Elevated Nocturnal Convection - The Role of Microphysical Processes

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

This award is for participation in the Plains Elevated Convection at Night (PECAN) field campaign. PECAN will take place in the central United States in the summer of 2015. The focus of the project is on overnight thunderstorm complexes that regularly occur in the Great Plains area. A variety of observational systems will be put in place for the field experiment including multiple aircraft, mobile radars, and ground-based systems that can profile the wind and particles in the lower atmosphere. This project will provide funding for researchers to take part in the deployment of the NOAA P-3 research aircraft. The P-3 will have a variety of sensors with cloud particle probes and airborne radar as key measurements. The researchers will help collect, quality control, and analyze the data in order to study the key questions surrounding nocturnal elevated convection. The main impact from this research will be better forecasts of overnight storms, which often come with severe winds and flooding rains. The project will also help train the future generation of scientists by involving multiple graduate students in the research. The steering committee for the PECAN campaign has identified four main research topics to be addressed: 1) Nocturnal convection initiation and early evolution of mesoscale convective clusters; 2) Bore and other wave-like disturbances; 3) Dynamics and microphysics of nocturnal mesoscale convective systems; 4) Prediction of nocturnal convection initiation and evolution. This research will focus on the third topic. In-situ cloud microphysical data, ground based and airborne radar data, and the results of numerical modeling simulations will be used to test the main hypothesis; microphysical cooling processes in developing and mature stratiform regions of mesoscale convective systems force downdraft circulations that create bore and mesoscale gravity wave features on the stable nocturnal boundary layer that in turn focuses, organizes and maintains future convective activity.