Characterizing Buoy Wind Speed Error in High Wind Conditions

Buoys are a common source of remote sensing validation data over the open ocean and are one of only a small number of in situ sources in this data sparse region. Previous studies show the presence of a low wind speed bias for buoys in extremely high wind conditions, but data for high wind speed ranges are limited. Therefore, it is important to test the validity of using buoys as an in situ source for satellite calibration in high winds and high seas using a relatively long record of buoy winds. Scatterometers provide an independent source of wind speeds to compare with buoys over all ranges. Sub setting the scatterometer and buoy wind speed differences using wave parameters provides insight into the conditions under which wind speeds diverge between scatterometers and buoys. This study uses the KNMI ASCAT-A and ASCAT-B and the NASA JPL QuikSCAT L2 v3 Ocean Vector Wind 12.5km datasets to compare with buoy winds processed through the Global Telecommunications System and ECMWF ERA5 Reanalysis wave data from 1999 to 2018. The scatterometer, buoy and reanalysis data are triple collocated in space by less than 25 km, and time less than 30 minutes. A probability distribution function analysis with wind speed differences sub-divided by wind speed ranges and wave characteristics is performed to test for the dependence of wind speed differences on changing sea states. The wind speed differences are further binned by hull type and anemometer height to investigate how physical buoy characteristics affect the wind speed differences.