應用岸基微波雷達量測近岸海流空間分布

航海用微波雷達已被使用來作為海流觀測的工具，但大部分的研究是計算雷達掃射範圍內的平均海流，這對於近岸高度非均勻（non-homogeneous）海域並不合適。本文應用頻散關係（dispersion relation）對雷達海面回波進行濾波，疊代計算出表面海流結果，建立了以微波雷達分析近岸空間流場之架構，並以現場實測資料驗證了從雷達回波分析表面流場結果之準確性。本研究分別在新北市富貴角海域和基隆市海洋大學前方基隆嶼海域進行觀測研究，結果顯示，在富貴角離岸2公里外的海域開始，其平均流速有超過70%時間大於1m/s，觀測期間最大達3.92m/s，是潮流發電的理想場址。本文也觀測到富貴角西側海岸偶有離岸裂流（rip current）出現，對海域活動者帶來潛在危害。基隆海域的觀測結果顯示，在乾潮前後一小時內，基隆嶼東南方海面會出現一個半徑約一公里的逆時針渦漩。本文研究除驗證了微波雷達觀測近岸海流的準確性外，也提出了近岸空間海流變化在海洋能源開發、防災、環保與科學研究上應用的具體實例。

關鍵字

微波雷達；空間海流分布；裂流；潮流發電；渦漩

並列摘要

Microwave radar has been applied for nearshore current measurement. But most of them are implemented by a representative current from a whole image which is not reasonable for nearshore area. The purpose of this study is going to derive the spatial current distribution according to image spectral filter method based on dispersion relation. This study measured current at Fuguei Cape and Keelung sea area by microwave radar, and compared with Acoustic Doppler Current Profiler (ADCP) to verify the accuracy. The results confirm the reliance and correctness of current data form radar. The observation from Fuguei Cape found that the averaged current speed is higher than 1 m/s far from 2 km offshore area. The max. current speed observed is 3.92 m/s at Fuguei Cape coast. A strong flow and rip current were found in the east side of the Fuguei Cape and within the bay. They may cause by the interaction between tidal and coastal topography. The observation from Keelung sea area found a counterclockwise vortex one hour before and after low tide with one kilometer radius which occurs in the south-east of Keelung Sill. The strongest speed (1.55 m/s) occurs at 1.5 km from Keelung sill with depth of 20 m.

並列關鍵字

Microwave radar ； Spatial current distribution ； Rip current ； Tidal current power ； Eddy

國際替代計量

應用岸基微波雷達量測近岸海流空間分布

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