摘要
采用我国台站降水资料、NCEP/NCAR再分析资料,分析比较了高原东侧川渝盆地东、西部夏季降水及其大尺度环流特征。主要结论为：（1）1951-2004年来,盆西夏季降水总体呈减少趋势,盆东则呈增加趋势;盆地东西部夏季降水主要呈反位相变化,20世纪90年代以来最常见的两种雨型是西少东多、东西部一致偏少。（2）位于北半球中高纬度的乌拉尔山高脊、巴尔喀什湖至贝加尔湖之间的低压槽以及亚洲东部高脊的两脊一槽环流型发展、西太平洋副热带高压偏北,是盆西多雨年的环流背景。（3）乌拉尔山、巴尔喀什湖、西伯利亚地区的高脊偏强,贝加尔湖一线以南直到盆东附近地区上空为槽区,东亚中高纬地区以经向型环流为主,西太平洋副热带高压偏南,是盆东多雨年的环流背景。（4）亚欧大陆中高纬环流形势的显著不同,是盆地东西部夏季降水发生年代际变化的主要原因之一。
Based on monthly rainfall data from 160 primary stations in China during 1951 -2004 and NCEP/NCAR monthly reanalysis data ,variation of summer preeipitation in the west and east of Sichuan and Chongqing Basin on the eastern side of the plateau and their relationships with the circulation are compared in the paper, the main conclusions are： （ 1 ） the summer precipitation in West and East of Sichuan and Chongqing Basin maily changes out - of - phase, and the most frequent rain pattern is less precipitation in the west and more precipitation in the east from 1951 to 2004. In these 54 years, there was a decrease trend in the summer precipitation of the west and an increase trend of the east of the Basin. （2） Flood in the west of the Basin is associated with the circulation pattern that two ridges located Ural and the East of Asia respectively,and a trough between Balkhash and Baykal ,and also with the northward displacement of the western Pacific subtropical high. This pattern favors the flood of east of the basin. （3）Flood in the East of the Basin is associated with the circulation panern that ridge over Ural ,West Siberian and Balkhash, the trough from south of the Baykal to regions near the East of the Basin ,and with the meridional circulation pattern in the middle -high latitude of East Asia ;And also with the southward displacement of the western Pacific subtropical high. This pattern favors the flood of west of the basin. （4） The marked decadal difference of the circulation pattern in the middle - high latitude of the Eurasian land due much to the decadal variation in the west and east of the Basin. The developing circulation pattern that two ridges 1 ocated Ural and the East of Asia respectively,and a trough between Balkhash and Baykal in 1950s ,which is quite different from that of the 1990s in the wast,results in more rain in 1950s than 1990s. The developing ridge located Ural ,West Siberian and Balkhash and meridional circulation pattern in the middle -high latitude of the East Asian in 1
出处
《高原山地气象研究》
2008年第2期1-9,共9页
Plateau and Mountain Meteorology Research
基金
中国气象局气候变化专项(CCSF2007-23)
国家重点基础研究发展计划(2003CB415201-6)
国家自然科学基金(40675059)
中国气象局成都高原气象研究所高原气象研究专项(PMP2006006)
成都高原气象研究所基本科研业务专项(BROP200702)
关键词
川渝盆地
夏季降水
年际变化
大尺度环流
Sichuan and Chongqing Basin
summer precipitation
interannual variation
Large - scale circulation
