Impact of the Abnormalities oImpact of the Abnormalities of East Asia Subtropical Westerly Jet on Meiyuf East Asia Subtropical Westerly Jet on Meiyu

• 1、Aviation Meteorological Center

Abstract：According to the 1954 - 2012 NCEP / DOE (National Center for environmental prediction) of 200hPa monthly reanalysis data and the rainfall data of 160 stations, anomaly by the meteorological statistical correlation coefficient and the standard calculation method, discusses the important member of the East Asian summer monsoon circulation system -- Asian westerly jet, and the relationship between its position ,intensity and the abnormalities of Meiyu, whether the jet\'s changes in June and July will make the anomalies of Meiyu. Studies have shown that: East Asian subtropical westerly jet and the precipitation of Meiyu have significant correlation, and the correlation exists significant differences between June and July, so must be monthly discuss the impact of the abnormalities of westerly jet on the precipitation of Meiyu. When the jet at a multi-year average position, the intensity of jet is abnormally strong, the precipitation of Meiyu in Jiang- huai area is more than average, but the influence of the intensity of the jet on Meiyu is not very prominent. The influence of the abnormal position of the jet on Meiyu is prominent. In June, when the East Asia subtropical westerly jet is abnormally southward, the precipitation of Meiyu in June is fewer. On the contrary, when the jet is abnormally northward, the precipitation of Meiyu in July is more. In July, when the sub-tropical westerly jet is abnormally southward, the precipitation of Meiyu in July is more than average, but when the jet is abnormally northward, the precipitation of Meiyu is fewer.

Keywords： Meiyu；precipitation ；East Asia subtropical westerly jet.