Coastal waters are globally challenging areas to monitor not only because of the high resolution needed to resolve the scales at stake but also because most satellites are not yet suited to near-coast observations. We present here the analysis of an 8-year-long high-frequency RADAR (HFR) dataset off the coasts of Var region (France) in the North-Western Mediterranean Sea. Successive interruptions and errors intrinsic to the nature of the HFR remote-sensing technology have been compensated by the DINEOF statistical filling method. This unprecedented dataset enables the observation of many oceanic processes ranging from the interannual variability of large-scale structures to the identification of (sub)mesoscale features. Comparing and coupling this analysis with outputs from a regional ocean circulation model (GLAZUR), we also put emphasis on the extent of the possibilities of the HFR for the description of coastal surface circulation and its value as part of integrated observation systems. The data showed the diversity of the surface circulation in the region, mainly marked by the Northern boundary Current (NC), but undergoing a great variety of spatial and temporal fluctuations, interannually, seasonally, and at higher frequencies. Strong gusts of wind or regional upstream circulation can cause the undulations of the NC, modifying its shape and its strength, and fostering the emergence and zonal displacement of mesoscale to submesoscale eddies. Using an eddy tracking algorithm, we show that the occurrence of mesoscale eddies off this region display a strong inter-annual variability that is linked to the spatio-temporal variability of the NC’s characteristics. The NC system thus plays an intermittent role as a transport carrier or barrier of heat, energy, or matter, which has important consequences for neighbouring coastal areas.

沿海水域是全球监测具有挑战性的区域，不仅因为解决所涉尺度所需的高分辨率，而且因为大多数卫星尚不适合近海观测。我们在此介绍了对地中海西北部 Var 地区（法国）海岸的一个长达 8 年的高频雷达 (HFR) 数据集的分析。HFR 遥感技术固有的连续中断和错误已通过 DINEOF 统计填充方法得到补偿。这个前所未有的数据集可以观察许多海洋过程，从大尺度结构的年际变化到（亚）中尺度特征的识别。将此分析与区域海洋环流模型 (GLAZUR) 的输出进行比较和耦合，我们还强调了 HFR 描述沿海表面环流的可能性范围及其作为综合观测系统一部分的价值。数据显示该地区地表环流的多样性，主要以北边界流（NC）为标志，但经历了年际、季节和更高频率的大量时空波动。强阵风或区域上游环流会导致北卡罗来纳州的波动，改变其形状和强度，并促进中尺度到亚中尺度涡旋的出现和纬向位移。使用涡流跟踪算法，我们表明该区域外发生的中尺度涡流显示出强烈的年际变化，这与 NC 特征的时空变化有关。