EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

A case study of two simultaneous extreme aerosol events in the Mediterranean: The Mount Etna series of eruptions and major Saharan dust event in February 2021

Pasquale Sellitto1,2, Giuseppe Salerno2, Stefano Corradini3, Irène Xueref-Remy4, Aurélie Riandet4, Clémence Bellon4, Sergey Khaykin5, Gerard Ancellet5, Simone Lilli6, Ellsworth J. Welton7, Antonella Boselli6, Alessia Sannino8, Juan Cuesta1, Henda Guermazi1, Maxim Eremenko1, Luca Merucci3, Dario Stelitano3, Lorenzo Guerrieri3, and Bernard Legras9
Pasquale Sellitto et al.
  • 1Univ. Paris Est Créteil and Université de Paris, CNRS, Laboratoire Interuniversitaire des Systèmes Atmosphériques, Institut Pierre Simon Laplace, Créteil, France
  • 2Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Catania, Italy
  • 3Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy
  • 4Aix Marseille Univ, Avignon Université, CNRS, IRD, Institut Méditerranéen de Biodiversité et d'Écologie marine et continentale (IMBE), Marseille, France
  • 5Laboratoire Atmosphères, Milieux, Observations Spatiales, UMR CNRS 8190, IPSL, Sorbonne Univ./UVSQ, Guyancourt, France
  • 6Consiglio Nazionale delle Ricerche – Istituto di Metodologie per l’Analisi Ambientale (CNR-IMAA), C. da S. Loja, Tito Scalo, Potenza, Italy
  • 7NASA Goddard Space Flight Center, Code 612, Greenbelt, MD 20771, USA
  • 8Dipartimento di Fisica “Ettore Pancini”, Università Federico II di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy)
  • 9Laboratoire de Météorologie Dynamique, UMR CNRS 8539, École Normale Supérieure, PSL Research University, École Polytechnique, Sorbonne Universités, École des Ponts PARISTECH, Institut Pierre Simon Laplace, Paris, France

During the extended activity of Mount Etna volcano in February-April 2021, three distinct paroxysmal events took place from 21 to 26 February, which were associated with a very uncommon transport of the injected upper-tropospheric plumes towards the north. A major Saharan dust outbreak to central Europe occurred in the same period. Using a synergy of observations and modelling, we characterise the three-dimensional dispersion of these volcanic plumes and we disentangle their optical and radiative signature from the simultaneous Saharan dust transport. In the region of interest for our study, the volcanic and the dust plumes remain completely vertically-separated, thus facilitating the detection and spatiotemporal characterisation of the dispersion, properties and radiative impacts of these two different aerosol plumes, using vertically-resolved observations. With a satellite-based source inversion, we estimate the emitted sulphur dioxide (SO2) mass at an integrated value of 55 kt and plumes injections at up to 12 km altitudes, which qualifies this series as an extreme event for Mount Etna activity spectrum. Then, we combine Lagrangian dispersion modelling, initialised with measured temporally-resolved SO2 emission fluxes and altitudes, with satellite observations to track the dispersion of the individual volcanic and dust plumes. The general transport towards the north allowed the height-resolved downwind monitoring of the volcanic and dust plumes at selected observatories in France, Italy and Israel, using LiDARs and photometric aerosol observations. A specific effort has been dedicated to the characterisation of the volcanic aerosol plumes. Volcanic-specific aerosol optical depths in the visible spectral range ranging from about 0.004 to 0.03 and local daily average shortwave radiative forcing ranging from about -0.2 to -1.2 W/m2 (at the top of atmosphere) and from about -0.2 to -3.0 W/m2 (at the surface) are found. The composition (possible presence of ash), aerosol optical depth and radiative forcing of the volcanic plumes has a large inter- and intra-plume variability and thus depend strongly on the position of the sampled section of the plumes. The dust optical depth and radiative impact largely outweigh volcanic aerosols when the two plumes are co-located, for this event. This case study points at the complexity of the Mediterranean aerosol environment and pave the way to future studies at longer timescales, exploiting the available observational and modelling capabilities and their synergies.

How to cite: Sellitto, P., Salerno, G., Corradini, S., Xueref-Remy, I., Riandet, A., Bellon, C., Khaykin, S., Ancellet, G., Lilli, S., Welton, E. J., Boselli, A., Sannino, A., Cuesta, J., Guermazi, H., Eremenko, M., Merucci, L., Stelitano, D., Guerrieri, L., and Legras, B.: A case study of two simultaneous extreme aerosol events in the Mediterranean: The Mount Etna series of eruptions and major Saharan dust event in February 2021, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8281,, 2023.

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