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1.
1998年夏季南海环流的三维结构 总被引：1，自引：2，他引：1
利用1998年6月12日至7月6日南海的调查资料,采用三维海流诊断模式,计算了夏季南海三维海流,结合卫星海表面高度距平资料,得到结果如下:(1)南海北部,在吕宋岛以西海域和东沙群岛附近海域,分别存在一个反气旋式涡和东沙群岛西南的气旋式涡.(2)南海中部,越南以东海域出现由暖涡W3和冷涡C3组成的一个准偶极子.在冷涡C3和暖涡W3以北分别存在一个暖涡W2和冷涡C2.(3)在越南近岸存在较强的、北向的西边界射流,此北向射流在14°N附近离岸转为东,并流入两涡W3和C3之间.(4)南海南部,在巴拉望岛的西南海域,100m以浅水层存在反气旋式涡,而在其较深水层,此处变为气旋式涡.(5)南海环流的动力机制有两个:最重要的动力因子为斜压场与地形相互作用项,其次为风应力与地形相互作用项.(6)讨论了夏季南海环流垂向速度w分布,例如在30m层,Ekman抽吸对垂向速度w分布起着重要作用.(7)与2000年夏季南海环流的比较,1998年夏季计算海域涡旋W3,C3,C2等的位置变化并不大. 相似文献
2.
2000年夏季南海环流的改进逆方法计算 总被引：9，自引：3，他引：9
基于2000年8月航次在南海调查资料,采用改进逆方法,并结合TOPEX/ERS分析的SSH分布,获得以下的主要结果:(1)南海中部和西南部环流系统主要受反气旋环流所支配.主要有越南东南反气旋涡W1,其水平尺度约为300km,垂向深度可达1000m以深,流速很强,其最大流速为79cm/s左右,还有暖涡W2以及吕宋岛西南反气旋涡环流系统W3.其次,在反气旋涡W1与W2之间还存在气旋式涡C1.其水平尺度比暖涡W1小得多,流速也较强.两涡W1与C1之间存在一支南向流,它们组成一个准偶极子.(2)在暖涡W1的西侧存在西边界流,即北向射流,其流速很强,约在12°N流向转向东北.(3)南海北部环流系统主要受气旋环流所支配.在断面N2附近及以北存在一个气旋式环流系统.其次,在海南岛东南存在一个尺度不大的反气旋环流系统.(4)南海东南部环流系统主要受气旋环流所支配.主要有在巴拉望岛以西存在尺度较大的气旋环流系统,以及暖涡W1东南存在一个气旋环流系统.其次,在加里曼丹岛西北还存在范围不大的反气旋环流.(5)比较1998年夏季航次与2000年夏季航次时计算结果,虽然它们在定量上有些变化与差别,但在定性上它们的环流结构有十分相似之处.这表明,南海环流具有明显的季节特性.(6)比较2000年夏季南海水文结构,流函数分布以及TOPEX/ERS的SSH分布,它们在定性上十分吻合. 相似文献
3.
1998年冬季南海上层环流诊断计算 总被引：12，自引：2，他引：12
基于1998年11月28日至12月27日的调查航次的CTD资料,采用P矢量方法对调查期间南海环流进行了诊断计算,也对比了在此期间TOPEX/ERS卫星高度计SSH的资料,得到了1998年冬季南海上层环流的以下一些重要特征.(1)南海中部环流系统主要特征:在冬季越南近岸出现西边界南向射流.这支沿岸南向射流以东、114°E以西存在一个尺度大的、显著气旋式环流,它位于南自10°N左右北至16°N附近区域.在区域东中部存在一个尺度不大的、较弱的反气旋暖涡.该反气旋涡中心约位于14°N附近.在上述强的气旋式环流涡与较弱的反气旋式环流涡之间,存在一支强的、逆风方向的,即偏东北方向的海流.上述是冬季南海中部基本流态,并与200m处水平温度分布与密度分布有很好的对应.产生上述基本流态的动力原因有两个:1)在偏东北季风作用下,与地形变化相互作用,是本文首次提出的,并指出,其动力原因与冬季黄海暖流形成机制有相似之处;2)由于斜压场与地形的联合效应(JEBAT).(2)在海区南部存在一个反气旋式环流,在加里曼丹岛西北还有一个尺度不大、冷的气旋式涡.(3)南海北部环流系统:1)在吕宋岛西北明显地存在一个气旋环流系统,并有3个冷水中心;2)在此气旋式环流系统的一个冷水中心(约19°30'N,119°30'E)以西,存在一个反气旋式涡;3)在海南岛以南出现一个暖的、反气旋式环流;4)在南海北部,114°E以东、广东沿岸外侧存在一支东北向流.这是管秉贤首次指出的,冬季时出现南海暖流.(4)上述1998年冬季南海上层环流的一些重要特征都与此期间TOPEX/ERS-2卫星高度计SSH分布有较好的相对应. 相似文献
4.
