| 北太平洋副热带海洋环流强度异常对长江中下游夏季降水的影响 |
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| 引用本文： | 金啟华,王辉,姜华,何春,刘珊.北太平洋副热带海洋环流强度异常对长江中下游夏季降水的影响[J].海洋学报,2012,34(1):64-70. |
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| 作者姓名： | 金啟华 王辉 姜华 何春 刘珊 |
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| 作者单位： | 1.中国气象科学研究院, 北京 100081 |
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| 基金项目： | 国家自然科学基金(40805035;40976014);公益行业专项(GYHY-200906017);中国气象科学研究院基本科研业务费项目(2010Z001)和COPES(GYHY-200706005)联合资助。 |
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| 摘 要： | 利用SODA资料和ECCO资料计算得到的北太平洋副热带海洋环流强度,和国家气候中心整编的中国160站逐月降水资料,结合NCEP/NCAR再分析资料和Hadley中心海表面温度资料,分析了1970－2007年海洋环流强度异常同期的大尺度大气环流异常特征及对中国东部夏季降水的影响。结果表明:海洋环流强度变化与长江中下游地区降水存在密切的反相关。环流强度异常可以通过影响西太平洋副热带高压的南北位置异常进而影响长江中下游降水。海洋环流偏弱时,副高位置偏南,长江中下游地区受气旋性环流异常影响,来自副高西北侧的强西南水汽输送至此,在该地区形成强水汽辐合中心,同时伴随上升运动加强和对流的加强,进一步导致该地区降水偏多;当海洋环流偏强时,西太平洋副高位置偏北,长江中下游地区受反气旋性环流异常影响,伴随辐散下沉及水汽辐散,导致该地区降水偏少;海洋环流强度异常导致的中纬度海区海表面温度异常,可能是导致副高南北位置异常的主要原因。
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| 关 键 词： | 副热带海洋环流强度 长江中下游降水 西太平洋副热带高压 |
| 收稿时间： | 2010/8/31 0:00:00 |
| 修稿时间： | 2011/1/20 0:00:00 |
Impacts of the variations in the intensity of the northern Pacific subtropical ocean circulation on the rainfalls over the middle and lower reaches of the Changjiang River |
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| JIN Qihu,WANG Hui,JIANG Hu,HE Chun and LIU Shan.Impacts of the variations in the intensity of the northern Pacific subtropical ocean circulation on the rainfalls over the middle and lower reaches of the Changjiang River[J].Acta Oceanologica Sinica (in Chinese),2012,34(1):64-70. |
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| Authors: | JIN Qihu WANG Hui JIANG Hu HE Chun and LIU Shan |
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| Institution: | 1.Chinese Academy of Meteorological Sciences, Beijing 100081, China2.National Marine Environmental Forecasting Center, Beijing 100081, China3.Chinese Meterological Administration, Beijing 100081, China |
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| Abstract: | The impact of variability in the strength of the subtropical circulation in the North Pacific Ocean on the summer precipitation over the eastern China is investigated.The intensity of subtropical circulation in the North Pacific is diagnosed from SODA and ECCO dataset; the atmospheric circulation and the sea surface temperature (SST) are diagnosed from the NCEP/NCAR reanalysis dataset and the Hadley SST; the precipitation data is based on the monthly rainfall observations over 160 stations in China.This study is focused on the interaction between the atmospheric and oceanic circulations over the periods of 1970-2009.The results show that there exists a strong negative correlation between the variability of the sutropical circulatioin and the summer rainfall in the middle and lower reaches of the Changjiang River. When the subtropical gyre is relatively weaker (stronger) than normal, the subtropical high is located further south (north) than normal; an abnormal cyclonic (anticyclonic) circulation prevails over the Changjiang River basin, companied by the vigorous (weak) southwestern moisture transporting here to form a strong moisture convergence (divergence) center.This gives rise to an ascending vertical motion and at the same time the convection is strengthened (weakened).As a result, a very favorable large-scale circulation is established, which can sustain the heavy (weak) rainfalls in the middle and lower reaches of the Changjiang River.Furthermore, the variation in the subtropical wind-driven gyre can generate SST anomaly at middle latitudes, which may be the primarily reason for meridional shifting of the subtropical high in the North Pacific Ocean. |
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| Keywords: | intensity of the subtropical ocean circulation rainfall over the middle and lower reaches of the Changjiang River western Pacific subtropical high |
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