夏季南海低空越赤道气流变化与亚澳季风区降水异常的联系
投稿时间: 2016-11-22  最后修改时间: 2017-01-21  点此下载全文
引用本文:
摘要点击次数: 254
全文下载次数: 
作者单位E-mail
范倩莹 南京信息工程大学大气科学学院  
李忠贤 南京信息工程大学大气科学学院 lizhongxian@nuist.edu.cn 
王健治 中国民用航空厦门空中交通管理站气象台  
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目)
中文摘要:摘 要:本文利用1979-2014年ERA-Interim逐月的风场和水汽通量资料及GPCP逐月的降水率资料,分析了夏季南海低空越赤道气流的变化特征及其与亚澳季风区降水异常的联系。结果表明:(1)夏季南海低空越赤道气流强度年际变化特征明显,具有3-4a的周期;近36a来其强度仅存在微弱的下降趋势。(2)夏季南海低空越赤道气流强度变化与热带东印度洋和海洋性大陆区域的夏季降水异常具有显著的负相关关系,而与热带西太平洋的降水异常存在明显的正相关;此外,还与我国中部地区夏季降水异常有较好的负相关。(3)当夏季南海低空越赤道气流强度偏强时,自阿拉伯海向东,一直延伸到热带西太平洋的850hPa风场为西风异常,这种环流形势有利于水汽向热带西太平洋输送,使得该区域降水出现明显偏多;与此同时,热带东印度洋低层风场为东风异常,导致热带东印度洋和海洋性大陆区域出现水汽辐散,使得该区域降水偏少,反之亦然;此外,当夏季南海低空越赤道气流强度偏强(弱)时,在我国东南沿海为一个气旋式(反气旋式)风场异常,受其影响,不利于(有利于)来自热带海洋的水汽输送到达我国中部地区,从而使该地区降水可能出现偏少(偏多)。
中文关键词:越赤道气流  时空变化  降水  大气环流
 
Contact between the precipitation anomaly in the Asian Australian monsoon region and cross-equatorial flow of the South China Sea in summer
Abstract:Abstract: According to the latest released Interim reanalysis data by ECMWF and precipitation rate data by GPCP, we analyze the spatial and temporal variations of Cross-Equatorial Flow (CEF) over the South China Sea (SCS) and its connection with the Asian Australian monsoon region precipitation. The results show that the intensity of SCS low-level CEF has a significant inter-annual variation in summer, with a 3-4yr period. The intensity of SCS low-level CEF in summer shows a closely negative (positive) correlation with the precipitation anomaly in the tropical eastern Indian Ocean and the maritime continent (tropical western Pacific). In addition, the intensity of SCS low-level CEF has a clearly negative relationship with the summer precipitation anomaly in Central China. When the intensity of SCS low-level CEF is strong in summer, there are west wind anomalies from the Arabia Sea to tropical western Pacific and east wind anomalies in tropical eastern India Ocean at 850hPa level, leading to the convergence (divergence) of water vapor in the tropical western Pacific (tropical eastern India Ocean and maritime continent). As a result, more (less) precipitation occur in the tropical western Pacific (tropical eastern India Ocean and maritime continent).
keywords:Cross-equatorial flow  spatial and temporal variations  precipitation  atmosphere circulation
查看全文  查看/发表评论  下载PDF阅读器