9629343 Verlinde Much of the energy that drives atmospheric circulations is obtained through exchanges of heat, moisture, and momentum with the surface. Lake-effect events, where cold air masses are rapidly modified over the Great Lakes, are excellent natural laboratories for studying these exchanges. The Lake- Induced Convection Experiment (Lake-ICE) is a multiple- Principal Investigator project which seeks to use this natural laboratory to determine how boundary layer growth processes are controlled by mesoscale boundary layer convective structures and how the modified boundary layer effects the production of precipitation and the larger scale meteorological conditions The Principal Investigator will use a variety of in situ and remote measurements to attack the following objectives: Determine the extent to which mesoscale circulations modulate the entrainment processes at the top of the boundary layer; Determine if entrainment occurs through engulfment associated with large-eddy circulations n the boundary layer or through small-scale interfacial mixing and determine sensitivity of the processes to large and mesoscale conditions. Determine the impact of entrainment events on the drop size distribution at cloud top. These objectives will be accomplished by: Compiling a statistical data base of the spatial extent of entrainment events; The identification of cloud-top entrainment processes through analysis of radar derived vertical layer profiles; Categorizing the statistical data base according to large-, meso- and cloud-scale conditions; Case studies of the microphysical impact of entrainment events. The final products of the study will be a composite two-dimensional reflectivity and vertical velocity structure of a mesoscale band, with corresponding cloud-scale and cross-inversion turbulence intensity, and several descriptions of detailed case studies. These will provide a better quantitativ e physical understanding of the interaction between these different scales of motion. ***
