The relationship of SST to free air temperature in the Tropics is investigated using the Penn State/NCAR Mesoscale Model within a doubly periodic domain over an ocean surface with a uniform SST. Two sets of simulations are compared: one with the Coriolis force activated and one with it removed. Rotation is used as a probe to see how circulation affects the relationship between SST and air temperature. The SST is varied from 297-303 K to understand how SST affects the conclusions.

It is found that the air temperature profiles are warmer for the same SST when rotation is included than when rotation is neglected. The differences appear to be related to stronger surface winds that result from the inclusion of rotation. The stronger surface winds enhance evaporation and increase the rate at which the hydrological cycle of the model heats the atmosphere, and also affect cloud amounts and humidity. This result suggests that changes in large-scale circulation can affect the relationship between SST and air temperature. Applications to recent observed changes of SST, air temperature and tropical large-scale circulation patterns will be considered.