Scales and Characteristics of Convective Processes in Orographic Precipitation

North Carolina State University, Raleigh NC

Investigators

Abstract

Orographic precipitation is important both economically and from a public safety (flash flooding) standpoint. In this research, the Principal Investigator will investigate the physical processes that control orographic precipitation. Four questions to be addressed: 1. What are the relative contributions of coalescence and riming to accretional growth of precipitation in storms that extend several km above the freezing level? 2. Is there a significant difference in precipitation growth due to coalescence between storms that do and do not extend above the freezing level? 3. What is the size distribution of and spacing between precipitating convective elements that contribute to the observed small-scale variability of precipitation? 4. Is there a significant difference in the characteristics of the raindrop size distribution within fallstreaks and between fallstreaks? The study will be observationally based and will utilize data collected from two completed field programs - the Mesoscale Alpine Programme and the Pacific Landfalling Jets Experiment. The answers to the above questions will contribute to improvement of parameterized and explicit descriptions of cloud microphysics within numerical models of orographic precipitation and to better characterization of sampling and beam filling errors for satellite remote sensing applications.