New Perspectives on Observed and Simulated Antarctic Sea Ice Extent Trends Using Optimal Fingerprinting Techniques*

• DOI: 10.1175/jcli-d-14-00367.1
• Publication Date: 2014-11-11T21:06:32Z
• Authors: William Richard H...; Nathaniel L. Bindoff; Marilyn N. Raphael
• Keywords: Forcing (mathematics)

Abstract Using optimal fingerprinting techniques, a detection analysis is performed to determine whether observed trends in Southern Ocean sea ice extent since 1979 are outside the expected range of natural variability. Consistent with previous studies, it found that for seasons maximum cover (i.e., winter and early spring), not variability some West Antarctic sectors they may be partially due tropical However, when information about spatial pattern included analysis, summer autumn fall internal The detectable signal dominated by strong opposing Ross Sea Amundsen–Bellingshausen regions. In contrast pattern, an ensemble 20 CMIP5 coupled climate models shows decrease would response external forcings. simulated decreases Ross, Bellingshausen, Amundsen Seas season significantly different from unforced at 95% confidence level. Unlike earlier work, authors formally show forcing both conclude general do adequately represent forced system.