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

地面伽玛射线闪光（TGFs）是一种非常强烈但短暂的辐射爆发，与闪电和雷暴有关。大气电学研究人员几十年前就已经知道了tgf，但现在由于新的和改进的仪器，他们能够更好地研究这些事件的原因和影响。其中一个例子就是伽马射线暴监测器（GBM），它是由卫星发射的，现在给研究人员提供了一个前所未有的关于TGF事件的视角。然而，将在太空中看到的东西与雷暴中发生的事情联系起来并不是直截了当的。在这个研究项目中，研究者计划分析卫星数据，目的是确定雷暴中tgf的特征及其来源区域。提高对瞬变效应的认识对雷电安全具有重要意义，特别是与航空旅客的辐射暴露有关。这一项目也将是为早期职业科学家颁发的首个奖项。研究人员计划通过首先构建一组模拟的TGF事件来分析数据，然后比较这些事件在卫星传感器上的“样子”与它们实际“看到”的方式。研究计划的总体目的是利用地面雷达观测、闪电数据、LF无线电数据、GBM TGF伽玛射线数据和理论模型中有关TGF的所有信息来约束观测到的TGF总体的性质，以拟合整个GBM样本。提出了三个主要问题：1)能否从假设的tgf群体开始，重现gbm检测到的tgf样本，包括数量和性质与最低点的偏移量？2)对人口特征可以施加哪些约束？3)对TGF光束有哪些约束？

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?