Analysis of isentropic potential vorticities for the relationship between stratospheric anomalies and the cooling process in China  

平流层异常和我国冬季降温过程的等熵位涡分析(英文)

作　　者：陆春晖 丁一汇 

机构地区：[1]Laboratory for Climate Studies, National Climate Center, China Meteorological Administration

出　　处：《Science Bulletin》2015年第7期726-738,M0004,共14页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(41205041);Chinese Special Fund for Meteorology(GYHY201406020);National Basic Research Program of China(2012CB417205);LCS Open Funds for Young Scholars(2014)

摘　　要：We analyze the relationships between strato- spheric polar vortex anomalies and cooling events in eastern China using isentropic reanalysis data from the European Center for Medium-Range Weather Forecasts. Daily mean data from 2000 to 2011 are used to explore the effective stratospheric signals. First, diagnoses of the 2009/2010 winter show that after the stratospheric sudden warming （SSW） of the Atlantic-East Asian （AEA） pattern, the stratospheric high isentropic potential vorticity （IPV） center derived from the split polar vortex will move to the northeast of the Eurasian continent. The air mass, accom- panied by some southward and eastward movements and characterized by high IPV values, will be stretched verti- cally, leading to apparent reinforcements of the positive vorticity and the development of acold vortex system in the troposphere. The northerly wind on the western side of the cold vortex can transport cold air southward and down- ward, resulting in this distinct cooling process in eastern China. Secondly, the empirical orthogonal function ana- lyses of IPV anomalies on the 430 K isentropic surface during 2000-2011 winters indicate that the IPV distribution and time series of the first mode are able to represent the polar vortex variation features, which significantly influ- ence cold-air activity in eastern China, especially in the AEA-type SSW winter. When the time series increases significantly, the polar vortex will be split and the high-IPV center will move to the northeast of the Eurasian continent with downward and southward developments, inducing obvious cooling in eastern China. Moreover, all the four times SSW events of AEA pattern from 2000 to 2011 are reflected in the first time series, and after the strong polar vortex disturbances, cooling processes of different inten- sities are observed in eastern China. The cooling can sus- tain at least 1 week. For this reason, the first time series can be used as an available index of polar vortex oscillation and has the power to predict 我们从中等范围的天气预报的欧洲中心用 isentropic 分析数据在东方中国分析在同温层的极的旋涡异例和冷却事件之间的关系。从 2000 ～ 2011 的每天吝啬的数据被用来探索有效同温层的信号。首先， 2009/2010 冬季表演诊断在以后同温层的突然的温暖(SSW ) 大西洋东方亚洲人(AEA ) 模式，从切开的极的旋涡导出的同温层的高 isentropic 潜力涡度(IPV ) 中心将搬到欧亚的大陆的东北。空气团，由一些向南方、东方的运动伴随了并且由高 IPV 值描绘了，将垂直地被拉长，在对流层导致积极涡度的明显的加强和寒冷的旋涡系统的开发。冷旋涡的西方的方面上的在北方的风能搬运在东方中国向南方、在这个不同冷却过程向下，结果的冷空气。第二，实验直角的功能 IPV 分析异例在上 430 ?在 20002011 期间，冬季显示的 K isentropic 表面第一个模式的 IPV 分发和时间系列能代表极的旋涡变化，这展示，它显著地在东方中国影响冷空气的活动，特别在AEA类型 SSW 冬季。当时间系列显著地增加时，极的旋涡将被切开， high-IPV 中心将搬到欧亚的大陆的东北与向下并且向南方的开发，导致在东方中国的明显的冷却。而且，从 2000 ～ 2011 的 AEA 模式的所有四个次 SSW 事件在第一次系列被反映，并且在强壮的极的旋涡骚乱以后，不同紧张的冷却过程在东方中国被观察。冷却能支撑至少 1 ? 星期。为这个原因，第一次系列能被用作极的旋涡摆动的一个可得到的索引并且有力量在冬季预言冷空气的活动。

关 键 词：Isentropic potential vorticity Stratospheric sudden warming EOF analysis Polarvortex oscillation Cooling process 

分 类 号：P423[天文地球—大气科学及气象学]