| 关键区海温年代际异常对我国东部夏季降水影响 |
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| 引用本文： | 袁杰,巩远发,魏凤英,陈官军.关键区海温年代际异常对我国东部夏季降水影响[J].应用气象学报,2013,24(3):268-277. |
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| 作者姓名： | 袁杰 巩远发 魏凤英 陈官军 |
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| 作者单位： | 1.成都信息工程学院，成都 610225 |
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| 基金项目： | 〗公益性行业（气象）科研专项（GYHY200906016），中国气象科学研究院基本科研业务费项目（2010Z001）,国家自然科学基金项目（40975044，41275080） |
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| 摘 要： | 利用1931—2010年UKMO HADISST1全球月海表温度、NOAA再分析资料及我国东部96个站月降水量资料，使用REOF，SVD及合成分析等方法探讨了关键区冬季海表温度 (SST) 年代际异常对我国东部夏季降水的影响。结果表明:当冬季黑潮区SST年代际异常处于正位相时，夏季500 hPa中高纬度地区位势高度呈“+-+”距平分布，西风带经向环流盛行，西太平洋副热带高压加强、西伸；850 hPa风场距平场上，北方地区为反气旋性异常控制，南海上空为异常偏南气流，这样的环流配置有利于我国东部夏季多雨带出现在长江中下游地区；当冬季南印度洋偶极子 (SIOD) 年代际异常处于正位相时，夏季500 hPa中高纬度地区位势高度为正距平，阻塞形势发展，经向环流盛行，有利于冷空气南下，西太平洋副热带高压强度偏强，位置略偏南、偏西；850 hPa风场距平场上，北方地区为一反气旋性异常控制，异常偏北气流延伸至我国南方地区，索马里越赤道气流偏强。这种环流配置使得副热带锋区偏南，夏季多雨带位于华南及东南沿海地区。
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| 关 键 词： | 雨带类型 海表温度 大气环流 |
| 收稿时间： | 2012-08-23 |
Effects of Key Regional SST Inter-decadal Anomaly on Summer Precipitation in Eastern China |
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| Affiliation: | 1.Chengdu University of Information Technology, Chengdu 6102252.State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081 |
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| Abstract: | By the influence of the summer wind, the summer rain-band in Eastern China advances gradually from the south to the north in China, but under the influence of a variety of complicated factors, the rain-band propulsion speeds up or delays in a certain area, finally forms the different rain-band distribution types. First, four rain-band patterns are defined in summer precipitation in Eastern China and then four sea surface temperature (SST) modes which lead to summer precipitation anomaly are found using singular value decomposition (SVD) method, from which four key sea regions related significantly with summer rain-band patterns in Eastern China are selected, and characteristics of summer precipitation distribution in Eastern China and atmospheric circulation in East Asia are analyzed with composite analysis in the background of key sea regional winter sea surface temperature anomaly (SSTA) in terms of NOAA Twentieth Century reanalysis data, UKMO HADISST1 global monthly SST and monthly precipitation of 96 stations in Eastern China during 1931—2010.When the winter Kuroshio SST inter-decadal anomaly is positive phase, 500 hPa geopotential height field in summer shows that the blocking highs develop in the mid-high latitudes of Eurasia, the meridional circulation in westerlies are intensified, the cold forces are strong and the western Pacific subtropical high strengthens and shifts westwards. 850 hPa wind field anomaly in summer shows that the north of China is governed by anomalous anticyclone, over the South China Sea is southerly winds anomalies, and the East Asian summer monsoon is weak. The circulations are useful for Pattern Ⅲ in summer precipitation in Eastern China where the rain belt is located in the mid-lower reaches of the Yangtze. When the winter Southern Indian Ocean Dipole inter-decadal anomaly is positive phase, 500 hPa geopotential height field in summer shows that a positive anomaly distribution develops in the mid-high latitudes, the blocking highs develop, meridional circulation are intensified, cold forces are strong and the western Pacific high becomes strong and shifts southward and westwards. 850 hPa wind field anomaly in summer shows that north China is controlled by anti-cyclonic anomaly, the anomaly north airflow extends to Southern China region and the Somalia cross-equatorial flow strengthens, which bring more rainfall in the Southern China region. |
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| Keywords: | rainfall band patterns sea surface temperature atmospheric circulation |
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