中国冬季地面气温10~30 d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: 2017-03-14  点此下载全文
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谭桂容 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044;南京信息工程大学 大气科学学院, 江苏 南京 210044 tanguirong@nuist.edu.cn 
张文正 南京信息工程大学 大气科学学院, 江苏 南京 210044  
基金项目:公益性行业(气象)科研专项(GYHY201206016;GYHY201306028);国家科技支撑计划课题(2015BAC03B00);国家自然科学基金资助项目(41475088;41475090)
中文摘要:基于国家气象信息中心冬季(12月—次年2月)逐日气温和NCEP/NCAR再分析资料,采用非滤波方法提取10~30 d低频成分,分析了1979—2011年中国低频气温及与之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10~30 d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涛动(North Atlantic Oscillation,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)中国冬季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约15 d时,两者相关关系最好。即乌拉尔山高度场的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:中国气温  低频变化  大气环流  非滤波方法
 
The 10-30 d low-frequency variation of winter surface air temperature in China and its relationship with Ural mountain circulation
Abstract:Based on the winter(DJF) daily surface air temperature data from China National Meteorological Information Center and the NCEP/NCAR global reanalysis data,the non-filtering method is applied to extract the low-frequency signals of 10-30 d from the air temperature and atmospheric circulation.The low-frequency air temperature in China in winter from 1979 to 2011 and associated atmospheric circulation characteristics are analyzed,focusing on the influence of the Ural mountain circulation on the low-frequency surface air temperature in China in winter.Results show 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 10-30 d low-frequency surface air temperature accounts for more than 30% of the total in the typical years.2)Circulation anomalies in the North Atlantic to the polar region,Ural Mountain and Lake Baikal are significantly related to winter temperature anomalies in China.When the polar vortex is weaker or the NAO is a positive anomaly,the high pressure ridge in the Ural mountain area is stronger,which is conducive to strengthening of Siberian cold high near Lake Baikal at the surface,so that it is cold in China;and vice versa.3)The low-frequency air temperature in China in winter is closely related to the Ural mountain circulation.When the circulation anomaly over the Ural mountain area leads 15 d earlier than the surface air temperature,their relationship is best.That is,the positive height anomalies over the Ural mountain area is conducive to strengthening of the Ural mountain high ridge and Siberian high,in such a way that East Asian winter monsoon is strengthened,which leads to low temperature in China in winter.
keywords:China air temperature  low-frequency change  atmospheric circulation  non-filtering method
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