Australian Black Summer smoke observed by lidar at the French Antarctic station Dumont d’Urville

Florent Tencé (1) , Julien Jumelet (1) , Slimane Bekki (1) , Sergey Khaykin (1) , Alain Sarkissian (1) , Philippe Keckhut (1)

1 STRATO - LATMOS

In the follow-up of the Australian ”Black Summer” event that persisted from August 2019 to March 2020, we present the optical properties of the stratospheric aerosols injected into the atmosphere by these wildfires. The outbreak of pyrocumulonimbus (PyroCb) activity triggered between 2019/12/29 and 2020/01/04 have raised the stratospheric aerosol load of the Southern Hemisphere to unprecedented levels. Long-range transport brought some of the plumes down to the Antarctic region, where general circulation patterns kept them circling around the continent. The 532nm Rayleigh/Mie/Raman ground-based lidar of the French Antarctic station Dumont d’Urville (DDU, 66.6°S – 140°E) acquired unprecedented time series of these carbonaceous aerosols starting approximately 20 days after the injection and up to the most recent measurements in October 2019 where local radiosonde reported anomalous ozone depletion as compared to the decadal average. The lidar provides a first and unique time series at high vertical and temporal resolution, complemented by satellite measurements from OMI, OMPS and MLS. Aerosol backscatter ratio decreases from 1.9 to 1.2 between January and June 2020. Aerosol origin and persistence are characterized, as well as their optical properties and vertical distribution on several months.

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

Florent Tencé, Julien Jumelet, Slimane Bekki, Sergey Khaykin, Alain Sarkissian, et al.. Australian Black Summer smoke observed by lidar at the French Antarctic station Dumont d’Urville. Journal of Geophysical Research: Atmospheres, 2022, 127 (4), pp.e2021JD035349. ⟨10.1029/2021JD035349⟩. ⟨insu-03548361⟩