Lightning-Environment Relationships

Abstract

Lightning-environment relationships Recent results from ground and space-based radars have shown an early pick-up in convective rainfall with increasing tropospheric humidity, while stratiform rain has a later pick-up. However, the rainfall increase after the pickup is much stronger for stratiform rain because of its large areal coverage. This proposal will explore the lightning-moisture relationship, esp. in relation to the threshold that lightning begins to increase and how rapid the increase occurs. We will explore how this relationship varies geographically as the precipitation-moisture relationship shows significant variation between land and ocean and amongst continents and ocean basins. We will repeat the exercise for grid-scale omega. Environmental variables will come from NASA’S MERRA2 reanalysis and lightning data will be utilized from LIS and GLM. When available, we will use coincident rain information from the TRMM and GPM precipitation radars to link lightning properties to convective and stratiform rain intensity, areal coverage, and total accumulation. An ideal end result would be an understanding of what environmental conditions contribute most strongly to lightning onset and flash rate increase, how this varies between important regions in the global water cycle, including the ascending branches of the Walker and Hadley circulations, and if these conditions are associated with rainfall-environment relations, esp. in then extremes (e.g., high moisture and high omega).