春季赤道印度洋纬向—垂直环流的变化特征及其与Walker环流的关系
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摘要
利用1951~2010年20CR(20th Century Reanalysis Version 2)再分析资料和NOAA海表温度资料研究了赤道印度洋纬向—垂直环流的季节性差异、变化特征及其与Walker环流的关系。本文首先分析了四个季节赤道印度洋上空纬向—垂直环流的结构特征,发现春季和秋季存在严格东西方向上的赤道印度洋纬向—垂直环流。随后,针对春季赤道印度洋纬向—垂直环流变化特征作进一步的分析,研究结果表明,春季纬向—垂直环流的强度及其变率在1951~2010年间持续增强,而该垂直环流的中心位置则表现出明显的年代际变化特征:1981年之前垂直环流的中心位置表现为向西移动,而在1981年后则转为向东移。春季赤道印度洋纬向—垂直环流与Walker环流之间的相关关系同样存在年代际转折,1981年之前两者之间并不存在显著的相关,而在1981年之后,两者之间的关系显著增强。不同年代际时段内赤道印度洋纬向—垂直环流与海温的关系也发生了明显的改变,1981~2010年赤道印度洋纬向—垂直环流主要受到前期和同期太平洋上的ENSO型海温信号的影响,而在此之前该垂直环流主要受到前期和同期赤道东印度洋海温的影响。
Based on the 20 CR reanalysis dataset and the sea surface temperature(SST) dataset provided by NOAA, seasonal differences and variations of the equatorial Indian Ocean zonal–vertical circulation(EIOZVC) and its correlation with the Walker circulation are investigated. First, structures of the EIOZVC in the four seasons are analyzed,and the results suggest that the EIOZVC in a strictly zonal direction only appears in the spring and autumn. Further studies on variations of the EIOZVC in the spring show that the intensity of the EIOZVC and its variability increased during the period of 1951–2010, while the position of the EIOZVC center experienced a remarkable interdecadal variation: prior to 1981, the EIOZVC center shifted westward; however, it shifted eastward after 1981. There is also a noticeable interdecadal variation in the correlation between the EIOZVC and the Walker circulation in the spring. No high correlation is found between them prior to 1981, whereas the two circulations are found to be highly correlated after 1981. The relationship between the spring EIOZVC and seasonal mean SSTs over the Indian and Pacific Oceans also exhibits different patterns between the two periods, indicating that the EIOZVC is influenced primarily by the Pacific ENSO-like SST signals in the previous winter and the subsequent spring after the year of 1981. Before 1981, however, the EIOZVC was mainly influenced by the equatorial eastern Indian Ocean SSTs.
Based on the 20 CR reanalysis dataset and the sea surface temperature(SST) dataset provided by NOAA, seasonal differences and variations of the equatorial Indian Ocean zonal–vertical circulation(EIOZVC) and its correlation with the Walker circulation are investigated. First, structures of the EIOZVC in the four seasons are analyzed,and the results suggest that the EIOZVC in a strictly zonal direction only appears in the spring and autumn. Further studies on variations of the EIOZVC in the spring show that the intensity of the EIOZVC and its variability increased during the period of 1951–2010, while the position of the EIOZVC center experienced a remarkable interdecadal variation: prior to 1981, the EIOZVC center shifted westward; however, it shifted eastward after 1981. There is also a noticeable interdecadal variation in the correlation between the EIOZVC and the Walker circulation in the spring. No high correlation is found between them prior to 1981, whereas the two circulations are found to be highly correlated after 1981. The relationship between the spring EIOZVC and seasonal mean SSTs over the Indian and Pacific Oceans also exhibits different patterns between the two periods, indicating that the EIOZVC is influenced primarily by the Pacific ENSO-like SST signals in the previous winter and the subsequent spring after the year of 1981. Before 1981, however, the EIOZVC was mainly influenced by the equatorial eastern Indian Ocean SSTs.
引文
Bayr T,Dommenget D,Martin T,et al.2014.The eastward shift of the Walker circulation in response to global warming and its relationship to ENSO variability[J].Climate Dyn.,43(9-10):2747-2763,doi:10.1007/s00382-014-2091-y.
