南印度洋副热带偶极子型海温异常与全球环流和我国降水变化的关系
Indian Ocean subtropical dipole and variations of global circulations and rainfall in China
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摘要: 用1951~2001年观测资料,研究了南印度洋副热带偶极子型(IOSD)海温异常对全球500hPa环流和我国降水的影响.结果表明,冬季IOSD激发出极显著的南北半球环绕太平洋的波列结构(CP),其年际变化周期是2.0和6.5 a,与赤道中东太平洋海温也有密切联系.北半球冬季异常峰值后的第二年春季欧亚中高纬度地区500 hPa环流出现显著的EUP型低频流型持续异常,同时中太平洋和北美地区出现CPNP流型和澳大利亚南部的南半球中高纬地区呈现极显著的西南太平洋遥相关型(SWP).当冬季赤道南印度洋副热带呈极显著的西负东正海温距平分布时,后期春季欧亚中高纬地区负EUP型遥相关波列持续偏强,导致东亚大槽明显偏弱,长江以北地区(特别是黄河中上游地区)多雨.反之,春季东亚大槽加强且稳定,我国东部地区大范围少雨.它反映了南印度洋地区海气系统相互作用与东亚热带内外环流低频变化的联系.因此,上一年冬季南印度洋副热带偶极子型(IOSD)海温异常强度是预测春季华北地区旱涝变化的重要因子之一.
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关键词:
- 南印度洋海温偶极子型(IOSD) /
- 全球环流 /
- CP型 /
- SWP型 /
- 中国降水
Abstract: Based on the observed data during the period of 1951~2001,the effects of the subtropical dipole of SST in the southern Indian Ocean(IOSD)on the global 500 hPa circulations and the rainfall in China are investigated.Results show that the low frequency wavetrain of circum-Pacific pattern(CP)exists over Pacific Ocean for the extreme phase of IOSD in the Northern Hemisphere winter,in which the main periods are about 2.0 and 6.5 a,and is closely linked to SST in the equatorial central and eastern Pacific.The Eurasian Pacific pattern(EUP)and the central Pacific/the North Pole(CPNP)wavet rain in the Northern Hemisphere and southwestern Pacifict eleconnection pattern(SWP)in the Southern Hemisphere are dominant for the following spring.When there is a pattern with west negative and east positive in the subt ropical southern Indian Ocean in winter,the negative EUP pattern is stronger during the next spring,leading to a weak trough in eastern Asia and plenty rainfall in north of Changjiang River Valley,in particular the upper and middle reaches of Huanghe River Valley.Conversely,the stronger and stable trough in East Asia,resulting in the rare rainfall in east China.It is reflected the connections between the interactions of air-ocean system in the southern Indian ocean and low frequency variations in the tropical and extratropical eastern Asia.Thus,the intensity of IOSD in the Northern Hemisphere winter is considered as one of the main factor for the predicting of the rainfall in the north of China in the following spring. -
陈烈庭.阿拉伯海-南海海温距平纬向差异对长江下游降水的影响,大气科学,1991,15(1):33-42. 陈烈庭,金祖辉,罗绍华.印度洋和南海海温变化的特征及其与大气环流的某些联系[J].海洋学报,1985,7:103-110. 邓爱军,陶诗言,陈烈庭.印度洋海表温度的时空分布特征及其与我国汛期降水关系的探讨[J].大气科学,1989,13(4):393-399. 吴国雄,孙凤英,王敬方,等.降水对热带海表温度异常的邻域响应:I.数值模拟[J].大气科学,1995,19(4):422-434. 吴国雄,刘平,刘屹岷,等.印度洋海温异常对西太平洋副热带高压的影响--大气中的两级热力适应[J].气象学报,2000,58(5):513-522. SAJI N H,GOSWAMI B N,VINAYACHANDRAN P N,et al.A dipole mode in the tropical Indian Ocean[J].Nature,1999,401:360-363. WEBSTER P J,ANDREW M M,JOHANNES P,et al.Coupled ocean-atmosphere dynamics in the Indian Ocean during 1997-98[J].Nature,1999,401:356-360. IIZUKA S,MATSUURA T,YAMAGATA T.The Indian Ocean SST dipole simulated in a coupled general circulation model[J].Geophys Res Lett,2000,27:3 369-3 372. CHAMBERS D P,TAPLEY B D,STEWART RH.Anomalous warming in the Indian Ocean coincident with El Nin o[J].J Geophys Res,1999,104:3 035-3 047. BEHERA S K,SALVEKAR P S,YAMAGATA T.Simulation of interannual variability in the tropical Indian Ocean[J].J Climate,2000,13:3 487-3 499. SAJI N H,YAMAGATA T.Structure of SST and surface wind variability during Indian Ocean Dipole mode events:COADS Observations[J].J Climate,2003,16(16):2 735-2 751. LI Chong-yin,MU Ming-quan.The influence of the Indian Ocean Dipole on atmospheric circulation and climate[J].A A S,2001,18(5):831-843. XIE S-P,ANNAMALAI H,SCHOTT F A,et al.Structure and mechanisms of South Indian Ocean climate variability[J].J Climate,2002,15(8):864-878. REASON C J C,MULENGA H M.Relationships between South African rainfall and SST anomalies in the SW Indian Ocean[J].Int J Climatol,1999,19:1 651-1 673. BEHERA S K,YAMAGATA T.Subtropical SST dipole events in the southern Indian Ocean[J].Geophys Res Lett,2001,28:327-331. SCHICKEDANZ P T,BOWEN E G.The computation of climatological power spectrum[J].J Appl Met,1977,16:359-367. WANG Huijun.The circum-Pacific teleconnection pattern in meridional wind in the high troposphere[J].Adv Atmos Sci,2005,22(3):463-466. 罗哲贤.大尺度流型年际变化可能机制的研究[J].气象学报,1993,51(3):266-273. -
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