中国东部夏季水汽输送的年代际变化特征  

Interdecadal variation characteristics of water vapor transfer over eastern China in summer

作　　者：郭志荣[1] 陈旭红[1] 江燕如[1] 董丽娜[2] 

机构地区：[1]南京信息工程大学气象台,江苏南京210044 [2]南京信息工程大学气象灾害预报预警与评估协同创新中心,江苏南京210044

出　　处：《大气科学学报》2014年第5期568-574,共7页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(41075069)

摘　　要：基于1948—2012年NCEP/NCAR月平均再分析资料,采用9 a滑动平均、EOF分析及合成分析方法,研究了我国东部夏季水汽输送的年代际变化特征。结果表明:6—8月水汽输送由强转弱发生在1975年前后,水汽输送异常显著区域主要位于东部地区;6月南海到我国东部地区的水汽输送存在年代际变化,7月孟加拉湾、南海和西太平洋(8月印度洋、南海和西太平洋)到我国东部的水汽输送同样存在年代际变化;6—8月年代际变化前后水汽输送矢量分布与相应月份水汽输送通量年代际特征向量场的空间分布基本一致;显著的水汽通量散度辐合区位于华中以西经华北到东北地区,长江以北水汽辐合(辐散)异常显著区域由风场的辐合(辐散)异常和水汽平流异常共同造成,长江以南地区水汽辐合(辐散)异常显著区域主要由风场的辐合(辐散)异常造成。Based on NCEP / NCAR monthly reanalysis data from 1948 to 2012,the interdecadal variation of summer water vapor transport over eastern China is investigated using the 9-yr moving average,EOF analysis and compositive analysis methods. Results show that summer( June—August) water vapor transport is characterized with a turning point from strong to weak around 1975. The abnormal area of water vapor transport mainly locates in the eastern China. Water vapor transport from South China Sea to eastern China has interdecadal variation in June. Water vapor transport from the Bay of Bengal,South China Sea and western Pacific in July( Indian Ocean,South China Sea and western Pacific in August) to eastern China also has interdecadal variation. Distribution of summer water vapor transport flux vectors is consistent with that of the first component of interdecadal water vapor transport before and after the interdecadal variation. Significant water vapor flux convergence zone locates in the southwest to the northeast China. In the northern Yangtze River,water vapor convergences( divergence) are caused by the wind field convergence(divergence) and the water vapor advection,but in the southern Yangtze River,which is mainly caused by the wind field convergence( divergence).

关 键 词：中国东部 水汽输送异常 年代际变化 夏季 

分 类 号：P426[天文地球—大气科学及气象学]