Analysis of Summer Precipitation Anomaly and the Feature of Water Vapor Transport and Circulation in Northwest China

Summer precipitation anomaly and the feature of water vapor transport and circulation in Northwest China are studied by using the NCEP/NCAR reanalysis data from 1951 to 2000 and rainfall observations of 31 representative stations in Northwest China. It is found that the phases between precipitation anomaly in Northwest China and that in east coast of China are opposite, and the influencing systems and periods to summer rainfall are different between those two aeras. Results show that the circulation and water vapor transport of dry years in the related areas are significantly different from those of wet years.