AS3.17
PICO: Wed, 26 Apr | PICO spot 5
Atmospheric particulate matter with an aerodynamic diameter < 2.5 µm (PM2.5) is associated with adverse effects on the climate system, the human health, vegetation and the ecosystems. The World Health Organization (WHO) lowered the guideline limit for PM2.5 in autumn 2021 and this is exceeded in many regions including rural and remote areas in mainland Europe. Measurements of the chemical composition of PM2.5 is essential to assess the sources which contribute to PM2.5 mass concentrations and to further design meaningful policies to tackle sources at their origin.
Here we report 6 years (2014- 2020) of PM2.5 mass and chemical speciation at five remote sites across France belonging to the EMEP network (European Monitoring and Evaluation Programme). The seasonal and spatial variability of aerosol composition and source contributions based on the proximity of sources and long-range transport are discussed. Trends in PM2.5 and the main components at the five locations were evaluated by means of random-forest modelling coupled with a de-weathering algorithm. This approach is advantageous as resulting trends are driven by changes in emission or atmospheric processes and not by changes in weather conditions and/or long-range transport patterns. Random-forest regression modelling was built using meteorological data, backtrajectory information and temporal variables at each site and quantified the most important factors that explain PM2.5 concentrations at remote rural areas in France.
All sites observed statistically significant downward trends in PM2.5 at a rate of -4 to -9% year-1 for the period 2014 – 2020. The decrease in PM2.5 concentrations was mostly explained by changes in the secondary inorganic species (sulphate, nitrate and ammonium) and not by changes in primary PM2.5 emissions. The variability in trends in PM2.5 and components observed across the sites is discussed with their implications for policy makers.
How to cite: Font, A., Bourin, A., Gouillou, C., Debevec, C., Bonnaire, N., Sauvage, S., F. de Brito, J., and Riffault, V.: Aerosol composition at EMEP remote sites in France : mass balance and de-weathered trends of PM2.5 and its main components, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-940, https://doi.org/10.5194/egusphere-egu23-940, 2023.
High levels of fine particulate matter (PM2.5) pose a severe air pollution challenge in China. In this talk, we present results of a comprehensive analysis of PM2.5 trends over China during 1980–2020 using the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The monthly mean PM2.5 concentrations of MERRA-2 show a good agreement with independent surface measurements across mainland China from 2013 to 2020. For the trend analysis, China was subdivided into six regions based on land use and ambient aerosols types. PM2.5 levels significantly increased over all regions during 1980-2020. Over the forest regions of China, significant increasing trends were observed in the northern (0.073 µg.m-3 per year) and northeastern (0.34 µg.m-3 per year) regions. In northwest China, PM2.5 experienced a significant increasing trend during 1980-2020 with a rate of 0.2 µg.m-3 per year. The Tibet region in southwest China also experienced a significant increase in PM2.5. Comparatively, the upward trends of PM2.5 were most pronounced in the eastern and southern regions with significant rates of 0.6 and 0.25 µg.m-3 per year, respectively. However, PM2.5 concentration trends changed from upward to downward around 2007 over the eastern and southern regions. The trend reversal around 2007 is mainly attributed to Chinese air pollution control measures.
How to cite: Yousefi, R., Shaheen, A., Wang, F., Ge, Q., and Wu, R.: Fine particulate matter (PM2.5) trends over China during 1980–2020 using MERRA-2 data, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1809, https://doi.org/10.5194/egusphere-egu23-1809, 2023.
There are many features that affect air pollution in Istanbul such as industrial and ship emission, Saharan dust transport events, secondary aerosols from the border countries, local traffic emissions, local domestic heating emissions, road and soil dust, and dust from the construction activities. In this study the spatio-temporal variation of particulate matters (PM10 and PM2.5) concentrations measured from 2015 to 2021 in 37 air quality measurement stations in Istanbul were studied. The main purpose of the study is to describe the trend rate of coarse and fine particles, the contribution of pollutants increament in urban, traffic, industrial and ship activity sites against the urban bacground in Istanbul. Average PM10 concentration in all over the European side of Istanbul with 48.1 µg/m3 is higher than all over the Asian side with 37.7 µg/m3. However, the average PM2.5 in both sites are the same value in 20.1 µg/m3. According to the Theil-Sen trend analysis, it is clearly seen that the PM10 and PM2.5 concentrations have significant (p<0.01) negative trends with the average 6.02 % and 6.97 % in Istanbul, respectively. Contrast, the coarse fraction PM (PM2.5-10) trends are increasing at the urban-industrial and urban-traffic, constant at the urban background and rural and decreasing urban and traffic stations (lower than PM2.5). The highest significant industrial increments above the urban were determined for PM10 (23.8 µg/m3) and its contribution to urban is 65.5 %. It is mostly related to the industrial air quality stations which are located near the stone mining industrial area. The urban and traffic increments of PM2.5 are 7.5 µg/m3 and 1.7 µg/m3, these are higher than in Europe, lower than in Asia cities. The limit value of PM2.5 is not defined yet in Turkey. According to the findings in this study, although the fine particles has the decreasing trend, the secondary particulate matter can be the main contributor of fine particles in Istanbul. On the other hand the coarse fraction of particle has been constant or increasing timely. For policy implementation to improve the air quality the authorities should focus on the sources of PM which may be calculated by PMF.
Financial support
This research has been supported by the Scientific and Technical Research Council of Turkey (TÜBITAK) (grant number 115Y263, 112Y079 and 1059B191801445). Thanks to the Department of Environmental Protection and Control, Air Qaulity Management in Istanbul Metropolitan Municipality and Republic of Türkiye, Ministry of Environment, Urbanization and Climate Change for their support in providing air pollutants.
How to cite: Alver Sahin, U.: Spatio-Temporal Trend Analysis of Particulate Matter and the Increments of Traffic, Urban, Industrial and Ship emission in Istanbul., EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8264, https://doi.org/10.5194/egusphere-egu23-8264, 2023.
Fine particulate matter (PM2.5) is one of the major atmospheric components that is responsible for poor air quality and adverse health and climate effects. An identification of both primary emission sources as well as secondary formation mechanisms of PM2.5 is important to develop effective and efficient strategies to control and mitigate these adverse effects.
The COVID-19 pandemic had a significant impact on air quality across the globe through reduction in source emissions. This study examines the impact of the lockdown measures on PM2.5 and its chemical composition in Bhopal, India by comparisons with pre-lockdown period. Positive Matrix Factorization (PMF) (Paatero and Tapper, 1994) is the most widely used approach for factor analysis-based source apportionment studies. In this study the EPA PMF program version 5.0, was used to solve the PMF model. A comprehensive suite of instruments was used to measure the 24-hour integrated PM2.5 mass and its chemical composition collected onto various filter substrates every other day for two years (2019-2020) at Bhopal. This period coincides with the pre-lockdown, lockdown, and post-lockdown phases in India. The mass concentrations during the study period ranged between 54.7 µg m-3 during pre-lockdown and 45.1 µg m-3 in lockdown phase. PMF5 was applied to a dataset of organic and elemental carbon fractions (OC1, OC2, OC3, OC4, OP, EC1, EC2, EC3), nine major water-soluble inorganic components namely F-,Cl-, NO3- ,SO4-2,Na+, NH4+,Mg+2, K+, Ca+2, and elements (Al, Mg, Ca, Si, P, K, V, Ti, Co, Ni, Cu, As, Cr, Cd, Fe, Ni, Zn, Se, Sb, Ba, Pb) were used in the analysis.
Overall, the combined datasets (2019-2020) approach helped in better model resolution as several zeroes were present in both the loading and score matrices compared to a model run with 2019 data alone. An 8-factor solution was resolved with factors identified as coal and gasoline combustion, biomass burning, secondary sulfate, secondary nitrate, re-suspended crustal dust, diesel emissions, brick kiln emissions and mixed industrial emissions. Further, assessment of the pre-COVID and lockdown scenarios revealed a decreased in the mass contribution of diesel emissions (21.3%), mixed industrial emissions (13.7%), secondary sulfate (10.6%) and secondary nitrate (4.7%) during the lockdown phase compared to the pre-lockdown period at the study site. However, there was no decrease in the biomass burning source contribution due to no curbs on agricultural activities during the lockdown period in India. Overall, this study provides key insight into the source composition and contribution variations due to the reduction of specific anthropogenic source emissions due to COVID-19 lockdowns. Further, it is an added impetus for policymakers to implement targeted strategies and regulations, to reduce local and regional air pollution.
How to cite: Pullokaran, D., Sunder Raman, R., Bhardwaj, A., Shukla, D., and Haswani, D.: Insights into the impact of COVID-19 lockdowns on USEPA PMF-5 derived PM2.5 source contributions at Bhopal, India, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12077, https://doi.org/10.5194/egusphere-egu23-12077, 2023.
Our globalised world, with its many acute natural and social problems, has now created all the conditions for pandemics. The COVID-19 pandemic is the first real manifestation of this in our modern history, affecting every geographical region, every social class and almost every single economic sector. The spread of the epidemic, which was accompanied by extremely severe social and economic devastation and damage, was sanctioned by reducing people's social activity and high mobility. The measures have also been accompanied, obviously, by a reduction in some of the environmental stresses resulting from anthropogenic activity.
Our research investigates the relationship between satellite remote sensing air pollution data and sanctions related to the coronavirus epidemic, taking into account complex physical- and socio-geographical factors. Spatially and temporally differentiated COVID-19 sanctions and lockdowns (home office orders, curfews, service closures, shutdowns) have different atmospheric environmental impacts in different physical geographic regions (topography and circulation, vegetation cover, natural aerosol loads, etc.) and in areas with different socio-economic characteristics. Our aim was to identify the individual effects of the complex processes underlying the changes in atmospheric environment indicators that have not been observed before.
In this paper, NO2 and atmospheric aerosol are presented in detail, with a clear distinction between atmospheric substances of purely anthropogenic origin and those typically interpreted as natural pollutants (e.g. Saharan dust). A comparative analysis of these, using data from 2019, 2020 and 2021, highlights the spatiotemporal characteristics of the period before, during and after COVID-19 sanctions. For this purpose, Sentinel-5p and MODIS Aerosol Optical Depth data were used. The different changes in the air environment in Western and Eastern European countries, and in particular in some industrial regions, are clearly visible in the series of maps presented.
The research was supported by the project POST-COVID2021-29 of the Hungarian Academy of Sciences.
How to cite: Varga, G., Csávics, A., and Gresina, F.: Complex geographical causes of different levels of air pollution changes caused by COVID-19 sanctions in Europe, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8845, https://doi.org/10.5194/egusphere-egu23-8845, 2023.
It is well known that in the climate and air quality studies, the monitoring process of aerosols and their temporal evolution is very important as they generate a significant impact on meteorology, air quality, climate, and human and ecosystem health. In this study, we present an overview of aerosol optical and microphysical properties over Cluj-Napoca, Romania- based on more than 12 years of observations from a Cimel sun-photometer operating in the framework of AErosol RObotic NETwork (AERONET) and part of the Aerosol, Clouds and Trace Gases Research Infrastructure (ACTRIS). This site is located in the north-western part of Romania and contributes to AERONET with sun photometer observation since 2010. As the atmosphere in the region is characterized by a mixture of aerosols from multiple sources: urban/industrial (dominant) biomass burning, Saharan dust, etc., this study aims to present the aerosol trends and the temporal variation of their properties based on long-term observations. The analysis highlighted that the aerosol load over the area is characterized by high inter-annual and seasonal variation of AOD due to variation of local sources and long-range transport. The same variability was observed for the Ångström Exponent, suggesting the presence of aerosols of different sizes. The methods used in this study can be extended to other stations for identifying the long-term variability of aerosols.
