ITS3.6/GMPV2

Monitoring active volcanoes activity passes through the detection of fluctuations in degassing levels which may reflect changes in the magma supply rate and help inform a short-term forecast of on-going eruptions. Infrared hyperspectral imagers, which is an imaging technology still little used for volcanoes monitoring, have been deployed for various field campaigns on active volcanoes recently. For example, the Hyper-Cam LWIR (LongWave InfraRed) ranging between 850-1300 cm^-1 (7.7 - 11.8 µm) with a spectral resolution up to 0.25 cm^-1, provided high spectral resolution images from ground-based measurements of the Mount Etna (Sicily, Italy) plume during IMAGETNA campaign in June 2015. Processing the raw data and retrieving the infrared spectra with the LATMOS (Laboratoire Atmosphères Milieux Observations Spatiales) Atmospheric Retrieval Algorithm (LARA), a robust and a complete radiative transfer model, require a calculation time of ~7 days per image.

One of the main ways of risk mitigation effects of explosive eruptions is to get a fast and accurate quantification of SO₂ fluxes emitted by volcanoes. In this context, using the dataset acquired during IMAGETNA campaign at Mount Etna, a spectra classification methodology has been developed to drastically decrease the calculation time and reach near real-time retrievals of SO₂ slant column densities. The methodology is based on a network built on two layers of information from the extraction of spectral features in the O₃ and SO₂ emission bands. A training dataset of five SO₂ slant column densities images retrieved with the time-consuming pixel-by-pixel retrieval method allowed the creation of a library. The spectra classification makes it possible to process each hyperspectral image in less than 40 seconds. It opens the possibility to infer near real-time estimation of SO₂ emission fluxes from IR hyperspectral imager measurements.

How to cite: Segonne, C., Huret, N., Payan, S., and Gouhier, M.: A spectra classification methodology of infrared hyperspectral images to reach near real-time SO2 emission flux estimation of Mount Etna plume, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15239, https://doi.org/10.5194/egusphere-egu21-15239, 2021.

Monitoring of volcanic emissions (gas, ash and aerosols) is crucial to our understanding of eruption mechanisms, as well as to developing mitigation strategies during volcanic eruptions. Ultraviolet (UV) spectrometers and cameras are now ubiquitous monitoring tools at most volcano observatories for quantifying sulphur dioxide (SO2) emissions. However, because they rely on scattered UV light as a source of radiation, their use is limited to daytime only, and measurement windows are often further restricted by unfavourable weather conditions. On the other end of the spectrum, Open Path Fourier Transform Infrared (OP-FTIR) instruments can be used to measure the concentrations of a series of volcanic gases, and they allow for night-time operation. However, the retrieval methods rely on the presence of a strong source of IR radiation in the background - either natural (lava flow, crater rim, the sun) or artificial – restricting their use to very specific observation geometries and a narrow range of eruptive conditions. Here we present a new approach to derive quantities of SO2, ash and aerosols from measurements of a drifting volcanic plume. Using the atmosphere as a background, we measured self-emitted IR radiation from plumes at Stromboli volcano (Italy) capturing both passive degassing and ash-rich explosive plumes. We use an iterative approach with a forward radiative transfer model (the Reference Forward Model – RFM) to quantify concentrations of sulphur dioxide (SO2), aerosols and ash in the line of sight of the spectrometer. This new method could significantly enhance the scientific return from OP-FTIR instruments at volcano observatories, ultimately expanding their deployment as part of permanent scanning networks (an alternative to DOAS instruments) to provide continuous data on the emissions of gas, ash and aerosols. 

How to cite: Smekens, J.-F., Mather, T., and Burton, M.: Quantifying gas, ash and aerosols in volcanic plumes using emission OP-FTIR measurements, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9794, https://doi.org/10.5194/egusphere-egu21-9794, 2021.

Precise knowledge of the location and height of the volcanic sulfur dioxide (SO₂) plume is essential for accurate determination of SO₂ emitted by volcanic eruptions, however so far not available in operational near-real time UV satellite retrievals. The FP_ILM algorithm (Full-Physics Inverse Learning Machine) enables for the first time to extract the SO₂ layer height information in a matter of seconds for current UV satellites and is thus applicable in NRT environments.

