The interdecadal change of the leading mode of the winter precipitation over China
The interdecadal change of the leading mode of the winter precipitation over China
复制标题
中国冬季降水主导模态的年代际变化
DOI：
10.1007/s00382-015-2970-x
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发表时间：
2016-10-01
期刊：
影响因子：
4.6
通讯作者：
Lin, Hai
中科院分区：
文献类型：
--
作者：
Ge, Jingwen;Jia, Xiaojing;Lin, Hai
利用1960 - 2012年的观测资料，分析了中国冬季平均降水量主导模态的年代际变化特征。中国冬季降水的主导经验正交函数（ERF）模（EOF 1）在东南部地区表现为单符号型，占降水总方差的49.7%。厄尔尼诺-南方涛动（ENSO）和东亚冬季风（EAWM）都可以影响EOF 1。正（负）EOF 1伴随着暖（冷）ENSO事件和弱（强）EAWM，后者可导致我国东南沿海沿着异常的南（北）风，并伴随着孟加拉湾和南海水汽的输送，有利于我国东南地区的湿（干）冬。在20世纪80年代中期左右观察到EOF 1的突然转变。因此，数据被分成两个子周期，即，1960-1987年（P1）和1988-2009年（P2）。在这两个子周期的大尺度大气环流和海表温度异常的EOF 1的显着差异。EOF 1在P1与中高纬大气环流密切相关，而在P2与热带的关系明显增强。偏回归分析结果表明，EOF 1的年代际变化是由20世纪80年代中期前后EAWM和ENSO的年代际变化共同引起的。在P1中，低层异常南风沿着中国东南沿海，伴随着水汽输送，导致降水偏多，这与中心位于中纬度西北太平洋的反气旋系统有关。在P2，东亚冬季风的影响较弱，中国东南沿海的偏南异常主要是由菲律宾上空的反气旋引起的，与ENSO有关。
The interdecadal change of the leading mode of the mean winter precipitation over China has been investigated using observational data for the period from 1960 to 2012. The leading empirical orthogonal function (EOF) mode (EOF1) of the winter precipitation over China displays a mono-sign pattern over southeastern China, accounting for 49.7 % of the total variance in the precipitation. Both the El Niño-Southern Oscillation (ENSO) and the East Asian winter monsoon (EAWM) can impact EOF1. A positive (negative) EOF1 is accompanied by warm (cold) ENSO events and weak (strong) EAWM, and the latters can cause anomalous southerlies (northerlies) along the coast of southeastern China, accompanied by the transportation of water vapor from the Bay of Bengal and the South China Sea favoring a wet (dry) winter over southeastern China. An abrupt transition of the EOF1 is observed around the mid-1980s. Therefore, the data are divided into two subperiods, i.e., 1960–1987 (P1) and 1988–2009 (P2). Significant differences in the large scale atmospheric circulation and sea surface temperature anomalies associated with EOF1 during these two subperiods are observed. EOF1 is closely related to the mid- to high-latitude atmospheric circulation in P1, while its relationship to the tropics obviously increases during P2. The partial regression analysis results show that the interdecadal change of EOF1 is caused by both the interdecadal changes of the EAWM and ENSO around the mid-1980s. In P1, the lower-level anomalous southerlies along the coastal southeastern China accompanied by water vapor transportation that causes above-average precipitation are related to an anti-cyclonic system centered over the mid-latitude western North Pacific associated with EAWM. In P2, the influence of the EAWM is weaker, and the southerly anomaly over the coastal southeastern China is mainly caused by the anticyclone over Philippines, which is related to the ENSO.