How to cite: Radovici, A., Stefanie, H., Mereuta, A., Camarasan, H., Botezan, C., Costin, D., and Ajtai, N.: Climatology and trends derived from columnar aerosol measurements in Cluj-Napoca, Romania., EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-193, https://doi.org/10.5194/egusphere-egu23-193, 2023.
Multiwavelength aerosol optical depth (AOD) has been defined as an essential climate variable for the Global Climate Observing System (GCOS) and the Global Atmosphere Watch (GAW) Program of the World Meteorological Organization. It is the most important parameter related to aerosol radiative forcing studies. PMOD/WRC have developed the Precision Filter Radiometer (PFR) that has been used for long term AOD measurements under a GAW-PFR Network of sun-photometers started in 1995 at Davos Switzerland and from 1999 at other locations, worldwide.
Here we present an overview of the stations measurements till 2021 including station statistics and AOD trends.
An overview of the results of the long term GAW-PFR AOD series for four high altitude stations (Izana/Spain, Mauna Loa/USA, Mt. Walliguan/China and Jungfraujoch/Switzerland). Mean AODs at 500nm were from 0.01 up to 0.1 with small negative changes per year for all stations.
Also we present an overview of the homogenization activities performed by the world aerosol optical depth research and calinration center (WORCC) towards a harmonization of AOD measurements worldwide and some examples on uncertainties and effects on global trend analysis and satellite AOD validation initiatives.
How to cite: Kazadzis, S., Kouremeti, N., and Groebner, J.: Aerosol Optical Depth Measurements and trends from the Global Atmospheric Watch - PFR Network and aerosol homogenization initiatives, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2340, https://doi.org/10.5194/egusphere-egu23-2340, 2023.
National parks or biosphere reserves are usually places far away from urban or industrial sites, which facilitates their protection from anthropogenic air pollution. Even though, transport of persistent air pollutants from distant sources may lead to evident effects on the natural protected area. On the other hand, there are also several examples of national parks located near cities or industrial facilities with significant emissions to the atmosphere, meaning a direct risk to the preservation of ecosystems. In such situations, not only synoptic but also regional effects must be considered to assess the air quality of the site.
This work shows that biosphere reserves and national parks require in situ tools to monitor and detect local and remote air pollution sources which may constitute a threat to flora, fauna, water, and soil. The rising of new industries in surrounding areas, traffic, and remote transport, can change with time and meteorology and so each national park should have a historical database of the air quality in the site. This study reports the research of air pollutants in ‘Las Tablas de Daimiel’ a wetland Mediterranean national park bordered by different cities and new industries in the field of the revalorization of agricultural wastes. Simultaneous data from San Pablo de los Montes, a background station in a rural area isolated from air pollution, are considered as reference.
The work was extended from March 2020 to July 2021, involving the continuous measurement of meteorological data, of surface O3, NO, NO2, CO, SO2 and PM2.5 inside the park. Twelve campaigns, one week duration, were also performed to sample air in sorbent tubes and analyse volatile organic compounds from anthropogenic sources. The results are discussed considering meteorology, especially wind and speed direction together with the assessment of back-trajectories of remote air masses. The results show that air quality in the park was affected slightly by local and remote air pollution, excepting for the observed high levels of ozone, with a mean value of 71mg.m-3. Measured mass loadings for the rest of pollutants were low and not in exceedance of the air quality standards. NOx and SO2 average concentrations (3.2 and 0.4 mg m-3, respectively) were below the recommended critical levels for vegetation. The results confirmed the presence of 26 VOCs, potentially coming from anthropogenic sources, mainly aromatics, including BTXs in average concent ration levels below 0.5 mg m-3. Although a clear diurnal behavior couldn´t be established, slightly higher concentrations were observed during working days. From the study of local winds and diurnal profiles of VOCs, we could not identify local sources of these pollutants. This indicates that potential nearby sources did not emit significant quantities of these compounds or emissions were sufficiently diluted by dispersion before reaching the park.
Saharan dust events were frequent and contributed to PM2.5 levels in the site. AOT-40 values above the established threshold for the protection of vegetation were obtained, 25,500 and 19,900 mg m-3 for 2020 and 2021, respectively.
How to cite: Rodriguez Cervantes, A. M.: Air quality and air pollution sources in a national park. A case study, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1154, https://doi.org/10.5194/egusphere-egu23-1154, 2023.
The accumulation of both particulate matter (PM10, PM2.5) and gaseous species (NO2, CO, SO2, O3) in the atmosphere in urban agglomerations can cause a significant degradation of air quality. The additional impact on human health, visibility, cultural heritage and urban climate has been recognized in studies worldwide. This study represents an air quality assessment in the urban agglomeration of Ploiesti, which is located north of Bucharest (the highest polluted city of Romania), in the central-northern part of Romanian Plain. In Ploiesti operates some of the most important refineries of the country. The city also represents an important link between Bucharest and south of Romania and the northern and western parts of the country.
The study is focused on major air pollutants, particulate matter (PM10, PM2.5), and also gaseous species (NO2, CO, SO2, O3) at six monitoring sites (traffic, industrial and background). To highlight temporal and spatial variations, a synthetic database covering a four-year period (2018-2021) consisting of time series of hourly and daily values of major air pollutants mass concentrations were statistically investigated. To analyze the influence of meteorological conditions on the air quality in Ploiesti area meteorological observations was constructed.
Present research shows that although Ploiesti is significantly smaller than Bucharest, the anthropogenic activity in Ploiesti strongly affects atmospheric pollution levels on daily timescales (multiannual mean ratio PM2.5/PM10 = 0.71) at almost same level that in Bucharest area. Additionally, we found the central area impact on surroundings is major, as significant differences were not identified.
We identified both local and regional pollution episodes, but also episodes strongly influenced by the long-range transport of dust pollution.
PM10 pollution roses showed the dominance of local pollution sources in most of the time. On shorter timescale, the long-range transport of fine particulate matter coming from desert dust (Saharan or from Middle East deserts) contributed supplementary to increased pollution as we identified in 13 episodes (during 2018-2021). It has been shown that the atmospheric stability has an important role in the accumulation of PM10 at the scale of Ploiesti urban agglomeration. Trend analysis of annual pollutant mass concentrations for all air quality stations was performed using a larger dataset, since 2008 (first monitoring year) to present (end of 2021), using Mann-Kendal and Sen’slope analysis. Diurnal profile of particulate matter PM10 and the influence of the lockdown restrictions in spring 2020 on PM10 levels were also quantified.
Acknowledgment
The research leading to these results has received funding from the NO Grants 2014-2021, under Project contract no. 31/2020, EEA-RO-NO-2019-0423 project. Data regarding ground-level air pollution and local meteorology by site was extracted from the public available Romanian National Air Quality Database, www.calitateaer.ro, last accessed in December 2022. Meteorological data were extracted from Copernicus Climate Change Service (C3S) Climate Data Store (CDS) ERA5 hourly data on single levels and pressure levels from 1959 to present https://cds.climate.copernicus.eu (last accessed in December 2022).
How to cite: Mihalache, B., Colt, M., Stefan, S., and Iorga, G.: A comprehensive study on atmospheric pollution over Ploiesti, Romania, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3209, https://doi.org/10.5194/egusphere-egu23-3209, 2023.
Abstract
It has been proven that air pollution is closely related to the level of socio-economic development of a country. Various levels of development generate different level of by-products, including air pollution, deteriorating therefore the air quality at regional levels in peculiar ways. Romania is the largest country in southeastern Europe with a very complex economic development level and air pollution disparities among cities.
This paper aims to study main socio-economic indicators (as measures of the effect of human activities on air pollution and climate) for over 30 cities in Romania with diferent levels of economic development, to determine the relationship between these variables and air pollution condition. We focused on the spatial relationship between main gaseous air pollutants and the following indicators GDP, GDP/capita, resident population, number of private vehicles and life expectancy.
In this research we created two data sets as follow: first one consists of daily values of air pollutant (CO, NO2, O3, SO2) mass concentrations extracted from the Romanian National Air Quality Network and the second set consists of socio-economic indicators (GDP, GDP/capita, resident population, number of private vehicles and life expectancy) obtained from Romanian National Institute of Statistics. The study was conducted over five years, from 01.01.2016 to 31.12.2020 using yearly means of air pollutants from the first dataset in all selected urban areas in the Romanian territory and corelate them with the socio-economic indicators from the second data set using univariate LISA and bivariate LISA statistical analysis methods.
The analysis demonstrated the correlation of socio-economic indicators with the increase of the air pollution in the study area. Other highlights of the study: (a) Range of major air pollutant levels in 30 urban agglomerations across Romania from 2016 to 2020 was assessed (b) Maps of interpolated mass concentrations reveal regional significant differences with pollutant-specific hot- and cold-spots in Romania. Regional significant differences can be observed; (c) Results show pollution decreases for most pollutants in most cities in 2020 due to pandemic restrictions.
The results of present study can be beneficial to local authorities in order to help them in their decisions for abatement pollution strategies at the country scale combined with regional measures.
Acknowledgment
The research leading to these results has received funding from the NO Grants 2014-2021, under Project contract no. 31/2020, EEA-RO-NO-2019-0423 project. Data regarding ground-based air pollutants were extracted from the Romanian National Air Quality Database, www.calitateaer.ro. Economy indicators were provided by National Institute of Statistics http://statistici.insse.ro:8077/tempo-online/. Databases were last accessed in December 2022.
How to cite: Chiritescu, R. V. and Iorga, G.: Air pollution over Romania: spatial relationship betweensocio-economic indicators and air pollutants using univariate and bivariate local indicators, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4913, https://doi.org/10.5194/egusphere-egu23-4913, 2023.
Within the framework of the EUMETSAT AC SAF project, the production of climate data records (CDRs) of short lived O3 precursors (HCHO and NO2) is under development, based on the three GOME-2 instruments and the future S5 and S4 Copernicus platforms.
This work presents the development of the formaldehyde CDR, combining the current GOME-2 A, B and C operational AC SAF Level-2 orbital products to create one single L3 averaged product using advanced gridding tools. To this aim, the consistency between the three GOME-2 instrument needs to be improved by means of suitable correction schemes accounting for inter-sensor biases due to inconsistent auxiliary data or instrumental issues. The use of the CAMS model reanalysis as a source of prior HCHO profiles is explored with the aim to produce one consistent dataset from 2007 to now. Estimation of the random and systematic uncertainty is included for each grid cell. Furthermore, we plan to include meteorological re-analysis data (surface temperature and winds) in the output files to further support the interpretation of the data and of their observed variations.
Validation results of this new monthly averaged CDR dataset will be presented, with a special focus on bias, precision and stability in time. To this aim, long-term ground-based HCHO measurements are collected and assessed.
