Sea Surface Height

Sea surface altimetry is derived from specialized radar-equipped satellites in near-earth orbit. These satellites are different from their ocean color and sea surface temperature kin in that rather than just looking at wide swaths of the ocean, they bounce a thin radio beam off the surface and capture its return. Maps are in turn made from multiple satellite passes. Sea surface height varies due to the motion of the water and the rotation of the earth. Large ocean eddies with diameters of around 200 km cause "bumps" and "dimples" in the ocean surface on the order of tens of centimeters which makes the challenge of measuring them akin to measuring the thickness of a sheet of paper from a commercial jet! In the eastern Caribbean these eddies can steer the Orinoco River plume. Some open ocean fish can respond to the water mass movements caused by eddies.