The presence of substantial pack ice strongly influences the development of convective boundary layers over the North American Great Lakes and associated lake-effect snowstorms. Previous studies, however, have not quantified the atmospheric response to Great Lakes pack ice cover of varying concentration. The primary goal of the Great Lakes Ice Cover – Atmospheric Flux (GLICAF) project, conducted during February 2004 over Lake Erie, was to collect unique field data for examination of surface heat exchange processes and the boundary layer evolution that occurs over the pack ice fields of the Great Lakes. Measurements of atmospheric thermodynamic, state, and radiative properties were collected by the University of Wyoming King Air.

Analysis of data collected on 26 February 2004 suggests that weak positive sensible turbulent heat fluxes were present over the lake throughout the day despite significant ice coverage and surface-air temperature differences of less than 2°C. Interestingly, despite weak positive heat fluxes over the lake, there is evidence of the development of a lake breeze circulation during the early afternoon. This presentation will briefly outline the goals and operations of the GLICAF field project and present analyses of the 26 February 2004 case.