P矢量方法在南海夏季环流诊断计算中的应用 总被引：8，自引：4，他引：8
基于1998年6～7月南海调查航次的CTD资料,对南海环流采用最近发展的P矢量方法进行诊断计算.计算结果:黑潮向西入侵南海,然后做反气旋弯曲向东北方向流动,最终有通过巴士海峡流出南海的趋势.在南海北部存在一个气旋性环流,这个环流的强度和范围随深度增加而减小.该环流的冷中心位置随深度增加稍向南移.南海中部、越南以东海域存在一个明显的气旋涡和反气旋涡,尤其在200m及其以上水层均相当稳定,反气旋涡位于越南以东,其中心位置在11°53'N,111°50'E,气旋涡的中心位置在13°17'N,112°55'E,两者的尺度皆约为250km.吕宋岛西侧存在一个反气旋涡.在计算海区南部、巴拉望岛西南海域,100m以上层存在一个反气旋式涡.从各层流场分布均可以显示海流在西部强化的现象. 相似文献
5.
1998年夏季季风爆发前后南海环流的多涡特征 总被引：10，自引：0，他引：10
利用南海季风实验（SCSMEX－IOP1、IOP2）期间（1998年4月底－7月初）所获得的温盐深（CTD）、声学多普勒流速剖面仪（ADCP）资料及TOPEX／POSEIDON卫星高度计遥感资料，分析了南海表层、1．0MPa层和3．0MPa层得力势异常场的分布格局，探讨了夏季季风爆发前后南海的环流特征。结果表明：在夏季季风爆发前（IOP1期间）南海北部以气旋试流动为主，并在此气旋式环流的东部镶嵌着一个较小的反气旋型涡；南海中部和南部以反气旋式流动为主，其中越南以东海域存在着两个南北对峙分布的反气旋型涡，在它们的东侧伴随一气旋型涡。季风爆发后（IPO2期间），南海北部仍然以气旋式流动为主，黑潮水越过巴士海峡南北中线，一部分可能入侵南海北部，另一部分向东北折回黑潮主干；南海中部和南部仍以反气旋式流动为主，越南以东海域北部的反气旋型涡消失，但南西的反气旋型涡加强，与IOP1类似，仍伴随着一个气旋型涡。总体而方，强流区出现在巴士海峡西北侧和南海西部（尤其是越东南东沿岸），南海东部和东南部为弱流区。 相似文献
6.
越南离岸流跨海盆特征初步分析 总被引：3，自引：0，他引：3
为了更加清晰地分析南海的环流结构,本文利用南海表层卫星跟踪漂流浮标轨迹,结合卫星高度计资料,分析了南海中、南部跨海盆尺度海流。结果表明,2011年9~10月,越南沿岸流向南,并分别在11.5°N和8.5°N(等深线出现弯曲处)转向东形成越南离岸流。之后,这支离岸流在11°~16°N呈现蛇形路径,从越南东岸跨越南海南部海盆到达菲律宾西岸。分析卫星高度计数据,结果表明,秋季南海中北部被气旋式环流控制,气旋式环流南部为东向流,可从越南东部一直到菲律宾沿岸,从而决定了越南离岸流跨海盆的特征。越南离岸流的蛇形路径主要是由反气旋-气旋-反气旋-气旋交错出现的中尺度涡决定的。 相似文献
7.
