Variations of Northern Hemisphere Storm Track and Extratropical Cyclone Activity Associated with the Madden–Julian Oscillation
Variations of Northern Hemisphere Storm Track and Extratropical Cyclone Activity Associated with the Madden–Julian Oscillation
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DOI：
10.1175/jcli-d-16-0513.1
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发表时间：
2017-05
影响因子：
4.9
通讯作者：
Yanjuan Guo;T. Shinoda;Jialin Lin;E. Chang
中科院分区：
文献类型：
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作者：
Yanjuan Guo;T. Shinoda;Jialin Lin;E. Chang
本文利用ERA-TIMATION 36年(1979-2014)再分析资料，研究了北半球风暴轴的季节内变化与北方冬季延长的Madden-Julian振荡(MJO)有关。有两种方法被用来诊断风暴路径的变化。在第一种方法中，风暴路径由250百帕经向风(Vv250)或平均海平面气压(Pp)的时间滤波方差来量化。VV250的季节内异常由8个MJO相组合而成，表现为一条由太平洋至北美洲和大西洋至北欧的强正(或负)异常纬向带，在一侧或两侧有较弱的反号异常。基于pp的结果与基于vv250的结果一致，只是纬向差异较大，这可能是由表面地形引起的。在第二种方法中，使用了一种客观的气旋跟踪方案来跟踪热带气旋。
AbstractThis study investigates the intraseasonal variations of the Northern Hemispheric storm track associated with the Madden–Julian oscillation (MJO) during the extended boreal winter (November–April) using 36 yr (1979–2014) of reanalysis data from ERA-Interim. Two methods have been used to diagnose storm-track variations. In the first method, the storm track is quantified by the temporal-filtered variance of 250-hPa meridional wind (vv250) or mean sea level pressure (pp). The intraseasonal anomalies of vv250 composited for eight MJO phases are characterized by a zonal band of strong positive (or negative) anomalies meandering from the Pacific all the way across North America and the Atlantic into northern Europe, with weaker anomalies of opposite sign at one or both flanks. The results based on pp are consistent with those based on vv250 except for larger zonal variations, which may be induced by surface topography. In the second method, an objective cyclone-tracking scheme has been used to track the ...