Abstract
We have characterized the magnitude and spatial extent of observed regional and inter‐regional air temperature trends and warming extremes across Antarctica. Prior studies have used localized observational records to analyze air temperature trends across distinct geographical regions, leaving local and inter‐regional variations to be undetected. Using the high‐resolution temperature product AntAir ICE, air temperature trends and extreme warming events were identified across Antarctica for the period 2003–2021. Unsupervised clustering was applied to austral summer and annual mean air temperature trends to divide Antarctica into 12 regions exhibiting similarity in temperature trends. Our results show a significant annual mean cooling trend of ‒0.12 °C/Yr for the terrestrial Antarctic Peninsula, and an austral summer (annual) warming trend of +0.08 °C/Yr (+0.07 °C/Yr) in the Ross Sea region's Victoria Land and Transantarctic Mountains. The spatial extent of each of the 12 clusters' extreme air temperature events was mapped in austral summer revealing that West Antarctica has spatially confined events, while East Antarctica events are widespread. ERA5 data indicate that West Antarctica's extreme air temperature events are associated with consistent meridional atmospheric flows. Local to regional extreme warming events in East Antarctica are associated with inland high‐pressure systems, which enhance katabatic winds. Localized warming events around complex coastal geographies appear to be related to mesoscale wind systems such as foehn but require further investigation using mesoscale numerical weather models. This work highlights the necessity for ongoing and new monitoring in regions where critical ecological and physical thresholds are being surpassed.
In this study, we identify air temperature trends and extreme events across Antarctica for the period 2003–2021 using AntAir ICE, a new, state‐of‐the‐art satellite derived air temperature product. To achieve this, we divide Antarctica into 12 regions based on austral summer and annual mean air temperature trends. Our analysis confirms the recent, significant cooling over the Antarctic Peninsula that has been reported in other studies. Of interest, we identified significant warming in the Ross Sea Region, especially near coastal Victoria Land and the Transantarctic Mountains. Extreme air temperature events are also mapped for each region, and their relationship with regional weather patterns explored. West Antarctica experiences localized extreme temperatures due to the transport of warm moist air from further north while East Antarctica shows widespread warming driven by a large inland high‐pressure system leading to northward air flow from the interior toward the coastline.