Low- and Mid-High Latitude Components of the East Asian Winter Monsoon and Their Reflecting Variations in Winter Climate over Eastern China
Low- and Mid-High Latitude Components of the East Asian Winter Monsoon and Their Reflecting Variations in Winter Climate over Eastern China
复制标题
DOI：
10.1080/16742834.2012.11446985
复制
发表时间：
2012-01
影响因子：
2.3
通讯作者：
Liu Ge;Ji Liren;Sun Shuqing;Xin Yu-Fei
中科院分区：
文献类型：
--
作者：
Liu Ge;Ji Liren;Sun Shuqing;Xin Yu-Fei
本文定义了东亚冬季风（EAWM）的低纬度分量（10-25°N， 105-135°E范围内的冬季平均1000 hpa v型风）和中高纬度分量（30-50°N， 110-125°E范围内的冬季平均1000 hpa v型风），分别记为EAWM- l和EAWM- m。研究了反映中国东部冬季气候变化的变化特征，以及与这两个分量相对应的相关大气环流。主要结果如下：1)EAWM-L和EAWM-M在某些年份变化一致，而在其他年份变化相反；2) EAWM-M指数主要反映中国东部地区广泛的气温变化，而EAWM-L指数更能反映中国东部大部分地区冬季降水的变化；3)东亚中高纬地区的距平风对高纬冷空气南下的影响与EAWM-M指数的变化相对应。结合EAWM-L指数的变化，异常低纬风调节了热带海洋向中国东部的水汽输送，导致冬季降水异常。EAWM- l和EAWM- m之间的这些显著差异表明，在EAWM研究中有必要探索季风的个体特征和影响。
Abstract The present study defines a low-latitude component (regionally averaged winter 1000-hPa V-winds over 10-25°N, 105-135°E) and a mid-high-latitude component (regionally averaged winter 1000-hPa V-winds over 30-50°N, 110-125°E) of the East Asian winter monsoon (EAWM), which are denoted as EAWM-L and EAWM-M, respectively. The study examines the variation characteristics, reflecting variations in winter climate over eastern China, and associated atmospheric circulations corresponding to the two components. The main results are as follows: 1) the EAWM-L and EAWM-M have consistent variation in some years but opposite variations in other years; 2) the EAWM-M index mainly reflects the extensive temperature variability over eastern China, while the EAWM-L index better reflects the variation in winter precipitation over most parts of eastern China; and 3) corresponding to the variation in the EAWM-M index, anomalous winds over the mid-high latitudes of East Asia modulate the southward invasion of cold air from the high latitudes and accordingly affect temperatures over eastern China. In combination with the variation in the EAWM-L index, anomalous low-latitudinal winds regulate the water vapor transport from tropical oceans to eastern China, resulting in anomalous winter precipitation. These pronounced differences between the EAWM-L and the EAWM-M suggest that it is necessary to explore the monsoons’ individual features and effects in the EAWM study.