How to cite: De Smedt, I., Pinardi, G., Valks, P., Heue, K.-P., Compernolle, S., Van Gent, J., Vlietinck, J., Yu, H., Loyola, D., Theys, N., and Van Roozendael, M.: Development of a merged HCHO climate data record from the EUMETSAT AC SAF GOME-2 Level-2 products, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7891, https://doi.org/10.5194/egusphere-egu23-7891, 2023.
We present two inventories of anthropogenic emissions as well as an air quality atlas linked to Copernicus, the European earth observation system. CAMS-GLOB-ANTv5.3, a global anthropogenic emissions inventory, has been developed and provides emission data for the major atmospheric pollutants and greenhouse gases, as well as 25 speciated Volatile Organic Compounds (VOCs), for the period 2000-2023. This inventory is used as input for the Copernicus Atmosphere Monitoring System (CAMS) atmospheric reanalysis and forecasts.
A mosaic inventory of anthropogenic emissions was also developed as part of the Copernicus CO2 project (CoCO2) focusing on greenhouse gases emissions. This mosaic uses the CAMS-GLOB-ANTv5.3 inventory as a global basis, and the DACCIWA2 (Dynamics-Aerosol-Chemistry-Cloud interactions in West Africa) inventory, a regional African emissions inventory. DACCIWA2 provides 0.1x0.1 degree resolution emissions of greenhouse gases and atmospheric pollutants for the period 2010-2018.
The CAMS reanalysis is being used to develop an atlas of air quality called AQWA (Air Quality Worldwide Atlas). The AQWA atlas gives precious information about historical, climatological and current atmospheric composition, as well as air quality indexes. These statistics are available for all countries around the world, as well as states/provinces for the United States and China.
This presentation describes the methodology used to develop and evaluate the two inventories and shows a few visualization examples from the atlas, which is still in development.
How to cite: Soulie, A., doumbia, T., Keita, S., Granier, C., Denier Vand der Gon, H., Kuenen, J., Arellano, S., Darras, S., Gauss, M., Guevara, M., Jalkanen, J.-P., Liousse, C., Simpson, D., and Sindelarova, K.: Global and regional anthropogenic emissions inventories for air quality atlases, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3232, https://doi.org/10.5194/egusphere-egu23-3232, 2023.
Air quality is not only dependent on emissions, but on climate and meteorology as well. This makes the study of the evolution of air pollution varying some of its drivers crucial. In this study, the present day and near future air quality in Central Europe is studied following RCP4.5 and RCP8.5 scenarios for the 2026-2035 and 2046-2055 decades, while considering present-day climate conditions. We assume that the climate changes a little while the main driver for air-quality changes in near future are the modified emissions. The emission input for the 2010-2019 decade were compiled using the Flexible Universal Processor for Modeling Emissions (www.fume-ep.org), and the two future decades are being prepared by scaling the present day emissions based on the mentioned RCPs. We are performing simulations using the Weather Research and Forecast with online chemistry version 4.0.3 (WRF-Chem) model and the Comprehensive Air-quality Model (CAMx). Several pollutants and meteorological variables will be studied and compared with observational data.
How to cite: Prieto Perez, A. P., Huszar, P., and Karlicky, J.: Modelling the near future air-quality over Central Europe, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5673, https://doi.org/10.5194/egusphere-egu23-5673, 2023.
Ammonia (NH3) is one of the most common nitrogen gas species and pollutants present in the lower troposphere. Ammonia enters the atmosphere through volatilisation from soils through the usage of nitrogen-based fertilisers in agriculture [1]. Because of its short lifetime (up to a few hours) [2], ammonia is highly reactive and can react chemically with acids in the atmosphere to form fine particulate matter (PM2.5), playing an important role in secondary aerosol formation [3]. Wet and dry deposition of ammonia on soils and water bodies has shown to be detrimental to ecosystem biodiversity as it leads to acidification of the environment [3]. Therefore, observations of ammonia are essential for establishing air quality and environmental regulations for agricultural practices.
By using combined satellite measurements from the Infrared Atmospheric Sounding Interferometer (IASI) and the Cross-track Infrared Sounder (CrIS) instruments, we aim to study trends and the diurnal cycle of ammonia on regional scales, particularly in areas subjected to intensive agricultural activity, such as the Indo-Gangetic Plain (northern India). This research makes use of an optimal estimation-based method of monitoring ammonia with satellites called the University of Leicester IASI retrieval Scheme (ULIRS).
References:
[1] Van Damme M. et al (2021), Environ. Res. Lett., 16 055017
[2] Dammers E. et al (2019), Atmos. Chem. Phys., 12261–12293
[3] Erisman, J. W. et al (2007), Environ. Pollut., 150, 140– 149
How to cite: Iorga, A., Harrison, J., and Moore, D.: Air Pollution from Agriculture: Using Satellite Observations to Study Ammonia Emissions , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2755, https://doi.org/10.5194/egusphere-egu23-2755, 2023.
Seasonal, annual and long-term changes of carbon monoxide (CO) are investigated in the tropical (30° N ̶ 30° S) middle atmosphere (20 ̶ 80 km) for the period 2005 ̶ 2021. CO shows a semi-annual oscillation in the higher heights of both stratosphere and mesosphere. The CO response to the solar cycle increases with altitude (>2 ppmv/100 SFU) in the mesosphere. CO response to Quasi Biennial Oscillation (QBO) and El Niño and Southern Oscillation (ENSO) is negligible in stratosphere, however, that to ENSO is significantly negative in mesosphere. In the altitude range 60 ̶ 70 km, we find a positive trend (0.03 ppmv/dec) at 64 km. Furthermore, the CO trend is positive in mesosphere (70 ̶ 80 km), with a peak at 75 km (0.19 ppmv/dec). The observed changes in middle atmospheric CO in the tropics are well reproduced by the Whole Atmospheric Chemical Climate Model (WACCM). Therefore, this study provides new insights into the long-term changes in the tropical middle atmospheric CO and its connection to dynamics of the region.
How to cite: Nath, O.: Seasonal, inter-annual and long-term changes in the middle atmospheric Carbon Monoxide over the tropics, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-250, https://doi.org/10.5194/egusphere-egu23-250, 2023.
In recent times, Surface Ozone has become a widely studied constituent due to its emergence as a short-lived secondary pollutant and its damaging impacts on human health and crop production. Recent studies show increased surface ozone across different parts of the world including the Indian region. The modern reanalysis dataset provides meteorological parameters as well as atmospheric chemical compositions such as tropospheric ozone etc. In this study, we validated the spatial-temporal ozone variability using ground-based observation and reanalysis datasets such as over the North-west Indo Gangetic region. Reanalysis datasets are the Copernicus Atmospheric Monitoring Service reanalysis (CAMSRA) and NASA Modern-Era Retrospective analysis for Research and Application version 2 (MERRA2) which tells the spatial-temporal variability of surface ozone over the Northwest region of India. The result shows a lesser correlation over the study region. Through a validation process, it was determined that the CAMSRA compares fairly to ground-based observations with correlations (> 0.5) over the Northwest region of India. This agreement has also been quantified in terms of range, Mean Absolute Error (MAE), and Root Mean Square Error (RMSE). The CAMSRA captures seasonal variations regardless of location, according to a time series analysis. Spatial distribution of surface ozone shows higher concentration during pre-monsoon followed by post-monsoon. Over the northwest region, a notable rise is noticed during May over the Indo-Gangetic Plains in particular (IGP) of the Indian region. These seasonal differences are associated with solar radiation (SR), temperature, low-level circulation, and boundary layer height (BLH).In order to further examine the spatial and temporal variability of surface ozone, we have performed the Principal Component Analysis (PCA). PCA explains the relationship between dominant modes of spatial variability and their temporal evolution. Overall, the findings show that variations in the precursors or in the meteorological conditions have a considerable impact on the surface ozone concentrations across the northwest region of India.
How to cite: Saroj, P., Ghosh, C., and Singh, S.: Evaluation of surface ozone variability using ground-based observation and reanalysis dataset over the North-West Indo-Gangetic Plain of Indian region., EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-660, https://doi.org/10.5194/egusphere-egu23-660, 2023.
Stratosphere-to-troposphere transport (STT) is an important source of ozone for the troposphere, particularly over western North America. STT in this region is predominantly controlled by a combination of the variability and location of the Pacific jet stream and the amount of ozone in the lower stratosphere, two factors which are likely to change if greenhouse gas concentrations continue to increase. Here we use Whole Atmosphere Community Climate Model experiments with a tracer of stratospheric ozone (O3S) to study how end-of-the-century Representative Concentration Pathway (RCP) 8.5 sea surface temperatures (SSTs) and greenhouses gases (GHGs), in isolation and in combination, influence STT of ozone over western North America relative to a preindustrial control background state.
We find that O3S increases up to 39% at 700 hPa over western North America in response to RCP8.5 forcing with the largest increases occurring during late winter and tapering off during spring and summer. The GHGs are primarily responsible for these tropospheric O3S changes. Both the future SSTs and the future GHGs accelerate the Brewer Dobson circulation, which increases extratropical lower stratospheric ozone mixing ratios. While the GHGs promote a more zonally symmetric lower stratospheric ozone change due to enhanced ozone production and some transport, the SSTs increase lower stratospheric ozone predominantly over the North Pacific via transport associated with a stationary planetary-scale wave. Ozone accumulates in the trough of this anomalous wave and is reduced over the wave’s ridges, illustrating that the composition of the lower stratospheric ozone reservoir in the future is dependent on the stationary planetary-scale wave response to future SSTs. In addition, the future SSTs are found to prompt most changes to the large-scale circulation in the troposphere and stratosphere compared to the effect of the GHGs. These changes include modifying the position and speed of the future North Pacific jet, lifting the tropopause, accelerating both the Brewer-Dobson Circulation’s shallow and deep branches, and enhancing two-way isentropic mixing in the stratosphere.
How to cite: Elsbury, D., Butler, A. H., Albers, J. R., Breeden, M. L., and Langford, A. O.: The response of the North Pacific jet and stratosphere-to-troposphere transport of ozone over western North America to RCP8.5 climate forcing, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3498, https://doi.org/10.5194/egusphere-egu23-3498, 2023.