The FP_ILM combines a principal component analysis (PCA) and a neural network approach (NN) to extract the information about the volcanic SO₂ layer height from high-resolution UV satellite backscatter measurements. So far, UV based SO₂ layer height retrieval algorithms were very time-consuming and therefore not suitable for near-real-time applications like aviation control, although the SO₂ LH is essential for accurate determination of SO₂ emitted by volcanic eruptions.

In this presentation, we will present the latest FP_ILM algorithm improvements and show results of recent volcanic eruptions.

The SO₂ layer height product for Sentinel-5p/TROPOMI is developed in the framework of the SO₂ Layer Height (S5P+I: SO₂ LH) project, which is part of ESA Sentinel-5p+ Innovation project (S5P+I). The S5P+I project aims to develop novel scientific and operational products to exploit the potential of the S5P/TROPOMI capabilities. The S5P+I: SO₂ LH project is dedicated to the generation of an SO₂ LH product and its extensive verification with collocated ground- and space-born measurements.

How to cite: Hedelt, P., Koukouli, M., Michaelidis, K., Isabelle, T., Balis, D., Grainger, D., Efremenko, D., and Loyola, D.: Extremely fast retrieval of volcanic SO2 layer heights from UV satellite data using inverse learning machines, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3107, https://doi.org/10.5194/egusphere-egu21-3107, 2021.

Along with monitoring of seismic activity and ground deformation, the measurement of volcanic gas emissions and composition plays a key role in the surveillance of active volcanoes and the mitigation of volcanic hazards. Volcanic gas emissions also potentially impact the environment, human health and climate, providing further motivation for study. Currently, volcano observatories typically employ ground-based or airborne techniques to monitor volcanic gas emissions, mainly sulfur dioxide (SO₂) fluxes and its ratios over other species (e.g., CO₂, H₂S). However, in recent years there have been significant breakthroughs in satellite observations of passive volcanic SO₂ emissions, including high-resolution ultraviolet (UV) measurements from the Tropospheric Monitoring Instrument (TROPOMI) on the Sentinel-5 Precursor (S5P) satellite, and the development of long-term records of volcanic SO₂ degassing from the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite. Satellite measurements offer some advantages over traditional gas monitoring techniques, e.g., synoptic coverage of large regions, relative immunity to variations in wind direction, and ability to map the spatial extent and dispersion of volcanic SO₂ plumes with applications for health hazard mitigation. Although these satellite datasets are potentially valuable for active volcano monitoring and as a supplement to other gas monitoring techniques, significant barriers remain to their use at many volcano observatories, particularly in low-income countries. Notably, the increasing volume of satellite datasets (NASA’s database is bigger than 3 petabytes) and the demands of data processing represent challenges to their operational use at observatories with limited internet connectivity or computational capacity. Here, we present an ongoing effort to develop open-source Python software to access and process SO₂ data directly through NASA’s Earthdata portal Application Processing Interface (API), in order to streamline the satellite SO₂ data processing workflow for a volcano observatory. By allowing server-side satellite data subsetting around the volcano of interest, this API greatly reduces the processing burden and only requires an internet connection to the NASA server hosting the required datasets (including S5P/TROPOMI, Aura/OMI and many others). We present some examples of software output and potential applications. Our current goal is to deploy and test the software for operational use in a volcano observatory.  

How to cite: Epiard, M. and Carn, S.: Towards operational use of satellite SO2 measurements in a volcano observatory, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16345, https://doi.org/10.5194/egusphere-egu21-16345, 2021.

