Assessing the Impact of Building Morphology on Boundary Layer Turbulence using NCAR FastEddy® Microscale Model in Urban Areas

Turbulence and its downstream effects in the urban environment can vary based on spatial density and size of buildings. These turbulence effects are of importance to the UAS community as they pose challenges to UAS deployment in complex urban terrain. Forecast models with 1-meter resolution are preferred for UAS route planning and decision support in urban regions. However, such resolutions can come with high computational costs. The National Center for Atmospheric Research (NCAR) has recently developed the NCAR GPU-accelerated LES FastEddy® model that can simulate turbulent flow around buildings. This study uses FastEddy® to explore the impacts of urban morphology on turbulence statistics near the Salt Lake City International Airport, UT. The capabilities of FastEddy® to simulate the turbulence within the boundary layer prior to, during, and after the passage of a lake breeze front on 3 June 2022 are examined. Large-scale features within the 10x10 km domain are contrasted to surface station and Terminal Doppler Weather Radar (TDWR) observations. Comparisons are also made to the High-Resolution Rapid Refresh and Weather Research and Forecasting model grids that are used to initialize and provide lateral boundary conditions for the FastEddy simulations.