Current approaches to estimate NOx emissions fail to account for new and small sources, sources with large spatial and temporal variability, and sources which have significantly changed. Furthermore, the current generation of NOx emissions estimates don’t provide a sufficiently robust uncertainty analysis. They tend to use a fixed combination of localized models (in space and time), and do not adequately consider the variability in observed chemistry, dynamics, and thermodynamics. This work introduces a new, model-free analytical approach that assimilates daily-scale remotely sensed tropospheric columns of NO2 from TROPOMI in a mass-conserving manner, to invert daily NOx emissions. This approach is flexibly applied over a rapidly developing and energy-consuming region of Northwest China which is chosen due to substantial economic and population changes, new environmental policies, large use of coal, and access to independent emissions measurements for validation [EGT]. It is also applied over two densely urbanized regions, as well as their surrounding rural and rapidly developing outer suburban regions, including the Pearl River Delta and the Yangtze River Delta, both of which are chosen due to the amount and variability of sources, rapid economic development, and strong changes in environmental emissions policy and regulation. Over the EGT area, this technique computes a net NOx emissions gain of 70% distributed in a see-saw manner: emissions are more than doubled in cleaner regions, at chemical plants, and in regions thought to be emissions-free, while at the same time, emissions are more than halved in city centers and at other well-regulated and large commercial locations such as steel smelters and powerplants. There is a considerable amount of NOx emissions observed in suburban areas and rapidly developing rural areas, while a priori datasets do not account for these sources. A few interesting scientific points are explained in detail. First, the error over land surfaces which are not changing is smaller than the day-to-day variability, supporting the idea that daily variability is essential. The errors over areas undergoing land-use change and water are similar to or larger than the day-to-day variability. Second, source attribution is quantified with respect to the local thermodynamics of the combustion temperature, with measured atmospheric transport, and with in-situ chemical processing. Third, there are a significant number of sources identified which do not exist in the a priori datasets, but which are consistent with surface observations. Fourth, sensitivity runs are performed which account for the wide-range of uncertainty estimates of TROPOMI and the self-consistency of the estimated emissions is analyzed on a grid-by-grid and day-by-day basis, showing that the physically realistic constrains on the first order differential equation terms and bootstrapping approach are robust. It is hoped that these findings will drive a new approach to emissions estimation, one in which emissions are based consistently on remotely sensed measurements and associated uncertainties. Such approaches are essential in rapidly developing regions and in the Global South, where local measurements do not otherwise exist.
How to cite: Lu, L., Qin, K., and Cohen, J. B.: Computing Daily NOx Inversion over Energy Consuming and Urbanized Regions Using TROPOMI Data – A Novel Model Free Approach, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10999, https://doi.org/10.5194/egusphere-egu23-10999, 2023.
Atmospheric chemistry models play a major role for relating greenhouse gases and pollutants concentrations to emissions at high temporal resolutions over large areas. On that account, it is fundamental to use up-to-date anthropogenic emissions maps as model inputs. Despite efforts by researchers to create global emission datasets with high temporal resolutions, for countries with no national data, generic activity maps and emission factors are used, thus the accurate representation of the anthropogenic emissions in a local scale still remains challenging. This study presents an improved spatially explicit dataset for anthropogenic emissions of CO2 and NOx over the Middle-East, a region characterized by extensive gas power plants and heavy industries operations. Our dataset was developed by combining a detailed infrastructure map for point sources in the area and it is used to simulate the distribution of CO2 and NO2 using the WRF-Chem mesoscale atmospheric transport chemistry model. Furthermore, the chemistry scheme of the WRF-Chem model in the simulation of CO2 and NO2 plumes is examined, in comparison with satellite observations.
In the framework of the Eastern Mediterranean and Middle East – Climate and Atmosphere Research (EMME-CARE) project, our new detailed infrastructure map for power plants and gas flaring has been implemented in WRF-Chem simulations for the Middle-East region to complete the Emission Database for Global Atmospheric Research (EDGAR) as input. The EDGAR data consists of emissions by various sectors such as power plants, industry, residential, transportation and agriculture. Furthermore, hourly scaling factors have been applied to the anthropogenic emissions according to the electricity consumption of the particular urban areas, taking into account the weekly as well as the monthly variations. The periods under study are January 2021 and June 2021. By comparing the WRF-Chem outputs to TROPOMI satellite observations for NO2, the results show that the addition of point sources was crucial for the detection of some NO2 plumes. Moreover, the WRF-Chem model systematically overestimated the NO2 concentrations in the area with the current EDGAR dataset, therefore we introduced a new relationship between monthly and annual emissions for the Middle-East region. By carrying out WRF-Chem simulations with NO2 acting as a passive tracer it was also possible to examine the impact of the model chemistry in NO2 plumes development. Finally, CO2 was also simulated by the WRF-Chem model as a passive tracer and the results showed a good agrement with XCO2 data observed by the OCO-2 and OCO-3 instruments.
How to cite: Cheliotis, I., Lauvaux, T., Lian, J., Christoudias, T., Georgiou, G., Chevallier, F., Lei, R., and Ciais, P.: Optimization of simulated CO2 & NO2 concentrations for a detailed infrastructure map in the Middle East, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9518, https://doi.org/10.5194/egusphere-egu23-9518, 2023.
In Japan, concentrations of precursors of photochemical oxidants such as nitrogen oxides (NOx) and non-methane hydrocarbons (NMHCs) are decreasing year by year, but an improvement regarding photochemical oxidants is recently stagnant. To elucidate the reason, we have planned seasonal intensive observations in Tokyo, in which comprehensive measurements of speciated reactive nitrogen NOy and non-methane volatile organic compounds are performed. In summer of 2022, the observation was carried out at a campus of Tokyo Metropolitan University, a suburban area of Tokyo. In the intensive observation, NO, NO2, ΣPANs, ΣONs, HONO, HNO3, H2O2, SO2, O3, NH3, 28 NMHCs, and 10 oxygenated volatile organic compounds (OVOCs) were measured simultaneously. The ΣPANs and ΣONs were measured by thermal dissociation-cavity attenuated phase shift (CAPS) spectroscopy. The HONO, HNO3, and H2O2 were measured by negative ion chemical ionization mass spectrometry using I−·(H2O)n as the reagent ion. The NMHCs, OVOCs and NH3 were measured by selected ion flow tube mass spectrometry and the data of NMHCs were compared and corrected with the data from gas chromatography/flame ionization detector (GC/FID). The ozone formation in Tokyo will be discussed.
How to cite: Inomata, S., Tanimoto, H., Matsumoto, J., Sadanaga, Y., and Kato, S.: Comprehensive measurements of speciated reactive nitrogen NOy and non-methane volatile organic compounds in Tokyo, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11532, https://doi.org/10.5194/egusphere-egu23-11532, 2023.
Volatile organic compounds (VOCs) are important gaseous constituents in the troposphere, impacting local and regional air quality, human health, and climate both directly and indirectly (IPCC, 2013). With the participation of nitrogen oxides (NOx), oxidation of VOCs leads to tropospheric ozone (O3) formation, causing regional photochemical smog (Atkinson, 2000). In recent years, with the decline of ambient concentrations of other pollutants (e.g., fine particulate matter), the concentrations of O3 in many locations increased. Therefore, accurately apportioning the emission sources of ambient VOCs and then controlling them more effectively will play an important role in reducing O3 and secondary organic aerosol pollution in the atmosphere and improving public health.
In this study, field measurements were conducted at a coastal site (Hok Tsui; HT) in Hong Kong from October to November 2020 with proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS). VOC data coupled with air mass back trajectory cluster analysis and receptor modelling were applied to discuss the pollution pattern, regional transport, and emission sources of ambient VOCs at Hok Tsui in autumn 2020. Seven sources were identified from positive matrix factorization (PMF) analysis, namely vehicular + industrial, solvent usage, primary oxygenated VOCs (OVOCs), secondary OVOCs 1, secondary OVOCs 2 (aged), biogenic emissions, and background + biomass burning, contributing on average to 20.8%, 10.5%, 13.1%, 33.6%, 6.7%, 4.3%, and 10.9% of total VOC mixing ratios, respectively. Secondary OVOCs and vehicular + industrial emissions are the vital sources of ambient VOCs at Hok Tsui supersite. Integrated with backward trajectory analysis, long-range transport of air masses from inland and coastal regions of Southeast China brought more hydrocarbons from vehicular and industrial sources, and consequently more OVOCs in aged air masses. The results of this study highlighted the regional transport of anthropogenic VOCs should be considered in control strategies of VOCs and secondary air pollutants.
How to cite: Yuan, Q., Wang, M., Wang, T., and Lee, S.: Source characterization of VOCs at a coastal site in Hong Kong, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10637, https://doi.org/10.5194/egusphere-egu23-10637, 2023.
There are widespread policy assumptions that the phase-out of gasoline and diesel internal combustion engines will over time lead to much reduced emissions of Volatile Organic Compounds (VOCs) from road transport and related fuels. However, the use of real-world emissions measurements from a new mobile air quality monitoring station demonstrated a large underestimation of alcohol-based species in road transport emissions inventories. Scaling of industry sales statistics enabled the discrepancy to be attributed to the use of ancillary solvent products such as screenwash and deicer which are not included in internationally applied vehicle emission methodologies. A fleet average non-fuel non-exhaust VOC emission factor of 58 ± 39 mg veh−1 km−1 was calculated for the missing source, which is greater than the total of all VOCs emitted from vehicle exhausts and their associated evaporative fuel losses. These emissions are independent of the vehicle energy/propulsion system and therefore applicable to all road vehicle types including those with battery-electric powertrains. In contrast to predictions, vehicle VOC emissions may actually increase given a predicted growth in total vehicle kilometers driven in a future electrified fleet and will undergo a complete VOC respeciation due to the source change.
How to cite: Cliff, S., Lewis, A., Shaw, M., Lee, J., Flynn, M., Andrews, S., Hopkins, J., Purvis, R., and Yeoman, A.: Unreported VOC emissions from road transport including from electric vehicles, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12745, https://doi.org/10.5194/egusphere-egu23-12745, 2023.
Toxic volatile organic compounds (VOCs) or air toxics are part of the hazardous air pollutants (HAPS) to affect public health. In this work, the thermal desorption (TD) technique was coupled with gas chromatography mass spectrometry (GC/MS) to form an online technique to provide hourly data of 86 air toxics. Due to the perennial high humidity of the sub-tropical weather, water removal prior to TD-GC/MS analysis is necessary to prevent icing during cryo-trapping but still kept limited water vapor to maintain the required recoveries for the target species. Adding internal standards drastically offset the instrumental drift in detection and greatly secured the accuracy of the analytes. A month-long field measurement of TD-GC/MS was conducted near an industrial park with two other techniques of proton transfer mass spectrometry (PTR-MS) and flask sampling for validation. Time series data of TD-GC/MS showed distinct spikes in the hourly measurements induced by the pollution plumes, which were divided into two categories of non-chlorinated vs chlorinated compounds. The non-chlorinated species showed consistency in the occurrence of spikes between the online GC and PTR-MS. The canister data, however, missed most of the spikes of the measured species, but captured the single most prominent spikes of carbon tetrachloride and styrene by pure coincidence, showcasing the superiority of the online vs. the offline method. The strength of plume detection by online TD-GC/MS was further illustrated by back trajectories of the pronounced spikes of benzene and carbon tetrachloride, which were only several hours apart but pointed to entirely different directions of the upwind sources due to the rapid change in wind directions in this brief period.
How to cite: Wang, J.-L., Wang, C.-H., Hsieh, H.-C., Chu, C.-H., Tseng, M.-H., Lee, K.-C., and Tseng, P.-S.: Online measurement of ambient toxic volatile organic compounds using thermal desorption gas chromatography-mass spectrometry (TD-GC/MS), EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1940, https://doi.org/10.5194/egusphere-egu23-1940, 2023.
Sulfur dioxide (SO2) plays a pivotal role in the chemistry of the troposphere, ultimately affecting the Earth’s radiation balance and climate. Within the atmosphere, SO2 is oxidised by gas- and aqueous-phase chemistry to sulfate and is therefore a major precursor to atmospheric aerosols, particularly in the remote marine atmosphere. Both the direct radiative forcing from aerosols and the indirect forcing from aerosol-cloud interactions are poorly understood and produce large uncertainties in climate models. Therefore, it is of interest to precisely quantify the concentration of atmospheric SO2 if we are to predict the effects of changing emission rates on both climate and air quality.
