Robust warming over East Asia during the boreal winter monsoon and its possible causes
Robust warming over East Asia during the boreal winter monsoon and its possible causes
复制标题
DOI：
10.1088/1748-9326/8/3/034001
复制
发表时间：
2013-07
影响因子：
6.7
通讯作者：
Sun‐Seon Lee;Seon‐Hwa Kim;J. Jhun;K. Ha;Y. Seo
中科院分区：
文献类型：
--
作者：
Sun‐Seon Lee;Seon‐Hwa Kim;J. Jhun;K. Ha;Y. Seo
通过对1960-2009年东亚冬季地表气温年际变化的分析发现，东亚冬季风在20世纪80年代中期后显着减弱。东亚地区对流层中下层和地表的剧烈变暖主要是由北太平洋和欧亚大陆环流的变化引起的。与冷潮密切相关的300 hPa东亚急流和EA地区上空500 hPa低压槽在20世纪80年代中期后显着减弱。西伯利亚高地和EA区北部偏北风减弱，干扰了吹向EA区的冷平流。由于类似北太平洋涛动（NPO）的海平面压力（SLP）模式增强，东海出现异常东南风，导致东海地区出现异常暖平流。研究还发现，20世纪80年代中期以后，异常风对平均气温的平流作用和平均风对平均气温的平流作用是东亚区异常暖平流的主要贡献因素。因此，这些异常环流为东亚冬季风的减弱提供了更有利的环境。
An analysis of the interannual variability of surface air temperature during the boreal winter in the East Asian (EA) region from 1960 to 2009 reveals that the East Asian winter monsoon (EAWM) significantly weakens after the mid-1980s. The robust warming over the EA region in the lower and middle troposphere as well as at the surface is caused mainly by changes in circulations over the North Pacific and Eurasian continent. The 300 hPa East Asian jet and 500 hPa trough over the EA region, which are closely linked to cold surges, significantly weaken after the mid-1980s. The weakened northerly wind in the Siberian high region and north of the EA region interfere with cold advection toward the EA region. The anomalous southeasterlies over the East China Sea due to an enhanced North Pacific oscillation (NPO)-like sea level pressure (SLP) pattern lead to anomalous warm advection over the EA region. It is also found that the advection of mean temperature by anomalous wind and the advection of anomalous temperature by mean wind mainly contribute to the anomalous warm advection in the EA region after the mid-1980s. Consequently, these anomalous circulations provide a more favorable environment for weakening of the EAWM.