1995与1996年夏季琉球群岛两侧海流 总被引：4，自引：3，他引：4
基于1995,1996年夏季日本调查船的观测资料,采用P矢量方法对琉球群岛两侧的海流进行了计算.结果表明:黑潮为琉球群岛以西海域的一支东北向强流,1996年夏季的流速比1995年夏季的强,在深层出现南向逆流.黑潮东、西两侧分别存在一个反气旋式暖涡和一个弱的气旋式冷涡.1995年夏季,琉球群岛以东,从表层至以下层都存在一支沿岸北上的海流,即琉球海流.该海流来自黑潮分支,为本海区的一个主要物理特征.琉球海流以下出现弱的南向流.冲绳岛以东海域,在25°～25°30'N,128°30'～129°10'E附近从表层至700m水深存在一个中尺度的反气旋式暖涡.在温、盐水平分布图上,对应的出现一个较高温、低密水块.1996年夏季,冲绳岛西南海域存在一个中尺度的反气旋式暖涡和一个气旋式冷涡,形成一个偶极子,中间为较强的南向流,该现象为本海区的一个重要物理特征,属首次报道.冲绳岛以东表层主要被南向流控制,琉球海流不明显.200m以深在近岸出现北向流,这表明琉球海流的核心位于次表层.琉球海流的下面出现南向流.计算海区东北部从表层到700m水深出现一个中尺度的反气旋式暖涡,与1995年夏季时比较,其位置向北移动.此外在1996年夏季从近表层到深层,垂直方向和水平方向上的等温线、等盐线波动很大,例如在C断面上冷、暖涡相间出现,且暖 相似文献
8.
南海环流动力机制研究综述 总被引：40，自引：9，他引：31
南海的环流复杂,但通过近20 a来的研究工作,国内外学者对此已取得了不少的成果.本文就南海环流框架性的问题,综述了有关的文献,认为对南海上层海洋三方面的环流分量的驱动机制已有了初步的认识.这三方面分别是:(1)准季节性风场;(2)黑潮向南海的净输运;(3)黑潮向南海的涡度平流输送.但是对这些驱动的时空变化仍相当不清楚.三者皆增强了南海北部的海盆尺度气旋式环流,其强化的西南向西边界流靠近东沙群岛,建议称为“东沙海流”.没有水文证据显示黑潮水是以分支形式进入南海,其向南海的输运也不可能主要通过中尺度涡过程,具体机制有待研究.每年在南海生成的中尺度涡平均约有10个,风场与沿岸地形所生成的强风应力旋度可能是其主要的驱动机制.作为框架性的认识,也有三方面的工作进行得较少,即:(1)吕宋海峡的上层水交换;(2)南海的中尺度涡生成机制,虽然强风应力旋度及前述的第三种环流驱动机制也有中尺度涡伴生;(3)自吕宋海峡进入的深层水对南海上层海洋环流的影响. 相似文献
9.
1998年冬季南海环流的三维结构 总被引：10，自引：3，他引：7
利用1998年11月28日至12月27日南海的调查资料,采用三维海流诊断模式,计算了冬季南海三维海流,所得结果如下:(1)冬季南海环流系统方面:1)南海北部,在吕宋西北海域分别存在一个气旋式、反气旋式涡.2)南海中部,在越南近岸存在较强的、南向的西边界射流.其以东海域出现较强的气旋式环流.南海中部东侧海域存在一个较弱的反气旋式环流.3)南海南部,一般流速较弱.在112°E以西受反气旋式环流所控制,加里曼丹岛西北海域存在气旋性环流.由于受调查海域所限,这两个环流只部分出现.(2)上述环流系统与200 m层水平温度、密度分布对应较好.(3)南海冬季环流垂向速度分布方面:1)表层,南海北部,在吕宋西北为范围较大的上升流海区.而在东沙群岛附近海域出现了下降流.海南岛以南及东南海域也存在下降流.南海中部,越南以东海域出现范围较大的下降流,其以东为上升流海域,而在巴拉望岛西北海域又出现下降流.南海南部,基本上被上升流海域所控制.2)次表层与表层不同,例如在次表层,海南岛东南部海域出现上升流.中层和深层垂向速度分布与次表层相似.(4)关于南海垂向速度分量分布的动力原因:在表层,风应力旋度场起着主要作用;在次表层,β效应与斜压场相互作用是重要的动力因子,而风应力旋度场和β效应与正压场相互作用也有一定影响;在南海中部等区域的中层以及在南海的深层,主要受B效应与斜压场相互作用和B效应与正压场相互作用的共同作用. 相似文献
10.
南海中尺度海洋现象研究概述 总被引：15，自引：1，他引：15
南海是一个地形复杂的半封闭海盆，受季风，黑潮等因素的作用南海呈现独特的中尺度变异特征，一些中尺度信号的强度可以和南海定常环流的强度相比拟，甚至更强，本文回顾了近20a来南海中尺度海洋现象研究的进展，并就南海的黑潮入侵，黑潮涡环，次海盆尺度多涡环流，浅海亚潮波动，近岸陷波，海洋锋等中尺度现象做若干探讨。 相似文献
11.
