Observational bifurcation of Wyrtki Jets and its influence on the salinity balance in the eastern Indian Ocean
|
摘要
使用2014年印度洋春季航次布放的GPS漂流浮标阵列观测到了Wyrtki急流分叉现象,并研究了Wyrtki急流及分叉对东印度洋盐度平衡的影响,研究指出Wytki急流分叉经度位置是由赤道上压力梯度和风应力的平衡决定的。使用Argo混合层盐度数据以及OSCAR海流数据进行盐度收支分析显示,Wytki急流和Wyrtki急流的分叉对东印度洋盐度分配有着重要的影响,Wyrtki急流东向输送西印度洋高盐水,Wyrtki分叉输送赤道高盐水分别到达苏门答腊-爪哇沿岸和孟加拉湾,抑制那里的海水淡化。
The eastward-propagation phenomenon from GPS-tracking drifters is characterized by strong Wyrtki Jets(WJs),with a maximum velocity of over 1.3 m s~(-1).Based on data gathered during a 2014 spring sea cruise in the Indian Ocean,the trajectories show the WJs bifurcate at the equator near the eastern boundary and flow northward and southward in two narrow strong currents.Surface currents reverse and flow westward in the east of the bifurcation longitude.In addition,Aquarius satellite data show the high-salinity water flows eastward from the western Indian Ocean,associated with WJs.Salinity budget analyses in the mixed layer using salinity data from Argo and currents data from OSCAR indicate that the WJs do indeed transport the high-salinity water eastward at the equator,and WJs bifurcation transports high-salinity water away from the equator and suppresses the Bay of Bengal and Java coast from freshening.Therefore,the WJs and WJs bifurcation play an important role in maintaining the salinity balance in the eastern Indian Ocean.
The eastward-propagation phenomenon from GPS-tracking drifters is characterized by strong Wyrtki Jets(WJs),with a maximum velocity of over 1.3 m s~(-1).Based on data gathered during a 2014 spring sea cruise in the Indian Ocean,the trajectories show the WJs bifurcate at the equator near the eastern boundary and flow northward and southward in two narrow strong currents.Surface currents reverse and flow westward in the east of the bifurcation longitude.In addition,Aquarius satellite data show the high-salinity water flows eastward from the western Indian Ocean,associated with WJs.Salinity budget analyses in the mixed layer using salinity data from Argo and currents data from OSCAR indicate that the WJs do indeed transport the high-salinity water eastward at the equator,and WJs bifurcation transports high-salinity water away from the equator and suppresses the Bay of Bengal and Java coast from freshening.Therefore,the WJs and WJs bifurcation play an important role in maintaining the salinity balance in the eastern Indian Ocean.
引文
Bonjean,F.,and G.Lagerloef.2002."Diagnostic Model and Analysis of the Surface Currents in theTropical Pacific Ocean."Journal of Physical Oceanography 32:2938-2954.
Cane,M.A.,and D.W.Moore.1981."A Note on Low-frequency Equatorial Basin Modes."Journal of Physical Oceanography 11:1578-1584.
Clarke,A.J.1983."The Reflection of Equatorial Waves from Oceanic Boundaries."Journal of Physical Oceanography 13(7):1193-1207.
Cutler,A.N.,and J.C.Swallow.1984."Surface Currents of the Indian Ocean(to 25°S,100°E)."IOS Technical Report.Institute of Oceanographic Sciences,Wormley,187.
Feng,M.,P.Hacker,and R.Lukas.1998."Upper Ocean Heat and Salt Balances in Response to a Westerly Wind Burst in the Western Equatorial Pacific during TOGA COARE."Journal of Geophysical Research 103(C5):10289-10311.
Gordon,A.L.2001."Interocean Exchange."In Ocean Circulation and Climate,edited by G.Siedler,J.Church,and J.Gould,303-314.New York:Elsevier.
Han,W.,and J.P.McCreary.2001."Modeling Salinity Distributions in the Indian Ocean."Journal of Geophysical Research 106(C1):859-877.
Jensen,T.G.2003."Cross-equatorial Pathways of Salt and Tracers from the Northern Indian Ocean:Modelling Results."Deep Sea Research PartⅡ:Topical Studies in Oceanography 50(12-13):2111-2127.