Anthropogenic SO2 emissions have fallen dramatically in recent decades, resulting in significant reductions in atmospheric concentrations. Current commercial SO2 detection techniques, for example pulsed fluorescence, are no longer sensitive enough to detect trace levels of SO2 such as those found in remote marine environments. We report the development of a laser-induced fluorescence instrument for in situ SO2 measurements using a custom-built, tunable fiber-amplified laser system. Based on the system initially developed by Rollins et al. (2016), the University of York LIF-SO2 system has a detection limit of 50 ppt for 30 seconds and its relatively small size, weight and power requirements makes this instrument suitable for a variety of field campaigns.
Here we present aircraft measurements of SO2 made by the York LIF-SO2 instrument on board the UK FAAM research aircraft in both the remote and polluted marine boundary layer. These are then compared to simultaneous SO2 measurements made by the University of Manchester I- chemical ionisation mass spectrometer (I- CIMS) instrument and the FAAM pulsed fluorescence commercial SO2 detector.
How to cite: Temple, L., Young, S., Bannan, T., Batten, S., Bauguitte, S., Coe, H., Lee, J., Matthews, E., Pasternak, D., Rollins, A., Vallow, J., and Edwards, P.: A Comparison of Aircraft SO2 Measurements in Remote and Polluted Marine Environments, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11726, https://doi.org/10.5194/egusphere-egu23-11726, 2023.
Merging data records from different instruments into a consistent long-term data record is challenging process, especially when the parent datasets have a very short overlap or do not overlap at all. In addition, parent datasets can have different vertical resolutions and temporal and spatial samplings. In these cases, there is a need for a transfer standard - an independent data record that overlaps with parent datasets, allowing to characterize differences between the parent datasets and to derive absolute adjustments. In this study we discuss requirements for the transfer standard including long-term stability, spatial and temporal sampling. We estimate how various properties of the transfer standard affect stability of the merged record and derived long-term trends. We assess the impact of the transfer function on the trends of merged datasets from satellite observations, on the examples of merging ozone records from SAGE II / MIPAS / OMPS NASA and temperature records from HALOE / MIPAS, using EMAC, CMAM and WACCM model fields as transfer standards.
How to cite: Laeng, A.: Creating long-term climate data records using transfer functions, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13965, https://doi.org/10.5194/egusphere-egu23-13965, 2023.
Water vapour in the upper troposphere and stratosphere has a significant impact both on the radiative and chemical properties of the atmosphere. Reliable water vapour climate data records (CDRs) are essential for use in climate research, to assess vertically resolved trends and associated radiative impacts. Within the ESA Water Vapour Climate Change Initiative (WV_cci), new vertically resolved water vapour CDRs in the stratosphere and UTLS were merged from a range of satellite observations. In this contribution, we provide an overview of these CDRs, highlighting innovations in the merging methodologies and results from a detailed quality assessment. In particular, the long-term trends derived from the new water vapour CDRs are compared to other merged datasets, reanalyses, and simulations from chemistry-climate models, with the ESA WV_cci CDRs deemed to be valuable new datasets for climate studies. We conclude that, mostly driven by dynamical variability, the derived water vapour trends vary significantly depending on the dataset used, chosen time period and location in the atmosphere. Using an off-line radiative transfer model, we estimate the consequence of these differences on the radiative forcing from water vapour changes in the upper troposphere and stratosphere over the past 30+ years.
How to cite: Ye, H., Hegglin, M., Hubert, D., Lambert, J.-C., Walker, K., Sioris, C., Millan, L., Manney, G., Froidevaux, L., Kerridge, B., Siddans, R., Wang, R., Plummer, D., Krämer, M., Rolf, C., and Shine, K.: Long-term trends and radiative impact in vertically resolved stratospheric water vapour from ESA WV_cci data records, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9271, https://doi.org/10.5194/egusphere-egu23-9271, 2023.
The Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) is a high spectral resolution (0.02 cm-1) spectrometer on the SciSat satellite that has been taking solar occultation measurements of the Earth’s limb since February 2004. ACE-FTS measures vertical profiles of temperature/pressure and concentrations of over 60 trace gases, including ozone and water vapour, with a vertical resolution of ~2-6 km. From the beginning of the mission, ACE-FTS water vapour data exhibits a significant positive trend on the order of a few percent per decade throughout the stratosphere and mesosphere, in agreement with similar measurements from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instruments. This study will investigate the link between ACE-FTS water vapour trends and decadal variations in other atmospheric parameters, including local and tropopause temperatures, ozone and methane concentrations, and solar flux, and will discuss how ACE-FTS measurements of HDO can be used to continue measuring background water vapour trends post-eruption of the Hunga Tonga-Hunga Ha’apai volcano, which injected ~160 Tg of water vapour (more than 10% of the stratospheric water vapour budget) into the stratosphere.
How to cite: Sheese, P., Walker, K., Jeffery, P., and Boone, C.: ACE-FTS water vapour trends in the stratosphere-mesosphere, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9414, https://doi.org/10.5194/egusphere-egu23-9414, 2023.
Water vapour is the most important greenhouse gas in the Earth’s atmosphere, both, due to radiative forcing and the formation of clouds. The upper troposphere and lowermost stratosphere (UTLS) region is an especially sensitive region for climate radiative forcing. In the UTLS the air is cold with a large spatial and temporal variability of water vapour. With the MOZAIC (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft) data it was recently shown that in the extratropical UT close to the tropopause the air is nearly saturated with respect to ice and contains a significant fraction of ice-supersaturated regions (ISSRs) (Petzold et al., ACP, 2020, doi.org/10.5194/acp-20-8157-2020).
In the present study we investigate the long-term changes of water vapour in the tropopause region using the combined time series of MOZAIC and IAGOS (In-Service Aircraft for a Global Observing System; www.iagos.org). Their observation systems are deployed on a fleet of commercial aircraft and aim at the provision of long-term, regular, and spatially resolved in situ observations of the atmospheric composition on a global scale. The combined water vapour and relative humidity time series spans now more than 27 years and is comprised of nearly 65000 flights. This makes the data set well-suited for long-term characterization of the water vapour distribution in the extratropical UTLS, namely at mid-latitudes with highest flight densities.
We will present analyses of the time series from 1996 to 2020 for long-term changes of absolute humidity, temperature, relative humidity with respect to ice (RHice) and occurrence of ISSRs. Our focus lies on different altitude levels in the UTLS at northern mid-latitudes over the regions Eastern North America, North Atlantic and Europe.
How to cite: Rohs, S., Smit, H., Blomel, T., Li, Y., Bundke, U., and Petzold, A.: Evaluation of long-term changes of upper tropospheric and lower stratospheric water vapour and ice supersaturated regions in different altitudes and geographical regions derived from MOZAIC and IAGOS routine in-situ observations, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14733, https://doi.org/10.5194/egusphere-egu23-14733, 2023.
Consistent and long-term monitoring and understanding spatiotemporal distributions of carbon dioxide (CO2) in the atmosphere and local emission sources are essential to achieve the carbon neutrality by 2050. Quantifying accurate spatiotemporal CO2 enhancements is uneasy task because of its relatively long lifetimes in the atmosphere compared with methane and nitrogen dioxide. If the observatory is situated close to the area affected by transboundary air pollutants and local emission sources (e.g., cities, power plant, industrial areas etc.), estimating CO2 enhancements are even more challenging. Satellite CO2 observations are powerful to examine local to regional CO2 enhancements from the emission hotspot regions with wider spatial coverage compared with ground-based observatory. Especially, NASA's Orbiting Carbon Observatory-3 (OCO-3) has demonstrated its feasibility to quantify local CO2 emissions from the emission hotspots. To better understand source-sink characteristics of CO2 in South Korea, we examined spatiotemporal distributions in local CO2 enhancements of the several hotspots from the OCO-3 Level 2 bias-corrected column-averaged dry-air mole fractions of CO2 (XCO2) v10.4r. We determined CO2 enhancements utilizing monthly climatology statistics from the Fourier Transform Spectrometer (FTS) XCO2, Anmyeon-do (36.5382◦N, 126.3311◦E) in South Korea, subtracted from OCO-3 XCO2 at each pixel. We used FTS-XCO2 measurements from the update Total Carbon Column Observing Network (TCCON) GGG2020 retrieval algorithm. Our preliminary results suggest that CO2 enhancements over the major hotspots in South Korea showed wide ranges from -5 ~ 12 ppm measured from Snapshot Area Maps (SAMs) measurement modes. This large variability may be associated with the definition of enhancement determination, geographical location, and seasonal wind characteristics. We will discuss these potential error sources of uncertainties and how we can enhancement estimates to better quantify CO2 emissions. We anticipate our study provide insights for the robust and reliable quantifications of CO2 enhancements, establish an advanced level of the greenhouse gases and air quality monitoring strategy in South Korea.
How to cite: Park, S.-B., Kang, Y., Oh, Y., Song, C.-K., and Park, S. S.: Characterizing CO2 enhancements at major hotspots in South Korea using OCO-3 XCO2 retrievals , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11229, https://doi.org/10.5194/egusphere-egu23-11229, 2023.
According to the 6th IPCC report, the concentration of greenhouse gases has increased about 20% since pre-industrial revolution, and 17% of them have increased over the last 10 years. The Korea Metoeorological Administration has analyzed satellite-based greenhouse gases to monitor climate change and support government’s achievement of net zero. The KMA has validated satellite-based greenhouse gases using CO2 observed in situ and retrieved TCCON in Anmyeon, the South Korea which is a GAW site. Both ground- and satellite-based CO2 showed a good agreement in their increasing trends with seasonal variations. However, satellite-based CO2 observed total column appear smaller than in situ observations affected by local sources due to observe near the surface, but agree well with TCCON observed the total column. The RMSD of GOSAT, and OCO2 with in situ and TCCON is estimated about 14.85, 16.93 and 2.81, 2.01 ppmv for a 1.0 degree × 1.0 degree spatial resolution on a daily time scale from January 2014 to December 2018. The results show that satellite-based products could be used greenhouse gases monitoring, but it needs to be verified more validation data. We will present the detailed methods and results in the conference.
This work was funded by the Korea Meteorological Administration’s Research and Development Program “Technical Development on Weather Forecast Support and Convergence Service using Meteorological Satellites” under Grant (KMA2020-00120).
How to cite: Lee, B., Sohn, E., Heo, J., Oh, Y., Joo, S., Choi, J., Park, H., Lee, M., and Kim, Y.: Greenhouse Gases Validation and Monitoring over the East Asia by Satellite-based Observation, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11281, https://doi.org/10.5194/egusphere-egu23-11281, 2023.
