High-resolution modeling of the nighttime boundary layer evolution in the Owens Valley: Sensitivity studies

This paper focuses on the evolution of the nighttime boundary layer in the lower Owens Valley during a period of nearly clear skies and weak to moderate synoptic forcing. Key sensitivities determining the development of the nighttime boundary layer are analyzed by undertaking high-resolution large-eddy simulations with the Advanced Regional Prediction System (ARPS). The simulations are run with a grid resolution of 100m on the finest grid. Sensitivity experiments include different initializations of the land surface and simulations with and without synoptic forcing. Simulations with varied land surface forcing are utilized to discern the importance of east-west and elevational variations in soil moisture, vegetation type and snow cover along the valley sidewalls to the complexity of Owens Valley flow. Synoptic foring sensitivities are used to discern the robustness of canonical valley flow strucutres. In a companion paper, the simulation results are compared with comprehensive observations from the T-REX field compaign.