CEDAR/GEM Postdoc: Fully Electrodynamic 3D Time-Domain Model of Lightning-Ionosphere Interactions

CEDAR/GEM 博士后：闪电-电离层相互作用的全电动 3D 时域模型

• 批准号: 1027070
• 负责人: Supriya Chakrabarti
• 金额: $ 15.99万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1027070&HistoricalAwards=false
• 关键词: CEDAR; GEM; Postdoc; Fully; Electrodynamic

The investigators will develop a full 3-dimensional time-domain model of the lightning-ionosphere interaction, including nonlinear effects and propagation into the magnetosphere. The model will enable accurate measurements of the effects of lightning on the lower ionosphere (70-110 km), in terms of electron density depletions and enhancements, as well as estimates of the fractional energy transmitted through the ionosphere into the magnetosphere. The model calculations can be calibrated against parameters such as the background ionospheric density, lightning peak current and duration, time of day, and type of lightning (cloud-to-ground versus in-cloud). Using this information, a global estimate of the density enhancement due to lightning can be made from existing satellite and ground-based worldwide lightning data. Comparison with analytical models and experimental data will also be made. The coupling of lightning energy to the ionosphere and magnetosphere has remained an unsolved problem for decades. The study will quantify the coupling process through both electrostatic and electromagnetic energy, both on a per-stroke basis and on a global basis, through comparison with worldwide lightning distribution statistics. The model results will provide calibration of lightning energy to the ionosphere and magnetosphere as a function of lightning peak current, duration, geographic location, time of day, and ionospheric conditions. This study will contribute greatly to understanding of the energy coupling between the lower atmosphere and the D-region ionosphere due to lightning, as well as coupling of energy into the inner magnetosphere. Lightning-generated whistler-mode waves are responsible for precipitation of energetic particles from the radiation belts, in the form of Lightning-induced Electron Precipitation (LEP) events.The model will be instrumental in support of the upcoming ASIM (European Space Agency) and TARANIS (CNES, France) satellite missions, which will monitor TLE activity globally beginning in 2012. The model will be disseminated to interested users and will readily run on a reasonable desktop computer; as such, scientists studying TLEs can determine the electric field intensities and ionospheric disturbances associated with their optical observations. The same comparisons will be enabled with ground-based observations of Transient Luminous Events.

研究人员将开发闪电-电离层相互作用的全三维时间域模型，包括非线性效应和向磁层的传播。该模型将能够准确测量闪电对较低电离层(70-110公里)的电子密度损耗和增强的影响，以及估计通过电离层进入磁层的部分能量。模型计算可以根据背景电离层密度、闪电峰值电流和持续时间、一天中的时间和闪电类型(云对地与云内)等参数进行校准。利用这一信息，可以从现有的卫星和地面全球闪电数据中对闪电造成的密度增加进行全球估计。并与分析模型和实验数据进行了比较。闪电能量与电离层和磁层的耦合问题几十年来一直是一个悬而未决的问题。这项研究将通过与全球闪电分布统计数据的比较，在每次冲程的基础上和在全球的基础上，通过静电和电磁能量来量化耦合过程。模型结果将提供电离层和磁层的闪电能量作为闪电峰值电流、持续时间、地理位置、一天中的时间和电离层条件的函数的校准。这项研究将有助于理解低层大气与D区电离层之间由于闪电而产生的能量耦合，以及能量进入内部磁层的耦合。闪电产生的哨声模波以闪电诱发的电子降水事件的形式从辐射带产生高能粒子的降水。该模式将有助于支持即将开始的ASIM(欧洲航天局)和Taranis(法国国家空间研究中心)卫星飞行任务，这些卫星将从2012年开始监测全球的TLE活动。该模型将分发给感兴趣的用户，并将很容易在一台合理的台式计算机上运行；因此，研究TLE的科学家可以确定与其光学观测相关的电场强度和电离层干扰。对瞬变发光事件的地面观测也可以进行同样的比较。