Trace gas measurements are routinely performed using ground-based solar absorption spectroscopy in measurement networks such as NDACC (Network for Detection of Atmospheric Composition Change) and TCCON (Total Carbon Column Observing Network). For water vapour there exist radiosonde measurements providing high vertical resolution but limited temporal resolution. Retrievals from infrared emission spectrometry bridge a temporal gap in the measurement of trace gases during polar night. Measurements are possible dayround under cloud free conditions. At the AWIPEV site in Ny-Ålesund, Svalbard, we deploy a Bruker Vertex 80 FTIR emission spectrometer with a maximum resolution of 0.08 cm⁻¹ which is able to resolve individual spectral lines. We present optimal estimation retrievals of water vapour and methane. The results are compared to daily radiosonde measurements and TCCON retrievals. First results of applying our retrieval to emission spectra with a reduced resolution are also shown. This will in the future allow to include the retrieval on E-AERI-type instruments with their lower resolution deployed e.g. during the MOSAiC campaign.
How to cite: Heizmann, L., Palm, M., Notholt, J., and Buschmann, M.: Trace gas retrievals from infrared emission spectrometry in the Arctic, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13122, https://doi.org/10.5194/egusphere-egu23-13122, 2023.
This work aimed at showing the potential of continuous CO2 and CO observations at the ICOS atmospheric class-2 station Mt. Cimone (CMN, 2165 m a.s.l. - Italy) in revealing, together with transport modeling and satellite observations, the presence of European open fire plumes in the northern Italian Apennines, and then providing a first assessment of their impact to the atmospheric CO2 observed at CMN. Based on the analysis of a case study occurred during March 2020, an algorithm providing indications about the possible presence of fire plumes from different European source regions was implemented. The algorithm used observed CO/CO2 at CMN, active open fire detection by MODIS, air mass back-trajectories and time series of simulated CO2 at the measurement site.
The results suggested that CMN could be affected for a not-negligible fraction of time by fire plumes: 5.5% of the September - May period and the 19.6% of the June - August period. We found a potential important contribution of open fires from Eastern Europe during September - May (51% of events), while during summer there was a prevalence from the Mediterranean sector (53% of events).
Looking at the possible impact of these events to the observed CO2, we detected an increase with respect to periods not affected by fire perturbations during September - May (+3.4 ppm, on average), while we did not find any significant variations during summer months, possibly related to the CO2 uptake related with biospheric activity.
We discussed limitations and caveats related to the sensitivity of results as a function of the set-up of the selection methodology, uncertainties in the transport modeling and in the CO2 modelling. Even if it is still preliminary, our study indicated that the observations from CMN can represent, if supported by adequate diagnostic tools, a powerful dataset to evaluate the impact of open fires to the atmospheric CO2 variability.
How to cite: Cristofanelli, P., Putero, D., Fratticioli, C., Trisolino, P., Calzolari, F., Calidonna, C. R., Marinoni, A., and Renzi, L.: Influence of European fires to Carbon Dioxide (CO2) variability at the Mt. Cimone station (Italy, 2165 m asl): a first assessment., EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3897, https://doi.org/10.5194/egusphere-egu23-3897, 2023.
This paper highlights the main findings of the eighteenth annual Greenhouse Gas Bulletin (https://library.wmo.int/index.php?lvl=notice_display&id=22149) of the World Meteorological Organization (WMO). The results are based on research and observations performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW) Programme (https://community.wmo.int/activity-areas/gaw).
The Bulletin presents global analyses of observational data collected according to GAW recommended practices and submitted to the World Data Center for Greenhouse Gases (WDCGG). Bulletins are prepared by the WMO/GAW Scientific Advisory Group on Greenhouse Gases in collaboration with WDCGG.
Observations used for the global analysis are from more than 100 marine and terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other greenhouse gases. The globally averaged surface mole fractions calculated from this in situ network reached new highs in 2021, with CO2 at 415.7 ± 0.2 ppm, CH4 at 1908 ± 2 ppb and N2O at 334.0 ± 0.1 ppb. These values constitute, respectively, 149%, 262% and 124% of pre-industrial (before 1750) levels. The increase in CO2 from 2020 to 2021 was equal to that observed from 2019 to 2020 and larger than the average annual growth rate over the last decade. For CH4, the increase from 2020 to 2021 was higher than that observed from 2019 to 2020 and considerably higher than the average annual growth rate over the last decade. For N2O, the increase from 2020 to 2021 was slightly higher than that observed from 2019 to 2020 and also higher than the average annual growth rate over the last decade.
The Bulletin highlights the exceptional growth of CH4 in 2020 and 2021. The causes of these exceptional increases are still being investigated though analyses of measurements of atmospheric CH4 abundance and its stable carbon isotope ratio 13C/12C indicate that the increase in CH4 since 2007 is associated mostly with biogenic processes, but the relative contributions of anthropogenic and natural sources to this increase are unclear.
The Bulletin further highlights that the accuracy of emissions estimates from atmospheric measurements depends on the geometry of the surface network, pointing to the large observational gaps in tropical regions and the interior of the Asian continent. The tropics accommodate not only highly uncertain emissions from natural wetlands, but also the atmospheric hydroxyl radical sink of CH4, which is largest there. Surface measurements provide limited information to distinguish between increasing surface emissions and decreasing atmospheric sinks, which could both explain the increasing atmospheric CH4 abundance.
WMO is working with the broader greenhouse gas community to develop a framework for sustained, internationally coordinated global greenhouse gas monitoring. These efforts are envisaged to result in an internationally coordinated approach to observing network design and acquisition, international exchange and use of the observations. It is foreseen that this will result in the expansion of the in-situ network, especially in currently undersampled regions and lead to reduced uncertainties in the quantification of the net atmospheric balance of CH4 and other greenhouse gases.
How to cite: Tarasova, O., Vermeulen, A., Sawa, Y., Houweling, S., and Dlugokencky, E.: The state of greenhouse gases in the atmosphere using global observations through 2021, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15201, https://doi.org/10.5194/egusphere-egu23-15201, 2023.
Sulfur hexafluoride (SF6) is a most potent anthropogenic greenhouse gas with a global warming potential of 23,900 over a 100-year time horizon. There are no natural sink sources in the troposphere and they are destructed by photolysis and electron attachment in the mesosphere. SF6 is mainly used for electrical insulation, circuit breaker, and plasma etching processes in the semiconductor industry. For monitoring changes in atmospheric SF6 in Korean Peninsula, 3 surface in-situ greenhouse gas monitoring stations, Anmyeondo (AMY), Jeju Gosan (JGS), and Ulleungdo (ULD), have been operating. AMY started its operation in 2007 and JGS and ULD followed in 2017. Due to the advantage of their locations surrounding the Korean Peninsula at the Western, Southern, and Eastern ends, they can provide information on the inflow and outflow of the SF6 in the Korean Peninsula. According to the data from 2017 to 2020, the increasing trend of background mole fraction of SF6 from the stations was in good agreement with that of the global monitoring stations, Mauna Loa and Cape Grim. Each station shows the characteristic enhancement tendency by wind direction and speed, which implies the possible influence of the regional emission source and long-range transport. In addition, based on the analysis with HYSPLIT model the central area of the Korean Peninsula is identified as an emission source region, as well as central part of China and Japan.
How to cite: Lee, S., Lee, H., and Li, S.: The characteristics of atmospheric SF6 in the Korean Peninsula during 2017-2020, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5347, https://doi.org/10.5194/egusphere-egu23-5347, 2023.
The continuous population and economy growth demands more energy, currently provided predominantly by burning of fossil fuels. However, the depletion of fossil fuel resources and the detrimental environmental impacts of burning fossil fuels are driving the public opinion and governments towards renewable energy (RE) sources. Solar and wind power are the most promising, but its reliability is shadowed by their weather dependence. Hydrogen is considered as a very promising energy carrier which can overcome the limitations of the existing RE sources. Producing hydrogen at the solar panel fields or incorporating water electrolysers within wind turbines will smooth the energy supply, and even reduce the energy transport. If the hydrogen economy takes effect as anticipated, then the hydrogen impact on the climate needs to be re-assessed. In order to simulate future hydrogen concentrations, it is necessary to build a model which can simulate present day hydrogen emissions and sinks, and resultant atmospheric concentrations, which are currently infrequently measured. Building a history of hydrogen measurements opens up possibilities in the future to determine background and pre-existing hydrogen sources, and gives a baseline before the switch to a hydrogen economy.
Historically, Reduction Gas Analysers (RGA) were the workhorse in the laboratory and field, where reductive gasses like hydrogen or carbon monoxide release mercury gas by passing along a heated solid mercuric oxide bed, which in turn is analysed by ultraviolet (UV) absorption. The method is well established but lacks linear response and stability. CSIRO is working on novel methods for more accurate and precise hydrogen measurement. The Pulsed Discharge Helium Ionization Detector, or simply PDD, is an alternative to the RGA. CSIRO has been operating a PDD for hydrogen at Cape Grim (along with the classic RGA) for 7.5 years using shared calibration tanks. The mean difference between them (50,000+ matched data points, when pollution events are removed) is just 0.02 ppb, proving PDD’s incredible compatibility with the established RGA technique. The PDD also has a demonstrated superior precision and linearity compared to the RGA. Another two PDD systems are operational at Aspendale measuring urban hydrogen since 2019 and 2021. The later one is to be deployed at the CSIRO Clayton site, where Aspendale will relocate to in 2025. Another PDD system is in a development stage, able to measure not just hydrogen, but many other atmospheric gases (CH4, CO2, N2O, Kr, Xe). The inability of optical instruments to measure hydrogen (homonuclear diatomic molecule) will mean that there will be an increased demand for RGA or PDD measurements of hydrogen in the future.
How to cite: Mitrevski, B., Guerette, E.-A., Langenfelds, R., Woodhouse, M., Spenser, D., Krummel, P., and Steele, P.: Measuring Atmospheric Hydrogen Ahead of the Anticipated Hydrogen Economy, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16386, https://doi.org/10.5194/egusphere-egu23-16386, 2023.
In addition to being harmful to the ozone layer (for chlorinated and brominated compounds), halocarbons are also potent greenhouse gases. Their monitoring is therefore essential. Here we exploit measurements from the infrared satellite sounder IASI which offers the potential to robustly assess trends in the atmospheric abundances of trace gases owing to the stability and the consistency of the measurements made by three successive instruments over a period of more than 15 years. Despite their weak spectral signatures, we have recently reported the detection of eight long-lived halocarbons in IASI spectra: CFC-11, CFC-12, HCFC-22, HCFC-142b, HFC-134a, CF4, SF6 and CCl4.
In this work we exploit the available record of continuous IASI measurements to (1) determine the temporal evolution in atmospheric abundance of these species (2) quantify their radiative impact for the first time. We calculate their global radiative forcing based on integration over specific bands of IASI spectrally resolved fluxes (Whitburn et al., 2020[1]). Our results are validated with ground-based measurement networks and other remote sensors data. We conclude by assessing the usefulness of IASI and follow-on missions to contribute to the global monitoring of CFCs and their substitutes.
[1] Whitburn, S. et al. Spectrally resolved fluxes from IASI data: retrieval algorithm for clear-sky measurements. J. Clim. 33, 6971—6988 (2020).
How to cite: De Longueville, H., Clarisse, L., Whitburn, S., Clerbaux, C., and Coheur, P.: Radiative impact of long-lived halocarbons and their atmospheric trends, derived from 15 years of IASI/Metop measurements, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13141, https://doi.org/10.5194/egusphere-egu23-13141, 2023.
