On Wave Dependency of Altimeter Sea Returns—Weak Fetch Influence on Short Ocean Waves

Abstract At low and intermediate winds, altimeter returns are from ocean waves having their length longer than the radar wavelength. These waves, mainly ripples, are generated and modified by wind stress and dominant ocean waves. The wind stress coefficient is greater with steeper dominant waves prevailing at shorter fetches, and the attenuation of ripples is also stronger with steeper dominant waves. The combined influence of dominant waves on the altimeter wind algorithm is shown to be small as a result of these compensatory effects at short fetches, with an intensified generation by the augmented wind stress and an escalated suppression by steeper dominant waves.