Cruz, Maria Antonia Carniello, Emily Sturdivant, Francisco Navarro-Rosales, Marcia Macedo, Wayne Walker, and Imma Oliveras Menor

Fire is a natural disturbance capable of altering plant distributions and community assemblages, influencing species evolution through the selection of traits and strategies, and affecting biogeochemical cycles. This powerful tool of landscape transformation can negatively impact even a fire-dependent ecosystem when natural fire regimes are altered. In recent times, interactions between human activities in the Cerrado (e.g., deforestation and intentional fires used to clear land), and a hotter and drier climate (due to climate change), have altered natural fire regimes causing more frequent and intense fire events, negatively impacting biodiversity, human health, and the regional climate. These fire-disturbed areas are widespread and highly vulnerable to future degradation from compounding disturbances, but they still harbour valuable biodiversity and carbon stocks that deserve protection and restoration. Monitoring the impacts of fire disturbance on vegetation structure and the potential pathways of recovery is critical to understand and protect resilient ecosystems under a rapidly changing climate. Robust monitoring requires the integration of modelled and field-based data tools and techniques. Field inventories alone are insufficient to capture the spatiotemporal variability of impacts of fire on native vegetation and should be coupled with remotely sensed data, among which, LiDAR (light detection and ranging) is unparalleled in characterising 3-D vegetation structure. Thus, the combination of LiDAR and forest inventory data is ideally suited for scaling the impacts of fire on forest vegetation and associated carbon stocks. In this study, we are assessing key metrics of vegetation structure derived from a combination of LiDAR and field data collected at the Experimental Station Serra das Araras, Mato Grosso state, Brazil. This field site comprises Cerrado vegetation that has been subject to three experimental fire treatments: every year, every two years, and every three years beginning in 2017, as well as fire suppression for over three decades. We are investigating whether key vegetation structural metrics can capture different fire treatments and identify spatial patterns of disturbance. We are also assessing if these patterns are different when comparing LiDAR data collected with a handheld scanner versus an airborne drone. This study aims to refine our methods and improve our understanding of vegetation structure responses across a gradient of fire disturbance regimes and potential post-fire recovery trajectories, which are key not only for ecological studies but also for emerging carbon markets – one of several mechanisms aimed at achieving climate change mitigation, conservation, and sustainable development outcomes. We hope to improve the process of carbon stock mapping in disturbed ecosystems and use the outputs to drive scenarios modelling at larger scales, providing a more comprehensive assessment of what future Cerrado carbon dynamics might look like under a range of possible disturbance/recovery dynamics.

How to cite: Machado, M., da Cruz, W., Carniello, M. A., Sturdivant, E., Navarro-Rosales, F., Macedo, M., Walker, W., and Oliveras Menor, I.: "Fire impacts in the Cerrado: Integrating LiDAR and field data to monitor vegetation structure and post-fire recovery.", EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19716, https://doi.org/10.5194/egusphere-egu24-19716, 2024.

X1.32
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EGU24-13416
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ECS
Michaela Flegrova and Helen Brindley

Fire is an important, widespread Earth-system process, influencing local ecosystems and climate around the globe. Over half of global burned area occurs in Africa, with over 10% of the continent affected by fire every year. Fire temporarily alters the surface properties, including surface albedo, causing long-lasting changes to the surface radiation budget.

We present the analysis of 20 years of fire and albedo data in Africa, using the MODIS product suite. We show that fire causes an average immediate albedo decrease, recovering exponentially with a time constant of several weeks. While the magnitude of albedo changes shows large spatial and temporal variations and a strong land cover type (LCT) dependency, exponential recovery is observed in the majority of LCTs. We show that fires cause long-term brightening, observing on average a small positive albedo change 10 months after a fire, but we find this is driven almost exclusively by slow vegetation recovery in the Kalahari region.

Using downward surface shortwave flux estimates we calculate the fire-induced surface radiative forcing (RF), peaking at 5±2 Wm−2 in the burn areas, albeit with a significantly smaller effect when averaged temporally and spatially. We find that the average long-term RF is negative because of the brightening observed.

