近年来厄尔尼诺期间北赤道流输运的年际变化
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摘要
为了研究近年来厄尔尼诺期间北赤道流输运的年际变化,本文利用海洋客观分析数据MOAA GPV(Grid Point Value of the Monthly Objective Analysis)以及P-vector方法计算了北太平洋绝对地转流,探讨了2001~2013年期间厄尔尼诺与北赤道流输运之间的关系。在此期间发生的4次厄尔尼诺事件中,北赤道流输运在2002~2003、2006~2007、2009~2010年的厄尔尼诺成熟期都出现了明显的增强,但是在2004~2005年的厄尔尼诺成熟期并没有明显的增强。进一步分析发现,在2002~2003年、2006~2007年、2009~2010年的厄尔尼诺成熟期,10°N以南的热带西北太平洋区域出现了负的海面高度异常和气旋式环流异常,这主要是由热带环流区域出现的西风异常和正的Ekman抽吸通过Rossby波西传到热带西太平洋区域所致;但是在2004~2005年厄尔尼诺成熟期,海面温度异常的分布明显不同,西风异常和正的Ekman抽吸异常明显北移,导致负的海面高度异常和气旋式环流异常出现在了10°N以北的西北太平洋区域,使得北赤道流输运在2004~2005年的厄尔尼诺成熟期没有明显的增强。
In this study,we calculated the absolute geostrophic currents in the North Pacific Ocean using the P-vector method and ocean Grid Point Value of the Monthly Objective Analysis using Argo data(MOAA GPV).We then investigated the relationship between the North Equatorial Current(NEC) transport and El Ni?o events occurring between 2001~2013.During the four El Ni?o events since 2001,the NEC transport significantly increased during the mature phases of the 2002~2003、2006~2007 and 2009~2010 El Ni?o events,but did not significantly increase in the mature phase of the 2004~2005 El Ni?o event.We performed further analyses and found that negative sea surface height and cyclonic gyre anomalies took place south of 10° N in the tropical North Pacific Ocean during the mature phases of the 2002~2003、2006~2007 and 2009~2010 El Ni?o events.These were mainly induced by the westerly wind anomaly and positive Ekman pumping in the tropical gyre area through westward-propagating Rossby waves.However,during the mature phase of the 2004~2005 El Ni?o event,the distribution of sea surface temperature anomalies was obviously different.The westerly wind anomaly and positive Ekman pumping moved significantly northward,which led to negative sea surface height and cyclonic gyre anomalies taking place north of 10° N in the northwest Pacific Ocean.As such,the NEC transport did not significantly increase during the mature phase of the 2004~2005 El Ni?o.
In this study,we calculated the absolute geostrophic currents in the North Pacific Ocean using the P-vector method and ocean Grid Point Value of the Monthly Objective Analysis using Argo data(MOAA GPV).We then investigated the relationship between the North Equatorial Current(NEC) transport and El Ni?o events occurring between 2001~2013.During the four El Ni?o events since 2001,the NEC transport significantly increased during the mature phases of the 2002~2003、2006~2007 and 2009~2010 El Ni?o events,but did not significantly increase in the mature phase of the 2004~2005 El Ni?o event.We performed further analyses and found that negative sea surface height and cyclonic gyre anomalies took place south of 10° N in the tropical North Pacific Ocean during the mature phases of the 2002~2003、2006~2007 and 2009~2010 El Ni?o events.These were mainly induced by the westerly wind anomaly and positive Ekman pumping in the tropical gyre area through westward-propagating Rossby waves.However,during the mature phase of the 2004~2005 El Ni?o event,the distribution of sea surface temperature anomalies was obviously different.The westerly wind anomaly and positive Ekman pumping moved significantly northward,which led to negative sea surface height and cyclonic gyre anomalies taking place north of 10° N in the northwest Pacific Ocean.As such,the NEC transport did not significantly increase during the mature phase of the 2004~2005 El Ni?o.
引文
[1]Toole J,Millard R,Wang Z,et al.Observations of the Pacific North Equatorial bifurcation at the Philippinecoast[J].J Phys Oceanogr,1990,20(2):307-318.
[2]Hu D X,Cui M C.The western boundary current of the Pacific and its role in the climate[J].Chin J Oceanol Limnol,1991,9(1):1-14.
[3]Yaremchuk M,Qu T D.Seasonal Variability of the Large-Scale Currents near the Coast of the Philippines[J].J Phys Oceanogr,2004,34(4):844-855.
[4]Qiu B,Lukas R.Seasonal and interannual variability of the North Equatorial Current,the Mindanao Current and the Kuroshio along the Pacific western boundary[J].J Geophys Res,1996,101(C5):12315-12330.
