Collaborative Research: Investigations of the Mid-Latitude Ionosphere during Magnetic Disturbances: Observations, Modeling and Space Weather Impacts

合作研究：磁扰期间中纬度电离层的调查：观测、建模和空间天气影响

• 批准号: 1242038
• 负责人: J Michael Ruohoniemi
• 金额: $ 11.89万
• 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: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1242038&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigations; Mid; Latitude

The investigators will study the source and evolution of the large scale (several hundred kms) and small scale (tens-of-km to tens-of-m) plasma at mid-latitudes during the main phase of magnetic storms. During major magnetic storms, the interaction between the solar wind and the magnetosphere under interplanetary magnetic field (IMF) southward conditions causes a change in the region 1 field-aligned currents leading to a sudden increase in the dawn-to-dusk polar cap potential. The region 2 field-aligned currents associated with an inner magnetospheric electric field directed in the dusk-to-dawn direction are no longer able to shield the mid- and equatorial latitudes from high-latitude electric fields. This results in a near-instantaneous penetration of an electric field from high latitude to the middle and the equatorial ionosphere. The prompt penetration electric field is eastward during the daytime to dusk sector and westward in the midnight to dawn sector. Thus this penetration electric field leads to a significant re-distribution of plasma throughout the plasmasphere and ionosphere by enhancing the layer height, and thereby the plasma density, during daylight hours and increasing the decay rates of ionization in darkness. The recent extension of several NSF-funded instrument arrays at American longitudes and assimilation models have made this collaborative research possible for the first time. The large scale plasma density behavior is best tracked by following the GPS measured total electron content (TEC) from equatorial regions using a newly-formed array through the Caribbean and into the continental US to determine the low latitude contribution to mid-latitude enhancements known as storm enhanced density (SED). A variety of data-assimilation models are now available to model the generation of the SED and test the extent of the equatorial contribution to this mid-latitude feature, thereby developing a climatology of such coupled phenomena. This collaborative research will be the first attempt to determine the contribution of the low latitude TEC on mid-latitudes at American longitudes to understand the source of ionization in the SED, to determine the 2D structure and velocity of hundreds of km scales to decameters and to determine the impact of TEC gradients and phase scintillations on space-based navigation systems. This research is also important for better implementation of the Wide-Area Augmentation System (WAAS), which supports civilian and commercial aviation.

研究人员将在磁性风暴的主要阶段中的中间段落研究大规模（几百公里）和小尺度（数十亿至m）等离子体的小规模（数十亿至m）等离子体的来源和演变。 在重大磁场期间，在星际磁场（IMF）向南条件下太阳风与磁层之间的相互作用会导致区域1田间对准电流的变化，从而导致黎明至dusk极性盖电位突然增加。与沿黄昏到黎明方向的内部磁层电场相关的区域2场对准电流不再能够屏蔽高纬度电场的中间和赤道纬度。这导致电场从高纬度到中间和赤道电离层的近乎触觉渗透。迅速穿透电场在白天向东向东，在午夜前往黎明部门向西，向西。因此，这种渗透电场通过提高层高度，从而在白天小时内增加了层高度，从而导致整个等离子球和电离层的血浆重新分布，从而增加了等离子密度，并增加了黑暗中电离的衰减速率。最近在美国纵向和同化模型中扩展了几个由NSF资助的仪器阵列扩展，这使这项协作性研究成为可能。通过遵循GPS测得的总电子含量（TEC），使用新形成的阵列通过加勒比海和美国大陆以确定低纬度对中纬度增强的低纬度贡献（SED）的低纬度贡献。现在可以使用多种数据鉴别模型来对SED的产生进行建模，并测试赤道贡献对此中纬度特征的贡献，从而开发了这种耦合现象的气候。这项协作研究将是首次尝试确定低纬度TEC对美国纵向中期的贡献，以了解SED中的电离源，以确定数百个KM量表对脱型人的2D结构和速度，并确定TEC梯度和相位闪光的影响。这项研究对于更好地实施了支持平民和商业航空的广域扩展系统（WAAS）也很重要。