GEM: Study the Precipitation of Radiation Belt Electrons during the Rapid Dropout Events

GEM：研究快速丢失事件期间辐射带电子的沉淀

• 批准号: 1613081
• 负责人: Weichao Tu
• 金额: $ 15.23万
• 依托单位: West Virginia University Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1613081&HistoricalAwards=false
• 关键词: GEM; Study; Precipitation; Radiation; Belt

With the launch of the Van Allen Probes in 2012 a new era in radiation belt studies has begun. This is a project to investigate the scientifically and societally important issue of radiation belt electron dynamics. The emphasis in this research will be on understanding the losses of electrons that occur during magnetic storms. These are significant in that the flux of relativistic electrons decreases by an order of magnitude in a few hours. There are two possible explanations for this: One is loss to the solar wind through the magnetopause and the other is loss to the atmosphere due to precipitation. The former is relatively easy to evaluate but the latter is much more difficult because the loss cone is small in the magnetosphere and because satellite observations provide a limited picture. This proposal will apply a creative approach combining satellite observations from the Van Allen Probes and NOAA POES satellites and a new Drift-Diffusion simulation to quantify the losses. The team will start by determining which observed events are candidates for magnetopause loss, which are candidates for precipitation loss and which are combinations of both types of loss. Then they will use the observations and the simulation iteratively to improve the simulation. They will determine the pitch angle diffusion coefficients as a function of magnetic local time and from that the local time and L shell (radial) dependence of the plasma waves responsible for the precipitation. They will compare this with Van Allen Probes wave observations. They plan a detailed calibration of the POES observations and those from the NSF Colorado Student Space Weather Experiment (CSSWE).Understanding electron dynamics is important societally for understanding space weather. In addition this project will support a young woman scientist and a graduate student. Finally the detailed calibration of the POES and CSSWE data will be useful well beyond this application.

随着2012年Van Allen探测的推出，辐射带研究的新时代已经开始。这是一个研究辐射带电子动力学的科学和社会重要问题的项目。 这项研究的重点是了解磁风暴中发生的电子的损失。 这些很重要的是，相对论电子的通量在几个小时内降低了数量级。有两个可能的解释：一个是通过磁磁带损失太阳风，另一个是由于降水而损失了大气。前者相对容易评估，但是后者更加困难，因为磁层中的损耗很小，并且卫星观测值有限。该提案将采用一种创造性的方法，结合了Van Allen Poes卫星中的卫星观察结果，以及新的漂移扩散模拟来量化损失。团队将首先确定哪些观察到的事件是磁笼损失的候选者，这些事件是降水损失的候选者，哪些是两种损失的组合。然后，他们将使用观测值和迭代模拟来改善模拟。 他们将确定磁力局部时间的倾斜角扩散系数，并从局部时间和L壳（径向）依赖性的等离子体波的依赖性。他们将将其与Van Allen探针波的观测值进行比较。他们计划对POES观察的详细校准以及NSF Colorado学生太空天气实验（CSSWE）的观察结果。理解电子动力学对于了解太空天气至关重要。此外，该项目将支持一位年轻女科学家和研究生。最后，POE和CSSWE数据的详细校准将远远超出此应用程序。