Field observations of the influence of pack ice cover on surface heat fluxes

The development of extensive pack ice fields on the Great Lakes significantly influences lake-effect snowstorms and the intensification of extratropical cyclones, as well as the Great Lakes hydrologic cycle and lake levels. It is important to understand the atmospheric boundary layer response to variations in the concentration and arrangement of ice on the Great Lakes; however past investigations have lacked observations needed to quantify this over-lake interaction. The Great Lakes Ice Cover – Atmospheric Flux (GLICAF) project was conducted in February 2004 over Lake Erie to collect unparalleled new field data to enable a better understanding of surface heat exchange processes that occur over pack ice fields. GLICAF utilized the University of Wyoming King Air to collect measurements of the (1) surface pack ice concentration over different areas of the lake and (2) turbulent surface heat fluxes (latent and sensible) over a range of ice concentrations. This presentation will outline the field efforts during GLICAF and describe findings of initial analyses.