Variability of Antarctic Sea Ice: and Changes in Carbon Dioxide

• Published in: Science
• Main Authors: Zwally, H. Jay, Parkinson, C. L., Comiso, J. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1983
• Subjects: Antarctic; Weddell; Weddell Sea; Antarc*; Sea ice
• Online Access: http://dx.doi.org/10.1126/science.220.4601.1005; https://www.science.org/doi/pdf/10.1126/science.220.4601.1005

A definitive long-term decrease in the extent of antarctic sea ice is not detectable from 9 years (1973 to 1981) of year-round satellite observations and limited prior data. Regional interannual variability is large, with sea ice decreasing in some regions while increasing in others. A significant decrease in overall ice extent during the mid-1970's, previously suggested to reflect warming induced by carbon dioxide, has not been maintained. In particular, the extent of ice in the Weddell Sea region has rebounded after a large decrease concurrent with a major oceanographic anomaly, the Weddell polynya. Over the 9 years, the trends are nearly the same in all seasons, but for periods of 3 to 5 years, greater winter ice maxima are associated with lesser summer ice minima. The decrease of the mid-1970's was preceded by an increase in ice extent from 1966 to 1972, further indicating the presence of cyclical components of variation that obscure any long-term trends that might be caused by a warming induced by carbon dioxide.