Collins M,An S I,Cai W J,et al.2010.The impact of global warming on the tropical Pacific Ocean and El Ni?o[J].Nat.Geosci.,3(6):391-397,doi:10.1038/ngeo868.
Compo G P,Whitaker J S,Sardeshmukh P D,et al.2011.The twentieth century reanalysis project[J].Quart.J.Roy.Meteor.Soc.,137(654):1-28,doi:10.1002/qj.776.
Fischer A S,Terray P,Guilyardi E,et al.2005.Two independent triggers for the Indian Ocean dipole/zonal mode in a coupled GCM[J].J.Climate,18(17):3428-3449,doi:10.1175/JCLI3478.1.
Flohn H,Fleer H.1975.Climatic teleconnections with the equatorial Pacific and the role of ocean/atmosphere coupling[J].Atmosphere,13(3):96-109,doi:10.1080/00046973.1975.9648391.
Gill A E.1982.Atmosphere-Ocean Dynamics[M].New York:Academic Press,662pp.
Hastenrath S.2007.Circulation mechanisms of climate anomalies in East Africa and the equatorial Indian Ocean[J].Dyn.Atmos.Oceans,43(1-2):25-35,doi:10.1016/j.dynatmoce.2006.06.002.
Hastenrath S,Polzin D,Mutai C.2011.Circulation mechanisms of Kenya rainfall anomalies[J].J.Climate,24(2):404-412,doi:10.1175/2010JCLI3599.1.
何敏.1999.热带环流强度变化与我国夏季降水异常的关系[J].应用气象学报,10(2):171-180.He Min.1999.Relationship between tropical circulation intensity and summer precipitation anomaly in China[J].Quart.J.Appl.Meteor.(in Chinese),10(2):171-180,doi:10.3969/j.issn.1001-7313.1999.02.005.
Held I M,Soden B J.2006.Robust responses of the hydrological cycle to global warming[J].J.Climate,19(21):5686-5699,doi:10.1175/JCLI3990.1.
Holton J R.2004.An Introduction to Dynamic Meteorology[M].4th ed.San Diego:Academic Press,535pp.
Klein S A,Soden B J,Lau N C,et al.1999.Remote sea surface temperature variations during ENSO:Evidence for a tropical atmospheric bridge[J].J.Climate,12(4):917-932,doi:10.1175/1520-0442(1999)012<0917:RSSTVD>2.0.CO;2.
L'Heureux M L,Lee S,Lyon B.2013.Recent multidecadal strengthening of the Walker circulation across the tropical Pacific[J].Nat.Climate Change,3(6):571-576,doi:1038/nclimate1840.
Luo J J,Sasaki W,Masumoto Y.2012.Indian Ocean warming modulates Pacific climate change[J].Proc.Natl.Acad.Sci.U.S.A.,109(46):18701-18706,doi:10.1073/pnas.1210239109.
Mcgregor S,Timmermann A,Stuecker M F,et al.2014.Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming[J].Nat.Climate Change,4(10):888-892,doi:10.1038/nclimate2330.
Meng Q J,Latif M,Park W,et al.2012.Twentieth century Walker circulation change:Data analysis and model experiments[J].Climate Dyn.,38(9-10):1757-1773,doi:10.1007/s00382-011-1047-8.
孟文,吴国雄.2000.赤道印度洋-太平洋地区海气系统的齿轮式耦合和ENSO事件II.数值模拟[J].大气科学,24(1):15-25.Meng Wen,Wu Guoxiong.2000.Gearing between the Indo-monsoon circulation and the Pacific-Walker circulation and the ENSO.Part II:Numerical simulation[J].Chinese Journal of Atmospheric Sciences(in Chinese),24(1):15-25,doi:10.3878/j.issn.1006-9895.2000.01.02.
Nagura M,Konda M.2007.The seasonal development of an SST anomaly in the Indian Ocean and its relationship to ENSO[J].J.Climate,20(1):38-52,doi:10.1175/JCLI3986.1.