Raikoke, a remote volcano in the Kuril Islands, erupted on the 21^st June 2019. The eruption injected significant quantities of SO₂ into the atmosphere along with volcanic ash. These plumes have been studied with tools developed for the Infrared Atmospheric Sounding Interferometer (IASI) by the Earth Observation Data Group (EODG) at the University of Oxford. IASI is a hyperspectral sensor onboard of three meteorological satellites (Metop A, B and C). Each instrument obtains near global coverage twice a day and has a spectral range which includes sensitivity to both SO₂ and ash: making them useful for studying the Raikoke plumes. A fast linear SO₂ retrieval was first applied to flag pixels with elevated amounts of SO₂. With this tool it was possible to follow the Raikoke plume as it circulated the northern hemisphere above 30 degrees, with parts of the plume still visible around 2 months after the eruption took place. Next an iterative SO₂ retrieval was used to quantify the amount and height of the SO₂ in each pixel. In the first few days after the eruption took place, very high column amounts are recorded, in some cases exceeding 600 DU. Using this retrieval, a preliminary estimate of 1.6 Tg was obtained for the total amount of SO₂ emitted (measured on the 23^rd of June). Height information from this technique shows that there were probably multiple injection heights during the eruption and that SO₂ was emitted into both the troposphere and stratosphere. The tropospheric plume remains visible for just a few days after the eruption, while the stratospheric portion of the plume persists for several weeks.

How to cite: Taylor, I. A., Grainger, R. G., and Mather, T. A.: Observations of plumes from the 2019 Raikoke eruption with the Infrared Atmospheric Sounding Interferometer (IASI), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11828, https://doi.org/10.5194/egusphere-egu21-11828, 2021.

We have developed a new trajectory tool to reconstruct the altitude and the position of SO₂ in a volcanic plume. Starting with 2D map of satellite observed SO₂, known volcano location, and reanalysis wind fields from the NASA Goddard Earth Observing System (GEOS) model, the Goddard trajectory tool allows us to estimate the altitude and concentration of SO₂ in the volcanic plume at time of observation. We used this tool for the June 21, 2019 Mt. Raikoke eruption and the June 15, 1991 Mt. Pinatubo event. We used SO₂ data from the Ozone Mapping and Profiler Suite/Nadir Mapper (OMPS/NM) onboard the NASA-NOAA Suomi satellite and obtained a distribution of SO₂ altitudes between 1 and 19 kilometers in different parts of the Raikoke SO₂ clouds, with the highest SO₂ concentration between 11 and 16 km, in good agreement with data from independent SO₂ layer height retrievals from the Ozone Monitoring Instrument (OMI) aboard the NASA Aura spacecraft; the Tropospheric Monitoring Instrument (TROPOMI) onboard the European Copernicus Sentinel 5 precursor satellite and Infrared Atmospheric Sounding Interferometer (IASI) on the European Space Agency's (ESA) MetOp series of a polar orbiting satellites. We then applied this method to the Pinatubo eruption using SO₂ column measurements from the NASA Total Ozone Mapping Spectrometer (TOMS) and using wind fields from the National Centers for Environmental Prediction Reanalysis version 2. We found that the southern part of the Pinatubo plume is located in the troposphere, and the northern part is in the stratosphere.

How to cite: Gorkavyi, N., Krotkov, N., Li, C., Lait, L., Carn, S., Colarco, P., Fedkin, N., DeLand, M., Schoeberl, M., Vasilkov, A., and Joiner, J.: Calculating the Height and the Position of Volcanic Cloud SO2 With a Lagrangian Trajectory Tool, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7916, https://doi.org/10.5194/egusphere-egu21-7916, 2021.

The emission of volcanic gases can occur both during volcanic eruptions and in quiescent stages of the volcanic activity. This process can affect the air quality in the areas downwind; in fact, many gas species can be a threat to human health and even life at concentrations and doses above species-specific thresholds. Gas emissions can be of different types, the two main categories being dilute passive degassing and heavy gas flow. The former occurs when the gas concentration is low and/or temperature is high, hence its density is lower than the atmospheric density; the latter takes place when the gas density is higher than the atmosphere and the gas accumulates onto the ground and may flow as a gravity current more or less affected by the wind. Examples of the first and second types of emissions are fumaroles and limnic explosions, respectively.

