理想台风驱动的涡旋对吕宋海峡黑潮影响的数值研究
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摘要
吕宋海峡以东即北太平洋热带地区常年存在着大量的涡旋,这些涡旋在向西运动的过程中遇到吕宋海峡黑潮后是否会穿越黑潮进入南海值得研究。文章用数值模式来模拟吕宋海峡的黑潮以及吕宋海峡以东的众多涡旋,结果表明没有一个涡旋可以穿越吕宋海峡进入南海。在此基础上引入了一个理想台风风场,通过风应力旋度的形式驱动出强劲的气旋式和反气旋式涡旋,这两个涡旋分别添加在源区黑潮附近,也是在源区黑潮流量最小的8月。以往研究表明,黑潮流量小而涡旋强劲的时候涡旋容易穿越吕宋海峡进入南海,但由何种原因产生的涡旋可以穿越吕宋海峡难以确定;而文章的数值计算结果表明,即使在黑潮较弱的夏季8月,由风应力旋度产生的中尺度涡,无论是气旋式还是反气旋式,都受到了吕宋海峡的阻挡而难以穿越。
There are many westward-propagating eddies in the subtropical regions in the North Pacific Ocean;therefore,it is worth studying whether these eddies can travel across the Kuroshio and through the Luzon Strait(LS).In this paper,a numerical model is employed to simulate the Kuroshio in the vicinity of the LS and the eddies east of the LS.Our results show that none of these eddies can propagate through the LS and enter the South China Sea(SCS).On this basis,an idealized typhoon is added to the model.Strong cyclonic and anticyclonic eddies can be generated by the positive and negative typhoon wind stress curl,respectively.Each eddy so generated is located near the source region of the Kuroshio in August when the volumetric transport of the Kuroshio is minimal.Previous studies indicated that these eddies are more likely to penetrate through the LS when the Kuroshio transport is low;however,it remains unclear which factor plays the dominating role in pushing eddies through the LS.Our study indicates that,although the Kuroshio is the weakest in August,all eddies generated through the wind stress forcing,either cyclonic or anticyclonic,are blocked by the Kuroshio and cannot penetrate through the LS to enter the SCS.
There are many westward-propagating eddies in the subtropical regions in the North Pacific Ocean;therefore,it is worth studying whether these eddies can travel across the Kuroshio and through the Luzon Strait(LS).In this paper,a numerical model is employed to simulate the Kuroshio in the vicinity of the LS and the eddies east of the LS.Our results show that none of these eddies can propagate through the LS and enter the South China Sea(SCS).On this basis,an idealized typhoon is added to the model.Strong cyclonic and anticyclonic eddies can be generated by the positive and negative typhoon wind stress curl,respectively.Each eddy so generated is located near the source region of the Kuroshio in August when the volumetric transport of the Kuroshio is minimal.Previous studies indicated that these eddies are more likely to penetrate through the LS when the Kuroshio transport is low;however,it remains unclear which factor plays the dominating role in pushing eddies through the LS.Our study indicates that,although the Kuroshio is the weakest in August,all eddies generated through the wind stress forcing,either cyclonic or anticyclonic,are blocked by the Kuroshio and cannot penetrate through the LS to enter the SCS.
引文
[1]QIU B,CHEN S.Interannual variability of the North Pacific Subtropical Countercurrent and its associated mesoscale eddy field[J].Journal of Physical Oceanography,2010,40:213-225.
[2]LACASCE J H,PEDLOSKY J.The instability of Rossby basin modes and the oceanic eddy field[J].Journal of Physical Oceanography,2004,34:2027-2041.
[3]YOSHIDA S,QIU B,P HACKER.Wind generated eddy characteristics in the lee of the island of Hawaii[J].Journal of Geophysical Research,2010,115.doi:10.1029/2009JC005417.
[4]HWANG C,WU C R,KAO R.TOPEX/Poseidon observations of mesoscale eddies over the Subtropical Countercurrent:Kinematic characteristics of an anticyclonic eddy and a cyclonic eddy[J].Journal of Geophysical Research,2004,109:C08013.doi:10.1029/2003JC002026.
[5]仇德忠,杨天鸿,郭忠信.夏季南海北部一支向西流动的海流[J].热带海洋,1984,3(4):65-73.
[6]李立,伍伯瑜.黑潮的南海流套---南海东北部环流结构探讨[J].台湾海峡,1989,8(1):89-95.
[7]黄企洲,郑有任.1992年3月南海东北部巴士海峡的海流[G]//中国海洋学文集:第六集.北京:海洋出版社,1996:42-52.
