Last updated October 10, 2018

Non‐annular atmospheric circulation change induced by stratospheric ozone depletion and its role in the recent increase of Antarctic sea ice extent

  • Demonstrates that the annual mean extent of Antarctic sea ice has increased at a statistically significant rate of 0.97% dec−1 since the late 1970s, based on a new analysis of passive microwave satellite data
  • Finds that the largest increase has been in autumn when there has been a dipole of significant positive and negative trends in the Ross and Amundsen-Bellingshausen Seas respectively
  • Finds that the autumn increase in the Ross Sea sector is primarily a result of stronger cyclonic atmospheric flow over the Amundsen Sea
  • Model experiments suggest that the trend towards stronger cyclonic circulation is mainly a result of stratospheric ozone depletion, which has strengthened autumn wind speeds around the continent, deepening the Amundsen Sea Low through flow separation around the high coastal orography
  • Finds, however, that statistics derived from a climate model control run suggest that the observed sea ice increase might still be within the range of natural climate variability