Measurements of BrO obtained in situ from the NASA ER-2 aircraft and balloons (HALOZ balloon-borne ClO/BrO instrument) between 1987 and 2000 are used to estimate the trend in total inorganic bromine (Bry). Despite the significance of ozone destruction by BrO, due to the analytical difficulty in quantifying very low abundances of bromine radicals present in the stratosphere these were the only direct observations of the dominant species of inorganic bromine that were made often enough over this period to allow for this analysis. In particular, this work focuses on observations in the perturbed polar vortices when BrO chemistry is dominated by reaction with ClO, and thus is less sensitive to systematic errors due to uncertainties in reactions with compounds such as HOx and NOx that dominate at lower latitudes. We use a detailed one-dimensional photochemical model with recommended rate parameters for key chemical processes, initialized with simultaneous observations of ClO and O3, to determine the atmospheric bromine partitioning under the specific photochemical conditions of each observation. We find that total inorganic bromine increased by ~43% over this time and reaches a value in 2000 that agrees well with the other observations that have since shown a leveling off, and small decrease, of inorganic bromine in the stratosphere since 2000. Within the accuracies of the BrO measurements and modeled partitioning, our results are consistent with a relatively constant value of 4 ppt find for very short-lived bromine substances (VSLSs) over the period of these observations. These results extend the Bry record deduced in recent WMO ozone assessments by 13 years and add further confidence to our understanding of ozone depletion due to bromine compounds over this critical period when inorganic bromine was increasing rapidly due to emissions of anthropogenic compounds, such as Halons and methyl bromide used in fire extinguishers and for fumigating crops.
How to cite: Toso, L. and Toohey, D. W.: The trend in stratospheric bromine from 1987 to 2000 deduced from in situ measurements of BrO in the Winter Polar Vortices, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14464, https://doi.org/10.5194/egusphere-egu23-14464, 2023.
Accurate quantification of long-term trends in stratospheric ozone can be challenging due to their sensitivity to natural variability, the quality of the observational datasets, non-linear changes in forcing processes as well as the statistical methodologies. Multivariate linear regression (MLR) is the most commonly used tool for ozone trend analysis. However, the complex coupling in most atmospheric processes makes it prone to the over-fitting or multi-collinearity-related issue when using the conventional Ordinary Least Squares (OLS) setting. To overcome the multi-collinearity, we adopt a regularised (Ridge) regression method to quantify ozone trends and the influence of individual processes. Our MLR model setup is similar to the one used in Dhomse et al., (2022). Here, we use the Stratospheric Water and OzOne Satellite Homogenized (SWOOSH, Davis et al., 2016) merged data set (v2.7) to derive stratospheric ozone profile trends for the period 1984-2020. Beside SWOOSH, we also analyse a machine-learning-based satellite-corrected gap-free global stratospheric ozone profile dataset from a chemical transport model (ML-TOMCAT) (Dhomse et al., 2021), and output from two chemical transport model (TOMCAT) simulations forced with ECMWF reanalyses ERA-Interim and ERA5 (Li et al., 2022).
With Ridge regression, the stratospheric ozone profile trends from SWOOSH data show smaller declines during 1984-1997 compared to OLS with the largest differences in the lowermost stratosphere (>4 % per decade at 100 hPa). Upper stratospheric ozone has increased since 1998 with maximum (~2 % per decade near 2 hPa) in local winter for mid-latitudes. Negative trends with large uncertainties are observed in the lower stratosphere and are most pronounced in the tropics. The largest difference in post-1998 trend estimates between OLS and Ridge regression methods also appears in the tropical lower stratosphere (about ~7 % per decade difference at 100 hPa). Ozone variations associated with natural processes such as solar variability, ENSO, AO and AAO also indicate that Ridge regression coefficients are somewhat smaller and less variable compared to the OLS-based estimates. The ML-TOMCAT data set shows similar results to those using SWOOSH data while model simulations show larger inconsistencies especially in the lower stratosphere. The considerable differences between the satellite data and model simulations indicate that there are still large uncertainties in ozone trend estimates especially in the lower stratosphere where dynamical processes dominate, and caution is needed when discussing results if explanatory variables used are correlated.
References:
Davis, S. M., et al., The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database: a long-term database for climate studies, Earth Syst. Sci. Data, 8, 461–490, https://doi.org/10.5194/essd-8-461-2016, 2016.
Dhomse, S. S., et al., ML-TOMCAT: machine-learning-based satellite-corrected global stratospheric ozone profile data set from a chemical transport model, Earth Syst. Sci. Data, 13, 5711–5729, https://doi.org/10.5194/essd-13-5711-2021, 2021.
Dhomse, S. S., et al., A single-peak-structured solar cycle signal in stratospheric ozone based on Microwave Limb Sounder observations and model simulations, Atmos. Chem. Phys., 22, 903–916, https://doi.org/10.5194/acp-22-903-2022, 2022.
Li, Y., et al., Effects of reanalysis forcing fields on ozone trends and age of air from a chemical transport model, Atmos. Chem. Phys., 22, 10635–10656, https://doi.org/10.5194/acp-22-10635-2022,2022.
How to cite: Li, Y., Dhomse, S., Chipperfield, M., Feng, W., Xia, Y., Guo, D., and Bian, J.: Stratospheric ozone trends and attribution over 1984-2020 based on satellite data and model simulations with a regularised regression method, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-12788, https://doi.org/10.5194/egusphere-egu23-12788, 2023.
Amount of ozone in the stratosphere is very small as compared to other trace gases in the atmosphere. Yet, significant changes in its concentrations have great consequences in the environment and ecosystems. However, such drastic changes in ozone happens only in the high and middle latitudes, particularly in the polar spring, where chemical ozone loss occurs due to halogen-catalysed chemistry on polar stratospheric clouds. In the tropics, the amount of column ozone is very small and the ozone loss is also very small over the years, as compared to high and mid-latitudes. The ozone analyses in the tropical latitudes show a consistent picture of ozone evolution in the past four decades, as there is no significant loss or increase, although small negative trends are found. Recent studies have demonstrated that these negative trends in the tropical upwelling region are due to the increase in the speed of Brewer-Dobson Circulation, which brings tropospheric ozone to the lower stratosphere. This is clearly pictured in the time series of tropical ozone in recent years. The long-term trend in tropical total column ozone also shows no noticeable difference in recent years from the past decades. No measurements and no analyses show any signature of ozone hole in the tropics and all claims so far made are scientifically not sound and unconvincing. It is very unlikely that we would get an ozone hole outside the polar region.
How to cite: Kuttippurath, J. and Gopikrishnan, G. P.: Is there an Ozone hole in the Tropics?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11273, https://doi.org/10.5194/egusphere-egu23-11273, 2023.
Total ozone is a measure of the protection of the biosphere from UV radiation. Extratropical total ozone recovery trends of about +0.5%/decade are consistent with the continuous decline in stratospheric halogen loading since the middle 1990s as a consequence of the Montreal Protocol and its Amendments on phasing out ODS. Nevertheless, the recovery (or chemistry-related) trends in the northern hemisphere (NH) are compensated by changes in atmospheric dynamics leading to stable ozone levels since about 2000 (apart from year-to-year variability). The near-global (60°S-60°N) average total ozone level is currently about 2-3% below the 1964-1980 mean.
Lower stratospheric ozone, the dominating contributor to the total ozone column and derived from limb satellite observations, shows globally (below 60° latitude) a slightly negative (but mostly statistically insignificant) trend of about -1.5%/decade since 2000, which is not consistent with the stable total ozone levels in the NH. Some studies suggested that increases in tropospheric ozone compensate for negative lower stratospheric trends leading to stable column levels. The trend regression models applied to ozone profiles and total ozone also differ. For instance, proxies representing changes in atmospheric dynamics and transport have been included for total ozone, but not for ozone profiles, which may also lead to inconsistencies between total and stratospheric column trends.
This presentation will report updated total ozone trends from five merged total ozone datasets up to 2022. The same regression model, including proxies representing atmospheric dynamics and transport, will be then applied to ozone profiles from the merged limb dataset (SAGE II-SCIAMACHY-OMPS) to evaluate the consistency between column and profile trends.
How to cite: Weber, M., Arosio, C., Rozanov, A., Burrows, J. P., Sofieva, V., Coldewey-Egbers, M., Loyola, D., Fioletov, V., Frith, S. M., and Wild, J. D.: Are trends in total ozone consistent with stratospheric ozone trends from satellite observations? Are trends in total ozone consistent with stratospheric ozone trends from satellite observations?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13119, https://doi.org/10.5194/egusphere-egu23-13119, 2023.
Observations in limb geometry from satellite platforms are very valuable for monitoring the stratospheric ozone layer on a global scale, as they provide information with high spatial and temporal coverage and good vertical resolution. At the University of Bremen, ozone profiles were retrieved from observations from two limb sounders, SCIAMACHY (2002-2012) and OMPS-LP (2012-present), using similar retrieval algorithm setups. These two data sets were merged to obtain a consistent time series of longitudinally resolved global ozone distribution, referred to below as SCIA+OMPS. Recently, the OMPS-LP data set has been re-processed by using improved L1 data produced by the NASA team, with the main aim to mitigate the long-term drift affecting the OMPS-LP time series. The results of this re-processing will be presented; the use of the updated data set gives more confidence in the trend studies from the SCIA+OMPS time series.
The overarching aim of this study is the investigation of vertically consistent patterns in the longitude-resolved trends, particularly at northern mid- and high-latitudes above 30 km altitude, detected in the SCIA+OMPS data set. Large positive trends are found over the Atlantic sector, whereas close-to-zero changes are detected over the Siberian/Pacific sector. To investigate the origin of this behaviour, we performed full chemistry simulations of the TOMCAT global 3-D chemistry transport model (CTM), forced by ERA5 reanalysis, for the 2003-2020 period. We then applied a multi-linear regression model including dynamical proxies to both the satellite observations and TOMCAT simulations. First, we compare the trend resulting from the merged data set with those from the model simulations to check the consistency of the detected zonal and longitudinally resolved patterns. Then, seasonally and monthly resolved trends are studied as they provide valuable insight into the observed zonal asymmetry of the trends. We find the largest variability with longitude occurring in winter- and springtime, and a good consistency between observations and the CTM.
By comparing ozone changes, with trends in temperature and meridional wind fields from ERA5, we investigated potential mechanisms driving the observed asymmetry. Dedicated TOMCAT simulations showed the negligible role of photochemical processes for the observed pattern. We therefore consider the behaviour to be mainly dynamically driven. A composite analysis supports the hypothesis that the long-term change in the position of the polar vortex has influenced the winter- and springtime ozone concentrations and has led to the zonal asymmetry identified in the data and model.
How to cite: Arosio, C., Chipperfield, M. P., Rozanov, A., Weber, M., Dhomse, S., Feng, W., and Burrows, J. P.: Investigating zonal asymmetry in stratospheric ozone trends at northern high latitudes using satellite limb observations and CTM simulations, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7671, https://doi.org/10.5194/egusphere-egu23-7671, 2023.
Monitoring the atmospheric concentrations of the reactive species in the stratosphere, including greenhouse gases (GHGs), is crucial in order to improve our understanding of their climate impact. Although progress has been made towards construction of long-term ozone profile data sets, limited long-term profile data are available for other species. Here, we merge TOMCAT chemical transport model (CTM) output and profile measurements from two solar occultation instruments, the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS), to construct a long-term (1991-2021), gap-free stratospheric profile data set (hereafter TCOM). The Extreme Gradient Boosting (XGBoost) regression model is used to estimate the corrections needed to apply to the CTM profiles to bring them into line with the observations.