[8]LI L,NOWLIN W,SU J L.Anticyclonic rings from the Kuroshio in the South China Sea[J].Deep-Sea Research:PartⅠ,1998,45:1469-1482.
[9]苏纪兰.南海环流动力机制研究综述[J].海洋学报,2005,27(6):1-8.
[10]刘秦玉,刘倬腾,郑世培,等.黑潮在吕宋海峡的形变及动力机制[J].青岛海洋大学学报,1996,26(4),413-426.
[11]方国洪,魏泽勋,王凯,等.中国近海域际水、热、盐输运:全球变网格模式结果[J].中国科学:D辑,2002,45(12):969-977.
[12]WANG D X,XU H Z,LIN J,et al.Anticyclonic eddies in the northeastern South China Sea during winter2003/2004[J].Journal of Oceanography,2008,64(6):925-935.
[13]CHEN G X,HU P,HOU Y J,et al.Intrusion of the Kuroshio into the South China Sea in September2008[J].Journal of Oceanography,2011,67:439-448.
[14]WYRTKI K.Physical Oceanography of the Southeast Asia waters[R]//NAGA Report.1961:195.
[15]WANG J,CHERN C S.The warm-core eddy in the northern South China SeaⅠ.Preliminary observations on the warm-core eddy[J].Acta oceanographica Taiwan,1987,18:92-103.
[16]FARRIS A,WIMBUSH M.Wind-induced Kuroshio intrusion into the South China Sea[J].Journal of Oceanography,1996,52:771-784.
[17]袁东亮,李锐祥.中尺度涡旋影响吕宋海峡黑潮变异的动力机制[J].热带海洋学报,2008,27(4):1-9.
[18]SHEU W J,WU C R,OEY L Y.Blocking and westward passage of eddies in the Luzon strait[J].Deep-sea researchⅡ,2010,57:1783-1791.
[19]CHEN G X,HOU Y J,CHU X Q.Mesoscale eddies in the South China Sea:mean properties,spatio-temporal variability and impact on thermohaline structure[J],Journal of Geophysical Research,2011,116:C06018.doi:10.1029/2010JC006716.
[20]靖春生,李立,朱大勇.西太平洋-南海中尺度水位波动的耦合传播特征[J].科学通报,2006,51(20):2422-2428.
[21]ZHAI X M,HELEN L,DAVID P.Significant sink of ocean-eddy energy near western boundaries[J].Nature Geoscience,2010.doi:10.1038/NGEO943.
[22]BLUMBERG A F,MELLOR G L.A description of a three-dimensional coastal ocean circulation model[G]//HEAPS N.Three dimensional coastal models,4.Washington D C:American Geophysical Union,1987:208.
[23]NENCIOLI F,DONG C,TOMMY D,et al.A vector geometry based eddy detection algorithm and its application to high-resolution numerical model products and high-frequency radar surface velocities in the Southern California Bight[J].Journal of Atmospheric and Oceanic Technology,2010,27:564-579.doi:10.11.1175/2009JTECHO725.1.
[24]YANG H,LIU Q,LIU Z,et al.General circulation model study of the dynamics of the upper ocean circulation of the South China Sea[J].Journal of Geophysical Research,2002,107:3085.doi:10.1029/2001JC001084.
[25]OKUBO A.Horizontal dispersion of floatable particles in the vicinity of velocity singularities such as convergences[J].Deep-sea research,1970,17:445-454.
[26]NITANI H.Beginning of the Kuroshio[M]//STOMMEL H,YOSHIDA K.Kuroshio:Physical aspects of the Japan Current.Seattle:University of Washington Press,1972:129-163.
[27]SHEREMENT V.Hysteresis of a western boundary current leap across a gap[J].Journal of Physical Oceanography,2001,31:1247-1259.
[28]HOLLAND G J.An analytical model of the wind and pressure profiles in hurricane[J].Monthly Weather Review,1980,108:1212-1218.
[2]LACASCE J H,PEDLOSKY J.The instability of Rossby basin modes and the oceanic eddy field[J].Journal of Physical Oceanography,2004,34:2027-2041.
[3]YOSHIDA S,QIU B,P HACKER.Wind generated eddy characteristics in the lee of the island of Hawaii[J].Journal of Geophysical Research,2010,115.doi:10.1029/2009JC005417.
[4]HWANG C,WU C R,KAO R.TOPEX/Poseidon observations of mesoscale eddies over the Subtropical Countercurrent:Kinematic characteristics of an anticyclonic eddy and a cyclonic eddy[J].Journal of Geophysical Research,2004,109:C08013.doi:10.1029/2003JC002026.
