Sea foam, in particular, has a very high emissivity and roughening the surface will increase the emissivity. The manner in which wind roughens the surface is important. Fortunately, capillary waves are also very responsive to changes in wind speed. Small gusts will create these waves quickly. They dissipate equally rapidly in calm winds.
Larger waves require long duration winds to build.
From the images below, one can see that the algorithm cannot determine the surface wind speed if the sensor is over land, ice, or rain. I relies on the differences between the 19V and 22V channels. Water vapor is a good emitter, making it appear warmer than the ocean background on the 22V, while 19V does not show a corresponding increase. I's most accurate products. The original algorithm has changed little since the late 1970's.