中国冬季地面气温10-30d低频变化及其与乌拉尔山环流的关系
投稿时间: 2016-11-15  最后修改时间: 2017-03-13  点此下载全文
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作者单位E-mail
张文正 南京信息工程大学大气科学学院 1543233740@qq.com 
基金项目:国家公益性行业专项,国家科技支撑计划课题,国家自然科学基金项目
中文摘要:本文使用国家气象信息中心冬季(12-2月)逐日气温和NCEP/NCAR再分析资料及非滤波方法提取10-30d低频成分,分析了1979-2011年中国低频气温及其关联的大气环流特征,着重讨论了乌拉尔山环流对中国冬季地面低频气温的影响。结果表明:(1)全国气温第一模态呈现全国大部偏冷(暖) 的空间分布型;典型年气温10-30d低频方差贡献率占30%以上。(2)北大西洋到极地、乌拉尔山及贝加尔湖地区环流异常与中国冬季气温异常显著相关。当极涡偏弱或北大西洋NAO正异常,乌拉尔山地区高压脊偏强时,有利于地面贝加尔湖附近的冷高压加强,使中国冬季气温偏冷;反之亦然。(3)中国12-2月低频气温与乌拉尔山环流密切相关,且当乌拉尔山环流异常超前15天左右时,两者相关关系最好。即乌拉尔山高度场异常加强有利于乌拉尔山高压脊及西伯利亚高压加强,对应东亚冬季风加强,导致中国冬季气温偏低。
中文关键词:关键词 中国低频温度;非滤波法  低频;乌拉尔山
 
Low frequency variation of 10-30d air temperature and its relationship with the Ural mountain circulation in winter in China
Abstract:In this paper, winter daily surface air temperature data of National Climate Center and the NCEP / NCAR global reanalysis data, the non-filtering method was applied to extract the low-frequency signals of 10-30 days from the air temperature and atmospheric circulation.The low-frequency air temperature in China from 1979 to 2011 during December and February and associated atmospheric circulations are analyzed, focusing on the influence of the Ural mountain circulation on the low frequency air temperature in winter China. The results showed that: (1) the first mode of surface air temperature in winter demonstrates a consistent cold (warm) pattern over most part of China. The variance of the 10-30d low frequency surface air temperature accounts for more than 30% of the total. (2) When the polar vortex is weaker or the North Atlantic NAO is abnormal, high pressure ridge in the Ural Mountain area is stronger than normal. It is conducive to strengthening of Siberian cold high at surface, so that it is cold over China; and vice versa. (3)The low frequency air temperature in winter is closely related to the Ural mountain circulation. When circulation over Ural Mountain leads 15 days earlier than the surface air temperature, the relationship is best. That is, the positive height anomalies over Ural mountain is conducive to strengthening the Ural mountain high ridge and Siberian high, and East Asian winter monsoon, and then lead to a lower temperature anomaly winter in China.
keywords:Key words Chinese low frequency temperature  non-filtering method  low frequency  Ural Mountains
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