Subtidal variability in the Taiwan Strait induced by combined forcing of winter monsoon and topography
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摘要
As an important channel connecting the East and South China Seas, circulations in the Taiwan Strait are strongly influenced by the East Asian monsoon and the topography of the strait, especially the Taiwan Bank(TWB), which is a remarkable topographic feature located at the southern entrance to the strait. Based on a series of pressure gauges deployed roughly 40 km offshore along the western Strait, subtidal sea-level variability under the combined impact of winter monsoon and topography was studied. The analyses show significant along-strait coherences of subtidal sea levels and their coherences with the large-scale monsoon wind for periods from 2 to 14 days. It is suggested that these fluctuations are mainly forced waves driven by the large-scale winds. In addition to the normal cross-shore wind setup, a sea-level setup in the along-strait direction is confirmed, which is induced by the combined forcing of the fluctuating winter monsoon and the blocking of the TWB. A southward current surge driven by a northerly wind event will cause a rising sea level over the TWB inducing a southward alongshore slope anomaly to the north of the TWB and a reversed slope anomaly to the south The subtidal current through the channel to the west of the TWB is found to be influenced by the reversed slope anomalies generated via the along-shore setup.
As an important channel connecting the East and South China Seas, circulations in the Taiwan Strait are strongly influenced by the East Asian monsoon and the topography of the strait, especially the Taiwan Bank(TWB), which is a remarkable topographic feature located at the southern entrance to the strait. Based on a series of pressure gauges deployed roughly 40 km offshore along the western Strait, subtidal sea-level variability under the combined impact of winter monsoon and topography was studied. The analyses show significant along-strait coherences of subtidal sea levels and their coherences with the large-scale monsoon wind for periods from 2 to 14 days. It is suggested that these fluctuations are mainly forced waves driven by the large-scale winds. In addition to the normal cross-shore wind setup, a sea-level setup in the along-strait direction is confirmed, which is induced by the combined forcing of the fluctuating winter monsoon and the blocking of the TWB. A southward current surge driven by a northerly wind event will cause a rising sea level over the TWB inducing a southward alongshore slope anomaly to the north of the TWB and a reversed slope anomaly to the south The subtidal current through the channel to the west of the TWB is found to be influenced by the reversed slope anomalies generated via the along-shore setup.
As an important channel connecting the East and South China Seas, circulations in the Taiwan Strait are strongly influenced by the East Asian monsoon and the topography of the strait, especially the Taiwan Bank(TWB), which is a remarkable topographic feature located at the southern entrance to the strait. Based on a series of pressure gauges deployed roughly 40 km offshore along the western Strait, subtidal sea-level variability under the combined impact of winter monsoon and topography was studied. The analyses show significant along-strait coherences of subtidal sea levels and their coherences with the large-scale monsoon wind for periods from 2 to 14 days. It is suggested that these fluctuations are mainly forced waves driven by the large-scale winds. In addition to the normal cross-shore wind setup, a sea-level setup in the along-strait direction is confirmed, which is induced by the combined forcing of the fluctuating winter monsoon and the blocking of the TWB. A southward current surge driven by a northerly wind event will cause a rising sea level over the TWB inducing a southward alongshore slope anomaly to the north of the TWB and a reversed slope anomaly to the south The subtidal current through the channel to the west of the TWB is found to be influenced by the reversed slope anomalies generated via the along-shore setup.
