From March 16 to 18, 2022, East Antarctica experienced an unprecedented "heat wave" with temperatures on the high Antarctic Plateau 30 to 45°C above the March seasonal average. At this time of year, Antarctica normally enters winter, but these extreme temperatures rivaled the maximum temperatures observed in summer. During and shortly after the event, relatively heavy snowfalls were observed on the Antarctic shelf, heavy precipitation and (modest) melting were observed along the coastal regions of Wilkes Land and Adelie Land. Finally, part of the small "Conger" ice shelf collapsed, suggesting a causal relationship. Given the magnitude of the event, with temperatures exceeding previous records over a large part of East Antarctica, this warm spell has attracted the interest of the scientific community. Attention was on the existence of a very long and intense atmospheric river, which made landfall at the coast of Wilkes Land on March 14 and then continued to bring huge amounts of moisture and heat to the Antarctic interior. Satellite images and climate reanalysis outputs are unequivocal : an intense atmospheric blocking prevented the circulation of intense extratropical lows, which usually circle around the continent. This time, a large amount of moisture from the subtropics was transported in record time to the continent where the condensation of air masses, by releasing latent heat, amplified the heating of air masses. Everything was present to produce an "explosive" atmospheric river, and the records are there to prove it.

Updated on 22 août 2022