ABSTRACT

An oceanographic high-frequency radar system was deployed by Fisheries and Ocean Canada along Hecate Strait, British Columbia to strengthen regional marine safety, including search-and-rescue operations. The Hecate Strait CODAR system provides hourly surface currents on a grid that spans central-northern Hecate Strait at a horizontal resolution of 5 km. These observations are used to characterize regional tidal currents and the subtidal wintertime surface circulation. The HF radar currents are also used to assess results from the Coastal Ice Ocean Prediction System for the West Coast of Canada (CIOPS-W), a component of the pan-Canadian operational ocean modelling system. Comparisons of rotary spectra and tidal current ellipses with historical current metre observations show that vector currents from the Hecate Strait CODAR system are reasonably accurate and can be used to describe the circulation and variability of ocean currents over the strait on tidal and subtidal time scales. Variability of the subtidal flow, in particular the along-strait surface-layer transport, is closely related to local wind forcing and sea level variability. A vector regression to buoy winds demonstrates that the ocean response is highly anisotropic, with the magnitude and veering of the surface current strongly dependent on the direction of the wind. Comparisons with the CIOPS-W model currents show reasonable agreement with the HF radar currents, particularly with respect to the along-strait transport.

摘要

加拿大渔业和海洋部沿不列颠哥伦比亚省赫卡特海峡部署了海洋高频雷达系统，以加强区域海上安全，包括搜救行动。赫卡特海峡 CODAR 系统以 5 公里的水平分辨率在横跨赫卡特海峡中北部的网格上提供每小时的地表水流。这些观测结果用于表征区域潮流和潮下冬季地表环流。HF 雷达电流还用于评估加拿大西海岸沿海冰洋预测系统 (CIOPS-W) 的结果，该系统是泛加拿大业务海洋建模系统的一个组成部分。旋转光谱和潮汐流椭圆与历史海流计观测结果的比较表明，来自赫卡特海峡 CODAR 系统的矢量洋流相当准确，可用于描述海峡上潮汐和潮下时间尺度上洋流的环流和变率。潮下流的变化，特别是沿海峡的表层输送，与当地的风力和海平面变化密切相关。浮标风的矢量回归表明海洋响应是高度各向异性的，表面流的大小和转向强烈依赖于风向。与 CIOPS-W 模型电流的比较表明与 HF 雷达电流有合理的一致性，特别是在海峡运输方面。