AGS-PRF A Population Synthesis Model for GBM Terrestrial Gamma-ray Flashes

地面伽马射线闪光（TGFs）是非常强烈，但短暂的，与闪电和雷暴有关的辐射爆发。 大气电研究人员几十年来一直了解TGF，但由于新的和改进的仪器，现在能够更好地研究这些事件的原因和影响。 一个例子是伽马射线暴监测器（GBM），它是在一颗卫星上发射的，现在为研究人员提供了一个前所未有的TGF事件。 然而，将太空中看到的与雷暴中发生的事情联系起来并不简单。 在本研究项目中，研究人员计划分析卫星数据，以确定雷暴中TGF的特征及其来源区域。 提高对TGF的认识对雷电安全有影响，特别是与航空旅客的辐射暴露有关。 该项目也将代表一个早期职业科学家的第一个奖项。研究人员计划通过首先构建一组建模的TGF事件来分析数据，然后将这些事件在卫星传感器上的“外观”与实际“外观”进行比较。 该研究计划的总体目的是使用来自地面雷达观测，闪电数据，LF无线电数据，GBM TGF γ射线数据和理论模型的所有有关TGF的信息，以约束所观察到的TGF群体的属性，以拟合整个GBM样本。 提出了三个主要问题：1）可以从一个假设的TGF的人口和再现GBM检测TGF的样本，包括数量和属性与从最低点偏移？2)对人口特征有哪些限制？3)什么限制可以放置在TGF光束？

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?