Numerical modelling is one of the approaches used to quantify the hazard related to these processes. Ideally, for hazard quantification purposes numerous simulations originating from varying the most important input parameters (e.g. wind field, emission rates, etc.) in their range of uncertainty should be carried out. The whole process of gas dispersion modelling is time consuming, since it starts with the assessment of the wind field with an ad-hoc meteorological model, proceeds with the actual gas dispersion simulation and concludes with the post-processing stage. In order to simplify the whole workflow with the final aim to manage numerous simultaneous simulations for hazard assessment applications, we created APVGDM (Automatic Probabilistic Volcanic Gas Dispersion Modelling), a simulation tool made of a collection of Python scripts. APVGDM is interfaced with two dispersion models that can be selected by the user depending on the application of interest: a dilute (DISGAS) and a dense gas (TWODEE) dispersion model. The post-processing script is capable of building Empirical Cumulative Distribution Functions (ECDF) of the gas concentrations combining the outputs of multiple simulations; the ECDF can be interrogated by the user to produce outputs at the desired exceedance probability. Here we present APVGDM and some application examples showing the wide range of options that the tool offers.

How to cite: Dioguardi, F., Massaro, S., Chiodini, G., Costa, A., Folch, A., Macedonio, G., Sandri, L., and Selva, J.: A new simulation tool for automatic dilute and dense gas dispersion modelling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9606, https://doi.org/10.5194/egusphere-egu21-9606, 2021.

Volcanic eruption is one of the main natural sources of atmospheric particles. In particular, evidence of New Particle Formation (NPF) from volcanic emission is reported in previous studies (Boulon et al., 2011; Sahyoun et al., 2019), which also suggests an essential role of sulfuric acid in this process. In addition, Rose et al. (2019) highlighted a significant contribution of the particles formed in the volcanic plume of the piton de la Fournaise to the budget of potential CCN at the Maïdo observatory, located ~40 km from the vent of the volcano. Therefore, it is predicted that the number and size of the cloud droplets, cloud growing and precipitation processes might be affected by the frequency of occurrence and characteristics of volcanically induced NPF in both local and regional scales, because volcanic plumes can extend far from the vent and even lower heights under the influence of the wind field and atmospheric dispersion. 

Following the study of Planche et al. (2020), the effect of using the New Parameterization of Nucleation (NPN) derived from the measurements performed in the passive volcanic emission plume of Etna (37.748˚ N, 14.99˚ E; Italy) (Sahyoun et al., 2019) in the WRF-Chem model (Weather Research and Forecasting Model coupled with Chemistry) is assessed, with a specific focus on the cluster formation rate and particle number concentration including CCN. In particular, results obtained with the NPN are compared to the predictions obtained with the default model settings, and further with observations.

In the next step, the resulting aerosol fields will be used to further evaluate the influence of the newly formed and grown particles on cloud formation and properties in a 3D cloud-scale model using a detailed microphysics scheme (DESCAM; Flossmann and Wobrock, 2010; Planche et al. 2010; 2014) . 

How to cite: Arghavani, S., Rose, C., Banson, S., Planche, C., and Sellegri, K.: The Effect of using a New Parameterization of Nucleation in the WRF-Chem model on the Cluster Formation Rate and Particle Number Concentration in a Passive Volcanic Plume, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12058, https://doi.org/10.5194/egusphere-egu21-12058, 2021.

Fumarolic gas composition and temperature record deep processes that generate and transfer heat and mass towards the surface.  These processes are a result of the emplacement, degassing and cooling of magma and the overturning of the above hydrothermal system.  A reasonable expectation, and too often an unproved assumption, is that fumarole temperatures and the deep heat sources vary on similar timescales.  Yet signals from deep and shallow processes have vastly different temporal variations.  This indicates that signals arising from deep activity may be masked or modified by intervening hydrothermal processes, such as fluid-groundrock reactions in which secondary minerals play a major role.  Clearly, this complicates the interpretation of the signals such as the joint variation of fumarole vent temperature and geochemical ratios in terms of what is occurring at depth.  So what do the differences between the timescales governing deep and shallow processes tell us about the intervening transport mechanisms?

