How do unresolved variations in sea ice thickness alter the surface energy balance in the Arctic in climate models
Richard Davy
Unresolved variability in the sea ice thickness leads to increases in the heat flux through ice due to the non-linear dependency of fluxes on ice thickness. Here we test the effect of the new high resolution sea ice thickness dataset on the climatology of fluxes through sea ice and the resultant change in the near-surface air temperature using an ice-atmosphere model, NeXtSIM-ABL. In the configuration we use here this model has fixed sea ice conditions, uses the ERA5 reanalysis to force the atmosphere at a height of 850hPa, and has an atmospheric boundary layer and sea ice thermodynamic model to diagnose the temperatures in the ice and atmosphere. We use a tiling system to simulate an atmospheric column over ice and open water seperately. Here we use two different specifications of the surface conditions (using the high-resolution and low-resolution sea ice thickness data) and for the ERA5 forcing we take a climatology of the March and September conditions to drive the upper atmosphere conditions. We then compare the derived surface fluxes and surface air temperatures to quantify the effect of including high resolution sea ice thickness information on the surface climate.