southwest monsoon
2.THE RELATIONSHIP BETWEEN THE INTENSITY OF SUMMER SOUTHWEST MONSOON OVER NORTHWEST PACIFIC AND THE CIRCULATION PATTERNS OF THE SOUTHERN HEMISPHERE
6.By analyzing 500 hPa height field data in 1961_2002, it is found that the dipole index of sea temperature over eastern/western Indian Ocean has a close relation to the abnormal of Eurasia 500 hPa height field of Northern Hemisphere, which affects on the variation of precipitation and temperature of flood period over Qinghai-Xizang Plateau throush the strong and weak of Indian southwest monsoon.
7.The cold air could reach low latitude area when the stable meridional circulation pattern controls the Southern Hemisphere. The strong southeast wind to the north of lower layer cold high located behind the long wave trough could form a strong and persistent cross-equator flow in a relatively fixed narrow channel. In some favorable conditions of Northern Hemisphere circulation, this cross-equator flow could turn into southwest flow over the Northwest Pacific and lead to intensification of southwest monsoon.
8.The isotopic data(δ~18O and δD) in precipitation at New Delhi,the IAEA/WMO station in southwest monsoon region,were collected and analyzed. A few absentδD records were predicated based on the monsoonal water meteoric line,and finally the 36-year deuterium excess series was constructed by the isotopic data.
9.The rsults are as follows: (1) precipitation shows the decreasing trend and remarkable interannual and interdecadal variations in flood season in the last 44 years. (2) precipitation anomalies in flood season have a good correlations with southwest and southeast summer monsoon, polar vortex, west wind trough, the subtropical high over West Pacific and South Asia High.
