Seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait
Seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait
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DOI：
10.1007/s10872-011-0060-1
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发表时间：
2011-08
影响因子：
2.3
通讯作者：
Yinglai Jia;E. Chassignet
中科院分区：
文献类型：
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作者：
Yinglai Jia;E. Chassignet
高度计数据和混合坐标海洋模型全球同化运行的输出用于研究吕宋海峡黑潮入侵造成的涡流脱落的季节性变化。结果表明，大多数涡旋脱落事件发生在 12 月至 3 月，6 月、9 月或 10 月没有发生涡旋脱落事件。大约在涡流脱落前一个月，黑潮侵入体延伸到南海，黑潮环路内部出现封闭的反气旋涡旋，然后与黑潮侵入体分离。 12月至2月分离的反气旋涡流在脱落后以约0.1 m s−1的速度向西移动，而其他月份分离的涡流要么停留在原地，要么以非常慢的速度（小于0.06 m s−1）向西移动。 HYCOM 输出和 QuikSCAT 风数据清楚地表明涡旋脱落的季节变化受到季风的影响。涡量与综合埃克曼输运的比较表明，一旦综合埃克曼输运超过2×1012m3（大致相当于涡量），黑潮侵入范围就会扩大，并在1个月内发生涡脱落事件。我们推断，东北季风的埃克曼漂移将黑潮推入南海，形成向海峡的净向西输送，并导致黑潮的涡流脱离。
Altimeter data and output from the HYbrid Coordinate Ocean Model global assimilation run are used to study the seasonal variation of eddy shedding from the Kuroshio intrusion in the Luzon Strait. The results suggest that most eddy shedding events occur from December through March, and no eddy shedding event occurs in June, September, or October. About a month before eddy shedding, the Kuroshio intrusion extends into the South China Sea and a closed anticyclonic eddy appears inside the Kuroshio loop which then detaches from the Kuroshio intrusion. Anticyclonic eddies detached from December through February move westward at a speed of about 0.1 m s−1after shedding, whereas eddies detached in other months either stay at the place of origin or move westward at a very slow speed (less than 0.06 m s−1). The HYCOM outputs and QuikSCAT wind data clearly show that the seasonal variation of eddy shedding is influenced by the monsoon winds. A comparison between eddy volume and integrated Ekman transport indicates that, once the integrated Ekman transport exceeds 2 × 1012m3(which roughly corresponds to the volume of an eddy), the Kuroshio intrusion expands and an eddy shedding event occurs within 1 month. We infer that the Ekman drift of the northeasterly monsoon pushes the Kuroshio intrusion into the SCS, creates a net westward transport into the Strait, and leads to an eddy detachment from the Kuroshio.