The MITgcm is now able to generate Sea-Ice Donuts.
In a push to move forward MITgcm on the path of fundamental science and climate understanding, David Ferreira and Jean-Michel Campin simulated a Sea-ice Donut using a coupled AquaPlanet configuration (see movie here). This experiment was initialized with the T and S fields from a previous Aquaplanet run which has polar sea-ice caps. These caps are associated with salt-compensated temperature inversions in the upper ocean. The new run is initialized without sea-ice and within a month, large sea-ice caps grow over the poles, rejecting salt. This triggers convection which in turns brings relatively warm water to the surface and melts the ice close to the poles. Here we have a donut.
Look out for that chapter on aqua-planets in the next IPCC report!