A Synoptic Analysis of the Interannual Variability of Winter Cyclone Activity in the Aleutian Low Region
A Synoptic Analysis of the Interannual Variability of Winter Cyclone Activity in the Aleutian Low Region
复制标题
DOI：
10.1175/jcli4077.1
复制
发表时间：
2007-04
影响因子：
4.9
通讯作者：
Xiaojie Zhu;Jilin Sun;Zhengyu Liu;Qinyu Liu;Jonathan E. Martin
中科院分区：
文献类型：
--
作者：
Xiaojie Zhu;Jilin Sun;Zhengyu Liu;Qinyu Liu;Jonathan E. Martin
分析了与北太平洋多年强弱阿留申低气压相关的冬季气旋活动。从1958年到2004年，有10个冬季有较强的阿留申低压年被定义为强年，而8个冬季有较弱的阿留申低压年被定义为弱年。采用以系统为中心的拉格朗日方法，揭示了两组年份气旋活动的一些特征。强年和弱年的气旋频率、持续时间和强度几乎相同。强年份的气旋路径比弱年份的气旋路径更具地带性。强年比弱年发生更强烈的气旋事件和更多的大型气旋事件，并且强年气旋的加深比弱年更强。对 500 或 300 hPa 位势高度、风、静止罗斯贝波数和伊迪增长率指数的分析表明，强年比弱年更有利于更多纬向路径和更大的气旋增长。对气旋强度的相对变化和阿留申低强度的相对变化进行了估算，结果表明，气旋强度的年际变化约为阿留申低强度年际变化的73%。这一结果表明，单个气旋的演变可能是阿留申低气压变化的重要驱动因素。
An analysis of cyclone activity in winter associated with years of strong and weak Aleutian low in the North Pacific is presented. From 1958 to 2004, 10 winters with a strong Aleutian low are defined as the strong years, while 8 winters with a weak Aleutian low are defined as the weak years. Employing a system-centered Lagrangian method, some characteristics of the cyclone activity in both sets of years are revealed. The cyclone frequency, duration, and intensity are nearly the same in both strong and weak years. The cyclone tracks in the strong years are more zonal than those in the weak years. More intense cyclone events and more large cyclone cases occur in strong years than in weak years and the deepening of cyclones in strong years is stronger than that in weak years. The analyses of geopotential height, wind, stationary Rossby wavenumber, and Eady growth rate index at 500 or 300 hPa reveal that conditions are favorable for more zonal tracks and greater cyclone growth in strong years than in weak years. An estimation of the relative change of cyclone intensity and the relative change of Aleutian low intensity is made, which shows that the interannual change of cyclone intensity is about 73% of the interannual change of Aleutian low intensity. This result suggests that the evolution of individual cyclones may be a significant driver of changes in the Aleutian low.