A Preliminary Look at the Impacts of Assimilating UAS Data into High-Resolution WRF Simulations of the San Luis Valley

During the 2018 ISARRA flight week (entitled LAPSE-RATE), the WRF model was run over the northern San Luis Valley using a horizontal grid spacing of 100 m to provide forecast guidance for UAS operations. The boundary layer is resolved in these simulations, and its evolution depends on how the model represents the local interaction between the surface and atmosphere (e.g., surface fluxes and terrain features) as well as local circulations which can vary spatially across the Valley. The UAS flights that occurred during LAPSE-RATE provide highly localized and high frequency data across the Valley which can be assimilated into WRF. In this preliminary study, vertical profiles of temperature, humidity, and wind data taken from UAS flights across the Valley are assimilated into WRF, and changes to the evolution of the simulated daytime boundary layer are evaluated compared to the original WRF forecasts. Various data assimilation methods will be used to explore how to best utilize UAS data in boundary-layer resolving forecasts.