[5]Qu T D,Meyers G,Godfrey J S,et al.Upper ocean dynamics and its role in maintaining the annual mean western Pacific warm pool in a global GCM[J].Int J Climatol,1997,17:711-724.
[6]Gordon A.Interocean exchanges of thermocline water[J].J Geophys Res,1986,91:5037-5046.
[7]White W,Hasunuma K.Interannual variability in the baroclinic gyre structure of the western North Pacificfrom1954–1974[J].J Mar Res,1980,38:651-672.
[8]Qiu B,Joyce T.Interannual variability in the mid-and low-latitude western North Pacific[J].J Phys Oceanogr,1992,22:1062-1079.
[9]Gu Y H.Zonal volume transports at 137oE in the northwestern Pacific[J].Chin J Oceanol Limnol,1996,27(1):79-85.
[10]Wang F,Chang P,Hu D X,et al.Circulation in the western tropical Pacific Ocean and its seasonalvariation[J].Chin Sci Bull,2002,47(7):591-595.
[11]Qu T D,Mitsudera H,Yamagata T.On the western boundary currents in the Philippine Sea[J].J Geophys Res,1998,103(C4):7537-7548.
[12]Kashino Y,Espa?a N,Syamsudin F,et al.Observations of the North Equatorial Current,Mindanao Current,and Kuroshio Current System during the 2006/07 El Ni?o and 2007/08 La Ni?a[J].J Oceanogr,2009,65(3):325-333.
[13]Kim Y,Qu T D,Jensen T,et al.Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM[J].J Geophys Res,2004,109(C03040):1-19.
[14]Zhai F G,Hu D X.Interannual variability of transport and bifurcation of the North Equatorial Current in the tropical North Pacific Ocean[J].Chin J Oceanol Limnol,2012,30(1):177-185.
[15]Zhai F G,Hu D X.Revisit the interannual variability of the North Equatorial Current transport with ECMWF ORA-S3[J].J Geophys Res,2013,118:1349-1366.
[16]Wang Q Y,Hu D X.Bifurcation of the North Equatorial Current derived from altimetry in the Pacific Ocean[J].J Hydrodyn,2006,18B:620-626.
[17]Hosoda S,Suga T,Shikama N,et al.Global surface layer salinity change detected by Argo and its implication for hydrological cycle intensification[J].J Oceanogr,2009,65:579-586.
[18]Kashino Y,Ishida A,Hosoda S.Observed ocean variability in the Mindanao Dome region[J].J Phys Oceanogr,2011,41:287-302.
[19]Kobashi F,Xie S.Interannual variability of the North Pacific Subtropical Countercurrent:Role of local ocean–atmosphere interaction[J].J Oceanogr,2012,68:113-126.
[20]Hosoda S,Ohira T,Nakamura T.A monthly mean dataset of global oceanic temperature and salinity derived from Argo float observations[J].Jam Rep Res Dev,2008,8:47-59.
[21]Balmaseda M,Vidard A,Anderson D.The ECMWF Ocean Analysis System:ORA-S3[J].Mon Wea Rev,2008,136:3018-3034.
[22]Chu P C.P-vector method for determining absolute velocity from hydrographic data[J].Marine Tech Soc J,1995,29(2):3-14.
[23]Chu P C.P-vector spiral and determination of absolute velocities[J].J Oceanogr,2000,56:591-599.
[24]Chu P C,Fan C,Lozano C,et al.An airborne expandable bathythermograph(AXBT)survey of the South China Sea,May 1995[J].J Geophys Res,1998,103(10):21637-21652.
[25]Chu P C,Lan J,Fan C.Japan Sea circulation and thermohaline structure Part I,Climatology[J].J Phys Oceanogr,2001,31:244-271.
[26]Zhang Z C,Yuan D L,Chu,P C.Meridional Volume Transport in the Tropical Northwest Pacific Ocean Based on Argo Profiles[J].Chin J Oceanol Limnol,2013,31(3):656-664.
[27]Yuan D L,Zhang Z C,Chu P C,et al.Geostrophic Circulation in the Tropical North Pacific Ocean Based on Argo Profiles[J].J Phys Oceanogr,2014,44(2):558-575.
[28]Wu C R.Interannual modulation of the Pacific Decadal Oscillation(PDO)on the low-latitude western North Pacific[J].P Oceanogr,2013,110:49-58.
[2]Hu D X,Cui M C.The western boundary current of the Pacific and its role in the climate[J].Chin J Oceanol Limnol,1991,9(1):1-14.
[3]Yaremchuk M,Qu T D.Seasonal Variability of the Large-Scale Currents near the Coast of the Philippines[J].J Phys Oceanogr,2004,34(4):844-855.
