CAREER: Understanding and Modeling the Mysterious Dropout of Radiation Belt Electrons

职业：理解辐射带电子的神秘消失并对其进行建模

基本信息

批准号：
1752736
负责人：
Weichao Tu
金额：
$ 65.77万
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：
2018
资助国家：
美国
起止时间：
2018-05-15 至 2025-04-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1752736&HistoricalAwards=false
关键词：
CAREER Understanding Modeling Mysterious Dropout

项目摘要

This project focuses modeling of the relativistic electron population dynamics in Earth's Radiation Belts. Without fully understanding the mysterious dropout of electrons, a full understanding and prediction of radiation belt dynamics cannot be reached. This is of considerable practical importance due to the hazards to space-borne systems. Many communications satellites and national security assets reside in this radiation environment and their lifetime depends on its dynamics. Advancing the science supports improvement of the predictive models and fits directly into the goals of the National Space Weather Strategy and Action Plan, which was released in 2015. The project supports a female faculty member and will train and educate graduate and undergraduate students in both research and outreach activities. The learning module will provide an unprecedented informal learning opportunity on space science to West Virginia K-12 schools. It is expected to increase the awareness and interest of middle school students in the STEM programs in the state, and inspire them to pursue STEM careers, especially the underrepresented female and lower socioeconomic status students. The opportunities to develop and deliver the learning module will also provide valuable educational and outreach experience for undergraduate and graduate students and enhance their science literacy and communication skills.Since the launch of NASA Van Allen Probes in 2012, significant progress has been achieved in understanding the strong enhancement of relativistic electrons. However, the fast and dramatic dropout of radiation belt electrons (orders of magnitudes in a few hours) remains unsolved. The open question exists: Where do the electrons go during the dropout? This award is to develop a new and comprehensive dropout model, named Relativistic Electron Dropout (RED), with physical and event-specific inputs to simulate the electron dropout and understand the governing processes. RED will include not only the traditional loss processes (pitch angle diffusion, magnetopause shadowing, and outward radial diffusion), but also the new mechanism called Drift Orbit Bifurcation (DOB). Physical quantification of these processes will be achieved based on realistic field and particle conditions. With these inputs, RED will simulate both the electron dropout observed at high altitudes and the electron precipitation observed at low altitudes to resolve the governing mechanisms. The wealth of energetic electron and wave measurements from Van Allen Probes, THEMIS, and MMS spacecraft that cover the region from the outer belt to the magnetopause and the multiple POES satellites at low altitudes will provide an excellent test base for the RED model. This model will be the first to incorporate all the major loss mechanisms during the dropout, including the new DOB process. It is capable of simulating both electron dropout at high altitudes and precipitation at low altitudes, which will make a significant contribution in understanding the governing processes during the dropout and resolving their relative importance. The physical and event-specific quantification of the magnetopause shadowing, DOB, and radial diffusion processes is new and critical for understanding the fast electron dropout as well as the overall radiation belt dynamics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目集中于地球辐射带中相对论电子种群动力学的建模。如果不完全了解电子的神秘辍学，就无法完全理解和预测辐射带动力学。由于对太空传播系统的危害，这具有相当实际的重要性。许多通信卫星和国家安全资产都存在于这种辐射环境中，它们的一生取决于其动态。推进科学支持预测模型的改进，并直接适合于2015年发布的国家太空天气战略和行动计划的目标。该项目支持一名女教师，并将在研究和外展活动中培训和教育研究生和本科生。该模块将向西弗吉尼亚州K-12学校提供空间科学的空前的非正式学习机会。预计它将提高中学生在该州的STEM计划中的认识和兴趣，并激发他们从事STEM职业，尤其是代表性不足的女性和较低的社会经济地位学生。开发和交付学习模块的机会还将为本科和研究生提供宝贵的教育和外展经验，并增强其科学素养和沟通技巧。随着NASA Van Allen Proces在2012年的推出，在理解相对论电子的强大增强方面取得了重大进展。但是，辐射带电子的快速和戏剧性辍学（几个小时内的大小订单）仍未得到解决。存在开放的问题：电子在辍学期间去哪里？该奖项是为了开发一种新的全面辍学模型，称为相对论电子辍学（RED），并具有特定于事件的输入，以模拟电子辍学并了解管理过程。红色不仅包括传统的损耗过程（螺距角扩散，磁笼阴影和向外的径向扩散），还包括称为漂移轨道分叉（DOB）的新机制。这些过程的物理量化将基于现实的场和粒子条件来实现。使用这些输入，红色将模拟在高海拔地区观察到的电子脱位，又模拟在低海拔处观察到的电子沉淀，以解决管理机理。范围覆盖从外带到磁层的区域的Van Allen探针，Themis和MMS航天器的能量电子和波浪测量的财富以及低海拔的多个POES卫星将为红色模型提供出色的测试基础。该模型将是第一个在辍学期间（包括新的DOB工艺）中结合所有主要损失机制的模型。它能够模拟高海拔高度的电子辍学和降水，这将在理解辍学过程中的管理过程并解决其相对重要性方面做出重大贡献。磁笼阴影，DOB和径向扩散过程的物理和事件特异性量化对于理解快速电子辍学以及整体辐射带动力学是新的，至关重要的。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛的影响来评估的支持。

项目成果

期刊论文数量（17）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Estimating the Azimuthal Mode Structure of ULF Waves Based on Multiple GOES Satellite Observations

DOI：
10.1029/2019ja026927
发表时间：
2018-12
期刊：
Journal of Geophysical Research: Space Physics
影响因子：
0
作者：
M. Barani;W. Tu;T. Sarris;K. Pham;R. Redmon
通讯作者：
M. Barani;W. Tu;T. Sarris;K. Pham;R. Redmon

Quantifying event‐specific radial diffusion coefficients of radiation belt electrons with the PPMLR‐MHD simulation

使用 PPMLR–MHD 模拟量化辐射带电子的事件–特定径向扩散系数

DOI：
10.1029/2019ja027634
发表时间：
2020
期刊：
Journal of Geophysical Research: Space Physics
影响因子：
0
作者：
Li‐Fang Li;Weichao Tu;Lei Dai;Bin‐Bin Tang;Chi Wang;Mohammad Barani;Gang Zeng;Chao Wei;J.L. Burch
通讯作者：
J.L. Burch

Modeling the Dynamics of Energetic Protons in Earth's Inner Magnetosphere