Changes in the air-sea interactions in the warm pool during summer around the mid-1990s

The annual mean sea surface temperature (SST) of the western Pacific warm pool (hereafter, the warm pool) covering the region 120E and 155E and from 10N to 10S is persistently higher than 28 celsius degree and is increasing consistently. We investigate the changes in the air-sea interactions over the warm pool by analyzing cloud, heat flux, SST and precipitation during summer (June-July-August). It is found that the relationship between SST and cloud variability over warm pool is significantly changed around the mid-1990s. Especially, each of relationships with SST and clouds such as stratocumulus and cumulus are changed. In addition, a lead-lag relationship of latent heat flux - cumulus cloud and stratus cloud has been changed around the mid-1990s. We speculate that the changes in the air-sea interactions over the warm pool might be associated with the modification of atmospheric teleconnections from the tropics to the mid-latitudes.