The WINDEX measurement experiment

The field of interest of the R&T project WINDEX (Wind resources and forecasting in complex terrain of Croatia) is the development and application of numerical models for wind energy utilization in complex terrain, facilitated with the extensive use of advanced measurement techniques.

The WINDEX measurement experiment is sited in the hinterland of the mid-Adriatic coast, the area most feasible for wind energy utilization in Croatia and prone to stronger mountain-induced wind systems, such as bora and “jugo” (a channeled branch of sirocco) winds. The wind tower at the location of Pometeno Brdo, NNE from the city of Split, is equipped with 2 classic cup and vane anemometers at 30 m and 60 m AGL, as well as 3 ultrasonic Gill anemometers at 10 m, 22 m and 40 m AGL at 5 Hz sampling rate. In addition, a SODAR measurement system is located at the airport of Split for a 3-month period.

The modeling component of the experiment includes operational set-up of the ALADIN model at 8 km resolution, dynamical adaptation at 2 km resolution and WRF two-way nested runs ranging from 9 km down to 1 km horizontal grid resolutions. Selected cases of bora events are planned to be analyzed with the WRF model and CDF model WindSim at cutting-edge horizontal grid resolutions.

The design of the measurement and modeling components of the experiment is envisaged to enable the study of different aspects important for wind energy utilization, such as short-range wind forecasting, dynamical downscaling and high resolution wind resource estimates as well as the analysis of bora turbulence and pulsations in the near-surface layer.