SPATIO-TEMPORAL VARIATION OF SEASONAL EXTREME WET DAYS IN CHINA AND ITS RELATIONSHIP WITH SST ANOMALIES  

作　　者：汪卫平 杨修群 谢益军 邹用昌 房佳蓓 谢倩 

机构地区：[1]Institute for Climate and Global Change Research,School of Atmospheric Sciences,Nanjing University [2]Hunan Meteorological Bureau [3]Institute of Meteorology,PLA University of Science and Technology

出　　处：《Journal of Tropical Meteorology》2012年第4期485-493,共9页热带气象学报（英文版）

基　　金：National Basic Research Program of China (2010CB428504);National Natural Science Foundation of China (40730953,40805025);National Public Benefit Research Foundation of China(GYHY200806004,GYHY200706005);Jiangsu Natural Science Foundation (BK2008027)

摘　　要：With daily precipitation records at 586 stations in China for 1960-2004, this study investigates the spatio-temporal variation of the number of extreme wet days (NEWD) for each season in China and its relationship with SST anomalies and associated atmospheric circulation anomaly patterns, in which a threshold of extreme precipitation for a season and a station is defined as the value of the 90th percentile when the precipitation records for wet days during the season are ranked in an increasing order. Results show that there are significant increases of the NEWD along the Yangtze River valley during winter and summer, in North China during winter, in South China during spring, in Northeast China during winter and spring, and in Northwest China throughout the seasons, while there is a remarkable decrease in North China during summer. Besides the linear trend, the NEWD also exhibits considerable interannual and interdecadal variabilities. After eliminating the linear trend, the NEWD anomalies show distinct seasonal patterns. The NEWD anomalies are characterized by a "dipole" mode with opposite phases between northern and southern China in spring and autumn, a "tri-pole" mode with opposite phases between Yangtze River valley and southern and northern China in summer, and a "monopole" mode with the same phase over most of China in winter. The relationship of the NEWD anomalies in China with the SST anomalies in Indian and Pacific Oceans is found to be mainly dependent on the ENSO, and associated atmospheric circulation anomaly patterns for the ENSO's impact on the NEWD in China are identified.With daily precipitation records at 586 stations in China for 1960-2004, this study investigates the spatio-temporal variation of the number of extreme wet days （NEWD） for each season in China and its relationship with SST anomalies and associated atmospheric circulation anomaly patterns, in which a threshold of extreme precipitation for a season and a station is defined as the value of the 90th percentile when the precipitation records for wet days during the season are ranked in an increasing order. Results show that there are significant increases of the NEWD along the Yangtze River valley during winter and summer, in North China during winter, in South China during spring, in Northeast China during winter and spring, and in Northwest China throughout the seasons, while there is a remarkable decrease in North China during summer. Besides the linear trend, the NEWD also exhibits considerable interannual and interdecadal variabilities. After eliminating the linear trend, the NEWD anomalies show distinct seasonal patterns. The NEWD anomalies are characterized by a ＂dipole＂ mode with opposite phases between northern and southern China in spring and autumn, a ＂tri-pole＂ mode with opposite phases between Yangtze River valley and southern and northern China in summer, and a ＂monopole＂ mode with the same phase over most of China in winter. The relationship of the NEWD anomalies in China with the SST anomalies in Indian and Pacific Oceans is found to be mainly dependent on the ENSO, and associated atmospheric circulation anomaly patterns for the ENSO’s impact on the NEWD in China are identified.

关 键 词：extreme precipitation number of extreme wet days SST anomaly ENSO 

分 类 号：P426.61[天文地球—大气科学及气象学]