Newell R E.1979.Climate and the ocean:Measurements of changes in sea-surface temperature should permit us to forecast certain climatic changes several months ahead[J].Amer.Sci.,67(4):405-416.
Nicholls N.2008.Recent trends in the seasonal and temporal behaviour of the El Ni?o-Southern Oscillation[J].Geophys.Res.Lett.,35(19):L19703,doi:10.1029/2008GL034499.
Nicholson S E.2014.The predictability of rainfall over the Greater Horn of Africa.Part I:Prediction of seasonal rainfall[J].J.Hydrometeorol.,15(3):1011-1027,doi:10.1175/JHM-D-13-062.1.
Pohl B,Camberlin P.2006.Influence of the Madden-Julian oscillation on East African rainfall.I:Intraseasonal variability and regional dependency[J].Quart.J.Roy.Meteor.Soc.,132(621):2521-2539,doi:10.1256/qj.05.104.
Pohl B,Camberlin P.2011.Intraseasonal and interannual zonal circulations over the equatorial Indian Ocean[J].Theor.Appl.Climatol.,104(1-2):175-191,doi:10.1007/s00704-010-0336-1.
Power S B,Kociuba G.2011.What caused the observed twentieth-century weakening of the walker circulation?[J].J.Climate,24(24):6501-6514,doi:10.1175/2011JCLI4101.1.
商树荣,蒋尚城.2002.卫星双通道反演的赤道纬向环流的气候特征及与ENSO关系的研究[J].热带气象学报,18(1):56-64.Shang Shurong,Jiang Shangcheng.2002.The climatic characteristics of equatorial zonal circulation retrieved with dual satellite channels and its relationship with ENSO[J].Journal of Tropical Meteorology(in Chinese),18(1):56-64,doi:10.3969/j.issn.1004-4965.2002.01.007.
施能,马丽,袁晓玉,等.2001.近50 a浙江省气候变化特征分析[J].南京气象学院学报,24(2):207-213.Shi Neng,Ma Li,Yuan Xiaoyu,et al.2001.Climate variation features over Zhejiang Province in the last50 years[J].Journal of Nanjing Institute of Meteorology(in Chinese),24(2):207-213,doi:10.3969/j.issn.1674-7097.2001.02.009.
Simmons A J,Uppala S,Dee D,et al.2007.ERA-Interim:new ECMWFreanalysis products from 1989 onwards[J].ECMWF Newslett.,110:25-35.
Smith T M,Reynolds R W,Peterson T C,et al.2008.Improvements to NOAA's historical merged land ocean surface temperature analysis(1880-2006)[J].J.Climate,21(10):2283-2296,doi:10.1175/2007JCLI2100.1.
Sohn B J,Yeh S W,Schmetz J,et al.2013.Observational evidences of Walker circulation change over the last 30 years contrasting with GCMresults[J].Climate Dyn.,40(7):1721-1732,doi:10.1007/s00382-012-1484-z.
Tanaka H L,Ishizaki N,Kitoh A.2004.Trend and interannual variability of Walker,monsoon and Hadley circulations defined by velocity potential in the upper troposphere[J].Tellus A,56(3):250-269,doi:10.1111/j.1600-0870.2004.00049.x.
Tokinaga H,Xie S P,Deser C,et al.2012a.Slowdown of the Walker circulation driven by tropical Indo-Pacific warming[J].Nature,491(7424):439-443,doi:10.1038/nature11576.
Tokinaga H,Xie S P,Timmermann A,et al.2012b.Regional patterns of tropical Indo-Pacific climate change:Evidence of the Walker circulation weakening[J].J.Climate,25(5):1689-1710,doi:10.1175/JCLI-D-11-00263.1.
Trenberth K E,Fasullo J,Smith L.2005.Trends and variability in column-integrated atmospheric water vapor[J].Climate Dyn.,24(7-8):741-758,doi:10.1007/s00382-005-0017-4.
Uppala S M,Kallberg P W,Simmons A J,et al.2005.The ERA-40 reanalysis[J].Quart.J.Roy.Meteor.Soc.,131(612):2961-3012,doi:10.1256/qj.04.176.
