CEDAR: Mechanisms and Effects of Terrestrial Gamma-Ray Flashes

CEDAR：地面伽马射线闪光的机制和影响

• 批准号: 0535461
• 负责人: John Gill
• 金额: --
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0535461&HistoricalAwards=false
• 关键词: CEDAR; Mechanisms; Effects; Terrestrial; Gamma

A 3-year theoretical investigation of the mechanisms and effects of Terrestrial Gamma-ray Flashes (TGFs) will be carried out under this grant. Recent observations of TGFs from the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft have demonstrated the need for a revision of the current model for their generation. This project will investigate a new mechanism for the production of TGFs based on the possibility for production of runaway electron avalanche driven by electromagnetic impulses (EMP) radiated by rapidly moving lightning return strokes. The proposed program builds on previous models of TGF production developed by the proposing team and the main objective is to determine the quantitative feasibility of the EMP-driven mechanism. This includes the development of a kinetically based Monte Carlo model of the partially synchronized runaway acceleration of relativistic electrons by the lightning EMP. In addition, model results will be compared to experimental data, including TGF fluxes and energy spectra as observed on RHESSI.This project is cross-disciplinary in that it will advance understanding of the electrodynamic coupling between the lower (neutral) atmosphere, where thunderstorms occur, and the higher altitude ionized layers of the mesosphere and the ionosphere. In addition, relativistic runaway acceleration is a fundamentally new particle acceleration phenomenon and the results of this research project, therefore, will have broader scientific impact beyond atmospheric sciences.

利用该基金，将开展为期3年的关于地球伽马射线闪光（TGFs）的机制和影响的理论研究。最近从Ramaty高能太阳光谱成像仪（RHESSI）航天器对TGF的观测表明，有必要对其生成的当前模型进行修订。本项目将研究一种新的机制，为生产的TGFs的基础上生产的可能性失控电子雪崩的电磁脉冲（EMP）辐射的快速移动的闪电回击。拟议的计划建立在以前的模型的TGF生产提出的团队和主要目标是确定定量的EMP驱动机制的可行性。这包括一个基于动力学的Monte Carlo模型的相对论电子的部分同步失控加速闪电EMP的发展。此外，还将把模型结果与实验数据进行比较，包括在RHESSI上观测到的TGF通量和能谱，这一项目是跨学科的，因为它将增进对发生雷暴的低层（中性）大气与中间层和电离层的高空电离层之间的电动耦合的了解。此外，相对论性失控加速是一种全新的粒子加速现象，因此，该研究项目的结果将具有超出大气科学的更广泛的科学影响。