This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
This project undertakes theoretical investigation of the production mechanisms and properties of terrestrial gamma-ray flashes (TGF). The investigation will include full lightning and thunderstorm models, very low frequency radio wave observations, very low frequency wave propagation modeling, Monte Carlo simulations of energetic particle behavior, and analysis of satellite data. In addition, new electric field measurement techniques will be developed and evaluated in the context of TGF emissions. The satellite data will be searched for electron or low-energy photon emissions, which would provide information on the observed emissions, including their geolocations. Very low frequency wave observations, coupled with lightning modeling and satellite TGF observations, will yield additional geolocations as well as information on the dynamics of the source lightning. Particular topics to be addressed include the role of lightning in production of the driving electric fields and the effects of geographic and weather conditions on TGF occurrence. The project will help quantify the electrodynamic coupling between the lower atmosphere, the ionosphere, and the magnetosphere by performing an observational and modeling study focused on terrestrial gamma ray flashes. The project includes the development of a new technique to measure electric fields above thunderstorms and new models of lightning processes. Undergraduates will participate in the project through Stanford University's Research Experience for Undergraduates. They will be mentored by graduate students, providing them with additional educational experience as well as research and engineering opportunities.
