Investigation of the Relationship between Storm Enhanced Density and Scintillation in Antarctica

南极风暴增强密度与闪烁关系的调查

• 批准号: 1141923
• 负责人: Anthea Coster
• 金额: $ 22.04万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1141923&HistoricalAwards=false
• 关键词: Investigation; Relationship; between; Storm; Enhanced

Geomagnetic storms driven by solar wind perturbations are dynamic events that can cause dramatic reconfigurations of plasma in the ionosphere, plasmasphere, and magnetosphere. These events cause mesoscale redistributions giving rise to the formation of storm enhanced density (SED) plumes and polar tongues of ionization (TOI). Plasma patches are formed from the tongue of ionization and subsequently propagate across the polar cap by the prevailing E x B drift of charged particles in the Earth's magnetic field. Steep density gradients are formed along the edges of polar cap patches and the TOI and SED features; these gradients are the source region for plasma instabilities that produce cascades of electron density irregularities in the background plasma. As radio signals propagate through the irregularities, rapid fluctuations or scintillations are produced in the received radio signal amplitude and phase. Scintillation presents a considerable space weather hazard, especially for the high-precision GPS observations and navigation. Comprehensive system level studies are needed to link cause to effect through observations of SED, TOI, and polar cap patch histories simultaneously with direct polar cap scintillation data. With this award, scientists will study the formation of TOI and polar cap patches over Antarctica, and observe the relationship of SED and TOI to polar scintillation, using a combination of GPS data from multiple existing platforms and from specially equipped GPS scintillation receivers located at three different Antarctic sites. Educational opportunities will be provided through MIT Haystack?s ongoing involvement in programs like the NSF Research Experiences for Undergraduates, Research Experiences for Teachers, and focused high school internships.

由太阳风扰动驱动的地磁暴是动态事件，可导致电离层、等离子体层和磁层中等离子体的戏剧性重新配置。这些事件引起中尺度再分布，导致风暴增强密度(SED)羽流和极地电离舌(TOI)的形成。等离子体斑块是由电离的舌头形成的，随后由于地球磁场中带电粒子的主要E×B漂移而传播穿过极帽。沿极帽贴片的边缘以及TOI和SED特征形成陡峭的密度梯度；这些梯度是等离子体不稳定性的源区，等离子体不稳定性在背景等离子体中产生级联的电子密度不规则性。当无线电信号通过不规则性传播时，接收到的无线电信号的幅度和相位会产生快速波动或闪烁。闪烁是一种相当大的空间气象危害，特别是对于高精度的GPS观测和导航。需要进行全面的系统水平研究，通过同时观察SED、TOI和极地冰盖斑块历史与直接极地冰盖闪烁数据，将因果联系起来。有了这个奖项，科学家们将研究南极上空TOI和极冠斑块的形成，并结合来自多个现有平台的GPS数据和位于三个不同南极地点的特殊装备的GPS闪烁接收器，观察SED和TOI与极地闪烁的关系。教育机会将通过麻省理工学院的干草堆？S继续参与国家科学基金会本科生研究体验、教师研究体验和重点高中实习等项目提供。