KLEMAS, V., 2012. Remote sensing of coastal and ocean currents: an overview.

Ocean currents influence the global heat transport; weather and climate; larval transport; drift of water pollutants; sediment transport; and marine transportation. As a result, oceanographers, coastal managers, and ships need up-to-date information on ocean and coastal currents. Arrays of current meter moorings can measure currents at local scales. Shore-based high-frequency radars are able to map coastal currents over a range of up to 200 km. Ocean drifters can be tracked to obtain circulation patterns over larger areas, but may take months to accomplish it. Only satellite remote sensors can determine currents synoptically over extensive ocean and coastal regions. Satellite altimetry is one of the essential remote-sensing techniques for monitoring dynamic ocean conditions, including surface currents, local wind speed, and significant wave height. Satellite altimetry measures sea surface heights, providing data on geostrophic circulation, including major ocean currents. Ocean currents can also be determined by satellite synthetic aperture radar (SAR) or tracking the movement of thermal and color features in the ocean. The flow patterns of currents like the Gulf Stream are being mapped with satellite infrared scanners. The objective of this paper is to review practical remote-sensing techniques for measuring and mapping coastal and ocean currents.