Campaign TEAMx: First results of wind observations compared to model simulations at three sites in the Inn Valley (Austria)

In the framework of the campaign TEAMx, MeteoSwiss deployed a Doppler Wind Lidar (WL, Windcube-100S) in Radfeld, Austria. The WL provides high resolution wind speed and – direction measurements within the Inn Valley at several altitudes. These observations provide a reliable reference to investigate the performance of model wind estimates in alpine valleys. In this study, we use analyses data from the ICON NWP model computed with KENDA, a Km-scale ENsemble-based Data Assimilation system. These data from the KENDA-CH1 NWP system have a spatial resolution of 1.1x1.1 km and a temporal resolution of 1 hour. First results show a good model performance at Radfeld with an average root mean square vector difference (RMSVD) of 3.78 m/s during the period from 23 October 2024 to 16 December 2024.

Furthermore, the comparison between observations and model analyses is extended to the sites of Kolsass and Innsbruck, which are both located in the same valley (Inn Valley) and at both sites wind observations are obtained by a WL (Halo Photonics Systems). In addition, we analyse the observations from a WL permanently deployed in Payerne (Switzerland).

Our results show that the model has an average RMSVD lower than 3.8 m/s for all sites during the given time period. The only exception with a higher RMSVD occurs during the storm Caetano (19-23 November 2024). For Payerne, we find a RMSVD of 2.7 m/s, which is significantly better than for the other sites. This is explained by the assimilation of several observed atmospheric profiles (wind and temperature) in the model, which positively impacts the model analyses. Moreover, Payerne has a flatter topography. Overall, our results confirm a good performance of the simulated wind dynamics by the high resolution KENDA-CH1 NWP system.