A DIAGNOSTIC STUDY OF THE TELECONNECTION ASSOCIATED WITH THE WARM POOL OF THE WESTERN PACIFIC AND ASIAN MONSOON DURING EL NINO AND NON-EL NINO YEARS

Based on the monthly mean OLR, geopotential height and wind data from the NCEP/NCAR reanalyzed data sets for 1982-1996, the atmospheric teleconnection associated with the warm pool of the tropical western Pacific and Asian monsoon region during E1 Nino and non-El Niño years are studied diagnostically in this paper. It is found that, the teleconnection pattern caused by the activity of the Asian summer monsoon (ASM) emanates from the Asian monsoon region to the tropical eastern Pacific via the Aleutians in summer of the El Niño years. In the non-El Niño years, however, the ASM-related teleconnection pattern stretches northward and westward from the Asian monsoon region, exerting its influences mainly on the circulation over middle and high latitude rather than that over the tropical eastern Pacific. Evidences also show that the anomalous convection over the tropical western Pacific warm pool leads to the East Asia/Pacific(EAP) teleconnection pattern during the non-El Niño years. It is interesting to note that the teleconnection in the 500 height field associated with the warm pool convection disappears in the El Niño years. The differences of the teleconnection pattern between the El Niño years and the non-El Niño years suggest that the activities of the ASM and the convection over the warm pool of the tropical western Pacific, the most energetic weather events in boreal summer, are intertwined and interactive with other global-scale circulation in different ways under different climate backgrounds.