季风湿润区冬季水汽收支年际及年代际变化特征  

Interannual and Interdecadal Variations of Winter Water Budgets in the East Asian Monsoon Humid Region

作　　者：廖荣伟[1,2,3] 赵平[1] 

机构地区：[1]国家气象信息中心,北京100081 [2]中国气象科学研究院,北京100081 [3]中国科学院研究生院,北京100049

出　　处：《应用气象学报》2011年第6期641-653,共13页Journal of Applied Meteorological Science

基　　金：国家重点基础研究发展计划项目(2009CB421404)

摘　　要：采用1958-2007年NCEP/NCAR再分析资料和我国160站降水资料,对东亚大陆季风湿润区冬季的水汽收支变化与大气环流和我国降水异常特征的关系进行研究。结果表明:冬季水汽收支时间序列表现出明显的长期气候变化趋势。挑选的水汽收支高、低值年不仅能够指示季风湿润区经向风的异常变化,还能够指示东亚冬季风的强弱和降水的异常变化。高值年,蒙古冷高压和阿留申低压偏弱,对流层低层为异常偏南风,整层为异常逆时针环流,30°N以南的辐合和上升运动强,大气水分收入增多,降水增加;低值年则相反。差值合成的异常降水量中心值可达40 mm以上,差值合成的水汽异常输入主要集中在600～900 hPa。合成的经向水汽收支占净收支变化的91.3%,纬向上相差较小。季风湿润区南、北区域的水汽收支及降水的差异明显,纬向的收入支出对此差异贡献较大。水汽收支的年代际特征,不仅能够指示水汽输送的强弱及从海洋输入水汽的多少,还能够指示季风湿润区降水的变化,且差值合成的异常降水量最大可达30 mm以上。Using monthly means of NCAR/NCEP reanalysis datasets and rainfall data from 160 surface stations in China,a water budgets sequence over the East Asian Monsoon Humid Region is calculated by a water vapor transport method for the period from 1958 to 2007,referring to changes in water budgets associated with the anomalous atmospheric circulations and precipitation in the East Asia Monsoon Humid Region. Relationships between the water budget index and the variability of the atmospheric circulation and rainfall in China are examined.Results show that the established water budgets sequence displays the variability on the interannual and interdecadal scales.The higher-index values mainly occur in the 1960s and the 1980s and the low-index values mainly occur in the 1970s and the 1990s.The index reflects the variations of the meridional winds anomalies and indicates an intensity of winter monsoon and an anomaly of rainfall along the valleys in the East Asian Monsoon Humid Region.Corresponding to the higher-index values,the high pressure centering in Mongolia and the low pressure centering in the Aleutian Islands are weaker. Meanwhile,the southerly wind anomalies are prevailing in the lower troposphere in the East Asia and cyclonic circulation anomaly appears in the vertical troposphere over the mainland of China.This anomaly intensifies the convergence and upward motion to the south area of 30°N,driving the warm water vapor transport coming from the Bay of Bengal and the South China Sea,and increases the water budgets and precipitation,with the difference of rainfall above 40 mm.The anomalous water vapor transport mainly appears between 600 hPa and 900 hPa,where the western and southern boundaries are the major input regions, the eastern and northern boundaries are the major output regions.The anomalous water budget is larger in meridional than in zonal direction,accounting for 91.3%for the changes of net incoming and expenditure while the anomalous zonal water budget is smaller.So the main cause for the difference and s

关 键 词：水汽收支 大气环流 年际变化 年代际变化 

分 类 号：P426[天文地球—大气科学及气象学]