Our temporal analysis does not indicate a decrease in overall fire-induced RF, despite a well-documented reduction in burning in Africa in the recent decades, suggesting that the RF of individual fires is increasing because of higher levels of downward surface shortwave flux. We hypothesise this may be due to lower levels of smoke aerosols in the atmosphere.

How to cite: Flegrova, M. and Brindley, H.: Two decades of fire-induced albedo change and associated radiative effect over sub-Saharan Africa, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13416, https://doi.org/10.5194/egusphere-egu24-13416, 2024.

X1.33
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EGU24-7895
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ECS
Nils Rietze, Jakob Assmann, and Gabriela Schapeman-Strub

In 2020, the Northeastern Siberian lowland tundra faced an extreme drought and unprecedented wildfires. The burning of carbon-rich soils in this region can release large amounts of carbon, worsening climate change and Arctic warming.  However, we know little about of how droughts impact vegetation and how this vegetation might become fuel for large fires in the typically wet landscapes of the Northeastern Siberian lowland tundra. We studied the impact of the extreme summer drought in 2020 on the tundra vegetation and the resulting burn patterns in the Indigirka lowlands using a combination of in-situ, thermal, and multispectral remote sensing data from drone and high-resolution satellite imagery. The fine-scale vegetation types revealed increased landscape-wide drought susceptibility indicated by an overall loss of land surface cooling. This suggests a shift towards an energy budget dominated by sensible heat flux, which may feed back and intensify the heatwave.  Further, we found that mostly dry vegetation types were affected by fire in the NE Siberian coastal tundra, while wetter vegetation types did not burn, leading to a fine-scale heterogeneous burn pattern. Our results indicate that the enhanced drought susceptibility of vegetation types may have led to higher fire fuel connectivity of the tundra landscape. Consequently, this may have resulted in the large burn extents observed in 2019 and 2020. Our analysis is an effort toward the prediction of fire fuel connectivity and fire management in remote Arctic areas.

How to cite: Rietze, N., Assmann, J., and Schapeman-Strub, G.: Vegetation types influence fine-scale drought impact on land surface cooling and burn patterns in the Siberian coastal tundra, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7895, https://doi.org/10.5194/egusphere-egu24-7895, 2024.

X1.34
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EGU24-17935
Chantelle Burton, Stephen Plummer, Noah Liguori-Bills, Morgane Perron, Douglas Kelley, Miriam Morrill, Boris Vannière, Joanne Hall, Stijn Hantson, Matthias Forkel, Christoph Völker, Kebonye Dintwe, Cristina Santin, Jessie Thoreson, Benjamin Poulter, Matthew Jones, and Douglas Hamilton

Fire substantially influences and modulates the global carbon cycle through numerous processes, interactions, and feedbacks. Fires are also strongly intertwined with human activities; people act both as drivers of change through ignitions, suppression, land-cover change, prescribed burning, and climate change, and are affected in return by changes in fire regimes. 

Despite fire’s many complex interactions throughout the Earth System, it is often viewed only as a destructive process, and one that solely acts as a source of atmospheric carbon. In terms of fire’s carbon budget, the release of carbon only represents the very initial stages of the process, missing the drivers and complex ways in which fire shapes plant species evolution and ecosystem trajectories, nutrient cycling and redistribution, carbon allocation, deposition and sequestration over different spatiotemporal scales. Therefore, there is a clear need to fully understand the role of fire in the Earth System holistically. However, different aspects of fire’s role in the carbon cycle are often studied by different communities and disciplines, hindering this much-needed integrated understanding. 

Through the Fire Learning AcRoss the Earth Systems (FLARE) workshop (September 2023) we brought together fire scientists across multiple disciplines to facilitate transdisciplinary discussion. We propose that the visualization of fire processes as carbon colours across the Earth System can be a thematic tool for unifying disciplines. It explores all aspects of fire and smoke implications for living systems and opens questions about fire’s role in carbon budgets, afforestation, and climate change and related mitigation strategies. We also identified several scientific challenges for the community where, by working together, we can address some fundamental questions for fire’s role in the carbon cycle, such as: What is the contribution of fire and of individual fire events to the global carbon cycle? How do changes in fire regimes influence ecosystem stability across different timescales? How do future changes in fire regimes influence global climate, allowable emissions and carbon budgets, and temperature mitigation ambitions? In this presentation, we explore how we can bring a more interdisciplinary approach to fire science to address these fundamental questions.

