Increased variability of the Arctic summer ice extent in a warmer climate

• Published in: Geophysical Research Letters
• Main Authors: Goosse, H., Arzel, O., Bitz, C., de Montety, A., Vancoppenolle, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2009
• Subjects: Arctic; Antarc*; Antarctica; Sea ice
• Online Access: https://www.vliz.be/imisdocs/publications/292316.pdf

Simulations performed with general circulation models and a model of intermediate complexity show that the variability of the September sea ice extent in the Arctic of the 21st century increases first when the mean extent decreases from present-day values. A maximum of the variance is found when the mean September ice extent is around 3 million km 2 . For lower extents, the variance declines with the mean extent. The behavior is clearly different in Antarctica where the variance always decreases as the mean ice extent decreases, following roughly a square-root law compatible with very simple geometric arguments. Several mechanisms are responsible for the non-linear behavior of the Arctic. However, the strong interhemispheric contrast suggests that the difference in geometrical setting, with an open ocean in the south and a semi-closed basin in the north, plays a significant role.