Challenges in Simulating Boundary Layers and Turbulence in Complex Terrain: Insights from Recent Field Experiments

Accurate forecasts of winds, temperature structure, and turbulence in complex terrain are required for wind energy applications, pollutant transport, fire-fighting, and other applications. And yet, accurate forecasts in complex terrain are particularly challenging: numerical weather prediction models struggle with representations of steep terrain and subgrid-scale physical parameterizations. Recent experiments in complex terrain, namely the Wind Forecast Improvement Project 2 (in the Columbia River Gorge) and the Perdigão 2017 campaign (in northeastern Portugal), have provided insights into terrain wakes, valley recirculations, drainage flows, and cold pool mix-outs. This presentation will highlight new insights from these field experiments, with emphasis on the interactions of wind turbines with complex terrain phenomena.