Wednesday, 22 August 2012: 11:30 AM
Priest Creek C (The Steamboat Grand)
Midlatitude mixed-phase clouds are encountered in all parts of the word, and understanding these clouds is critical for improving cloud-resolving and global climate models. Mixed-phase clouds, consisting of a mix of ice, liquid, and water vapor, present a particular challenge to both observations and modeling. The vertical variation of phase within mixed-phase clouds affects single-scattering and radiative properties, and the range of temperatures over which these clouds can exist affects the radiation budget for climate models. At the same time, there is a very limited amount of data for mid-latitude mixed-phase clouds, and the observations are usually made either via remote sensing techniques or in-situ aircraft measurements. In winter 2010-2011, two concurrent field campaigns, Colorado Airborne Multi-Phase Cloud Study (CAMPS) and the Storm Peak Laboratory Cloud Property Validation Experiment (StormVEx) were carried at Steamboat Springs, CO, providing unique opportunity to both conduct measurements of orographic mixed-phase clouds via remote sensing instruments, and validate these measurements via in-situ cloud probes at Storm Peak Laboratory (SPL) and aboard aircraft. In the current study we are comparing in-situ observations of vertical distribution of liquid water in mixed-phase clouds at SPL and from the University of Wyoming King Air. During CAMPS, the King Air performed a total of 29 research flights, between Dec 15, 2010 and Feb 27, 2011. During 23 of these flights the aircraft was flying over SPL. At SPL, three cloud probes were operated continuously while the lab was in-cloud, between Nov 15, 2010 and March 31, 2011. Current study concentrates on four case studies (01/09, 02/07, 02/25 and 02/26) corresponding to different synoptic conditions typical for the Steamboat Spring Area in winter. For these days we compare FSSP measurements at SPL to CDP data abroad King Air to see how the liquid water distribution changes with altitude, and relate the differences in the vertical distribution of liquid water to the differences in the synoptic situation. In addition, we use aerosol measurements at SPL to explain the vertical structure of the cloud. These case studies will be carefully described, and the vertical structure of microphysical cloud properties, including size distribution, liquid water content, and effective diameter will be presented. A discussion of the implications of the results for our understanding of mixed-phase clouds, and the possible use of results for validation of remote sensing observations will be presented.
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