Assessing the Ability of the Coupled Hydrosphere-Atmosphere Research Model (CHARM) to Reproduce Great Lakes Water Temperature

The Coupled Hydrosphere-Atmosphere Research Model (CHARM) is a Regional Climate Model developed at the NOAA Great Lakes Environmental Research Laboratory for hydro-climatological studies in the Great Lakes basin. CHARM features a 40-km spatial resolution and an explicit representation of the Great Lakes thermal structure with a modified Hostetler formulation. Although primarily used for understanding the possible impacts of Climate Change on the lake water balance, recently CHARM projections of water temperature for future climate scenarios have been used to study the impact that climate change may have on Great Lakes fish population. As part of this application, we tested CHARM capabilities of representing the Great Lakes water temperature using both observed meteorological boundary conditions and boundary conditions generated by the Canadian General Circulation Model 3. Simulated water temperature for April to November replicates quite well water temperature characteristics observed by buoys and remote sensing or simulated by other thermodynamic models of the Lakes.