Remote Sensing of Coastal Plumes and Ocean Fronts: Overview and Case Study

Coastal plumes, which carry run-off from land, influence the circulation patterns and ecology of nearby coastal areas, causing eutrophication, turbidity, and spread of harmful pollutants. They can be observed along many coasts. Estuarine and ocean fronts result when denser water under-rides lighter water giving rise to an inclined interface and a strong convergence at the surface, which can concentrate phytoplankton and pollutants. To detect and map fronts and plumes, remote sensors exploit their differences in turbidity, color, temperature, or salinity from ambient background water. The most effective remote sensing techniques for observing coastal plumes and estuarine/ocean fronts are reviewed. Studies are presented, which use data from multispectral and hyperspectral imagers, thermal infrared (TIR) radiometers, microwave radiometers, and Synthetic Aperture Radar (SAR). Mounted on satellites and aircraft, these sensors provide the spatial/temporal resolution and coverage needed for tracking plumes and fronts, including their high temporal and spatial variability. This article reviews the most effective remote sensing techniques for observing coastal plumes and ocean fronts and illustrates the application of these techniques in a case study.