›› 2013, Vol. 25 ›› Issue (2): 0-346.

• 论文 •    

Preliminary analysis of the atmospheric circulation type of rainstorm events in Jiangsu Province

QIN Cheng-yun;WU Hong-jun;TANG Jie;FENG Yang;XIA Wang-ping   

  1. Huaian Meteorological Bureau,Huaian 223001,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2013-03-25 Published:2013-03-25

Abstract: Using the precipitation data at 64 stations of Jiangsu province during 1960—2008 and the reanalysis data of The National Centers for Environmental Prediction and National Center For Atmospheric Research (NCEP/NCAR), the pattern of typical rainstorm and the anomalies of associated atmospheric circulation were analyzed from EOF pattern of 500 hPa geopotential height. The results showed that there were three types of circulations through EOF method, the type with two ridge and one trough, zonal type and the type with two blocking, in the rainstorm events. Further analysis were performed on the current day and the day before at 500 hPa, 700 hPa height field, 850 hPa wind field and sea level pressure field in the various types of rainstorm. The results were as follows: (1) For the rainstorm type with two ridges and one trough, there was broad Lake Baikal groove at 500 hPa height field. The two ridges and one trough situation were even more obvious and stepped groove at 700 hPa height field, and the contour of height field was intensive. There was abundant watervapor at 850 hPa height, and there was a low pressure in Sichuan at the sea level pressure field eastward developing into inverted trough. Usually, this type could result in rainstorm for one day. (2) For the zonal type rainstorm, there was straight circulation, small multi\|trough, strong southwestern airstream and contour sparse at 500 hPa height field. There was wind speed and wind direction convergence at 850 hPa height in Northern Jiangsu. This type easily led to more large\|scale persistent regional rainstorms. (3) For the rainstorm type of two blocking, there were two blocking at 500 hPa high field. The low trough system in Lake Baikal area was deep, and the slot line was divided into north and south. The small trough at mid\|latitude was active at 700 hPa height field and the transfer of water\|vapor at 850 hPa height field was clear. This type easily led to persistent rainstorms.

Key words: Jiangsu province, rainstorm, objective analysis method, atmospheric circulation types