[4]Qiu B,Lukas R.Seasonal and interannual variability of the North Equatorial Current,the Mindanao Current and the Kuroshio along the Pacific western boundary[J].J Geophys Res,1996,101(C5):12315-12330.
[5]Qu T D,Meyers G,Godfrey J S,et al.Upper ocean dynamics and its role in maintaining the annual mean western Pacific warm pool in a global GCM[J].Int J Climatol,1997,17:711-724.
[6]Gordon A.Interocean exchanges of thermocline water[J].J Geophys Res,1986,91:5037-5046.
[7]White W,Hasunuma K.Interannual variability in the baroclinic gyre structure of the western North Pacificfrom1954–1974[J].J Mar Res,1980,38:651-672.
[8]Qiu B,Joyce T.Interannual variability in the mid-and low-latitude western North Pacific[J].J Phys Oceanogr,1992,22:1062-1079.
[9]Gu Y H.Zonal volume transports at 137oE in the northwestern Pacific[J].Chin J Oceanol Limnol,1996,27(1):79-85.
[10]Wang F,Chang P,Hu D X,et al.Circulation in the western tropical Pacific Ocean and its seasonalvariation[J].Chin Sci Bull,2002,47(7):591-595.
[11]Qu T D,Mitsudera H,Yamagata T.On the western boundary currents in the Philippine Sea[J].J Geophys Res,1998,103(C4):7537-7548.
[12]Kashino Y,Espa?a N,Syamsudin F,et al.Observations of the North Equatorial Current,Mindanao Current,and Kuroshio Current System during the 2006/07 El Ni?o and 2007/08 La Ni?a[J].J Oceanogr,2009,65(3):325-333.
[13]Kim Y,Qu T D,Jensen T,et al.Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM[J].J Geophys Res,2004,109(C03040):1-19.
[14]Zhai F G,Hu D X.Interannual variability of transport and bifurcation of the North Equatorial Current in the tropical North Pacific Ocean[J].Chin J Oceanol Limnol,2012,30(1):177-185.
[15]Zhai F G,Hu D X.Revisit the interannual variability of the North Equatorial Current transport with ECMWF ORA-S3[J].J Geophys Res,2013,118:1349-1366.
[16]Wang Q Y,Hu D X.Bifurcation of the North Equatorial Current derived from altimetry in the Pacific Ocean[J].J Hydrodyn,2006,18B:620-626.
[17]Hosoda S,Suga T,Shikama N,et al.Global surface layer salinity change detected by Argo and its implication for hydrological cycle intensification[J].J Oceanogr,2009,65:579-586.
[18]Kashino Y,Ishida A,Hosoda S.Observed ocean variability in the Mindanao Dome region[J].J Phys Oceanogr,2011,41:287-302.
[19]Kobashi F,Xie S.Interannual variability of the North Pacific Subtropical Countercurrent:Role of local ocean–atmosphere interaction[J].J Oceanogr,2012,68:113-126.
[20]Hosoda S,Ohira T,Nakamura T.A monthly mean dataset of global oceanic temperature and salinity derived from Argo float observations[J].Jam Rep Res Dev,2008,8:47-59.
[21]Balmaseda M,Vidard A,Anderson D.The ECMWF Ocean Analysis System:ORA-S3[J].Mon Wea Rev,2008,136:3018-3034.
[22]Chu P C.P-vector method for determining absolute velocity from hydrographic data[J].Marine Tech Soc J,1995,29(2):3-14.
[23]Chu P C.P-vector spiral and determination of absolute velocities[J].J Oceanogr,2000,56:591-599.
[24]Chu P C,Fan C,Lozano C,et al.An airborne expandable bathythermograph(AXBT)survey of the South China Sea,May 1995[J].J Geophys Res,1998,103(10):21637-21652.
[25]Chu P C,Lan J,Fan C.Japan Sea circulation and thermohaline structure Part I,Climatology[J].J Phys Oceanogr,2001,31:244-271.
[26]Zhang Z C,Yuan D L,Chu,P C.Meridional Volume Transport in the Tropical Northwest Pacific Ocean Based on Argo Profiles[J].Chin J Oceanol Limnol,2013,31(3):656-664.
[27]Yuan D L,Zhang Z C,Chu P C,et al.Geostrophic Circulation in the Tropical North Pacific Ocean Based on Argo Profiles[J].J Phys Oceanogr,2014,44(2):558-575.
[28]Wu C R.Interannual modulation of the Pacific Decadal Oscillation(PDO)on the low-latitude western North Pacific[J].P Oceanogr,2013,110:49-58.