佛山2008年初罕见低温阴雨过程与气候特征对比

Cause Analysis on a Rare Cold and Raing Weather in Foshan City in Early 2008 in Comparison with Climatic Features

基于佛山市1959～2008年气温和日照等资料,分析佛山2008年初罕见低温阴雨的成因及低温阴雨的气候特征,结果表明:2008年低温阴雨属于异常天气气候事件。佛山的重低温阴雨年集中在1960年代后期～1980年代中期,之后以轻年为主;重(轻)年景时,前期赤道中东太平洋SST持续为负(正)距平的可能性较大,2008年低温阴雨前期为典型La Nina事件。低温阴雨重、轻年的高度场差异显著:重年500 hPa西北欧到南亚呈"-+-"的环流分布型,轻年反之;2008年初环流与重年合成场基本一致,但也存在异常特征。850 hPa风场还表明佛山低温阴雨可能与全球大尺度环流异常有联系。

By using the temperature and sunshine data （ 1959 -2008 ） of Foshan and so on, the causes and climatic features of a rare cold and rainy weather in Foshan in early 2008 are investigated. The results show that it was an extreme weather -climate event, the serious years of which were mainly in the late 1960s to the middle 1980s, after that weak years were the chief features. Previous SST anomalies were more possibile to be negative （positive） in middle - east Equator Pacific Ocean during serious （weak） years. The height fields of serious years were significantly different from that of weak years. There was a ‘ - ＋ - ＇ distribution pattern of height anomaly field from North - West Europe to South Asia at 500 hPa in serious years, while it was opposite in weak years. A typical La Nina event happened before 2008 and the circulation in early 2008 was basically in agreement with that of serious years, despite of existing its own special features. Wind field at 850 hPa also suggusets that there is a potential relationship between the cold and rainy weather and the anomaly of large - scale circulation.