Evaluation of SAR wind retrieval algorithms in offshore areas of the Korean Peninsula

• The offshore wind speed retrieval algorithms from SAR satellite images were evaluated for the Korean offshore area where there is complicated offshore wind distribution due to the geographical effects of an archipelago.
• The Korea wind map which has been established by numerical weather prediction and validated by in-situ measurements such as buoy data was used as the reference.
• Through case analyses of four representative seasonal weather days, CMOD4 showed the smallest RMSE and then evaluated as the most stable algorithm for the Korean archipelago offshore.

The method of extracting offshore wind field from SAR satellite images for offshore wind resource assessment shows some discrepancies in the calculated wind speed depending on which of the CMOD algorithms is used. This paper compared different algorithms, such as CMOD_IFR2, CMOD4, CMOD5, in order to find the suitable CMOD algorithm for the southern offshore area of the Korean Peninsula, which belongs to the zone influenced by the archipelago, by calculating the relative errors with reference to the Korea wind map of representative weather days by season. The result is that CMOD-IFR2 shows a tendency towards excessive estimation of wind speed, while CMOD4 shows the lowest RMSE values of wind speed differences with respect to the Korea wind map. Based on this result, we have concluded that, for the southern offshore area of the Korean Peninsula which belongs to the medium-range wind speed zone, CMOD4 is the suitable algorithm.