The Role of Sea Ice Thickness Distribution in the Arctic Sea Ice Potential Predictability: A Diagnostic Approach with a Coupled GCM
AbstractThe intrinsic seasonal predictability of Arctic sea ice is investigated in a 400 yr long preindustrial simulation performed with the Centre National de Recherches Meteorologiques Coupled Global Climate Model, version 3.3 (CNRM CM3.3) The skill of several predictors of the pan Arctic sea ice area was quantified: the sea ice area itself, the pan Arctic sea ice volume, and some areal predictors built from the subgrid ice thickness distribution (ITD) Sea ice area provides a potential predictability of about 3 months, which is consistent with previous studies using model and observation data. Sea ice volume predictive skill for winter sea ice area prediction is weak. Nevertheless, there is a higher potential to predict the September ice area with the June volume anomaly than with the June area anomaly. Using ITD based predictors, two "regimes" of predictability were highlighted. The first one, a "persistence regime," applies to winter/early spring sea ice seasonal predictability. The winter sea ice c.