Impacts of summer North Atlantic sea surface temperature anomalies on the East Asian winter monsoon variability
Impacts of summer North Atlantic sea surface temperature anomalies on the East Asian winter monsoon variability
复制标题
夏季北大西洋海表温度异常对东亚冬季风变化的影响
DOI：
10.1175/jcli-d-19-0061.1
复制
发表时间：
2019
影响因子：
4.9
通讯作者：
Zhubiao Wang
中科院分区：
文献类型：
--
作者：
Zhang Chen;Renguang Wu;Zhubiao Wang
研究了北大西洋海温异常对东亚冬季风变率的影响。研究发现，EAWM变率的北方分量与1979-2016年夏季北大西洋海温异常的偶极子型相关。前期夏季北大西洋海温与东亚冬季风的联系过程包括北大西洋海气相互作用和北大西洋海温异常触发的大气波列。前期春夏大气风场异常通过地面热通量的变化形成偶极子型海温异常型。反过来，诱发的SST异常提供了对大气的反馈，改变了北大西洋上空异常风的位置和强度。与之相关的地面热通量异常使北大西洋海温异常分布由夏季的偶极型转变为冬季的三极型。冬季北大西洋三极海温异常激发了一个从北大西洋经欧亚大陆向东亚延伸的大气波列，导致东亚冬季风异常。然而，在20世纪70年代末之前，EAWM的北方分量与前期夏季北大西洋SST异常的关系较弱。1956- 1976年，由于北大西洋海气相互作用较弱，冬季没有形成明显的三极海温距平型。冬季大气波列位于高纬度地区，导致夏季夏季风北方分量与前期夏季北大西洋偶极子型海温距平场的联系较弱。
The present study investigates the impacts of the North Atlantic sea surface temperature (SST) anomalies on the East Asian winter monsoon (EAWM) variability. It is found that the northern component of the EAWM variability is associated with a dipole pattern of preceding summer North Atlantic SST anomalies during 1979–2016. The processes linking preceding summer North Atlantic SST to EAWM include the North Atlantic air–sea interactions and atmospheric wave train triggered by the North Atlantic SST anomalies. Atmospheric wind anomalies in the preceding spring–summer result in the formation of a dipole SST anomaly pattern through surface heat flux changes. In turn, the induced SST anomalies provide a feedback on the atmosphere, modifying the location and intensity of anomalous winds over the North Atlantic. The associated surface heat flux anomalies switch the North Atlantic SST anomaly distribution from a dipole pattern in summer to a tripole pattern in the following winter. The North Atlantic tripole SST anomalies excite an atmospheric wave train extending from the North Atlantic through Eurasia to East Asia in winter, resulting in anomalous EAWM. However, the relationship of the northern component of EAWM to preceding summer North Atlantic SST anomalies is weak before the late 1970s. During 1956–76, due to weak air–sea interaction over the North Atlantic, no obvious tripole SST anomaly pattern is established in winter. The atmospheric wave train in winter is located at higher latitudes, leading to a weak connection between the northern component of EAWM and the preceding summer North Atlantic dipole SST anomaly pattern.