引文
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Chang Y,Lee K T,Lee M A,Lan K W.2009.Satellite observation on the exceptional intrusion of cold water in the Taiwan Strait.Terr Atmos Ocean Sci,20:661-669
Chen C K.1975.A study of the movement of cold fronts and associated precipitation along the coast southeast China.Atmosp Sci,2:9-21
Chen D K,Su J L.1987.Continental shelf waves study along China coast(in Chinese).Acta Oceanol Sin,9:1-15
Chuang W S.1985.Dynamics of subtidal flow in the Taiwan Strait.J Oceanogr,41:65-72
Chuang W S.1986.A note on the driving mechanisms of current in the Taiwan Strait.J Oceanogr,42:355-361
Ekman V W.1905.On the influence of the earth's rotation on ocean currents.Ark Mat Astron Fys,2:1-53
Farris A,Wimbush M.1996.Wind-induced Kuroshio intrusion into the South China Sea.J Oceanogr,52:771-784
Garrett C,Toulany B.1982.Sea level variability due to meteorological forcing in the northeast Gulf of St.Lawrence.J Geophys Res,87:1968-1978
He Y,Cai S,Wang D,He J.2015.A model study of Luzon cold eddies in the northern South China Sea.Deep-Sea Res Part I-Oceanogr Res Pap,97:107-123
Hong B,Wang D.2006.Diagnostic analysis on the northern South China Sea winter counter-wind current.Chin Sci Bull,51:9-16
Hsieh H J,Hsien Y L,Jeng M S,Tsai W S,Su W C,Chen C A.2008.Tropical fishes killed by the cold.Coral Reefs,27:599-599
Hu J,Kawamura H,Li C,Hong H,Jiang Y.2010.Review on current and seawater volume transport through the Taiwan Strait.J Oceanogr,66:591-610
Jacobs G A,Preller R H,Riedlinger S K,Teague W J.1998.Coastal wave generation in the Bohai Bay and propagation along the Chinese coast.Geophys Res Lett,25:777-780
Jan S,Wang J,Chern C S,Chao S Y.2002.Seasonal variation of the circulation in the Taiwan Strait.J Mar Syst,35:249-268
Jia Y,Liu Q.2004.Eddy shedding from the Kuroshio Bend at Luzon Strait.J Oceanogr,60:1063-1069
Ko D S,Preller R H,Jacobs G A,Tang T Y,Lin S F.2003.Transport reversals at Taiwan Strait during October and November 1999.J Geophys Res,108:3370
Lane-Serff G F.2004.Topographic and boundary effects on steady and unsteady flow through straits.Deep-Sea Res PartⅡ-Top Stud Oceanogr,51:321-334
Lentz S J,Fewings M R.2012.The wind-and wave-driven inner-shelf circulation.Annu Rev Mar Sci,4:317-343
Li L.1989.A study of winter subtidal sea level fluctuation in the Taiwan Strait.Acta Oceanol Sin,11:275-283
Li L,Wu B Y.1989.A Kuroshio loop in South China Sea?—On circulations of the north-eastern South China Sea(in Chinese with English abstract).J Oceanogr in Taiwan Strait,8:89-95
Li L.1993.A study on winter subtidal sea level fluctuation along the northern coast of the South China Sea(in Chinese with English abstract).Tropic Oceanogr,12:52-60
Li L,Nowlin Jr.W D,Jilan S.1998.Anticyclonic rings from the Kuroshio in the South China Sea.Deep-Sea Res Part I-Oceanogr Res Pap,45:1469-1482
Liao E H,Jiang Y W,Li L,Hong H S,Yan X H.2013.The cause of the2008 cold disaster in the Taiwan Strait.Ocean Model,62:1-10
Lin S F,Tang T Y,Jan S,Chen C J.2005.Taiwan strait current in winter.Cont Shelf Res,25:1023-1042
Oey L Y,Chang Y L,Lin Y C,Chang M C,Varlamov S,Miyazawa Y.2014.Cross flows in the Taiwan Strait in Winter.J Phys Oceanogr,44:801-817
Pan A J,Wan X F,Guo X G,Jing C S.2013.Responses of the Zhe-Min coastal current adjacent to Pingtan Island to the wintertime monsoon relaxation in 2006 and its mechanism.Sci China Earth Sci,56:386-396
Pratt L J,Helfrich K R,Chassignet E P.2000.Hydraulic adjustment to an obstacle in a rotating channel.J Fluid Mech,404:117-149
Qiu C,Wang D,He Z,Chen C.2012.Seasonal variability of chlorophylla fronts in the Luzon Strait based on satellite observations.Aquatic Ecosyst Health Manage,15:46-52
Shao H,Li Y,Li L.2011.Sun glitter imaging of submarine sand waves on the Taiwan Banks:Determination of the relaxation rate of short waves.J Geophys Res,116:C06024