How to cite: Burton, C., Plummer, S., Liguori-Bills, N., Perron, M., Kelley, D., Morrill, M., Vannière, B., Hall, J., Hantson, S., Forkel, M., Völker, C., Dintwe, K., Santin, C., Thoreson, J., Poulter, B., Jones, M., and Hamilton, D.: The FLARE Workshop perspective on Fire’s Role in the Carbon Cycle, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17935, https://doi.org/10.5194/egusphere-egu24-17935, 2024.

X1.35
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EGU24-10377
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ECS
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Carlota Segura-Garcia, David Bauman, Vera L. S. Arruda, Ane Alencar, and Imma Oliveras Menor

The Brazilian Cerrado is a heterogeneous biome formed by a mosaic of savannas, grasslands, and smaller patches of denser woody forms. In this biome, fire is a natural disturbance agent that contributes to maintaining its open ecosystems and rich biodiversity. However, modern human activities and climate change are altering its fire regimes. In tropical savannas, land-use expansion is usually associated to a decrease in burned area primarily through land fragmentation, but also through active fire suppression. Meanwhile, climate change is fostering fire weather conditions, exacerbating fire activity. Hence, the two main drivers of fire could be pushing burned area in opposite directions, both with important ecological consequences for the Cerrado. However, it remains unclear how these two drivers interact, which is essential to devise effective fire management policies and conservation plans.

In this study, we use a causal inference framework to quantify the interaction between anthropic area percentage – as a proxy of human presence and fragmentation – and various climatic variables on their effects on Cerrado’s burned area. As well, we explore the spatial structure of temporal trends in burned area, anthropic expansion and climate change, and quantify the causal effect of the last two on the former.

We use geospatial data from different sources on a 0.2o grid over the Cerrado for the period 1985 to 2020. We use burned area and land use data from the MapBiomas project, and climate re-analysis data from ERA5 Land, CHIRPS and TerraClimate. We design our models using Directed Acyclic Graphs, a graphic representation of the causal relations between the predictors and burned area that informs variable selection for causal inference. Hence, based on these DAGs, we build multilevel Bayesian regression models to quantify the effects of the predictors and their interactions.

We find that a larger presence of land-use activities keeps burned area low and, importantly, hinders the effects of the climate. That is, while in landscapes composed mostly of native vegetation hotter and drier conditions increase burned area as expected; in anthropic landscapes, humans completely limit burned area responsiveness to climate. We also find spatially heterogeneous increasing and decreasing trends in burned area over the period, but concentrated in those areas of the Cerrado that were mostly natural in 1985. In these areas, a large anthropic expansion brought about a decrease in burned area, while we observe an increase in burned area in relation to climate change only in the areas that remained intact throughout the study period.

In conclusion, burned area in the Cerrado is shaped primarily by the extent of human presence in the landscape, even limiting the effects of the climate, while climatic effects become relevant in areas with larger tracts of native vegetation, suggesting that these areas may be more vulnerable to climate change.

How to cite: Segura-Garcia, C., Bauman, D., S. Arruda, V. L., Alencar, A., and Oliveras Menor, I.: Human land occupation regulates the effect of the climate on the burned area of the Cerrado biome, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10377, https://doi.org/10.5194/egusphere-egu24-10377, 2024.

