In the present paper ground truth and remotely sensed datasets were used for the investigation and quantification of the impact of Saharan dust on microwave propagation, the verification of theoretical results, and the validation of wind speeds determined by satellite microwave sensors. The influence of atmospheric dust was verified in two different study areas by investigations of single dust storms, wind statistics, wind speed scatter plots divided by the strength of Saharan dust storms, and wind speed differences in dependence of microwave frequencies and dust component of aerosol optical depth. An increase of the deviations of satellite wind speeds to ground truth wind speeds with higher microwave frequencies, with stronger dust storms, and with higher amount of coarse dust aerosols in coastal regions was obtained. Strong Saharan dust storms in coastal areas caused mean relative errors in the determination of wind speed by satellite microwave sensors of 16.3% at 10.7 GHz and of 20.3% at 37 GHz. The mean relative errors were smaller in the open sea area with 3.7% at 10.7 GHz and with 11.9% at 37 GHz.

The METAR dataset was provided by NCAR/EOL (National Center for Atmospheric Research/Earth Observation Laboratory) under sponsorship of the NSF (National Science Foundation) and was downloaded from http://data.eol.ucar.edu. The METAR data were collected by the UCAR/JOSS (University Corporation of Atmospheric Research/Joint Office of Science Support) and included the hourly weather observations of worldwide airports. TMI data are produced by Remote Sensing Systems and sponsored by the NASA Ocean Vector Winds Science Team as well as by the NASA Earth Science REASON DISCOVER Project. The data are available at www.remss.com.

Supplement to: Ohde, Thomas (2010): Impact of Saharan Dust on Ocean Surface Wind Speed Derived by Microwave Satellite Sensors. Journal of Infrared Millimeter and Terahertz Waves, 31(10), 1225-1244