Shaw P T.1989.The intrusion of water masses into the sea southwest of Taiwan.J Geophys Res,94:18213-18226
Shi R,Guo X,Wang D,Zeng L L,Chen J.2015.Seasonal variability in coastal fronts and its influence on sea surface wind in the Northern South China Sea.Deep-Sea Res Part II-Top Stud Oceanogr,119:30-39
Shih C F,Shaw P T,Li H W.1986.Low Frequency sea level fluctuations around Taiwan(in Chinese).Acta Oceanogr Taiwanica,17:18-28
Thompson R O R Y.1983.Low-pass filters to suppress inertial and tidal frequencies.J Phys Oceanogr,13:1077-1083
Trowbridge J H,Chapman D C,Candela J.1998.Topographic effects,straits and the bottom boundary layer.In:Brink K H,Robinson A R,eds.The Sea.New York:John Wiley and Sons.63-88
Wang D,Liu Y,Qi Y,Shi P.2001.Seasonal variability of thermal fronts in the northern South China Sea from satellite data.Geophys Res Lett,28:3963-3966
Wang D,Xu H,Lin J,Hu J.2008.Anticyclonic eddies in the northeastern South China Sea during winter 2003/2004.J Oceanogr,64:925-935
Wang D,Hong B,Gan J,Xu H.2010.Numerical investigation on propulsion of the counter-wind current in the northern South China Sea in winter.Deep-Sea Res Part I-Oceanogr Res Pap,57:1206-1221
Wang D,Shu Y,Xue H,Hu J,Chen J,Zhuang W,Zu T T,Xu J.2014-Relative contributions of local wind and topography to the coastal upwelling intensity in the northern South China Sea.J Geophys ResOceans,119:2550-2567
Wang J,Chern C S.1988.On the Kuroshio branch in the Taiwan strait during wintertime.Prog Oceanogr,21:469-491
Wang J,Chen C S.1989.On cold water intrusions in the eastern Taiwan Strait during the cold season(in Chinese with English abstract).Acta Oceanogr Taiwaica,22:43-67
Wang Y H,Chiao L Y,Lwiza K M M,Wang D P.2004.Analysis of flow at the gate of Taiwan Strait.J Geophys Res,109:C02025
Zhao B R,Cao D M.1987.Wintertime low frequency fluctuations of Chinese coastal sea-level in the Huanghai sea and the East China Sea.Oceanol Limnol Sin,18:563-574
Chang Y,Lee K T,Lee M A,Lan K W.2009.Satellite observation on the exceptional intrusion of cold water in the Taiwan Strait.Terr Atmos Ocean Sci,20:661-669
Chen C K.1975.A study of the movement of cold fronts and associated precipitation along the coast southeast China.Atmosp Sci,2:9-21
Chen D K,Su J L.1987.Continental shelf waves study along China coast(in Chinese).Acta Oceanol Sin,9:1-15
Chuang W S.1985.Dynamics of subtidal flow in the Taiwan Strait.J Oceanogr,41:65-72
Chuang W S.1986.A note on the driving mechanisms of current in the Taiwan Strait.J Oceanogr,42:355-361
Ekman V W.1905.On the influence of the earth's rotation on ocean currents.Ark Mat Astron Fys,2:1-53
Farris A,Wimbush M.1996.Wind-induced Kuroshio intrusion into the South China Sea.J Oceanogr,52:771-784
Garrett C,Toulany B.1982.Sea level variability due to meteorological forcing in the northeast Gulf of St.Lawrence.J Geophys Res,87:1968-1978
He Y,Cai S,Wang D,He J.2015.A model study of Luzon cold eddies in the northern South China Sea.Deep-Sea Res Part I-Oceanogr Res Pap,97:107-123
Hong B,Wang D.2006.Diagnostic analysis on the northern South China Sea winter counter-wind current.Chin Sci Bull,51:9-16
Hsieh H J,Hsien Y L,Jeng M S,Tsai W S,Su W C,Chen C A.2008.Tropical fishes killed by the cold.Coral Reefs,27:599-599
Hu J,Kawamura H,Li C,Hong H,Jiang Y.2010.Review on current and seawater volume transport through the Taiwan Strait.J Oceanogr,66:591-610
Jacobs G A,Preller R H,Riedlinger S K,Teague W J.1998.Coastal wave generation in the Bohai Bay and propagation along the Chinese coast.Geophys Res Lett,25:777-780
Jan S,Wang J,Chern C S,Chao S Y.2002.Seasonal variation of the circulation in the Taiwan Strait.J Mar Syst,35:249-268
Jia Y,Liu Q.2004.Eddy shedding from the Kuroshio Bend at Luzon Strait.J Oceanogr,60:1063-1069
Ko D S,Preller R H,Jacobs G A,Tang T Y,Lin S F.2003.Transport reversals at Taiwan Strait during October and November 1999.J Geophys Res,108:3370