Posters virtual: Tue, 16 Apr, 14:00–15:45 | vHall X1

Display time: Tue, 16 Apr 08:30–Tue, 16 Apr 18:00
Chairpersons: Renata Libonati, Angelica Feurdean, Rebecca Scholten
Fire session-Posters virtual
vX1.1
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EGU24-19223
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ECS
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Dominika Leskow-Czyżewska, Stephan Bojinski, Julien Chimot, Andrea Meraner, Mark Parrington, and Federico Fierli

Satellite-borne observations offer the possibility to monitor wildfires and their impact worldwide. In addition, satellite products are increasingly used in early warning and forecasting systems for fire management. Europe is implementing a long-term and reliable observational programme and, within this frame, EUMETSAT, the European meteorological satellite operator, provides numerous observational products ranging from near-real-time wildfire identification (e.g. fire radiative power) to atmospheric impacts (e.g. major pollutants and smoke). 

Our presentation will focus on the satellite data value chain, e.g. the integration in the Copernicus Atmosphere Monitoring Service (CAMS) Global Fire Assimilation System (GFAS). To do that, we will firstly present datasets addressing wildfires (e.g. Fire Radiative Power, atmospheric composition, and smoke) currently generated at EUMETSAT and its Satellite Applications Facility (SAF). We will also introduce upcoming (based on the Flexible Combined Imager on-board the Meteosat Third Generation) and future products (Sentinel-4 and 5), with an example of potential joint use for a past intense fire case in the Mediterranean (Greece, August 2023).  

We will then show the entire value chain, including how the data is used in the Copernicus Atmosphere Monitoring Service (CAMS) Global Fire Assimilation System (GFAS), with an example on the recent intense and anomalous fire season in Canada (spring to summer 2023). This will show how distinct phases of wildfires management – from early warnings up to the impacts on yearly emissions – can be monitored with the synergy of satellite data and Copernicus forecast and analysis. Finally, we will touch also on the user support activities within EUMETSAT in this area. 

How to cite: Leskow-Czyżewska, D., Bojinski, S., Chimot, J., Meraner, A., Parrington, M., and Fierli, F.: Monitoring wildfires from satellite, integration in Copernicus services and characterizing atmospheric impacts from the regional to the global scales, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19223, https://doi.org/10.5194/egusphere-egu24-19223, 2024.

vX1.2
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EGU24-18811
José Maria Costa Saura, Valentina Bacciu, Donatella Spano, and Costantino Sirca

Fire risk analyses, usually focused on fire hazard (i.e. the probability of fire occurrence), often neglect an important issue such as the sensitivity/vulnerability (i.e., the degree of potential damage, sensus IPCC) of different locations within the area of interest.  Such lack of consideration comes from past data processing constrains that limited fire severity studies to analyse only single or few fire events. Nowadays, online data repositories and processing platforms (e.g. Google Earth Engine) allow to easily integrate and process a vast amount of data from multiple sources that might prove useful for developing tailored tools for decision making. Here, we present an example for predicting potential fire severity based on the analysis of more than 1 000 fire events from southern France and western Italy which integrates climate, topographical and remote sensing variables. Furthermore, we assessed if the model “used” the explanatory variables under a meaningful biophysical sense.   Using the random forest algorithm and the relativized difference of the Normalized Burn Ratio (rdNBR) as proxy of fire severity, we reach to explain up to 75% of the variability in the data with most of the variables showing a clear and interpretable effect. Our results suggests that this type of approach might prove useful for better address fire risk assessments.

How to cite: Costa Saura, J. M., Bacciu, V., Spano, D., and Sirca, C.: Taking advantage of satellite data, large datasets of fire records and cloud computing for modelling potential fire severity useful for better assess fire risk, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18811, https://doi.org/10.5194/egusphere-egu24-18811, 2024.

vX1.3
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EGU24-18894
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ECS
Eduardo Oliveira, João Gata, Diogo Lopes, Leonardo Disperati, Carla Gama, and Bárbara Silva

Agricultural residue burning is a common practice in various regions of the world, which may have several environmental impacts, including on air quality, and the potential for triggering wildfires. In Portugal, this practice is particularly prevalent during the wet season, spanning from October to April. It involves open field burning of pruning residues and extensive burning to clear shrubbery, creating pastures for livestock. This research, conducted within the framework of the PRUNING project - Mapping open burning of agricultural residues from Earth Observations and modelling of air quality impacts- aims to explore the potential for detecting such events through satellite remote sensing.

