BASIC FEATURES OF THE WARM POOL IN THE WESTERN PACIFIC AND ITS IMPACT ON CLIMATE
Li Kerang Zhou Chunping Sha Wanying (Institute of Geography, Chinese Academy of Sciences, Beijing 100101)
Based on the 〈Atlas of physical climate of the ocean〉 that has been compiled and on the indexes of warm pool that has been calculated, this study analyzes the basic features of warm pool in the western Pacific Ocean and its impact on climate and climate change, especially the relationships among the warm pool, subtropical high in the western Pacific and El Nin～o. The Atlas provides the basic data of monthly physical climate of the warm pool region of the ocean for 1949～1990, including the atmospheric thermal, kenetic and dynamic features of the ocean surace. The indexes of the warm pool are: areas, north (or south) boundary, east (or west) boundary, intensity and the location of its centre. The results show that there are close relations among the warm pool, subtropical high and El Nin～o. The warm pool and the subtropical high are positively correlated, including both seasonal variation of the area and its northern and southern boundaries. Variation of the warm pool usually precedes that of the subtropical high. The area of the warm pool expands (or contracts) and the location of the warm pool center in the western Pacific moves toward the north (or the south) from winter (February or March) to summer (July or August) (or from summer to winter). In general, the seasonal and interannual variation of the area and the location of the subtropical high are similar to those of the warm pool, with the latter preceding the former by a few months. The relationships between western Pacific warm pool and El Nin～o, including the SST and area size, are also discussed.