Lane-Serff G F.2004.Topographic and boundary effects on steady and unsteady flow through straits.Deep-Sea Res PartⅡ-Top Stud Oceanogr,51:321-334
Lentz S J,Fewings M R.2012.The wind-and wave-driven inner-shelf circulation.Annu Rev Mar Sci,4:317-343
Li L.1989.A study of winter subtidal sea level fluctuation in the Taiwan Strait.Acta Oceanol Sin,11:275-283
Li L,Wu B Y.1989.A Kuroshio loop in South China Sea?—On circulations of the north-eastern South China Sea(in Chinese with English abstract).J Oceanogr in Taiwan Strait,8:89-95
Li L.1993.A study on winter subtidal sea level fluctuation along the northern coast of the South China Sea(in Chinese with English abstract).Tropic Oceanogr,12:52-60
Li L,Nowlin Jr.W D,Jilan S.1998.Anticyclonic rings from the Kuroshio in the South China Sea.Deep-Sea Res Part I-Oceanogr Res Pap,45:1469-1482
Liao E H,Jiang Y W,Li L,Hong H S,Yan X H.2013.The cause of the2008 cold disaster in the Taiwan Strait.Ocean Model,62:1-10
Lin S F,Tang T Y,Jan S,Chen C J.2005.Taiwan strait current in winter.Cont Shelf Res,25:1023-1042
Oey L Y,Chang Y L,Lin Y C,Chang M C,Varlamov S,Miyazawa Y.2014.Cross flows in the Taiwan Strait in Winter.J Phys Oceanogr,44:801-817
Pan A J,Wan X F,Guo X G,Jing C S.2013.Responses of the Zhe-Min coastal current adjacent to Pingtan Island to the wintertime monsoon relaxation in 2006 and its mechanism.Sci China Earth Sci,56:386-396
Pratt L J,Helfrich K R,Chassignet E P.2000.Hydraulic adjustment to an obstacle in a rotating channel.J Fluid Mech,404:117-149
Qiu C,Wang D,He Z,Chen C.2012.Seasonal variability of chlorophylla fronts in the Luzon Strait based on satellite observations.Aquatic Ecosyst Health Manage,15:46-52
Shao H,Li Y,Li L.2011.Sun glitter imaging of submarine sand waves on the Taiwan Banks:Determination of the relaxation rate of short waves.J Geophys Res,116:C06024
Shaw P T.1989.The intrusion of water masses into the sea southwest of Taiwan.J Geophys Res,94:18213-18226
Shi R,Guo X,Wang D,Zeng L L,Chen J.2015.Seasonal variability in coastal fronts and its influence on sea surface wind in the Northern South China Sea.Deep-Sea Res Part II-Top Stud Oceanogr,119:30-39
Shih C F,Shaw P T,Li H W.1986.Low Frequency sea level fluctuations around Taiwan(in Chinese).Acta Oceanogr Taiwanica,17:18-28
Thompson R O R Y.1983.Low-pass filters to suppress inertial and tidal frequencies.J Phys Oceanogr,13:1077-1083
Trowbridge J H,Chapman D C,Candela J.1998.Topographic effects,straits and the bottom boundary layer.In:Brink K H,Robinson A R,eds.The Sea.New York:John Wiley and Sons.63-88
Wang D,Liu Y,Qi Y,Shi P.2001.Seasonal variability of thermal fronts in the northern South China Sea from satellite data.Geophys Res Lett,28:3963-3966
Wang D,Xu H,Lin J,Hu J.2008.Anticyclonic eddies in the northeastern South China Sea during winter 2003/2004.J Oceanogr,64:925-935
Wang D,Hong B,Gan J,Xu H.2010.Numerical investigation on propulsion of the counter-wind current in the northern South China Sea in winter.Deep-Sea Res Part I-Oceanogr Res Pap,57:1206-1221
Wang D,Shu Y,Xue H,Hu J,Chen J,Zhuang W,Zu T T,Xu J.2014-Relative contributions of local wind and topography to the coastal upwelling intensity in the northern South China Sea.J Geophys ResOceans,119:2550-2567
Wang J,Chern C S.1988.On the Kuroshio branch in the Taiwan strait during wintertime.Prog Oceanogr,21:469-491
Wang J,Chen C S.1989.On cold water intrusions in the eastern Taiwan Strait during the cold season(in Chinese with English abstract).Acta Oceanogr Taiwaica,22:43-67
Wang Y H,Chiao L Y,Lwiza K M M,Wang D P.2004.Analysis of flow at the gate of Taiwan Strait.J Geophys Res,109:C02025
Zhao B R,Cao D M.1987.Wintertime low frequency fluctuations of Chinese coastal sea-level in the Huanghai sea and the East China Sea.Oceanol Limnol Sin,18:563-574