NSWP: Predicting Geomagnetically Induced Fields Driven by Solar Wind Pressure Discontinuities

NSWP：预测由太阳风压不连续性驱动的地磁感应场

• 批准号: 0519072
• 负责人: David Murr
• 金额: --
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0519072&HistoricalAwards=false
• 关键词: NSWP; Predicting; Geomagnetically; Induced; Fields

Geomagnetically induced currents (GICs) are a direct consequence of space weather. They are caused primarily by intense and rapidly varying ionospheric currents that can be hazardous to technological systems on the surface of the Earth. Sudden impulse (SI) events caused by the passage of interplanetary shocks have been shown to produce magnetic variations on the ground large and fast enough to cause large GICs. The aim of this project is to develop empirical and physics-based models of the ionospheric portion of the SI current system and use these models to calculate, and ultimately predict, the geomagnetically induced fields at the surface of the Earth. The study will be accomplished by developing an empirical model of the SI currents using measurements from ground-based magnetometers combined with radar measurements of the ionospheric plasma drift. Also, a physics-based model of the SI currents system will be developed using a global magnetospheric model and upstream solar wind measurements to evaluate its ability to represent the current system. The induced magnetic and electric fields from these model current system will be calculated using the numerical techniques known as the method of auxiliary sources, the complex image method, and by utilizing the magnetotelluric equations and a model of the Earth's conductivity. The result of the project will be a predictive model, based on the upstream solar wind conditions, that will forecast the size, location, and duration of geomagnetically induced fields produced by SI events. In addition, techniques that combine magnetometer and radar data will be developed. This research has important scientific relevance becaue large GICs are known to cause severe effects on electric power grids, sometimes resulting in socioeconomic losses that can exceed tens of millions of dollars. The research will involve both undergraduate and graduate students in the engineering and physics departments.

地磁感应电流（gic）是空间天气的直接后果。它们主要是由强烈和迅速变化的电离层电流引起的，这种电流可能对地球表面的技术系统造成危险。由行星际冲击通过引起的突然脉冲（SI）事件已被证明能在地面上产生大而快的磁场变化，足以引起大的GICs。该项目的目的是开发基于经验和物理的SI电流系统电离层部分模型，并使用这些模型来计算并最终预测地球表面的地磁感应场。这项研究将通过利用地面磁力计测量和电离层等离子体漂移的雷达测量相结合，建立一个SI电流的经验模型来完成。此外，将使用全球磁层模型和上游太阳风测量来开发一个基于物理的SI电流系统模型，以评估其代表当前系统的能力。这些模型电流系统的感应磁场和电场将使用辅助源法、复像法、大地电磁方程和地球电导率模型等数值技术进行计算。该项目的结果将是一个基于上游太阳风条件的预测模型，该模型将预测由SI事件产生的地磁感应场的大小、位置和持续时间。此外，将开发结合磁力计和雷达数据的技术。这项研究具有重要的科学意义，因为已知大型gic会对电网造成严重影响，有时会导致超过数千万美元的社会经济损失。这项研究将涉及工程系和物理系的本科生和研究生。