CloudSat's View of the Global Distribution of Light Precipitation

While significant progress has been made in global precipitation measurement from satellite platforms, the vast majority of current sensors continue to suffer from an inherent lack of sensitivity to light rainfall. Accurate measurements of the distribution of light rain, however, is important for establishing closure of the global water cycle since it represents a significant fraction of total precipitation in many regions particularly those that lie poleward of 40 degrees. By virtue of its sensitivity, the CloudSat Cloud Profiling Radar (CPR), the first millimeter wavelength cloud radar to be flown in space, offers a unique opportunity to perform a global survey of light rainfall and to quantify its contribution to the global water cycle. This presentation will describe the theoretical basis and early validation of an experimental CloudSat precipitation product. Data from CloudSat's first year in orbit will be presented with a primary focus on establishing the global distribution of light rainfall and its spatial and temporal variability. Results will be compared with similar products from established platforms including the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar and the Advanced Microwave Scanning Radiometer (AMSR-E) aboard Aqua.