Kara,A.B.,P.A.Rochford,and H.E.Hurlburt.2000."An Optimal Definition for Ocean Mixed Layer Depth."Journal of Geophysical Research 105(C7):16803-16821.
Knox,R.A.1976."On a Long Series of Measurements of Indian Ocean Equatorial Currents near Addu Atoll."Deep-Sea Research 23:211-221.
McPhaden,M.J.1982."Variability in the Central Equatorial Indian Ocean.PartⅠ:Ocean Dynamics."Journal of Marine Research 40:157-176.
Miyama,T.,J.P.McCreary,T.G.Jensen,J.Loschnigg,S.Godfrey,and A.Ishida.2003."Structure and Dynamics of the IndianOcean Cross-equatorial Cell."Deep Sea Research PartⅡ:Topical Studies in Oceanography 50(12-13):2023-2047.
Molinari,R.L.,D.Olson,and G.Reverdin.1990."Surface Current Distributions in the Tropical Indian Ocean Derived from Compilations of Surface Buoy Trajectories."Journal of Geophysical Research 95:7217-7238.
Moore,D.W.,and S.G.H.Philander.1977."Modeling of the Tropical Oceanic Circulation."The Sea,Chapter 8,edited by E.D.Goldber.Journal of Marine Research 35(3):509-523.
Nyadjro,E.S.,B.Subrahmanyam,and J.F.Shriver.2011."Seasonal Variability of Salt Transport during the Indian Ocean Monsoons."Journal of Geophysical Research-Oceans116:C08036.
O'Brien,J.J.,and H.E.Hurlburt.1974."Equatorial Jet in the Indian Ocean:Theory."Science 184:1075-1077.
Qiu,Y.,L.Li,and W.D.Yu.2009."Behavior of the Wyrtki Jet Observed with Surface Drifting Buoys and Satellite Altimeter."Geophysical Research Letters 36:L18607.doi:10.1029/2009GL039120.
Quadfasel,D.,and G.Cresswell.1992."A Note on the Seasonal Variability of the South Java Current."Journal of Geophysical Research 97(C3):3685-3688.
Schott,F.A.,and J.P.McCreary.2001."The Monsoon Circulation of the Indian Ocean."Progress in Oceanography 51(1):1-123.
Sengupta,D.,G.N.B.Raj,and S.S.C.Shenoi.2006."Surface Freshwater from Bay of Bengal Runoff and Indonesian Throughflow in the Tropical Indian Ocean."Geophysical Research Letters 33:L22609.doi:10.1029/2006GL027573.
Shenoi,S.S.C,P.K.Saji,and A.M.Almeida.1999."Near-surface Circulation and Kinetic Energy in the Tropical Indian Ocean Derived from Lagrangian Drifters."Journal of Marine Research57(6):885-907.
Sprintall,J.,A.Gordon,R.Murtugudde,and R.D.Susanto.2000."A Semiannual Indian Ocean Forced Kelvin Wave Observed in the Indonesian Seas in May 1997."Journal of Geophysical Research 105(C7):17217-17230.
Vinayachandran,P.N.,D.Shankar,S.Vernekar,K.K.Sandeep,P.Amol,C.P.Neema,and A.Chatterjee.2013."A Summer Monsoon Pump to Keep the Bay of Bengal Salty."Geophysics Research Letter 40:1-6.doi:10.1002/grl.50274.
Wijffels,S.E.2001."Ocean Transport of Freshwater."In Ocean Circulation and Climate,edited by G.Siedler,J.Church and J.Gould,475-488.New York:Elsevier.
Wyrtki,K.1973."An Equatorial Jet in the Indian Ocean."Science181:262-264.
Cane,M.A.,and D.W.Moore.1981."A Note on Low-frequency Equatorial Basin Modes."Journal of Physical Oceanography 11:1578-1584.
Clarke,A.J.1983."The Reflection of Equatorial Waves from Oceanic Boundaries."Journal of Physical Oceanography 13(7):1193-1207.
Cutler,A.N.,and J.C.Swallow.1984."Surface Currents of the Indian Ocean(to 25°S,100°E)."IOS Technical Report.Institute of Oceanographic Sciences,Wormley,187.
Feng,M.,P.Hacker,and R.Lukas.1998."Upper Ocean Heat and Salt Balances in Response to a Westerly Wind Burst in the Western Equatorial Pacific during TOGA COARE."Journal of Geophysical Research 103(C5):10289-10311.
