A MAJOR LOW-LEVEL CROSS-EQUATORIAL CURRENT AT 110° E DURING THE NORTHERN SUMMER AND ITS RELATION TO TYPHOON ACTIVITIES
Wang Jizhi (Beijing Meteorological Center People's Republic of China)Preston W. Leftwich, Jr. (NOAA, NWS, National Hurricane Center Coral Gables, Florida, U. S. A.)
Observations of the summer monsoon circulation in the western Pacific suggest that variations in strength of a low-level southerly current may be one of precursors of tropical cyclone development. In an earlier study, this southerly current, which is embedded in the large-scale monsoon flow, was named the Asia-Australia Southern Monsoon. This study documents its mean structure as depicted by an operational analysis system utilized at the National Meteorological Center in Washington, D.C.This Southern Monsoon current is identifiable in cross-sections of monthly mean north-south wind components as a maximum at 850 mb near 110°E. The peak strength occurs in August.