Three dimensional diagnostic modeling study of the South China Sea circulation before onset of summer monsoon in 1998 总被引：1，自引：0，他引：1
The wind data from NCEP and hydrographic data obtained from April 22–May 24, 1998 have been used to compute the circulation
in the South China Sea (SCS) using three dimensional diagnostic models. The main numerical results with SSHA derived from
T/P altimeter are as follows: most of intruded Kuroshio bypasses. However, a part of Kuroshio intrudes westward above 300
m levels. This intruded westward flow is narrowly confined to the continental slope south of China, in agreement with the
findings of Qu et al. (2000). The basin-scale cyclonic gyre dominates in the northern SCS and consists of two cyclonic eddies, C2 and C3, above
300 m levels. However, it is separated into two parts by an anti-cyclonic eddy, W4, below 300 m. The basin-scale anti-cyclonic
gyre dominates in the central SCS and consists of three anti-cyclonic eddies, W1, W2 and W3, above 300 m levels. However,
below 300 m it consists of the anti-cyclonic eddies W1, W2 and W4 and extends northward to near 20°N. A northward coastal
jet is present near the coast of Vietnam at depths above 300 m, and develops northward further to about a distance of 3°15′
N than that in cruise 2. The most important dynamical mechanism is due to the joint effect of the baroclinity and relief.
The second dynamical mechanism is due to the interaction between the wind stress and relief. The topography effect is more
important than the β effect. The Sverdrup relation cannot be satisfied in the SCS. 相似文献
12.
On the basis of hydrographic data obtained from 12 June to 6 July, 1998, the three-dimensional structure of circulation in
the South China Sea (SCS) is computed using a three-dimensional diagnostic model. The combination of sea surface height anomaly
from altimeter data and numerical results provides a consistent circulation pattern for the SCS, and the main circulation
features can be summarized as follows: In the northern SCS there are a cyclonic eddy C1 near Dongsha Islands and an anti-cyclonic
eddy W1 west of Luzon Island. In the central SCS a strong anti-cyclonic eddy W3 and a cyclonic eddy C3 compose a quasi-dipole
southeast of Vietnam. A coastal northward jet is present at the western boundary near the Vietnam coast above 300 m level.
This northward coastal jet flows northward and turns eastward at about 14°N, and then flows southeastward into the area between
eddies W3 and C3. In the southern SCS the current is weaker. The most important dynamic mechanism underlying the circulation
in the SCS is the joint effect of the baroclinicity and relief (JEBAR), and the second dynamical mechanism is the interaction
between the wind stress and relief (IBWSR). Comparison of the characters of circulation in the SCS during summer 2000 with
that during summer 1998 reveals no obvious variability of the main characteristics. 相似文献
13.
Calculation of circulation in the South China Sea during summer of 2000 by the modified inverse method 总被引：3，自引：0，他引：3
YUAN Yaochu LIU Yonggang LIAO Guanghong LOU Ruyun SU Jilan WANG Kangshan 《海洋学报(英文版)》2005,24(1):14-30
On the basis of hydrographic data obtained in August 2000 cruise, the circulation in the South China Sea (SCS) is computed by the modified inverse method in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of summer circulation in the SCS, the diagnostic model (Yuan et al. 1982. Acta Oceanologica Sinica,4(1):1-11; Yuan and Su. 1992. Numerical Computation of Physical Oceanography.474-542) is used to simulate numerically the summer circulation in the SCS. The following results 相似文献
14.
