An extreme high temperature event in coastal East Antarctica associated with an atmospheric river and record summer downslope winds

• Published in: Geophysical Research Letters
• Main Authors: Turner, John, Lu, Hua, King, John C., Carpentier, Scott, Lazzara, Matthew, Phillips, Tony, Wille, Jonathan
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2022
• Subjects: East Antarctica; Amery; Amery Ice Shelf; Antarc*; Antarctica; Ice Shelf
• Online Access: http://nora.nerc.ac.uk/id/eprint/531893/; https://nora.nerc.ac.uk/id/eprint/531893/1/Geophysical%20Research%20Letters%20-%202022%20-%20Turner%20-%20An%20Extreme%20High%20Temperature%20Event%20in%20Coastal%20East%20Antarctica%20Associated%20With.pdf; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL097108

High surface temperatures are important in Antarctica because of their role in ice melt and sea level rise. We investigate a high temperature event in December 1989 that gave record temperatures in coastal East Antarctica between 60º and 100º E. The high temperatures were associated with a pool of warm lower tropospheric air with December temperature anomalies of >14º C that developed in two stages over the Amery Ice Shelf. Firstly, there was near-record poleward warm advection within an atmospheric river. Secondly, synoptically-driven downslope flow from the interior reached unprecedented December strength over a large area, leading to strong descent and further warming in the coastal region. The coastal easterly winds were unusually deep and strong, and the warm pool was advected westwards, giving a short period of high temperatures at coastal locations, including a surface temperature of 9.3ºC at Mawson, the second highest in its 66-year record.