Thursday, 6 June 2002
A volumetric characterization of cirrus cloud content and particle size using combined scanning and vertically pointing mm radar data and aircraft in situ data
During March 2000, a major intensive observing period (IOP) was conducted at the Amospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. Among other objectives, a goal of this IOP was to observe clouds over a limited geographical domain to characterize the advective tendencies of cloud microphsyical properties. The IOP included multiple cloud radars that were both vertically pointing and scanning as well as in situ and remote sensing aircraft. On 9 March 2000, an orographically enhanced cirrus cloud field evolved in a southewesterly flow between the ARM site and the upstream Rocky Mountains of New Mexico. As the cloud field evolved over the SGP domain, the system was sampled by in situ aircraft and surface instrumentation. We will describe this case in detail by examining the statistics of the evolving cloud content and particle size 3d fields in a 20 km domain centered on the ARM site. In particular we will examine the small scale structure of cirrus generating cells as revealed by scanning cloud radar as well as the larger scale structure of a series of mesoscale bands that composed the even larger scale cirrus cloud field.