Regional sea level changes for the 20th and the 21st century induced by the regional variability in Greenland ice sheet surface mass loss

Surface mass balance (SMB) variations of the Greenland ice sheet (GrIS) has been identified as an important contributor to contemporary and projected global mean sea level variations but their impact on the regional sea level change pattern is still poorly known. This study provides for the first time, consistent estimates of GrIS SMB over 1900-2100 based on the output of 32 atmospheric-ocean General Circulation Models and Earth system models involved in the Climate Model Intercomparison Project phase 5 (CMIP5). It is based on a downscaling technique calibrated against the MAR regional climate model in order to calculate an ensemble of 32 Greenland SMB estimates at regional scale. Because the GrIS SMB does not respond uniformly to green house gazes emissions. the southern part of the GrIS is more sensitive to climate warming. This study shows that it should be in imbalance in the 21st century sooner that the northern part. This regional variability affects significantly the associated relative sea level pattern over the entire ocean and particularly along the eastern coast of US and the western coast of Europe. This highlights the necessity of taking into account GrIS regional SMB changes to evaluate relative sea level changes in future projections.