Mulit-year Predictability of Greenland Sea Spring Sea-ice Volume in a Coupled Climate Model

• Main Authors: Hermanson, Leon, Sutton, Rowan, Keeley, Sarah
• Format: Conference Object
• Language: English
• Published: 2009
• Subjects: Meteorology and Climatology; Greenland; Greenland Sea; Sea ice
• Online Access: http://cedadocs.ceda.ac.uk/807/; http://cedadocs.ceda.ac.uk/807/1/poster-NCAS09-HermansonSuttonKeeley.ppt

Prediction of sea-ice is not only important for shipping but also for weather as it can have a signicant climatic impact. Therefore sea-ice predictions are important for accurate inter-annual to decadal prediction of climate in coupled climate models. However, to our knowledge there has been little work on how predictable sea-ice is in a coupled atmosphere-ocean-ice model. We have studied the predictability of sea-ice in HadCM3 using case study ensemble experiments with external forcing from the late 20th century designed to emphasize the predictability in the climate system due to initial conditions. Here, we will concentrate on spring (maximum) ice-volume in a box in the Greenland Sea (30W to 10E, 68N to 80N). Model climatology from a control-run shows that this region has high inter-annual variability in sea-ice volume. We find that although ice may almost completely disappear from this area in late autumn, the same anomalies re-appear in the following spring for at least the first four years in three out of four case studies. The mechanism for this appears to be related to persistence of ocean heat content in the initial conditions and the state of the meridional overturning circulation and its associated heat transport. In this model, the atmosphere appears to less important than the ocean in determining the predictability of sea-ice volume in the Greenland Sea.