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

• Published in: Geophysical Research Letters
• Main Authors: Goosse, Hugues, Arzel, Olivier, M. Bitz, C., de Montety, A., Vancoppenolle, Martin
• Other Authors: Université Catholique de Louvain = Catholic University of Louvain (UCL), Climate Change Research Centre Sydney (CCRC), University of New South Wales Sydney (UNSW), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Department of Atmospheric Sciences Seattle, University of Washington Seattle, Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Antarc*; Antarctica; Sea ice
• Online Access: https://hal.science/hal-00453446; https://doi.org/10.1029/2009GL040546

International audience 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 km2. 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.