Pause in cooling Antarctic summers due to earlier stratospheric final warming in recent decades

• Main Authors: Choi, H., Kwon, H., Kim, S., Kim, B.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Antarctic; Antarctic Peninsula; Austral; Ross Sea; The Antarctic; Antarc*; Antarctica; Sea ice
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016131

We explore the connection between the interannual and decadal variability in the timing of stratospheric final warming (SFW) occurrences and the Antarctic surface climate during austral summertime based on the reanalysis data and in-situ observation. The development of positive surface pressure anomalies over Antarctica associated with an earlier occurrence of SFW, via stratosphere-troposphere downward coupling, are observed during December-January, which leads to a colder surface in the Antarctic Peninsula (AP), but a warmer surface in the rest of Antarctica. On the contrary, the surface pressure and surface temperature anomalies associated with the later occurrence of SFW show almost opposite or weaker behaviors. A trend towards earlier SFW occurrences since 1999 might explain the cease of the cooling trend or slight reversal into the warming trend of the interior Antarctic surface through strengthening anti-cyclonic surface circulation in recent decades. The resulting surface temperature responses can make traces in sea-ice concentration trends over high-latitude SH, showing the dipole anomalies with an increase of sea ice over the AP region and a decrease of sea ice over the northern Ross Sea.