The primary focus of this study is to assess the limitations of satellite remote sensing detection, with the overarching aim of integrating these findings into a systematic monitoring framework for open burning of agricultural residues. Additionally, the study aims to predict pollutant emissions and assess their impacts on air quality, providing valuable insights for environmental management and sustainable agricultural practices.

To achieve this goal, an in-depth analysis of known burning events was conducted using infrared thermal sensors. Multiple products, including Fire Radiative Power and fire masks from various sensors (e.g., MODIS, VIIRS, and Sentinel 3), were employed to characterize these known open field burning events. The results of this work allow verifying the tradeoffs effects associated with spatial, spectral, and temporal resolutions for each sensor, elucidating their impacts on the precision and accuracy of event detections. In parallel, this study evaluated the accuracy of the MINDED-FBA method in characterizing these known events. This automatic detection method, allows incorporating data from higher spatial resolution sensors (e.g., Sentinel-1, Sentinel-2, Landsat), for determining the extent of burned areas through multiple multispectral indices. In this context, the MINDED-FBA method may also be used to validate thermal anomalies detection products. Finally, the results of this work have also been compared to a national level register database of open burning, provided by the ICNF (Institute for Nature Conservation and Forests).

How to cite: Oliveira, E., Gata, J., Lopes, D., Disperati, L., Gama, C., and Silva, B.: Mapping open burning of agricultural residues from Earth Observations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18894, https://doi.org/10.5194/egusphere-egu24-18894, 2024.

vX1.4
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EGU24-14748
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ECS
Prabhakaran Ramya Bala, Nithin Kumar, Diptimayee Behera, Anoop Ambili, and Raman Sukumar

Tropical dry forests are recognized globally as the first frontier of human land-use change, due to multiple factors that make them amenable to human occupation, especially with the use of fire. However, in southern India, biodiversity ‘hotspots’ with human habitation are not uncommon with a long-term co-existence of humans in pristine environments. This points to the need for more accurate evidence-based (using charcoal, pollen, phytoliths) understanding of if, when and how land use and land cover changes impact regional vegetation-fire relationships. We reconstruct the environmental history for Mudumalai National Park, a fire-prone dry forest with >30% of the park subject to annual fires and a west-to-east rainfall-vegetation gradient. We examined a 150 cm sediment profile from an excavation in a seasonal wetland in the wettest part. The record spans 1200 years in time (bracketing radiocarbon dates) with very low macrocharcoal counts (mean - 4), with highest numbers in the surface and near-surface layers. Molecular fire proxies Polycyclic Aromatic Hydrocarbons (PAHs) were also found present - Phenanthrene (Phe), Anthracene (Ant), Fluoranthene (Fl), Pyrene (Py), Benzo[ghi]fluoranthene (Bghi), Benz[a]anthracene (BaA), Chrysene (Chr), Benzo(b)fluoranthene (BbF), Benzo(k)fluoranthene (BkF), Benzo[e]pyrene (BeP), Benzo[a]pyrene (BaP), and Perylene (Pry). Notably, Fl, Py, Bghi, BbF, BaA,and BeP constituted 90% of the total concentrations. Diagnostic ratios of PAHs for source determination pointed at a pyrogenic source consistently across all samples. Paleovegetation proxies n-alkanes (C14-C33) were analyzed and the average chain length (ACL) showed a transition towards higher chain lengths towards the surface indicating a change towards grass sources (C31, C33) in addition to woody biomass-derived compounds (C27, C29). Further analysis to characterize the human-fire-vegetation relationships is underway and to our knowledge, as the first report from a protected forest in India, our study offers critical insights for forest fire management in forested landscapes.

How to cite: Ramya Bala, P., Kumar, N., Behera, D., Ambili, A., and Sukumar, R.: Reconstructing human-fire-vegetation inter-relationships in a protected dry tropical forest, Mudumalai National Park, southern India, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14748, https://doi.org/10.5194/egusphere-egu24-14748, 2024.