The variability of thermal fronts in eastern ocean boundaries has received increased attention because of being active regions of vertical fluxes of tracers and biological activity. Sea Surface Temperature (SST) images from three distinct satellite products are used to identify areas with enhanced surface thermal gradients (i.e. SST fronts) in the coastal ocean off central–southern Chile. The main objective is to evaluate their use in the study of SST frontal variability in a river-influenced continental shelf. In contrast with previous studies focused on the mesoscale structure of the upwelling front, this study highlights the importance of using high spatial resolution (i.e. 1 km) satellite products to resolve the small-scale surface thermal gradients on a relatively narrow continental shelf impacted by freshwater river outflows. An improved approach, merging Moderate Resolution Imaging Spectroradiometer (MODIS) imagery from Aqua and Terra satellites (MODIS-AT), increases the percentage of available SST data for the computation of SST gradients and frontal probability over these shelf waters. Overall, SST data from all three sources (Pathfinder, Geostationary Operational Environmental Satellite (GOES), and MODIS) resolve the major mesoscale frontal features along the offshore limit of the continental shelf. However, MODIS-AT considerably improves the detection of SST fronts over the continental shelf, especially during winter and spring when river outflows are important on the dynamics of coastal flows. A case study off the Itata River mouth reveals high spatio-temporal variability of thermal fronts over the continental shelf, which is not well detected from GOES and Pathfinder data. The analysis of MODIS-AT images is highly recommended for studies of thermal fronts over shelf waters. In contrast, the use of GOES imagery improves the monitoring of the mesoscale frontal activity farther offshore.

由于是示踪剂垂直通量的活跃区域和生物活动，东部大洋边界的热锋的变化受到了越来越多的关注。来自三个不同卫星产品的海面温度（SST）图像用于识别智利中南部的沿海海洋中地表温度梯度（即SST锋）增强的区域。主要目的是评估它们在研究河流影响的大陆架的SST锋面变化中的用途。与先前针对上升流中尺度结构的研究相反，本研究强调了使用高空间分辨率（即1 km）卫星产品来解决受淡水影响的相对狭窄的大陆架上的小尺度表面热梯度的重要性。河流流出。一种改进的方法是合并来自Aqua和Terra卫星的中等分辨率成像光谱仪（MODIS-AT）图像（MODIS-AT），从而增加了可用的SST数据百分比，用于计算这些陆架水的SST梯度和正面概率。总体而言，来自所有三个来源（Pathfinder，Geostationary Operational Environmental Satellite（GOES）和MODIS）的SST数据解析了大陆架近海边界的主要中尺度锋面特征。但是，MODIS-AT大大改善了大陆架上SST前沿的探测，尤其是在冬季和春季，这期间河水的流出对沿海水流的动态很重要。在伊塔塔河河口的案例研究表明，大陆架上热锋的时空变化很大，从GOES和Pathfinder数据中检测不到。强烈建议对MODIS-AT图像进行分析，以研究架子水的热锋。相反，使用GOES影像可以改善对近海中尺度额叶活动的监测。