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Non‐annular atmospheric circulation change induced by stratospheric ozone depletion and its role in the recent increase of Antarctic sea ice extent
Author(s) -
Turner John,
Comiso Josefino C.,
Marshall Gareth J.,
LachlanCope Tom A.,
Bracegirdle Tom,
Maksym Ted,
Meredith Michael P.,
Wang Zhaomin,
Orr Andrew
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl037524
Subject(s) - climatology , sea ice , environmental science , orography , atmospheric circulation , ozone depletion , arctic ice pack , arctic sea ice decline , oceanography , cryosphere , atmospheric sciences , antarctic sea ice , geology , stratosphere , geography , meteorology , precipitation
Based on a new analysis of passive microwave satellite data, we demonstrate 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. 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. 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. However, 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.