GEM: Developing a Highly Predictable Canonical Geomagnetic Index to Gauge Space Weather

地磁指数对不同的电流系统很敏感，例如磁层对流、极光活动和跨极帽电流。它们是根据测量结果构建的，例如地面磁力计的磁场，并用于表征和预测地磁活动。磁层活动，包括地磁风暴，是对太阳风的反应。这个项目将设计一个新的地磁指数，更准确地预测上游的太阳风测量。这将改善空间天气预报——这对于准备敏感系统（如卫星和高频通信）应对动态空间环境的影响非常重要。根据对上游太阳风的了解，将推导出一个高度可预测的综合地磁指数。这个“标准”地磁指数将由测量磁层-电离层系统中不同电流系统和活动类型的多个地磁指数构建而成，并将描述全球活动。一旦指数被推导出来，连同它的典型太阳风驱动函数，叠加历元分析和其他统计技术将被用来通过测量日冕物质抛射驱动的风暴、高速流驱动的风暴、亚风暴和稳定的磁层对流间隔来熟悉指数。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Geomagnetic indices are sensitive to diverse current systems, such as magnetospheric convection, auroral activity, and cross-polar-cap current. They are constructed from measurements, such as magnetic fields from ground magnetometers, and are used to characterize and predict geomagnetic activity. Magnetospheric activity, including geomagnetic storms, occurs in reaction to the solar wind. This project will devise a new geomagnetic index that more accurately predicts upstream solar-wind measurements. This will improve space weather predictions – important to preparing sensitive systems like satellites and high frequency communications for impacts from the dynamic space environment. A composite geomagnetic index will be derived that is highly predictable from a knowledge of the upstream solar wind. This “canonical” geomagnetic index will be constructed from multiple geomagnetic indices measuring different current systems and activity types in the magnetosphere-ionosphere system and will describe global activity. Once the index is derived, along with its canonical solar-wind driver function, superposed-epoch analysis and other statistical techniques will be used to familiarize the index by gauging coronal mass ejection driven storms, high-speed-stream-driven storms, substorms, and steady magnetospheric convection intervals.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.