| 摘要: |
| 随着海洋技术的发展, 中尺度的海洋过程越来越多的被揭示, 中尺度涡旋作为重要的中尺度海洋过程, 已经被大量的研究。但对于热带西北太平洋海区, 中尺度涡旋特征的空间分布、季节变化以及移动规律等方面的研究还有所欠缺。本文使用Chelton提供的涡旋数据集, 统计分析了热带西北太平洋海区涡旋特征的空间分布, 发现以往研究较少的北赤道逆流(North Equatorial Countercurrent, NECC)区(A 海区, 120°～180°E, 4°～6°N)较临近海域生成涡旋数量更多, 涡旋半径、振幅、生命周期及非线性强度更大, 移动距离更远, 并且A海区涡旋经向移动距离服从伽马分布。涡旋在靠近西边界的区域更易向南移动, 而在西边界以东的区域更易向北移动。A海区涡旋的生成数量具有明显的季节变化, 主要受到流场剪切强度的影响。同时ENSO会对该区涡旋生成产生影响, 其影响机制需要进一步的研究。 |
| 关键词: 中尺度涡 北赤道逆流 特征分布 季节变化 ENSO |
| DOI：10.11759/hykx20170508002 |
| 分类号: |
| 基金项目:国家自然科学基金项目(41406014); 中国科学院战略性先导科技专项(XDA11010204); “全球变化与海气相互作用”专项(GASI-03-01-01-05); 山东省科技发展计划(2013GRC31503) |
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| Statistical analysis of North Equatorial Countercurrent area in tropical western Pacific |
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LÜ Ming-kun,ZANG Nan,WANG Fan
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| Abstract: |
| With the development of ocean technology, more and more mesoscale ocean processes have been revealed. Mesoscale eddies are an important mesoscale ocean process that has been the subject of much research in recent decades. However, research on the spatial distribution, seasonal variation, and movement characteristics of mesoscale eddies in the northwestern Pacific is lacking. In this paper, we statistically analyzed the spatial distribution of eddies in the northwestern tropical Pacific using the eddy dataset provided by Chelton. We found that more eddies are generated in the North Equatorial Countercurrent (NECC) area (A zone, 120°–180°E, 4°–6°N) where less research effort has been focused. Moreover, the eddy radii, amplitudes, lifecycles, and nonlinear intensities are larger, the movement distances are farther, and the meridional eddy movement distances obey a gamma distribution in the A zone. Most eddies move southward in the region close to the western boundary, and most move northward far away from the western boundary. The quantity of eddies generated in the A zone exhibits obvious seasonal variation, which is mainly affected by the shear intensity of the currents. At the same time, eddy formation is affected by the ENSO in this area, and its mechanism requires further study. |
| Key words: mesoscale eddies North Equatorial Countercurrent characteristic distribution seasonal variation ENSO |