Vecchi G A,Soden B J.2007.Global warming and the weakening of the tropical circulation[J].J.Climate,20(17):4316-4340,doi:10.1175/JCLI4258.1.
Vecchi G A,Soden B J,Wittenberg A T,et al.2006.Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing[J].Nature,441(7089):73-76,doi:10.1038/nature04744.
Vecchi G A,Wittenberg A T.2010.El Ni?o and our future climate:Where do we stand?[J].Interdisciplinary Reviews Climate Change,1(2):260-270,doi:10.1002/wcc.33.
Wilks D S.2011.Statistical Methods in the Atmospheric Sciences[M].3rd ed.Waltham:Academic Press,669pp.
吴国雄,孟文.1998.赤道印度洋-太平洋地区海气系统的齿轮式耦合和ENSO事件I.资料分析[J].大气科学,22(4):470-480.Wu Guoxiong,Meng Wen.1998.Gearing between the Indo-monsoon circulation and the Pacific-Walker circulation and the ENSO.Part I:Data analyses[J].Chinese Journal of Atmospheric Sciences(in Chinese),22(4):470-480,doi:10.3878/j.issn.1006-9895.1998.04.09.
Xie S P,Du Y,Huang G,et al.2010.Decadal shift in El Ni?o influences on Indo-Western Pacific and East Asian climate in the 1970s[J].J.Climate,23(12):3352-3368,doi:10.1175/2010JCLI3429.1.
Yu B,Boer G.2002.The roles of radiation and dynamical processes in the El Ni?o-like response to global warming[J].Climate Dyn.,19(5-6):539-554,doi:10.1007/s00382-002-0244-x.
Yu B,Zwiers F W.2010.Changes in equatorial atmospheric zonal circulations in recent decades[J].Geophys.Res.Lett.,37(5):L05701,doi:10.1029/2009GL042071.
Zhang M H,Song H.2006.Evidence of deceleration of atmospheric vertical overturning circulation over the tropical Pacific[J].Geophys.Res.Lett.,33(12):L12701,doi:10.1029/2006GL025942.
Collins M,An S I,Cai W J,et al.2010.The impact of global warming on the tropical Pacific Ocean and El Ni?o[J].Nat.Geosci.,3(6):391-397,doi:10.1038/ngeo868.
Compo G P,Whitaker J S,Sardeshmukh P D,et al.2011.The twentieth century reanalysis project[J].Quart.J.Roy.Meteor.Soc.,137(654):1-28,doi:10.1002/qj.776.
Fischer A S,Terray P,Guilyardi E,et al.2005.Two independent triggers for the Indian Ocean dipole/zonal mode in a coupled GCM[J].J.Climate,18(17):3428-3449,doi:10.1175/JCLI3478.1.
Flohn H,Fleer H.1975.Climatic teleconnections with the equatorial Pacific and the role of ocean/atmosphere coupling[J].Atmosphere,13(3):96-109,doi:10.1080/00046973.1975.9648391.
Gill A E.1982.Atmosphere-Ocean Dynamics[M].New York:Academic Press,662pp.
Hastenrath S.2007.Circulation mechanisms of climate anomalies in East Africa and the equatorial Indian Ocean[J].Dyn.Atmos.Oceans,43(1-2):25-35,doi:10.1016/j.dynatmoce.2006.06.002.
Hastenrath S,Polzin D,Mutai C.2011.Circulation mechanisms of Kenya rainfall anomalies[J].J.Climate,24(2):404-412,doi:10.1175/2010JCLI3599.1.
何敏.1999.热带环流强度变化与我国夏季降水异常的关系[J].应用气象学报,10(2):171-180.He Min.1999.Relationship between tropical circulation intensity and summer precipitation anomaly in China[J].Quart.J.Appl.Meteor.(in Chinese),10(2):171-180,doi:10.3969/j.issn.1001-7313.1999.02.005.
Held I M,Soden B J.2006.Robust responses of the hydrological cycle to global warming[J].J.Climate,19(21):5686-5699,doi:10.1175/JCLI3990.1.