Gordon,A.L.2001."Interocean Exchange."In Ocean Circulation and Climate,edited by G.Siedler,J.Church,and J.Gould,303-314.New York:Elsevier.
Han,W.,and J.P.McCreary.2001."Modeling Salinity Distributions in the Indian Ocean."Journal of Geophysical Research 106(C1):859-877.
Jensen,T.G.2003."Cross-equatorial Pathways of Salt and Tracers from the Northern Indian Ocean:Modelling Results."Deep Sea Research PartⅡ:Topical Studies in Oceanography 50(12-13):2111-2127.
Kara,A.B.,P.A.Rochford,and H.E.Hurlburt.2000."An Optimal Definition for Ocean Mixed Layer Depth."Journal of Geophysical Research 105(C7):16803-16821.
Knox,R.A.1976."On a Long Series of Measurements of Indian Ocean Equatorial Currents near Addu Atoll."Deep-Sea Research 23:211-221.
McPhaden,M.J.1982."Variability in the Central Equatorial Indian Ocean.PartⅠ:Ocean Dynamics."Journal of Marine Research 40:157-176.
Miyama,T.,J.P.McCreary,T.G.Jensen,J.Loschnigg,S.Godfrey,and A.Ishida.2003."Structure and Dynamics of the IndianOcean Cross-equatorial Cell."Deep Sea Research PartⅡ:Topical Studies in Oceanography 50(12-13):2023-2047.
Molinari,R.L.,D.Olson,and G.Reverdin.1990."Surface Current Distributions in the Tropical Indian Ocean Derived from Compilations of Surface Buoy Trajectories."Journal of Geophysical Research 95:7217-7238.
Moore,D.W.,and S.G.H.Philander.1977."Modeling of the Tropical Oceanic Circulation."The Sea,Chapter 8,edited by E.D.Goldber.Journal of Marine Research 35(3):509-523.
Nyadjro,E.S.,B.Subrahmanyam,and J.F.Shriver.2011."Seasonal Variability of Salt Transport during the Indian Ocean Monsoons."Journal of Geophysical Research-Oceans116:C08036.
O'Brien,J.J.,and H.E.Hurlburt.1974."Equatorial Jet in the Indian Ocean:Theory."Science 184:1075-1077.
Qiu,Y.,L.Li,and W.D.Yu.2009."Behavior of the Wyrtki Jet Observed with Surface Drifting Buoys and Satellite Altimeter."Geophysical Research Letters 36:L18607.doi:10.1029/2009GL039120.
Quadfasel,D.,and G.Cresswell.1992."A Note on the Seasonal Variability of the South Java Current."Journal of Geophysical Research 97(C3):3685-3688.
Schott,F.A.,and J.P.McCreary.2001."The Monsoon Circulation of the Indian Ocean."Progress in Oceanography 51(1):1-123.
Sengupta,D.,G.N.B.Raj,and S.S.C.Shenoi.2006."Surface Freshwater from Bay of Bengal Runoff and Indonesian Throughflow in the Tropical Indian Ocean."Geophysical Research Letters 33:L22609.doi:10.1029/2006GL027573.
Shenoi,S.S.C,P.K.Saji,and A.M.Almeida.1999."Near-surface Circulation and Kinetic Energy in the Tropical Indian Ocean Derived from Lagrangian Drifters."Journal of Marine Research57(6):885-907.
Sprintall,J.,A.Gordon,R.Murtugudde,and R.D.Susanto.2000."A Semiannual Indian Ocean Forced Kelvin Wave Observed in the Indonesian Seas in May 1997."Journal of Geophysical Research 105(C7):17217-17230.
Vinayachandran,P.N.,D.Shankar,S.Vernekar,K.K.Sandeep,P.Amol,C.P.Neema,and A.Chatterjee.2013."A Summer Monsoon Pump to Keep the Bay of Bengal Salty."Geophysics Research Letter 40:1-6.doi:10.1002/grl.50274.
Wijffels,S.E.2001."Ocean Transport of Freshwater."In Ocean Circulation and Climate,edited by G.Siedler,J.Church and J.Gould,475-488.New York:Elsevier.
Wyrtki,K.1973."An Equatorial Jet in the Indian Ocean."Science181:262-264.