We have already released data sets for two important greenhouse gases: methane and nitrous oxide. For methane (TCOM-CH4), we use both HALOE and ACE satellite profile measurements (1992-2018) to train the XGBoost model and profiles from three later years (2019-2021) are used as an independent evaluation data set. As there are no nitrous oxide profile measurements for the earlier years, XGBoost-derived correction terms for TCOM-N2O profiles are derived using only ACE-FTS profiles for 2004-2018 time period with profiles from 2019-2021 again being used for the evaluation.
Overall, both TCOM-CH4 and TCOM-N2O profiles show excellent agreement with the available satellite measurement-based data sets. Biases in TCOM-CH4 and TCOM-N2O are less than 10% and 50% throughout the stratosphere, respectively. Daily zonal mean TCOM-CH4 and TCOM-N2O profile data sets on altitude (15--60~km) and pressure (300--0.1~hPa) are publicly available via https://doi.org/10.5281/zenodo.7293740 and https://doi.org/10.5281/zenodo.7293740, respectively.
Our presentation will discuss the construction, performance and availability of the TCOM data sets. We aim to release data sets for ozone (TCOM-O3), hydrogen chloride (TCOM-HCl), hydrogen fluoride (TCOM-HF), water vapour (TCOM-H2O), nitric acid (TCOM-HNO3), nitric oxide (TCOM-NO) and nitrogen dioxide (TCOM-NO2) shortly.
How to cite: Dhomse, S. and Chipperfield, M.: Using machine-learning to construct long-term, gap-free stratospheric species profile data sets based on satellite occultation measurements and TOMCAT 3-D model, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4542, https://doi.org/10.5194/egusphere-egu23-4542, 2023.
The ACE-FTS and MAESTRO instruments have now been operating on the Canadian Space Agency’s SCISAT satellite as the Atmospheric Chemistry Experiment (ACE) for nearly 20 years. The ACE satellite is approximately 1 m in diameter and 1 m deep and has a mass of 150 kg. The Measurement of Aerosol in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) spectrophotometer continues to measure ozone, water vapour and aerosol in the stratosphere and upper troposphere. Like the ACE‑FTS, MAESTRO delivers results from nearly 30 occultation measurements per day, but with a higher vertical resolution of just over 1 km over a range as large as 5 to 40 km as meteorological conditions allow. It measures from 500 nm to 1000 nm with a resolution of 1 to 2 nm. The instrument design and performance will be briefly discussed and the algorithms developed to process the data and deal with peculiarities in the performance of the satellite will be described.
Significant progress has been made recently in improving the retrievals that has resulted in improved accuracy and a larger number of successful retrievals at lower altitudes. A new dataset with these improvements will be available for other researchers. Some examples which illustrate the improvements will be presented.
The ACE satellite was funded by the Canadian Space Agency (CSA) and launched by NASA. The CSA funds the MAESTRO data processing. Environment Canada (EC) partly funded the construction of the MAESTRO instrument.
How to cite: McElroy, C. T., Walker, K. A., Drummond, J. R., Zou, J., and Jeffery, P. S.: The MAESTRO Spectrophotometer on Canada’s SCISAT satellite: Advances in data processing and improved data products, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-17382, https://doi.org/10.5194/egusphere-egu23-17382, 2023.
Stratospheric ozone (O3) absorbs biologically harmful solar ultraviolet radiation, mainly in the UV_B and UV_C spectral range. When reaching the surface, such UV radiation poses a well documented hazard to human health. In order to quantify this amount of UV radiation and to make it generally understandable, the World Health Organization has defined an UV Index[1]. It is calculated by weighting the incoming solar irradiance at surface level between 250 and 400 nanometers with their ”harmfulness” to the skin and scaling the results to values that normally range between 1 and 10, surpassing 10 for excessive UV exposure.
Implementing UV Index forecasts in numerical weather prediction (NWP) models allows to alert the public in time if special care for sun protection needs
to be taken. The German Weather Service (DWD) uses its NWP model ICON (ICOsahedral Nonhydrostatic Model)[2] to offer such a forecast for Germany[3]
using external data such as ozone forecasts by the Royal Dutch Weather Service (KNMI) and radiation lookup tables[4].
In our project we extend the capability of ICON to provide a configuration of self-consistent UV Index forecasts that do not require external data. For this, we use ICON-ART[5],[6] with a linearized ozone scheme (LINOZ)[7] and couple the prognostic ozone to the atmospheric radiation scheme Solar-J[8].
Here we present the current state of our UV Index forecast system and compare our results to available reference data.
References:
[1] World Health Organization, World Meteorological Organization, United Nations Environment Programme, and International Commission on Non-
Ionizing Radiation Protection. Global solar uv index : a practical guide,2002.
[2] Günther Zängl et al.. The icon (icosahedral non-hydrostatic) modelling framework of dwd and mpi-m:
Description of the non-hydrostatic dynamical core. Quarterly Journal of the Royal Meteorological Society, 2015.
[3] https://kunden.dwd.de/uvi/index.jsp.
[4] Henning Staiger and Peter Koepke. Uv index forecasting on a global scale. Meteorologische Zeitschrift, 2005.
[5] D. Rieger et al.. Icon–art 1.0 – a new online-coupled model system from the global to regional scale. Geoscientific Model Development, 2015.
[6] J. Schröter et al.. Icon-art 2.1: a flexible tracer framework and its application for composition studies in numerical weather forecasting and climate simulations. Geoscientific Model Development, 2018.
[7] C. A. McLinden et al. Stratospheric ozone in 3-d models: A simple chemistry and the cross-tropopause flux. Journal of Geophysical Research: Atmospheres, 2000
[8] J. Hsu, M. J. Prather et al.. A radiative transfer module for calculating photolysis rates and solar heating in climate models: Solar-j v7.5. Geoscientific Model Development, 2017.
How to cite: Hanft, V., Ruhnke, R., Seifert, A., and Braesicke, P.: Prognostic Ozone For ICON: Enabling UV Forecasts, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6135, https://doi.org/10.5194/egusphere-egu23-6135, 2023.
The rapid growth of the global aviation market has spurred commercial interest in the redevelopment of a civil supersonic aviation market. The emissions of these aircraft are expected to have an adverse impact on climate, as well as changing the composition of the ozone layer [1,2,3,4]. There is however still considerable uncertainty about the scale of future civil supersonic adoption, as well as future emissions, due to the rapid development of the technology and potential changes in regulations.
Evaluating the impacts of the wide range of future adoption scenarios is computationally demanding, but atmospheric sensitivities might be used to assist the evaluation. Here, we use the GEOS-Chem global chemistry transport model to evaluate the impact of supersonic fuel burn perturbations above the transatlantic flight corridor on global ozone in a modern atmosphere over a period of 10 years. Variations of this scenario are evaluated to assess global ozone sensitivities to the emission of NOx, SOx, H2O, CO, and hydrocarbons across multiple altitudes between 17.2 and 21.4 km, as well as the cross-sensitivities between the emissions of NOx, SOx, and H2O.
From the sensitivities it is found that changes in global ozone columns are primarily driven by NOx emissions in this emission region, followed by SOx and H2O, with marginal contributions from CO and hydrocarbon emissions. The impact of these emissions is found to depend strongly on altitude, with higher emission altitudes increasing ozone depletion from NOx, SOx, and H2O, emissions. For kerosene-based emissions above the transatlantic flight corridor, the effect of cross-sensitivities between the emitted species is estimated to be up to two orders of magnitude smaller than direct responses to emission species. This difference implies that the effect of cross-sensitivities on ozone may be neglected in predictive models at a small cost in accuracy, simplifying future development efforts. Considering this application, future work will first need to apply this method to global emission networks where the effect of cross-sensitivities might differ from the region presented here.
References:
[1] Matthes, S., Lee, D. S., …, Terrenoire, E., Review: The Effects of Supersonic Aviation on Ozone and Climate, Aerospace, 9(1), 41, (2022).
[2] Eastham, S. D., Fritz, T., …, Barrett, S. R. H., Impacts of a near-future supersonic aircraft fleet on atmospheric composition and climate. Environmental Science: Atmospheres. doi:10.1039/d1ea00081k, (2022).
[3] Zhang, J., Wuebbles, D., Kinnison, D., & Baughcum, S. L., Stratospheric Ozone and Climate Forcing Sensitivity to Cruise Altitudes for Fleets of Potential Supersonic Transport Aircraft. Journal of Geophysical Research: Atmospheres, 126(16), (2021).
[4] Grewe, V., Stenke, A., ..., Pascuillo, E., Climate impact of supersonic air traffic: an approach to optimize a potential future supersonic fleet – results from the EU-project SCENIC. Atmospheric Chemistry and Physics, 7(19), 5129-5145, (2007).
How to cite: van 't Hoff, J., Grewe, V., and Dedoussi, I.: Sensitivities of atmospheric ozone to supersonic emissions above the transatlantic flight corridor, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14974, https://doi.org/10.5194/egusphere-egu23-14974, 2023.
The decade, 2012 to 2021, was the warmest on record, with the global mean near-surface air temperature in the most recent seven years, 2015 to 2021, keeping hitting record high. Europe, with an increase of 1.94 to 2.01 °C in the mean annual temperature since pre-industry level, is warming much faster than the global average (1.11 to 1.14 °C) (https://www.eea.europa.eu/ims/global-and-european-temperatures). Surface warming disrupts upper-air temperature, which will affect the humidity fields in the upper troposphere. Both ambient temperature and relative humidity with respect to ice (RHice) are key factors determining the formation and persistence of contrail cirrus clouds, which exert a net warming radiative forcing among aviation emissions (Lee et al., 2009; Lee et al., 2021).
Previous studies have provided insights into the long-term trend and seasonal variability of upper-air temperature and relative humidity using airborne, radiosonde and reanalysis datasets (Petzold et al., 2020; Chen et al., 2015; Philandras et al., 2017; Essa et al., 2022). The variation of RHice in relation to the changing upper tropospheric temperature because of surface warming has, however, rarely been investigated.
In this work, we use the temperature and RHice measurements over Western Europe from the European research infrastructure IAGOS (In-Service Aircraft for a Global Observing System; www.iagos.org) to study how the upper-air temperature and RHice distributions in the warmest seven years have changed seasonally and regionally compared to the IAGOS-MOZAIC period, 1995 to 2010, when the surface warming was not so drastic. We will focus on whether the occurrence frequency of contrail forming regions, i.e., slightly ice subsaturated to supersaturated regions in the upper troposphere, would be affected by the increasing warming climate, which could promote our understanding of contrail mitigation.
[Note: This work is carried out under the frame of EU H2020 Research and Innovation Action “Advancing the Science for Aviation and Climate (ACACIA)”, Grant Agreement No. 875036.]
How to cite: Li, Y., Rohs, S., Krämer, M., and Petzold, A.: Does surface warming over Western Europe affect the occurrence frequency of contrail forming regions?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4629, https://doi.org/10.5194/egusphere-egu23-4629, 2023.
