Synoptic moisture pathways associated to virga and precipitation over coastal Adélie Land.

The Antarctic ice sheet store large amount of water under solid form over the continent. As climate change is going on, this reservoir already started to contribute to global sea level rise, and will contribute more in the future. With precipitation being the main input to the ice sheet, it is essential to understand the synoptic conditions determining moisture pathways that are being transported towards Antarctica. Because of katabatic flow, it was evidenced that coastal regions experiences low-level sublimation, reducing the amount of precipitation reaching the ground. This issue is not well represented in models, which can lead to wrong estimations of the surface mass balance. Using ground-based radar measurements deployed during the APRES3 campaign and the outcomes of the atmospheric reanalysis model LAGRANTO, it was possible to identify, and characterize the main synoptic conditions associated to virga and precipitation event at Dumont d’Urville station, Adélie Land, coastal Antarctica. It was found that precipitation there are associated to warm front, and that virga events proceed and succeed precipitation events. On their way to precipitate above Dumont d’Urville, virga experience a lifting much earlier in time, compared to precipitation. The trajectories, as well as localization of maximum lifting and moisture source of the air parcels show differences between virga, and precipitation events.