Relationship between Sea-Water Temperature in the Tropics and Winter Weather over Japan

Abstract

The simultaneous relationship between sea-surface temperature (SST), tropical convection. and weather over Japan is statistically examined for winter, using monthly-mean SST, outgoing longwave radiation (OLR), and the temperature over Japan. In a previous study (Miyazaki, 1989), it was clarified that the winter temperature over Japan is negatively correlated to convective activity around the Philippines. In this study, it is found that winter convective activity around the Philippines is positively correlated to SST in the warm-water pool over the western tropical Pacific and negatively to SST in the central and eastern equatorial Pacific. These results indicate that winter SST in the tropics can influence the atmospheric circulation in the xtratropical Northern Hemisphere through the fluctuation of tropical convection.
An examination is made of the direct correspondence between the January temperature over Japan and sea-water temperature in the western tropical Pacific observed along 137°E. In most cases, lower sea-water temperature corresponds to higher temperature over Japan. On the other hand, higher seawater temperature corresponds in many cases to lower temperature and in several cases (1972, 1989) to higher temperature. In Januaries 1972 and 1989, EU (Europe+) and PNA (Pacific+) patterns appeared at 500 mb. In January 1989, tropical convection shifted westward to the Indian Ocean.