# Small-scale volcanic aerosols variability, processes and direct radiative impact at Mount Etna during the EPL-RADIO/REFLECT campaigns

Pasquale Sellitto, Giuseppe Salerno, Alessandro La Spina, Tommaso

Caltabiano, Simona Scollo, Antonella Boselli, Giuseppe Leto, Ricardo Zanmar

Sanchez, Alessia Sannino, Suzanne Crumeyrolle, et al.

► To cite this version:

Pasquale Sellitto, Giuseppe Salerno, Alessandro La Spina, Tommaso Caltabiano, Simona Scollo, et al. Small-scale volcanic aerosols variability, processes and direct radiative impact at Mount Etna during the EPL-RADIO/REFLECT campaigns. EGU General Assembly 2020, May 2020, Vienne, Austria. 10.5194/egusphere-egu2020-8337. insu-02891851

HAL Id: insu-02891851

https://insu.hal.science/insu-02891851

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# Small-scale volcanic aerosols variability, processes and direct radiative impact at Mount Etna during the EPL-RADIO/REFLECT campaigns

Pasquale Sellitto<fnref n="1" />, Giuseppe Salerno<fnref n="2" />, Alessandro La Spina<fnref n="2" />, Tommaso Caltabiano<fnref n="2" />, Simona Scollo<fnref n="2" />, Antonella Boselli<fnref n="3" />, Giuseppe Leto<fnref n="4" />, Ricardo Zanmar Sanchez<fnref n="4" />, Alessia Sannino<fnref n="5" />, Suzanne Crumeyrolle<fnref n="6" />, Benjamin Hanoune<fnref n="7" />, Chiara Giorio<fnref n="8" />, Salvatore Giammanco<fnref n="2" />, Tjarda Roberts<fnref n="9" />, Alcide di Sarra<fnref n="10" />, Bernard Legras<fnref n="11" />, and Pierre Briole<fnref n="12" />

The aerosol properties of Mount Etna's passive degassing plume and its short-term processes and radiative impact were studied in detail during the EPL-RADIO/REFLECT campaigns (summer 2016, 17 and 19), using a synergistic combination of remote-sensing and in situ observations, and radiative transfer modelling. Summit observations show extremely high particulate matter concentrations, with no evidence of secondary sulphate aerosols (SA) formation. Marked indications of secondary SA formation, i.e. by the conversion of volcanic SO2 emissions, are found at larger spatial scales (<20 km downwind craters). Using portable photometers, the first mapping of small-scale spatial variability of the average size and burden of volcanic aerosols is obtained, as well as different longitudinal, perpendicular and vertical sections. A substantial variability of the plume properties is found at these spatial scales, revealing that processes (e.g. new particle formation and coarse aerosols sedimentation) are at play, which are not represented with current regional scale modelling and satellite observations. Vertical structures of typical passive degassing plumes are also obtained using observations from a fixed LiDAR station constrained with quasi-simultaneous photometric observations. These observations are used as input to radiative

<footnote n="1">¹Laboratoire Interuniversitaire des Systèmes Atmosphériques, Université Paris-Est Créteil, France (pasquale.sellitto@lisa.pec.fr)</footnote>

<footnote n="2">²Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy</footnote>

<footnote n="3">³Consiglio Nazionale delle Ricerche, Istituto di Metodologie per l'Analisi Ambientale, Tito Scalo (Potenza), Italy</footnote>

<footnote n="4">⁴Istituto Nazionale di AstroFisica. INAF Osservatorio Astrofisico di Catania, Catania, Italy</footnote>

<footnote n="5">⁵Dipartimento di Fisica, Università degli Studi di Napoli Federico II, Naples, Italy</footnote>

<footnote n="6">⁶Université de Lille, UMR CNRS 8518 - LOA - Laboratoire d'Optique Atmosphérique, Lille, France</footnote>

<footnote n="7">⁷Université de Lille, UMR CNRS 8522 - PC2A - Physico-Chimie des Processus de Combustion et de l'Atmosphère, Lille, France</footnote>

<footnote n="8">⁸Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Padua, Italy</footnote>

<footnote n="9">⁹Laboratoire de Physique et Chimie de l'Environnement et de l'Espace - LPCEE, UMR 7328, CNRS-Université d'Orléans, Orléans, France</footnote>

<footnote n="10">¹⁰ENEA, Laboratory for Observations and Analyses of the Earth and Climate (SSPT-PROTER-OAC), Rome, Italy</footnote>

<footnote n="11">¹¹Laboratoire de Météorologie Dynamique - LMD, UMR CNRS 8539, École Normale Supérieure, Institut Pierre Simon Laplace, Paris, France</footnote>

<footnote n="12">¹²Laboratoire de Géologie, École Normale Supérieure, Paris, France</footnote>
transfer calculations, to obtain the shortwave top of the atmosphere (TOA) and surface radiative effects of the plume. Moreover, the radiative impact of Mount Etna's emissions is studied using a medium-term time series (a few months during summer 2019) of coupled aerosol optical properties and surface radiative flux at a fixed station on Etna's eastern flank. These are the first available estimations in the literature of the radiative impact of a passive degassing volcanic plume and are here critically discussed. Cases of co-existent volcanic aerosol layers and aerosols from other sources (Saharan dust transport events, wildfire from South Italy and marine aerosols) are also presented and discussed.