Holton J R.2004.An Introduction to Dynamic Meteorology[M].4th ed.San Diego:Academic Press,535pp.
Klein S A,Soden B J,Lau N C,et al.1999.Remote sea surface temperature variations during ENSO:Evidence for a tropical atmospheric bridge[J].J.Climate,12(4):917-932,doi:10.1175/1520-0442(1999)012<0917:RSSTVD>2.0.CO;2.
L'Heureux M L,Lee S,Lyon B.2013.Recent multidecadal strengthening of the Walker circulation across the tropical Pacific[J].Nat.Climate Change,3(6):571-576,doi:1038/nclimate1840.
Luo J J,Sasaki W,Masumoto Y.2012.Indian Ocean warming modulates Pacific climate change[J].Proc.Natl.Acad.Sci.U.S.A.,109(46):18701-18706,doi:10.1073/pnas.1210239109.
Mcgregor S,Timmermann A,Stuecker M F,et al.2014.Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming[J].Nat.Climate Change,4(10):888-892,doi:10.1038/nclimate2330.
Meng Q J,Latif M,Park W,et al.2012.Twentieth century Walker circulation change:Data analysis and model experiments[J].Climate Dyn.,38(9-10):1757-1773,doi:10.1007/s00382-011-1047-8.
孟文,吴国雄.2000.赤道印度洋-太平洋地区海气系统的齿轮式耦合和ENSO事件II.数值模拟[J].大气科学,24(1):15-25.Meng Wen,Wu Guoxiong.2000.Gearing between the Indo-monsoon circulation and the Pacific-Walker circulation and the ENSO.Part II:Numerical simulation[J].Chinese Journal of Atmospheric Sciences(in Chinese),24(1):15-25,doi:10.3878/j.issn.1006-9895.2000.01.02.
Nagura M,Konda M.2007.The seasonal development of an SST anomaly in the Indian Ocean and its relationship to ENSO[J].J.Climate,20(1):38-52,doi:10.1175/JCLI3986.1.
Newell R E.1979.Climate and the ocean:Measurements of changes in sea-surface temperature should permit us to forecast certain climatic changes several months ahead[J].Amer.Sci.,67(4):405-416.
Nicholls N.2008.Recent trends in the seasonal and temporal behaviour of the El Ni?o-Southern Oscillation[J].Geophys.Res.Lett.,35(19):L19703,doi:10.1029/2008GL034499.
Nicholson S E.2014.The predictability of rainfall over the Greater Horn of Africa.Part I:Prediction of seasonal rainfall[J].J.Hydrometeorol.,15(3):1011-1027,doi:10.1175/JHM-D-13-062.1.
Pohl B,Camberlin P.2006.Influence of the Madden-Julian oscillation on East African rainfall.I:Intraseasonal variability and regional dependency[J].Quart.J.Roy.Meteor.Soc.,132(621):2521-2539,doi:10.1256/qj.05.104.
Pohl B,Camberlin P.2011.Intraseasonal and interannual zonal circulations over the equatorial Indian Ocean[J].Theor.Appl.Climatol.,104(1-2):175-191,doi:10.1007/s00704-010-0336-1.
Power S B,Kociuba G.2011.What caused the observed twentieth-century weakening of the walker circulation?[J].J.Climate,24(24):6501-6514,doi:10.1175/2011JCLI4101.1.
商树荣,蒋尚城.2002.卫星双通道反演的赤道纬向环流的气候特征及与ENSO关系的研究[J].热带气象学报,18(1):56-64.Shang Shurong,Jiang Shangcheng.2002.The climatic characteristics of equatorial zonal circulation retrieved with dual satellite channels and its relationship with ENSO[J].Journal of Tropical Meteorology(in Chinese),18(1):56-64,doi:10.3969/j.issn.1004-4965.2002.01.007.
施能,马丽,袁晓玉,等.2001.近50 a浙江省气候变化特征分析[J].南京气象学院学报,24(2):207-213.Shi Neng,Ma Li,Yuan Xiaoyu,et al.2001.Climate variation features over Zhejiang Province in the last50 years[J].Journal of Nanjing Institute of Meteorology(in Chinese),24(2):207-213,doi:10.3969/j.issn.1674-7097.2001.02.009.
