Signature of the stratosphere–troposphere coupling on recent record-breaking Antarctic sea-ice anomalies

In February 2023, the sea-ice extent around
Antarctica dropped to 1:79 106 km2, setting a satellite-era
record low for the second straight year. Recent records stress
the need for further research into the factors behind recordbreaking
Antarctic sea-ice anomalies. By influencing the circumpolar
westerly winds, the stratospheric polar vortex has
played a major role in the Antarctic surface climate in recent
decades. However, the footprint of the polar vortex variability
in the year-to-year changes in the Antarctic sea-ice
cover remains obscured. Here, we use satellite retrievals and
reanalysis data to study the response of the sea-ice extent
around Antarctica to changes in the polar vortex strength.
We focus on the last 2 decades that saw sharp changes in
the stratospheric zonal flow, the tropospheric westerly winds
and the sea-ice cover (the latter climbed to record highs in
2013 and 2014 before dropping to record lows in 2017, 2022
and 2023). Our results suggest that this unprecedented interannual
variability is noticeably influenced by the polar vortex
dynamics. The signature of the stratosphere–troposphere
coupling is apparent in recent records (highs and lows) in the
sea-ice extent around Antarctica.