Effect of Temporal Downscaling of Wind Data on Hindcasting Extreme Wave Events and Wind Power Density Studies over the Black Sea

Wind speed data are usually the main input of wave hindcasting, and wind power density studies. There are several institutions such as ECMWF that provides wind speed data in addition to various other climatologic parameters. However, these institutions provide wind data with different temporal intervals (24 hours - 6 hours - 1 hour) where high temporal resolution wind speed data are generally required. One solution to generate wind data at high sampling frequencies is to use statistical downscaling to interpolate available data to finer sampling interval data. There is limited study concerning the performances of these interpolation techniques in the scope of wind speed data on the overall effect on wave hindcasting and wind power density studies. In this study, performance of seven fundamental interpolation techniques is discussed focusing on both the long term data and the extreme storm events in the Black Sea. Study dataset is taken as hourly NCEP CFSR wind speed dataset between 1979 and 2010 at 522 points over the Black Sea. Extreme events are selected for each year at each of the study points. Performance of the interpolation techniques is assessed comparing the original and temporally downscaled wind speed data for both long term and extreme event cases, based on a penalty point system consisting of several statistical parameters. Wave hindcasting studies are performed using WAVEWATCH III for several selected extreme events. Furthermore, wind power density calculations are performed using the long term wind speed data. The effect of interpolation technique on wave hindcasting and wind power density studies are discussed by comparing the results obtained from original and temporally downscaled datasets. The importance of this study lies in that it would quantify the error originated from interpolation technique in terms of both wind speeds, wave properties, wind power density calculations in the Black Sea. Thus, it would be possible to improve the quality of wind speed data, and the error originated from interpolation technique in wave hindcasting and wind power density studies would be reduced