Processes and climate impacts of recent extreme volcanic eruptions and pyro-convective clouds
Pasquale Sellitto (LISA-IPSL)
Pasquale Sellitto travaille au Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA-IPSL)
Extreme volcanic eruptions and pyro-convective clouds events can impact the stratospheric composition and the climate system. In this seminar, I will discuss two major stratospheric-perturbing events occurred in the last few years: Australian fires 2019-2020 and the Hunga Tonga volcanic eruption 2022.
As a consequence of extreme heat and drought, record-breaking wildfires developed and ravaged south-eastern Australia during the fire season 2019–2020 and produced extreme pyro-convective activity on January 2020; this is considered the largest fire-induced perturbation to the stratosphere on records [Khaykin et al. 2020].
The Hunga Tonga volcano violently erupted on January 15th, 2022, producing the largest volcanic perturbation to the stratospheric composition – with aerosol and water vapour perturbations reaching >50 km altitudes – since the Pinatubo eruption in 1991. Through their large-scale and long-lived stratospheric perturbation, these events had large impacts on the radiative balance [Sellitto et al., 2022a; Sellitto et al., 2022b; Sellitto et al., 2022c].
Here we discuss the radiative forcing of these events in terms of top-of-the-atmosphere and surface imbalances and their in-plume localized heating/cooling, through a hybrid observations-modelling method. The fundamental differences of fire and volcanic perturbations, due to fundamentally different emissions and evolution processes, leading to different aerosol optical properties, as well as the concurrent radiative impacts of co-emitted species like water vapour, are also discussed.
The role of the in-plume absorption within Australian fires smoke plume to the generation of ascending smoke vortices in the stratosphere is also presented.
Pour en savoir plus
- Khaykin, S., Legras, B., Bucci, S., Sellitto, P. et al.: The 2019/20 Australian wildfires generated a persistent smoke-charged vortex rising up to 35 km altitude. Nature Commun. Earth Environ. 1, 22 (2020). https://doi.org/10.1038/s43247-020-00022-5
- Sellitto, P., Belhadji, R., Kloss, C., and Legras, B.: Radiative impacts of the Australian bushfires 2019–2020 – Part 1: Large-scale radiative forcing, Atmos. Chem. Phys., 22, 9299–9311, https://doi.org/10.5194/acp-22-9299-2022, 2022.
- Sellitto, P., Belhadji, R., Cuesta, J., Podglajen, A., and Legras, B.: Radiative impacts of the Australian bushfires 2019–2020 – Part 2: Radiative heating and the formation of ascending smoke vortices, in preparation, 2022b.
- Sellitto, P., Podglajen, A., Belhadji, R., Boichu, M., Carboni , E., Cuesta, J., Duchamp, C., Kloss, C., Siddans, R., Begue , N., Blarel, L., Jegou, F., Khaykin, S., Renard, J.-B., Legras, B.: The unexpected radiative impact of the Hunga Tonga eruption of January 15th, 2022, Nature Commun. Earth Environ., in review (minor revisions), 2022c.
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