WARM POOL HEAT-BUDGET AND SHORTWAVE CLOUD FORCING - A MISSING PHYSICS

Ship observations and ocean models indicate that heat export from the mixed layer of the western Pacific warm pool is small (<20 watts per s quare meter). This value was used to deduce the effect of clouds on th e net solar radiation at the sea surface. The inferred magnitude of th is shortwave cloud forcing was large (approximate to-100 watts per squ are meter) and exceeded its observed value at the top of the atmospher e by a factor of about 1.5, This result implies that clouds (at least over the warm pool) reduce net solar radiation at the sea surface not only by reflecting a significant amount back to space, but also by tra pping a large amount in the cloudy atmosphere, an inference that is at variance with most model results. The excess cloud absorption, if con firmed, has many climatic implications, including a significant reduct ion in the required tropics to extratropics heat transport in the ocea ns.