Lidar-based observations of flow regimes and turbulence in a small Alpine valley during TEAMx

The summer Extended Observation Period (sEOP) of the 2025 TEAMx observational campaign provided a unique opportunity to investigate multi-scale interactions in the mountain boundary layer (MoBL) and enhance our understanding of its structure and turbulent processes. In this study we present a preliminary analysis of observations from two Doppler wind lidars operated in the Weer Valley (Nafingalm, Austria) from 6 June to 24 July 2025. The focus is on 12 Intensive Observation Periods (IOPs) for which complementary airborne observations are available (June 29 and July 2, 5, 9, 11, 13, 15, 18, 19, 20, 22, and 23), though the latter are not included in this initial study. The aim is to characterize observed events by classifying different flow regimes and turbulent features, primarily using Doppler wind lidar data supported by a weather station network. This classification provides a framework for future in-depth studies and large-eddy simulations. Emphasis is placed on identifying recurring scale interactions between local and regional flows—such as valley winds and cross-mountain flows—and the resulting processes, including flow separation, waves, and shear-flow instabilities. Finally, initial turbulence metrics are calculated to support the event classification.