On the basis of hydrographic data obtained in November 28 to December 27, 1998 cruise, the calculation of the circulation in the South China Sea (SCS) is made by using the P-vector method, in combination with SSH data from TOPEX/ERS-2 analysis. For study of the dynamical mechanism, which causes the pattern of winter circulation in the SCS, the diagnostic model (Yuan et al., 1982; Yuan and Su, 1992) is used to simulate numerically the winter circulation in the SCS. The following results have been obtained.(1) The main characteristics of the circulation systems in the central SCS are as follows: A coastal southward jet in winter is present at the western boundary near the coast of Vietnam; there is a stronger cyclonic circulation with a larger horizontal scale east of this coastal southward jet and west of 114°E; there is a weaker anti-cyclonic circulation in the central part of eastern SCS; there is a stronger and northeastward flow opposing the northeasterly monsoon between above a stronger cyclonic circulation and a weaker anti-cyclonic circulation.(2) The circulation systems in the northern SCS are as follows: 1)There is a cyclonic circulation system northwest of Luzon, and it has three centers of the cold water; 2) There is an anti-cyclonic eddy. Its center is located near(20°N, 116°40' E); 3)There is a warm and anti-cyclonic circulation south of Hainan Island; 4) There is a northeastward flow, the South China Sea Warm Current, in winter off Guangdong coast in the northern SCS.(3) In the southem SCS there is an anti-cyclonic circulation, and also there is a smaller scale cold water and cyclonic eddy.(4) The above pattern of winter circulation in the SCS agrees qualitatively with the horizontal distribution of temperature at 200 m level.(5) The dynamical mechanism which produces the above basic pattern of winter circulation is because of the following two causes: 1) The joint effect of the baroclinity and relief (JEBAR) is an essential dynamical cause; 2) The interaction between the wind stress and bottom topographic (IBWT) under the strong northeasterly monsoon is the next important dynamical mechanism.(6) Comparing the hydrographic structure and the horizontal distribution of velocity with the SSH data from TOPEX/ERS-2 analysis in the SCS during December of 1998, it is found that they agree qualitatively. 相似文献
15.
On the basis of hydrographic data obtained from 28 November to 27 December, 1998, the three-dimensional structure of circulation
in the South China Sea (SCS) is computed using a three-dimensional diagnostic model. The combination of sea surface height
anomaly from altimeter data and numerical results provides a consistent circulation pattern for the SCS, and main circulation
features can be summarized as follows: in the northern SCS there are a cold and cyclonic circulation C1 with two cores C1-1
and C1-2 northwest of Luzon and an anticyclonic eddy (W1) near Dongsha Islands. In the central SCS there is a stronger cyclonic
circulation C2 with two cores C2-1 and C2-2 east of Vietnam and a weaker anticyclonic eddy W2 northwest of Palawan Island.
A stronger coastal southward jet presents west of the eddy C2 and turns to the southeast in the region southwest of eddy C2-2,
and it then turns to flow eastward in the region south of eddy C2-2. In the southern SCS there are a weak cyclonic eddy C3
northwest of Borneo and an anti-cyclonic circulation W3 in the subsurface layer. The net westward volume transport through
section CD at 119.125°E from 18.975° to 21.725°N is about 10.3 × 106 m3s−1 in the layer above 400 m level. The most important dynamic mechanism generating the circulation in the SCS is a joint effect
of the baroclinicity and relief (JEBAR), and the second dynamical mechanism is an interaction between the wind stress and
relief (IBWSR). The strong upwelling occurs off northwest Luzon. 相似文献
16.
The Kuroshio near the Luzon Strait and circulation in the northern South China Sea during August and September 1994 总被引：3，自引：0，他引：3
Wind data from NCEP and hydrographic data obtained from August 28 to September 10, 1994 have been used to compute circulation
in the northern South China Sea and near Luzon Strait using three-dimensional diagnostic models with a modified inverse method.
The numerical results are as follows: the main Kuroshio is located above 400 m levels near Taiwan’s eastern coast and above
800 m levels away from it. Near Luzon Strait above 400 m levels a branch of the Kuroshio joins with a part of the northward
current, which comes from an area west of Luzon’s western coast and intrudes northwestward, then it branchs into western and
eastern parts near 20°30′ N. The eastern part flows northward into an area east of Taiwan, while its western part continues
to intrude northwestward, flowing through an area southwest of Taiwan. Net westward intruded volume transport through longitude
Section AB at 121°00′ E from 19°00′ N to 21° 43′ N is about 3.5 × 106 m3s−1 in a layer above 400 m levels. The anticyclonic eddies W1 and W3 exist above 700 m levels east of Dongsha Islands and below
200 m levels in the eastern part of the region, respectively. The circulation in the middle region is dominated mainly by
a basin-scale cyclonic gyre, and consists of three cyclonic eddies. Strong upwelling occurs in the middle region. The joint
effect of baroclinity and relief and interaction between wind stress and relief both are important for real forcing of flow
across contours of fH
−1 in effecting the circulation pattern. 相似文献