Analysis of Characteristics and Influencing Factors of Persistent Rainstorm in Southern China
Based on the persistent rainstorm events in five southern provinces of China,this paper identified the per-sistent rainstorm events in southern China using meteorological station observation data and an improved definition of re-gional persistent rainstorm,and analyzed their characteristics and potential influencing factors.The results indicate that the persistent rainstorm events in the southern region of China predominantly occurred from May to August each year.The event locations were mainly concentrated in Guangdong,Guangxi,and the southern part of Guizhou.The majority of these events lasted for 3 to 5 days.Notably,there was a significant increasing trend in the affected area over time.The northwestern Pacific sea surface temperature(SST)and rainstorm in southern China is significant positive correlation.The northwestern Pacific SST index was established.Regression analysis of the index and contemporaneous atmospheric circulation revealed that when the northwestern Pacific SST is anomalously high,a positive anomaly in 500 hPa geopoten-tial height over the northern part of Lake Baikal and anomalous northward winds at 850 hPa influence southern China.These atmospheric conditions enhance upward motion in the southern region,increasing the likelihood of persistent rain-storm events.Further confirmation of this anomalous circulation pattern was obtained through composite analysis of ex-treme years using the index.
万方数据
维普