[5]仇德忠,杨天鸿,郭忠信.夏季南海北部一支向西流动的海流[J].热带海洋,1984,3(4):65-73.
[6]李立,伍伯瑜.黑潮的南海流套---南海东北部环流结构探讨[J].台湾海峡,1989,8(1):89-95.
[7]黄企洲,郑有任.1992年3月南海东北部巴士海峡的海流[G]//中国海洋学文集:第六集.北京:海洋出版社,1996:42-52.
[8]LI L,NOWLIN W,SU J L.Anticyclonic rings from the Kuroshio in the South China Sea[J].Deep-Sea Research:PartⅠ,1998,45:1469-1482.
[9]苏纪兰.南海环流动力机制研究综述[J].海洋学报,2005,27(6):1-8.
[10]刘秦玉,刘倬腾,郑世培,等.黑潮在吕宋海峡的形变及动力机制[J].青岛海洋大学学报,1996,26(4),413-426.
[11]方国洪,魏泽勋,王凯,等.中国近海域际水、热、盐输运:全球变网格模式结果[J].中国科学:D辑,2002,45(12):969-977.
[12]WANG D X,XU H Z,LIN J,et al.Anticyclonic eddies in the northeastern South China Sea during winter2003/2004[J].Journal of Oceanography,2008,64(6):925-935.
[13]CHEN G X,HU P,HOU Y J,et al.Intrusion of the Kuroshio into the South China Sea in September2008[J].Journal of Oceanography,2011,67:439-448.
[14]WYRTKI K.Physical Oceanography of the Southeast Asia waters[R]//NAGA Report.1961:195.
[15]WANG J,CHERN C S.The warm-core eddy in the northern South China SeaⅠ.Preliminary observations on the warm-core eddy[J].Acta oceanographica Taiwan,1987,18:92-103.
[16]FARRIS A,WIMBUSH M.Wind-induced Kuroshio intrusion into the South China Sea[J].Journal of Oceanography,1996,52:771-784.
[17]袁东亮,李锐祥.中尺度涡旋影响吕宋海峡黑潮变异的动力机制[J].热带海洋学报,2008,27(4):1-9.
[18]SHEU W J,WU C R,OEY L Y.Blocking and westward passage of eddies in the Luzon strait[J].Deep-sea researchⅡ,2010,57:1783-1791.
[19]CHEN G X,HOU Y J,CHU X Q.Mesoscale eddies in the South China Sea:mean properties,spatio-temporal variability and impact on thermohaline structure[J],Journal of Geophysical Research,2011,116:C06018.doi:10.1029/2010JC006716.
[20]靖春生,李立,朱大勇.西太平洋-南海中尺度水位波动的耦合传播特征[J].科学通报,2006,51(20):2422-2428.
[21]ZHAI X M,HELEN L,DAVID P.Significant sink of ocean-eddy energy near western boundaries[J].Nature Geoscience,2010.doi:10.1038/NGEO943.
[22]BLUMBERG A F,MELLOR G L.A description of a three-dimensional coastal ocean circulation model[G]//HEAPS N.Three dimensional coastal models,4.Washington D C:American Geophysical Union,1987:208.
[23]NENCIOLI F,DONG C,TOMMY D,et al.A vector geometry based eddy detection algorithm and its application to high-resolution numerical model products and high-frequency radar surface velocities in the Southern California Bight[J].Journal of Atmospheric and Oceanic Technology,2010,27:564-579.doi:10.11.1175/2009JTECHO725.1.
[24]YANG H,LIU Q,LIU Z,et al.General circulation model study of the dynamics of the upper ocean circulation of the South China Sea[J].Journal of Geophysical Research,2002,107:3085.doi:10.1029/2001JC001084.
[25]OKUBO A.Horizontal dispersion of floatable particles in the vicinity of velocity singularities such as convergences[J].Deep-sea research,1970,17:445-454.
[26]NITANI H.Beginning of the Kuroshio[M]//STOMMEL H,YOSHIDA K.Kuroshio:Physical aspects of the Japan Current.Seattle:University of Washington Press,1972:129-163.
[27]SHEREMENT V.Hysteresis of a western boundary current leap across a gap[J].Journal of Physical Oceanography,2001,31:1247-1259.
[28]HOLLAND G J.An analytical model of the wind and pressure profiles in hurricane[J].Monthly Weather Review,1980,108:1212-1218.