At the volcanic dome of La Soufrière de Guadeloupe, the Observatoire Volcanologique et Sismologique de la Guadeloupe has performed weekly-to-monthly in-situ vent gas sampling over many years.  These analyses reliably track several geochemical species ratios over time, which provide important information about the evolution of deep processes.  Vent temperature is measured as part of the in-situ sampling, giving a long time series of these measurements.  Here, we look to exploit the temporal variations in these data to establish the common processes, and also to determine why these signals differ.  By fitting sinusoids to the gas-ratio time series we find that several of the deep signals are strongly sinusoidal.  For example, the He/CH₄ and CO₂/CH₄ ratios, which involve conservative components and mark the injection of deep and hot magmatic fluids, oscillate on a timescale close to 3 years. We also analyse the frequency content of the temperature measurements since 2011 and find that such long signals are not seen.  This may be due to internal buffering by the hydrothermal system, but other external forcings are also present.  From these data we build up a more informed model of the heat-and-mass supply chain from depth to the surface.  This will potentially allow us to predict future unrest (e.g. thermal crises, seismic swarms), and distinguish between sources of unrest.

How to cite: Jessop, D., Moretti, R., Moune, S., and Robert, V.: Trade-offs between deep (magmatic) and shallow (hydrological) forcings on volcanic unrest at La Soufrière de Guadeloupe (Lesser Antilles), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8761, https://doi.org/10.5194/egusphere-egu21-8761, 2021.

Mount Etna (Italy) is the most high-impact volcanoes on Mediterranean scale mainly due to its eruptive activity and continuous passive degassing, and the inherent large amount of effluents released into the atmosphere. Mount Etna’s emission mainly originate from the summit craters at an altitude of about 3300 m, feeding frequently volcanic gases and aerosols into the free troposphere. Consequently, their effects on the atmosphere and regional climate system span over relatively long spatiotemporal scales.

In order to better understand the role that Mount Etna’s emissions play on the atmospheric composition and radiative balance in the Mediterranean area, multidisciplinary and multi-scale studies have been carried out since a few years within the different phases of the EtnaPlumeLab (EPL) research cluster. A part of the EPL effort is based on dedicated field campaigns, that aim at the characterization of volcanic sources emissions and nears-source plume dispersion and evolution.

In this work, we investigate the three-dimensional (3D) distribution of the volcanic aerosols from Mount Etna observed during the most recent EPL field campaign, named EPL-REFLECT (near-source estimations of Radiative EFfects of voLcanic aErosols for Climate and air quality sTudies) carried out within the Transnational Access component of the EUROVOLC project. This field campaign completes the previous EPL-RADIO (Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns) campaign. Here we discuss the observations of a multiparametric LiDAR system AMPLE. The LiDAR is equipped with a fast scanning, double depolarization (at 532 and 355 nm) and high repetition laser source (1kHz), which is an essential point to derive time series of 3D-resolved aerosol properties near Etna. During the 8-12^th of July 2019 period, day/night LiDAR measurements were performed by AMPLE from the astronomical observatory of the INAF-Catania in the location of Serra la Nave at 1725 m a.s.l., pointing towards the summit of Mount Etna. In particular, on the July 11^th, the scan was performed with time-steps of 15 minutes at different angles from the top of the volcano to the zenith. These acquisitions highlight the atmospheric evolution of two layers related to two distinct degassing episodes. A comparative analysis with wind speed information and the integration with complementary photometric ground measurements have further constrained this 3D characterization and the evolution of these layers, including those outside the LiDAR field of view.

How to cite: Sannino, A., Boselli, A., Leto, G., Scollo, S., Sanchez, R. Z., Amoruso, S., Spampinato, L., and Sellitto, P.: Three-dimensional distribution of Mount Etna’s emissions during the EPL-REFLECT campaign in July 2019, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10664, https://doi.org/10.5194/egusphere-egu21-10664, 2021.

Volcanic eruptions are events that can eject several tons of material into the atmosphere. Among these emissions, sulfur dioxide is the main sulfurous volcanic gas. It can form sulfate aerosols that are harmful to health or, being highly soluble, it can condense in water particles and form acid rain. Thus, volcanic eruptions can have an environmental impact on a regional scale.

The Mediterranean region is very interesting from this point of view because it is a densely populated region with a strong anthropogenic activity, therefore polluted, in which Mount Etna is also located. Mount Etna is the largest passive SO₂ emitter in Europe, but it can also sporadically produce strong eruptive events. It is then likely that the additional input of sulfur compounds into the atmosphere by volcanic emissions may have effects on the regional atmospheric sulfur composition.

