Whistler Mode Radio Sounding of Electrons, Ions and Density Irregularities in the Inner Magnetosphere from 90 to 5000 km

90 至 5000 公里内磁层中的电子、离子和密度不规则性的惠斯勒模式无线电探测

• 批准号: 1212593
• 负责人: Vikas Sonwalkar
• 金额: $ 35.17万
• 依托单位: University of Alaska Fairbanks Campus
• 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: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1212593&HistoricalAwards=false
• 关键词: Whistler; Mode; Radio; Sounding; Electrons

Determining the density and composition of plasma in the inner magnetosphere is a largely unexplored area of magnetospheric and ionospheric research. Using recently developed whistler mode (WM) radio sounding techniques and data from a new generation of space- and ground-based experiments, this three-year research program will investigate inner magnetospheric plasma density, ion composition and density irregularities from 90 to 5000km. Four research projects have been proposed: (1) Use WM radio sounding data from the Radio Plasma Imager (RPI) on the IMAGE satellite to measure the cold-plasma density (Ne), ion composition (H+, O+, He+) and density irregularities (10m to 10km scale size) along a magnetic field line as a function of geophysical conditions (e.g. location, local time, plasmapause position, geomagnetic and solar activity). (2) Study the variation (loss and refilling) of electron density and ion composition along geomagnetic field lines before, during, and after geomagnetic storms.(3) Build empirical models of plasma density, ion composition and density irregularities as functions of geophysical conditions along B0 from 90-5,000km. (4) Combine WM sounding results with those from complementary ground based (e.g. ionosonde, magnetometer), spacecraft based in situ (e.g. DMSP, CHAMP, CRESS, POLAR) and radio sounding (e.g. RPI sounding at higher altitude in free space modes) to augment and extend the empirical models and to build new field aligned models of the inner magnetospheric plasma density and composition up to equatorial altitudes.These empirical models will be used to gain new understanding into processes and mechanisms important to magnetosphere-ionosphere coupling and for use in space weather predictions. As a result these results should have broad application in space physics research. The proposal will support a graduate student.

确定磁层内部等离子体的密度和组成是磁层和电离层研究的一个很大程度上未被探索的领域。利用最近开发的哨声模式(WM)无线电探测技术和新一代空间和地面实验的数据，这项为期三年的研究计划将调查90至5000公里范围内磁层内等离子体密度、离子成分和密度不规则性。现已提出四个研究项目：(1)利用图像卫星上无线电等离子体成像仪提供的WM射电探测数据，测量随地球物理条件(如位置、当地时间、等离子体顶位置、地磁和太阳活动)而沿磁力线分布的冷等离子体密度(Ne)、离子成分(H+、O+、He+)和密度不规则性(10米至10公里尺度)。(2)研究了磁暴前、中、后电子密度和离子成分沿地磁力线的变化(损失和再充盈)，(3)建立了90-5000公里B0沿线等离子体密度、离子成分和密度不规则性随地球物理条件变化的经验模型。(4)将WM探测结果与补充地面(例如电离层探测仪、磁强计)、航天器现场探测(例如DMSP、CHAMP、CRESS、POLLE)和射电探测(例如在自由空间模式下在较高高度进行RPI探测)的结果结合起来，以增强和扩展经验模型，并建立新的磁场对准模型，以计算直到赤道高度的内部磁层等离子体密度和组成。因此，这些结果应该在空间物理研究中有广泛的应用。该提案将支持一名研究生。