Recorded presentation7.1
Using lidar and radar simulators to understand the number concentration of ice crystals in cirrus clouds
Jennifer M. Comstock, PNNL, Richland, WA; and S. A. McFarlane
Model simulation results are often poorly constrained because measurement and simulation scales can differ significantly, model predicted variables are often difficult to measure, and assumptions (often unstated) are required to retrieve microphysical properties from remote sensing instruments. To address these issues, instrument simulators have been developed to simulate measured quantities using model output. However, these simulators do require assumptions regarding particle shape, scattering properties, and sometimes particle size distribution (i.e. for bulk models). To further advance our ability to evaluate cloud resolving and mesoscale model simulations, we use an instrument simulator to compute lidar backscatter and extinction, and radar reflectivity and Doppler velocity using output from a cloud resolving model with bin microphysics. We will explore the sensitivity of simulated lidar and radar fields to our assumptions and evaluate the model simulations using both ground and aircraft based measurements. We will perform this analysis in the context of understanding ice crystal size distributions in cirrus clouds over the Department of Energy's Atmospheric Radiation Measurement program's Climate Research Facility located in the Southern Great Plains, Oklahoma.
Session 7, The Use of Lidar Measurements in Model Evaluation and Assimilation
Wednesday, 14 January 2009, 10:30 AM-12:00 PM, Room 122A
Next paper