A down-scaled regional climate model for the Great Lakes (In preparation)
Citation
Marjorie Perroud, and Brent Lofgren, A down-scaled regional climate model for the Great Lakes (In preparation): .
Summary
Objective 1: Revise an independent regional (or “downscaled�) climate model to forecast air and water temperature, water level, and ice cover into the late 21st century. Brent Lofgren (NOAA, co-PI) and Marjorie Perroud (NOAA, post-doctoral scientist) have worked on regional climate modeling and the associated simulation of lake temperature profiles under past (1964-2000) and future (2043-2070) time periods. This was accomplished by using the Coupled Hydrosphere-Atmosphere Research Model (CHARM), a regional climate model that couples the atmosphere to both land and lake surfaces, driven at its lateral boundaries by the Canadian Centre for Climate Modeling and Analysis’ (CCCma) Coupled General Circulation Model version 3 (CGCM3). [...]
Summary
Objective 1: Revise an independent regional (or “downscaled�) climate model to forecast air and water temperature, water level, and ice cover into the late 21st century. Brent Lofgren (NOAA, co-PI) and Marjorie Perroud (NOAA, post-doctoral scientist) have worked on regional climate modeling and the associated simulation of lake temperature profiles under past (1964-2000) and future (2043-2070) time periods. This was accomplished by using the Coupled Hydrosphere-Atmosphere Research Model (CHARM), a regional climate model that couples the atmosphere to both land and lake surfaces, driven at its lateral boundaries by the Canadian Centre for Climate Modeling and Analysis’ (CCCma) Coupled General Circulation Model version 3 (CGCM3). Two iterations of these model runs have been done: 1) A run in which the vertical mixing in the lakes is believed to be too high. This resulted in too small of an annual cycle in the lake surface temperature in both the past and future time periods, and very little ice formation even in the past. 2) A modified set of runs in which the coefficient controlling vertical mixing of the lakes is reduced. This results in a rather good match in lake surface temperatures throughout the year for Lake Michigan, with just a small warm bias during the early summer, and a cold bias during the fall. The projected change in lake surface temperature averaged over Lake Michigan in the 75 years separating these two simulations is about 3° C during the summer and about 2° C during other seasons. In the coming year, we will continue to make simulations with further refinement in the lake temperature formulation, and using different general circulation models as drivers for the lateral boundary conditions.
