收稿日期: 2006-04-24
修回日期: 2006-09-30
网络出版日期: 2006-11-15
基金资助
国家自然科学基金项目“太平洋和印度洋对印度尼西亚贯穿流年际变化贡献的研究”（编号：40306004）；国家重点基础研究发展计划项目“中国东部陆架边缘海海洋物理环境演变及其环境效应”（编号：2005CB422300）资助.
Seasonal Variability of Cool-core Eddy in the Western South China Sea
Received date: 2006-04-24
Revised date: 2006-09-30
Online published: 2006-11-15
基于美国海军的空间分辨率为0.5°×0.5°月平均的GDEM(Generalized Digital Environmental Model )三维温盐资料，采用P-Vector方法，计算了南海西部夏季冷涡及附近海域的三维环流，分析了此冷涡的水平结构和垂向结构及其季节变化规律。结果表明南海西部夏季冷涡所占据的海域为一上升流区，对应的是低温区和气旋式环流，其温度场具有明显的垂向层化结构，冷涡随深度增加而减弱。冷涡中心在上层靠近越南沿岸，在温跃层以下有离岸的趋势。此冷涡具有明显的季节性变化：在5、6月份冷涡开始形成，其范围达到110.75°E，最大切向流速为8 cm/s；在7、8月份冷涡达到强盛，其范围向东扩展至112.50°E，冷涡中心也向东移至(110.50°E，13.25°N)，最大切向流速增加为30 cm/s；在9、10月份冷涡开始衰减。
关键词： 季节变化; 南海西部夏季冷涡; P-Vector方法
李丕学 , 兰健 , 洪洁莉 . 南海西部夏季冷涡的季节变化特征[J]. 地球科学进展, 2006 , 21(11) : 1145 -1152 . DOI: 10.11867/j.issn.1001-8166.2006.11.1145
In order to investigate the temporal and spatial features of the cool-core eddy in the Western South China sea, this paper analyzes the GDEM (Generalized Digital Environmental Model) hydrographic data with resolution 0.5°×0.5°. The current system in the vicinity of the cool-core eddy is determined by the P-Vector Method from the GDEM data. The results confirm the existence of the cool-core cyclonic eddy, located on the coast of South Vietnam in which upwelling occurs. The cool-core eddy shows the evident vertical layered structure (mixed layer, thermocline, and layer below the thermocline). The horizontal temperature gradient and the maximum tangential velocity of the cool-core eddy decrease with depth. The eddy center is near the coast of the Vietnam in the upper layer, and spread offshore below thermocline. The cool-core eddy displays prominent seasonal variation: The period of May and June is its developing stage during which it reaches 110.75°E and its maximum tangential velocity is 8cm/s; the period of July and August is its strongest stage during which the eddy extends to 112.50°E and its maximum tangential velocity reaches 30 cm/s, and the eddy center moves northeastward to (110.50°E, 13.25°N); during September and October, the cool-core eddy is weakening.
Key words： Cool-core eddy; P-Vector method.; Seasonal variation
[1] Wyrtki K. Scientific results of marine investigations of the South China Sea and the Gulf of Thailand 1959-1961. Naga Report, Vol.2[R].University of California at San Diego, 1961:195.
[2] Chu P C, Wang G. Seasonal Variability of Thermohaline Front in the Central South China Sea[J]. Journal of Oceanography, 2003, 59: 65-78.
[3] Huang Qizhou, Wang Wenzhi, Li Yuxiang, et al. Overview of the Circulation and Eddies in South China Sea[J]. Advances in Earth Scinece,1992,7(5):1-9.[黄企洲, 王文质,李毓湘,等.南海海流和涡旋概况[J].地球科学进展,1992,7(5):1-9.]
[4] Dale W L. Winds and drift currents in the South China Sea[J]. Malayan Journal of Tropical Geography,1956, 8:1-31.
[5] Uda M, Nakao T. Water masses and currents in the South China Sea and their seasonal changes[C]. The Kuroshio-Proceedings of the 3rd CSK Symposium, Bangkok, Thailand, 1974:161-188.
[6] Chu P C, Fan C W, Lozano C J, et al. An airborne expandable bathythermogr- aph (AXBT) survey of the South China Sea, May 1995[J]. Journal of Geophysical Research,1998,103:21 637-21 652.
[7] Yang Haijun, Liu Qinyu. The seasonal features of temperature distributions in the upper layer of the South China sea[J]. Oceanologia et Limnologia Sinica,1998,29(5): 501-511.[杨海军, 刘秦玉. 南海上层水温分布的季节特征[J].海洋与湖沼,1998, 29(5): 501-511.]
[8] Xie S P, Xie Q, Wang Dongxiao, et al. Summer upwelling in the South China Sea and its role in regional climate variations[J]. Journal of Geophysical Research,2003,108(C8):3 261-3 273.
[9] Wunsch C, Grant B. Towards the general circulation of the North Atlantic ocean[J]. Progress in Oceanography,1982,11: 1-59.
[10] Chu P C. P-Vector method for determining absolute velocity from hydrographic data[J]. Marine Technology Society Journal,1995,29(3):3-14.
[11] Chu P C, Lan Jian, Fan C W. Japan sea thermohaline structure and circulation. Part 1: Climatology[J]. Journal of Physical Oceanography,2001,31:244-271.
[12] Liu Yonggang, Yuan Yaochu, Su Jilan, et al. South China sea circulation in summer,1998[J]. Chinese Science Bulletin, 2000, 45(12):1 252-1 259.[刘勇刚,袁耀初,苏纪兰,等.1998年夏季南海环流[J].科学通报,2000,45(12):1 252-1 259.]
[13] Wang Dongxiao, Chen Ju, Chen Rongyu, et al. Hydrographic and circulation characteristics in middle and southern South China sea in summer, 2000[J]. Oceanologia et Limnologia Sinica,2004,35(2): 97-109.[王东晓,陈举,陈荣裕,等.2000年8月南海中部与南部海洋温、盐与环流特征[J].海洋与湖沼,2004,35(2):97-109.]
[14] Lin Pengfei. Statistical analyses on mesoscale eddies in the South China Sea and the Northwest Pacific[D]. 2005.[林鹏飞.南海和西北太平洋中尺度涡的统计特征分析[D].2005.]
[15] Metzger E J, Hurburt H E. Coupled dynamics of the South China sea, the Sulu sea and the Pacific ocean[J]. Journal of Geophysical Research, 1996, 111(C5):12 331-12 352.
[16] Chao S Y, Shaw P T. Deep water ventilation in the South China sea[J]. Deep Sea ResearchⅠ, 1996, 43(4): 445-466.
/
| 〈 |
|
〉 |
甘公网安备62010202000687
