Simulation of Thermal Structure in the Great Lakes using a Coupled WRF-Lake Model
Location
Eccles Conference Center
Event Website
water.usu.edu/
Start Date
3-30-2011 10:35 AM
End Date
3-30-2011 10:40 AM
Description
A one-dimensional lake model has been successfully coupled to the Weather Research and Forecasting (WRF) model version 3.2 developed by the National Center for Atmospheric Research; the performance of the coupled model has been validated via simulations of physical processes in the Great Lakes. The results show that the coupled WRF-Iake model can realistically reproduce the thermal structure. in shallow waters (e.g., Lake Erie) while performing poorly in deep waters (e.g., Lake Superior). There are two main reasons that can explain why this lake model was unable to simulate the physical processes of deep waters. First, this lake model is one-dimensional, and many deep-lake physical phenomena that carry features of two or three dimensions cannot be described by a one-dimensional lake model. Second, the lake model uses a turbulent diffusion approach to parameterize the turbulent mixing in the lake, but such parameterization cannot generate sufficient turbulent mixing in the deep lake, which is essential to simulating water temperature profile and surface skin temperature. Through adjusting the eddy diffusivity in the lake model, the deep-lake temperature simulations are significantly improved when compared to observations. Such improvements will greatly benefit the research and prediction of regional weather, climate, and lake ecology.
Simulation of Thermal Structure in the Great Lakes using a Coupled WRF-Lake Model
Eccles Conference Center
A one-dimensional lake model has been successfully coupled to the Weather Research and Forecasting (WRF) model version 3.2 developed by the National Center for Atmospheric Research; the performance of the coupled model has been validated via simulations of physical processes in the Great Lakes. The results show that the coupled WRF-Iake model can realistically reproduce the thermal structure. in shallow waters (e.g., Lake Erie) while performing poorly in deep waters (e.g., Lake Superior). There are two main reasons that can explain why this lake model was unable to simulate the physical processes of deep waters. First, this lake model is one-dimensional, and many deep-lake physical phenomena that carry features of two or three dimensions cannot be described by a one-dimensional lake model. Second, the lake model uses a turbulent diffusion approach to parameterize the turbulent mixing in the lake, but such parameterization cannot generate sufficient turbulent mixing in the deep lake, which is essential to simulating water temperature profile and surface skin temperature. Through adjusting the eddy diffusivity in the lake model, the deep-lake temperature simulations are significantly improved when compared to observations. Such improvements will greatly benefit the research and prediction of regional weather, climate, and lake ecology.
https://digitalcommons.usu.edu/runoff/2011/Posters/25