Towards enabling spatially varying rates of change of Antarctic freshwater fluxes in HadGEM3-GC3.1

Abstract:

Sea ice and ocean processes important to climate are affected by fresh meltwater entering the Southern Ocean from ice shelves and icebergs around Antarctica. The Deep South National Science Challenge has funded sea ice model development research. Previous research found the spatial distribution of melt fluxes to be important to the sea ice and ocean response, and highlighted the need for a realistic spatial distribution, not only of the fluxes, but also of the rate at which they are changing, which varies widely around Antarctica. This project will address the question of sea ice sensitivity to freshwater fluxes, including with spatially varying rates of change of freshwater fluxes. This will be carried out through numerical experimentation and model development using HadGEM3-GC3.1 (the physical core of the NZESM). The model changes will facilitate calculation of updated projections as new observations of changing melt rates become available, without requiring changes to the model code. A further benefit of the proposed development would be the capability to conduct sensitivity experiments to investigate the sensitivity of climate to the behaviour of specific ice shelves. This will help identify key regions for future field observation and monitoring campaigns.”