We analyze the 2019 sudden stratospheric warming event that occurred in the Southern Hemisphere through its impact on the Antarctic ozone. Using temperature, ozone, and nitric acid data from the Infrared Atmospheric Sounding Interferometer (IASI), our results show that the average increase in stratospheric temperature reached a maximum of 34.4° on 20 September in the [60–90]°S latitude range when compared to the past 3 years. Dynamical parameters suggest a locally reversed and weakened zonal winds and a shift in the location of the polar jet vortex. This led to air masses mixing, to a reduced polar stratospheric clouds formation detected at a ground station, and as such to lower ozone and nitric acid depletion. 2019 total ozone columns for the months of September, October, and November were on average higher by 29%, 28%, and 26%, respectively, when compared to the 11‐year average of the same months.

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 has 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 532 nm Rayleigh/Mie/Raman ground‐based lidar of the French Antarctic station Dumont d’Urville (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 Ozone Monitoring Instrument, Ozone Mapping and Profiler Suite, and Microwave Limb Sounder. 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 over several months.

We analyze the long‐range transport to high latitudes of a smoke particle filament originating from the extra‐tropics plume after the Australian wildfires colloquially known as ‘Black Saturday’ on February 7^th 2009 and report the first Antarctic stratospheric lidar characterization of such aerosols. Using a high‐resolution transport/microphysical model, we show that the monitoring cloud/aerosol lidar instrument operating at the French Antarctic station Dumont d’Urville (DDU‐66°S‐140°E) recorded a signature of those aerosols. The 532 nm scattering ratio of this filament is comparable to typical moderate stratospheric volcanic plume, with values between 1.4 and 1.6 on the 1^st and 3^rd days of March above DDU station at around the 14 and 16 km altitude respectively. A dedicated model is described and its ability to track down fine optical signatures is validated against Antarctic lidar elastic aerosol and DIAL ozone measurements. Using one month of tropical CALIOP data to support a relatively simple microphysical scheme, we report modeled aerosol presence above DDU station after advection of the aerosol size distribution. In situ measurements also report associated positive ozone anomaly. This case study provides evidence that biomass burning events injecting significant amounts of material up to stratospheric altitudes can be transported towards high latitudes. We highlight a potential imprint of smoke particles on the Antarctic atmosphere over larger time scales. Any underestimation of the global impact of such deep particle transport will lead to uncertainties in modeling the associated chemical or radiative effects, especially in polar regions where specific microphysical and chemical processes take place.

Polar Stratospheric Clouds (PSCs) play a primary role in polar stratospheric ozone depletion processes. Aside from recent improvements in both spaceborne monitoring as well as investigations on microphysics and modeling, there are still caveats on building a comprehensive picture of the PSC particle population, especially considering the fine optical signatures of some particles. In that regard, groundbased instruments provide fine and long term reference measurements that complement the global spaceborne coverage.Operated at the French antarctic station Dumont d’Urville (DDU) in the frame of the international Network for the Detection of Atmospheric Composition Change (NDACC), the Rayleigh/Mie/Raman lidar provides over the years a solid dataset to feed both process and classification studies, by monitoring cloud and aerosol occurrences in the upper troposphere and lower stratosphere. Located on antarctic shore (66°S - 140°E), the station has a privileged access to polar vortex dynamics. Measurements are weather-dependent with a yearly average of 130 nights of monitoring. Expected PSC formation temperatures are used to evaluate the whole PSC season occurrence statistics.We hereby present a consolidated dataset from 10 years of lidar measurements using the 532nm backscatter ratio, the aerosol depolarisation and local atmospheric conditions to help in building an aerosol/cloud classification. Overall, the DDU PSC pattern is very consistent with expected typical temperature controlled thresholds. Supercooled Ternary Solution (STS) particles are the most observed particle type, closely followed by Nitric Acid Trihydrate (NAT). ICE clouds are more rarely observed. The measurements also feature significant and detailed signatures of various aerosols events having reached the polar antarctic stratosphere, like the Calbuco eruption (2015) or the 2 australian wildfires episodes (2009 and 2019). We aim at refining the identification of those aerosols to include their impact in the scope of the scientific questions studied at DDU.