Simmons A J,Uppala S,Dee D,et al.2007.ERA-Interim:new ECMWFreanalysis products from 1989 onwards[J].ECMWF Newslett.,110:25-35.
Smith T M,Reynolds R W,Peterson T C,et al.2008.Improvements to NOAA's historical merged land ocean surface temperature analysis(1880-2006)[J].J.Climate,21(10):2283-2296,doi:10.1175/2007JCLI2100.1.
Sohn B J,Yeh S W,Schmetz J,et al.2013.Observational evidences of Walker circulation change over the last 30 years contrasting with GCMresults[J].Climate Dyn.,40(7):1721-1732,doi:10.1007/s00382-012-1484-z.
Tanaka H L,Ishizaki N,Kitoh A.2004.Trend and interannual variability of Walker,monsoon and Hadley circulations defined by velocity potential in the upper troposphere[J].Tellus A,56(3):250-269,doi:10.1111/j.1600-0870.2004.00049.x.
Tokinaga H,Xie S P,Deser C,et al.2012a.Slowdown of the Walker circulation driven by tropical Indo-Pacific warming[J].Nature,491(7424):439-443,doi:10.1038/nature11576.
Tokinaga H,Xie S P,Timmermann A,et al.2012b.Regional patterns of tropical Indo-Pacific climate change:Evidence of the Walker circulation weakening[J].J.Climate,25(5):1689-1710,doi:10.1175/JCLI-D-11-00263.1.
Trenberth K E,Fasullo J,Smith L.2005.Trends and variability in column-integrated atmospheric water vapor[J].Climate Dyn.,24(7-8):741-758,doi:10.1007/s00382-005-0017-4.
Uppala S M,Kallberg P W,Simmons A J,et al.2005.The ERA-40 reanalysis[J].Quart.J.Roy.Meteor.Soc.,131(612):2961-3012,doi:10.1256/qj.04.176.
Vecchi G A,Soden B J.2007.Global warming and the weakening of the tropical circulation[J].J.Climate,20(17):4316-4340,doi:10.1175/JCLI4258.1.
Vecchi G A,Soden B J,Wittenberg A T,et al.2006.Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing[J].Nature,441(7089):73-76,doi:10.1038/nature04744.
Vecchi G A,Wittenberg A T.2010.El Ni?o and our future climate:Where do we stand?[J].Interdisciplinary Reviews Climate Change,1(2):260-270,doi:10.1002/wcc.33.
Wilks D S.2011.Statistical Methods in the Atmospheric Sciences[M].3rd ed.Waltham:Academic Press,669pp.
吴国雄,孟文.1998.赤道印度洋-太平洋地区海气系统的齿轮式耦合和ENSO事件I.资料分析[J].大气科学,22(4):470-480.Wu Guoxiong,Meng Wen.1998.Gearing between the Indo-monsoon circulation and the Pacific-Walker circulation and the ENSO.Part I:Data analyses[J].Chinese Journal of Atmospheric Sciences(in Chinese),22(4):470-480,doi:10.3878/j.issn.1006-9895.1998.04.09.
Xie S P,Du Y,Huang G,et al.2010.Decadal shift in El Ni?o influences on Indo-Western Pacific and East Asian climate in the 1970s[J].J.Climate,23(12):3352-3368,doi:10.1175/2010JCLI3429.1.
Yu B,Boer G.2002.The roles of radiation and dynamical processes in the El Ni?o-like response to global warming[J].Climate Dyn.,19(5-6):539-554,doi:10.1007/s00382-002-0244-x.
Yu B,Zwiers F W.2010.Changes in equatorial atmospheric zonal circulations in recent decades[J].Geophys.Res.Lett.,37(5):L05701,doi:10.1029/2009GL042071.
Zhang M H,Song H.2006.Evidence of deceleration of atmospheric vertical overturning circulation over the tropical Pacific[J].Geophys.Res.Lett.,33(12):L12701,doi:10.1029/2006GL025942.