| 英文摘要: | Terrestrial Gamma-Ray Flashes (TGFs) are very intense, but short-lived, bursts of radiation related to lightning and thunderstorms. Atmospheric electricity researchers have known about TGFs for decades, but are now better able to study the causes and impacts of these events due to new and improved instrumentation. One example is the Gamma-ray Burst Monitor (GBM) which was launched on a satellite and now gives researchers an unprecedented view of TGF events. However, relating what is seen in space to what is happening within a thunderstorm is not straightforward. In this research project, the investigator plans to analyze the satellite data with a goal of determining the characteristics of TGFs and their source regions within thunderstorms. Improved knowledge of TGFs has implications for lightning safety, especially related to radiation exposure for air travelers. This project will also represent the first award for an early-career scientist.
The researcher plans to analyze the data by first constructing a set of modeled TGF events and then comparing how those should "look" to the satellite sensor versus how they are actually "viewed". The overall purpose of the research program is to use all information about TGFs from ground based radar observations, lightning data, LF radio data, GBM TGF gamma-ray data, and theoretical models to constrain the properties of the observed TGF population for fitting the entire GBM sample. Three main questions are posed: 1) Can one start from an assumed population of TGFs and reproduce the sample of GBM-detected TGFs, including number and properties versus offset from the nadir? 2) What constraints can be placed on the population characteristics? 3) What constraints can be placed on TGF beaming? |