Magnetosphere - Ionosphere Coupling During Periods of Extreme Solar Wind Driving

极端太阳风驱动期间的磁层-电离层耦合

基本信息

批准号：
1216373
负责人：
Calvin Robert Clauer
金额：
$ 30.17万
依托单位：
Virginia Polytechnic Institute and State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1216373&HistoricalAwards=false
关键词：
Magnetosphere Ionosphere Coupling During Periods

项目摘要

The dynamics of the solar wind, magnetosphere and ionosphere system are driven by the solar wind electric field. Under normal solar wind conditions the cross polar cap potential (CPCP) difference scales with the solar wind electric field. However under extreme solar wind conditions such as those occurring during magnetic storms the CPCP becomes non-linear and saturates. This study will primarily support a post-doctoral scholar at Virginia Polytechnic and State University who will be taught about the operation of both coherent and incoherent scatter ionospheric radars.The goals of this study are to investigate the causes of the saturation and to understand why the northern and southern hemispheres behave differently. There have been two classes of explanations for CPCP saturation. In one dayside region 1 field aligned currents limit the magnetic reconnection rate for strong driving and in the other an Alfvén wing is set up in which a portion of the electric field set up by the solar wind is reflected at the ionosphere as the result of a conductance mismatch between the Alfvénic conductance of the solar wind and the Pedersen conductance of the ionosphere. The team proposes a third explanation that ionospheric plasma instabilities lead to limitations on ionospheric currents and that this feeds back into the magnetosphere. The research involves using a hybrid simulation code and observations from SuperDARN and ISR radar in the ionosphere, ACE solar wind observations and THEMIS data in the magnetosphere.

太阳能，磁层和电离层系统的动力学由太阳能电场驱动。在正常的太阳风条件下，交叉极盖电势（CPCP）差异尺度与太阳风电场。但是，在极端的太阳风条件下，例如在磁场期间发生的情况下，CPCP变为非线性和饱和。这项研究将主要支持弗吉尼亚理工大学和州立大学的博士后科学，他们将被教授有关相干和不连贯的散点电离电离雷达的运作。这项研究的目标是研究满意度的原因，并了解为什么北半球和南半球的行为会有所不同。有两类CPCP满意度的解释。在一日的地区，区域1场对齐电流限制了强驾驶的磁重新连接速率，而在另一个区域，建立了一个Alfvén机翼，在该机翼中，由于太阳能电导率是在电导层上反映了太阳能电场的一部分电场，这是由于Solar Wind的Alfvénic电导率之间的电导电导量与PederSen pedersen电导率的alfVénic电导之间的结果。团队提出了第三个解释，即电离层等离子体不稳定性导致了电离层电流的局限性，并且这会反馈到磁层中。该研究涉及使用混合模拟代码以及电离层中Superdarn和ISR雷达的观察结果，ACE太阳风观测和磁层中的Themis数据。