We are particularly investigating the eruption of Mount Etna on December 24, 2018 [Corradini et al, 2020]. This eruption took place along a 2 km long breach on the side of the volcano, thus at a lower altitude than its main crater. About 100 kt of SO₂ and 35 kt of ash were released in total, between December 24 and 30. With the exception of the 24th, the quantities of ash were always lower than the SO_2.

The availability of the TROPOMI SO₂column estimates, at fine spatial resolution (7 km x 3.5 km at nadir) and associated averaging kernels, during this eruptive period made it also an excellent case study. It allows us to follow the evolution of SO₂ in the volcanic plume over several days.

Using the CNRM MOCAGE chemistry-transport model (CTM), we aim to quantify the impact of this volcanic eruption on atmospheric composition, sulfur deposition and air quality at the regional scale. The comparison of the model with the TROPOMI observation data allows us to assess the ability of the model to properly represent the plume. In spite of a particular meteorological situation, leading to a complex plume transport, MOCAGE shows a good agreement with TROPOMI observations. Thus, from the MOCAGE simulation, we can evaluate the impact of the eruption on the regional concentrations of SO₂ and sulfate aerosols, but also analyse the quantities of dry and wet deposition, and compare it to surface measurement stations.

How to cite: Lamotte, C., Guth, J., Marécal, V., Salerno, G., Theys, N., Brenot, H., Corradini, S., and Bacles, M.: Impact of the Christmas 2018 Mount Etna Eruption on the Regional Air Quality, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2167, https://doi.org/10.5194/egusphere-egu21-2167, 2021.

The EPL-RADIO (Etna Plume Lab - Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns) and EPL-REFLECT (near-source estimations of Radiative EFfects of voLcanic aErosols for Climate and air quality sTudies) projects, funded by the EC Horizon2020 ENVRIplus and EUROVOLC Transnational Access to European Observatories programmes, aim to advance the understanding of Mount Etna as a persistent source of atmospheric aerosols and its impact on the  radiative budget at proximal to regional spatial scales. Research was tackled by carrying out three campaigns in the summers of 2016, 2017 and 2019 to observe the volcanic plume produced by passive degassing, proximally and distally from the summit craters, using a wide array of remote sensing and in situ instruments. Diverse data are collected to explore the link of inner degassing mechanisms to the characterisation of near-source aerosol physicochemical properties and subsequent impacts on the atmosphere, environment and regional climate system.

The results of the three campaigns have shown that the volcanic plume emitted by Mount Etna often mixes with aerosols of different origins generating a complex layered pattern. Frequent mineral dust transport events were observed by both LiDAR observations located at Serra La Nave (~7 km south-west from summit craters) and at a medium-term radiometric station, equipped with a Multi-Filter Rotating Shadowband Radiometer (MFRSR), and other instruments located at Milo (~10 km eastwards from the craters). LiDAR observations also allowed to study the coexistence of volcanic aerosols and biomass burning particles from local to more distal smoke plumes transports (like for the well-documented large fires from continental southern Italy in July 2017). In situ filter and optical particles counter measurements confirmed the presence of dust at Milo. The interaction/mixing among volcanic, wildfire, and dust aerosols occurs in an overall dynamical regime which appears to be dominated by sea breeze, which is strengthened by the presence of the dark volcanic lava flanks. Photolysis process also possibly play a role in determining the daily evolution of the aerosol plume.

The sources of these different aerosol types are studied in detail using Lagrangian trajectories and meteorological data. Off-line radiative transfer calculations, using EPL-RADIO/REFLECT observations as input data, are used to estimate the relative radiative impact of the different aerosol types with respect to the background passive-degassing aerosols coming from Mount Etna.

How to cite: Sellitto, P., Salerno, G., Scollo, S., di Sarra, A. G., Boselli, A., Leto, G., Zanmar Sanchez, R., Sannino, A., Caltabiano, T., Giammanco, S., Monteleone, F., Pace, G., Giorio, C., Crumeyrolle, S., and Legras, B.: The observation of different aerosols types in the Mount Etna environment and their relative and mutual impacts on local radiative balance, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12380, https://doi.org/10.5194/egusphere-egu21-12380, 2021.