9707165 Eloranta Much of the energy that drives atmospheric circulations is obtained through exchanges of heat, moisture, and momentum with the surface. Lake-effect weather 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. In this research effort, the Principal Investigator will study the four dimensional characteristics of the evolution of the boundary layer near the upwind shore of Lake Michigan. To accomplish this, the Principal Investigator will deploy and operate a Volume Imaging Lidar (VIL) on the west shore of Lake Michigan during the Lake-ICE project. The lidar will observe the growing convective boundary layer over the lake as cold air passes over the warm water. These observations will complement airborne and ground-based radar measurements planned for mid-Lake area and the eastern shore and will be coordinated with other research meteorological measurements. During a typical data session, the VIL will repetitively scan a three-dimensional volume extending to 21 km downwind. These images of aerosol backscatter will record the growth of convection as the air moves downwind. Specifically, the lidar data will be analyzed to provide: 1) the depth of the boundary layer as a function of distance downwind, 2) the wind speed and direction as a function of downwind distance and altitude, 3) the dimensions and aspect rations of the convective plumes, 4) the spatial organization of the convective cells in the convective field, 5) the decorrelation time for convective structures, 6) the d ownwind distance and altitude of first cloud formation. The primary application of the lidar data will be to evaluate numerical models of the boundary layer over the lake. In addition, the Principal Investigators will evaluate the ability of a large eddy simulation to derive an explicit description of the convective field. Successful completion of this research will increase fundamental understanding of the evolution of the lake boundary layer which is crucial to understanding and forecasting the very disruptive lake-effect snow events. ***
