Sensitivity studies on the role of the ocean in climate change

A number of numerical experiments has been carried out simulating several hundreds of years of time evolution of the seasonally forced North Atlantic Ocean Circulation. These experiments made use of the GFDL primitive equation model with 30 vertical levels and 1.0° × 1.2° horizontal resolution. The nature of the heat flux forcing and the importance of the implied evaporation minus precipitation (salinity) forcing will be described and the consequent meridional overturning circulation and related heat and fresh water transports examined. Speculation about the stability of the thermohaline circulation to realistic boundary forcing will be made. Finally, the role of seasonal thermohaline forcing at the sea surface (and improvements in its representation) and the role of the open boundaries (the boundary conditions at 65°N and 15°S) in determining these mass and heat transports by the North Atlantic circulation will be described. -Authors