利用1979-2014年ERA Interim再分析资料和NCAR CAM5.1大气环流模式,围绕海温对夏季亚洲急流变异主模态的影响展开研究.首先通过理论分析和动力诊断方法,对急流主模态的物理特征进行分析,并证实了海温与急流变异的显著联系.随后基于观测结果设计数值试验方案,探究不同区域海温对急流演变的具体贡献.结果表明,急流第一模态与太平洋及印度洋异常海温紧密联系,在二者相似的贡献下,高层异常风场表现为沿急流轴线南北偏移的纬向对称分布;急流第二模态的上、下游风场则受到不同海表热源影响,在印度洋、太平洋及北大西洋异常海温的协同作用下,亚洲上空形成了四极型纬向非对称的风场分布.该结果有利于更加综合地认识亚洲夏季副热带急流的变异特征,也为研究海温对急流的影响效应提供了新的依据.%Based on ERA-Interim(1979-2014) reanalysis data and NCAR Community Atmosphere Model (CAM 5.1),the influences of Sea Surface Temperature Anomaly (SSTA) on the dominant modes of summer Asian subtropical westerly jet variability were explored.Firstly,by using theoretical analysis and dynamic diagnostic methods,the physical characteristics of jet domain modes were analyzed and the significant association between SSTA and the summer jet variation was confirmed.Secondly,on the basis of observation,various numerical experiments were designed to explore the specific contribution of SSTA in different regions.Results show that the first mode is closely related to the Pacific and Indian Ocean SSTA,and under their similar influences,the high-level wind field showed a zonally symmetric distribution with meridional migration along axis;the upstream and downstream wind fields of the second mode are affected by different sea surface heat source,and the synergic effect of the Indian,Pacific and North Atlantic SSTA produce a quadrupole asymmetric distribution over Asia.These results help to understand the variation characteristics of the summer Asian subtropical westerly jet more comprehensively and provide a new basis for the study of SSTA effects on jet variability.
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