北非射出长波辐射(OLR)异常对中国西部秋季降水的影响  

Impact of the north Africa OLR anomaly on autumn precipitation in western China

作　　者：陈少勇[1,2] 乔立[2] 林纾[1] 夏权[2] 

机构地区：[1]中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,中国气象局干旱气候变化与减灾重点开放实验室,兰州730020 [2]白银市气象局,白银730900

出　　处：《干旱区资源与环境》2011年第12期64-70,共7页Journal of Arid Land Resources and Environment

基　　金：国家自然科学基金“中国西部地区秋季降水机制研究”(406750066);甘肃省气象局"十人计划"资助

摘　　要：利用中国西部280站地面降水资料和NCEP再分析月平均OLR资料,采用EOF、REOF、SVD等方法,分析了中国西部秋雨与OLR的关系,结果表明:西部秋季平均降水异常与前两年1月至当年4月北非-阿拉伯半岛-伊朗高原的OLR连续存在负相关,特别是与前两年夏季北非关键区的OLR呈显著的反相关;关键区的OLR与西部秋季降水的相关以9月份最显著,其次是11月份较显著,而10月份呈较弱的负相关;SVD分析结果表明,前两年夏季北非OLR异常偏高(偏低)时,对应后两年华西秋雨将会异常偏少(偏多),新疆和蒙甘宁区秋雨将会异常偏多(偏少);使用REOF分析把西部秋季降水分为12个子区域,用EOF方法分析了北非OLR对西部子区域秋季降水异常的影响。结果表明,北非前两年夏秋季OLR与广西-贵州的秋雨有显著的负相关,前一年夏秋季OLR与广西-贵州、四川的秋雨有显著的负相关、与西藏高原东部的秋雨有显著的正相关,当年夏秋季OLR与广西-贵州的秋雨有显著的负相关、与西藏高原东部和江河源的秋雨有较显著的正相关;关键区OLR影响中国西部秋季降水,但这种影响存在区域差异。Using SVD,correlation analysis and EOF method,we analyzed the relationship between the Autumn precipitation changes anomaly in western China and North Africa OLR anomalies.The main results were as follows： Autumn precipitation anomaly from January of the year before last year to the latest April had an negative correlation with the OLR of the area in the North Africa-Arabian Peninsula-Iran plateau（17.5°～27.5°N,15°～32.5°E）continuously,specially with that of the year before last summer,which assumed the remarkable trans-position distribution;The key area OLR had the most remarkable correlation with the western autumn precipitation in September,next was remarkable in November,but in October it assumed the weak negative correlation;The SVD analysis result indicated when North Africa essential area OLR in the year before last summer was exceptionally high（somewhat low）,it would correspond with the autumn rain to be exceptionally few（many） in the latest two years,and in Xinjiang and Mongolia-Gan-Ning area,the autumn rain would be able to be exceptionally many（few）.Using the REOF analysis we can divide the western autumn precipitation field into 12 subareas.Impact of the North Africa OLR on the western 12 subareas autumn precipitation anomaly were analyzed with the EOF method.The result indicated that the North Africa key area OLR of the summer and autumn of the year before last yeaf had the remarkable negative correlation with the Guangxi-Guizhou＇s autumn rain,the OLR of the summer and autumn of the last year had the remarkable negative correlation with the Guangxi-Guizhou,Sichuan＇s autumn rain and had the remarkable positive correlation with the east Tibet Plateau autumn rain.The past summer autumn OLR had the remarkable negative correlation with the Guangxi-Guizhou＇s autumn rain,and had the remarkable positive correlation with the east Tibet Plateau autumn rain;（6） The key area OLR affected the west China autumn precipitation,but the influences had the regional differences.

关 键 词：北非 OLR 中国西部秋季降水 EOF分析 SVD分析 

分 类 号：P426.6[天文地球—大气科学及气象学]