馬祖鄰近海域表層流場之初探

Preliminary Investigation of the Surface Circulation near Matsu

陳先文(Hsien-Wen CHEN)

《中央警察大學水上警察學報》 6期 (2017/12) Pp. 1-25

摘要

本研究在2013 年5 月及6 月於台灣海峽西北部靠近馬祖之水域施放兩顆GPS 表面浮標，配合風場資料，研究該海域之表面流場。觀察浮標漂流之軌跡，發現該處表層海流大致沿著等深線移動，且大陸沿岸流及台灣海峽暖流約以50 公尺等深線為分界，以東的表面流場以台灣海峽暖流為主，平均流速約為0.05 m/s；以西則以大陸沿岸流為主，流速約為0.17m/s。本研究利用調和分析探討該海域潮流各分潮之特性，結果顯示該海域之潮流是以M2 分潮為主要成分。濾除主要潮流後之殘餘流與風速做相關分析，得到殘餘流與風應力最佳相關性約在1.25 天至3.33 天之間 (相關係數約0.6-0.8)，而風應力約比殘餘流提早0 至10 小時，與過去相關學術研究成果相比較，潮流與殘餘流之特性以及殘餘流與風應力的相關性等結果均相當一致。

關鍵字

馬祖 ； 大陸沿岸流 ； 黑潮支流 ； 海上搜救

並列摘要

We have deployed two satellite-tracked surface drifters in the vicinity of the Matsu Islands in May and June 2013. According to the trajectories of these two drifters, the surface circulation is primarily topographic-steered. The boundary between the China Coastal Current and the Kuroshio Branch Water is approximately along the 50-m isobath. Both the harmonic and wavelet analyses of the current velocities indicate the dominant tidal current is the M2 constituent. The TPXO barotropic tidal model is employed to separate the tidal and residual currents. To the east of the 50-m isobath, the mean value of the residual current is about 0.05 m/s (Kuroshio Branch) and is about 0.17 m/s in the west (China Coastal Current). The correlation analysis between the wind stress and surface currents has also been conducted. The results show the best correlation between these two occurs at a period of 30-80 hours with correlation coefficients of 0.6-0.8 and the wind stress advances the residual currents in 0 to 10 hours. The results obtained in this study agree well with the previous works.

並列關鍵字

Matsu ； China Coastal Current ； Kuroshio Branch ； Marine Search and Rescue