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Numerical Simulations and Sensitivity Studies of a Florida Sea Breeze and Its Associated Convection in the Gray-Zone Grid Spacin

Posted on:2018-01-27Degree:M.SType:Thesis
University:The University of UtahCandidate:Hock, Nessa EFull Text:PDF
GTID:2470390020457273Subject:Atmospheric Sciences
Abstract/Summary:
The Florida (FL) peninsula has the most frequent occurrence of warm-season thunderstorms in the US, with the majority of this convection initiated by the sea breeze (SB) circulation. Previous numerical studies of FL SB convection have emphasized either large mesoscale grid scales (tens of kilometers or greater) or much smaller large-eddy simulation (LES) grid scales (less than a hundred meters). Few studies have been conducted in the numerical gray-zone scale (e.g., 1--5 km). In this thesis, numerical simulations of a convective FL SB case study are conducted using an advanced research version of the Weather Research and Forecasting (WRF) model with gray-zone grid spacing and 40 different simulation configurations. Simulations are evaluated against surface observations and analysis data to determine the accuracy of the model-simulated SB convective initiation (CI). The dependence of the SB and its associated convection on variations in physics parameterizations, initial conditions (ICs), stochastic perturbations, and grid scale spacing is also evaluated.;Results indicate that the WRF model can realistically reproduce the SB CI. However, large sensitivities of simulations to boundary layer parameterizations, ICs, grid scale, and stochastic perturbations of potential temperature and wind tendency fields are found in predicting the timing and intensity of the SB and its associated convective systems. Further analysis indicates that the specific representation of atmospheric variables (e.g., sensible surface heating, synoptic winds, and low-level convergence) and geophysical features (e.g., coastline shape and lake resolution) within the simulations are important for the accurate representation of the timing, location, and intensity of the SB and its associated convection.
Keywords/Search Tags:Associated convection, SB and its associated, Simulations, Grid, Numerical, Studies, Gray-zone
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