Effects of grid resolution in a three-dimensional hydrostatic model: Modeling field observations

Basin-scale internal waves drive the energy flux path in a stratified lake. Therefore, accurate modeling of lake response under environmental forcing is important when considering mixing and the transport of dissolved substances. The Estuary, Lake, and Coastal Ocean Model was used to determine the grid resolution required to model field observations from Ada Hayden Lake and West Okoboji Lake. The use of the hydrostatic assumption in modeling wind-forced motions across a wide frequency spectrum accurately reproduced field observations, supporting the use of the hydrostatic assumption. Model results were compared to field data using dimensionless variables for potential and kinetic energy to assess the model's ability to predict stratification and internal wave oscillations. The results indicated best model performance for a fine model grid: horizontal resolutions between 150-225 points per V1H1 wavelength and vertical resolutions between 95-140 points over the depth produced normalized energy values within 25% of field observations.