engleski

Dynamical downscaling of wind resources in complex terrain of Croatia

Global model reanalysis or forecast data needs to be downscaled to provide information for regional interpretation. This is especially true in complex terrain of Croatia, where a significant portion of the wind energy potential is related with phenomena resulting from the interaction of the mountains and the lower troposphere, such as Bora, the local downslope windstorm. Dynamical downscaling of ERA-40 reanalysis data to 8 km grid resolution was performed with the use of spectral, full-physics, prognostic mesoscale ALADIN model. In addition, the downscaled data was dynamically adapted to 2 km grid resolution over Croatia. The resulting wind climatology covers the 1992-2001 period, with 60-min data frequency at any height in planetary boundary layer, including wind speed, wind direction, and maximal gusts. The greatest average wind speeds and absolute wind speed maximums are associated with mountaintops and lee areas where gap flows and gravity-wave breaking take place during Bora episodes. The modeled wind field is compared with the observed time-series on a number of surface stations, reflecting various climate regions of Croatia. The performed verification suggests that the downscaling is successful and that the approach proposed provides an accurate tool for calculation of wind resources in complex terrain of Croatia.

wind energy; dynamical downscaling; complex terrain; ALADIN

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