The Extraordinary March 2022 East Antarctica 'Heat' Wave. Part II: Impacts on the Antarctic Ice Sheet
This record-shattering event saw numerous monthly temperature records being broken including a new all-time temperature record of -9.4° C on March 18 at Concordia Station despite March typically being a transition month to the Antarctic coreless winter. The driver for these temperature extremes was an intense atmospheric river advecting subtropical/mid-latitude heat and moisture deep into the Antarctic interior. The scope of the temperature records spurred a large, diverse collaborative effort to study the heatwave’s meteorological drivers, impacts, and historical climate context which included 54 scientists from 14 countries.
Antarctic cryosphere is highly sensitive to meteorological extremes originating from the mid-latitudes and sub-tropics. Despite the large positive temperature anomalies driven by strong downward longwave radiation, this event led to huge amounts of snowfall across the Antarctic interior desert. The isotopes in this snow of warm airmass origin will likely be detectable in future ice cores and potentially distort past climate reconstructions. Even measurements of space activity were affected. Also, the swells generated from this storm helped trigger the final collapse of an already critically unstable Conger Ice Shelf while further degrading sea-ice coverage. Publishing this study, which covered so many different aspects across different scientific disciplines, was only possible thanks to a massive international collaboration that facilitated rapid access to various datasets. This collaboration across nations continues, through ongoing research into Antarctic extreme weather and how it impacts sea level rise and demonstrates the value of peaceful international collaboration that is the rule in Antarctica.
In Part II, we continue our large, collaborative study by analyzing the widespread and diverse impacts driven by the AR landfall. These impacts included widespread rain and surface melt, which was recorded along coastal areas, but this was outweighed by widespread, high snowfall accumulations, resulting in a largely positive surface mass balance contribution to the East Antarctic region. An analysis of the surface energy budget indicated that widespread downward longwave radiation anomalies caused by large cloud-liquid water contents, along with some scattered solar radiation, produced intense surface warming. Isotope measurements of the moisture were highly elevated, likely imprinting a strong signal for past climate reconstructions. The AR event attenuated cosmic ray measurements at Concordia, something previously never observed. Finally, an extratropical cyclone west of the AR landfall likely triggered the final collapse of the critically unstable Conger Ice Shelf while further reducing an already record low sea ice.