Cirrus cloud microphysical properties and air motion statistics using cloud radar Doppler moments: Water content, particle size, and sedimentation relationships

Improved knowledge of ice cloud properties and the processes that maintain them is needed for modeling applications. A cirrus cloud property retrieval algorithm is applied to a 7-year Cloud Radar data set collected at the Atmospheric Radiation Measurement Program ground sites. With this dataset, the ice cloud vertical structure is studied in terms of Temperature (T). Then the interrelationships between the ice particle size, ice water content (IWC), and mass-weighted sedimentation rate are investigated. The mass-weighted sedimentation rate is usually parameterized as a function T only or IWC only. Here, the mass weighted sedimentation rate is parameterized as a joint function of ice water content and T for both midlatitude and tropical ice clouds. We further examine the validity of several commonly used GCM parameterizations of ice sedimentation rate in comparison to the cirrus cloud results derived from measurements.