| 项目编号: | 1503097
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| 项目名称: | GEM: Magnetotail Reconnection Signatures at Lunar Orbit |
| 作者: | Andrei Rounov
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| 承担单位: | University of California-Los Angeles
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| 批准年: | 2016
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| 开始日期: | 2016-03-01
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| 结束日期: | 2019-02-28
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| 资助金额: | 188495
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Atmospheric and Geospace Sciences
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| 英文关键词: | magnetic reconnection
; reconnection site
; near-earth reconnection
; solar wind
; earth radii
; lunar orbit
; earth-orbiting satellite
; magnetic field
; magnetotail field line
; near-earth
; magnetosphere
; magnetotail condition
; reconnection outflow
; distant tail reconnection
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| 英文摘要: | Earth's magnetic field encloses it in a protective cocoon, called the magnetosphere, deflecting most of the solar wind around it. The solar wind is a stream of charged particles and magnetic fields blowing outward from the Sun, which varies in intensity with solar activity. Because of its interaction with the solar wind, the magnetosphere is compressed on the dayside and extended in a long "magnetotail" on the nightside. The stretched magnetotail field lines store energy extracted from the solar wind. This energy is released by a process called magnetic reconnection, the subject of the present study, during which magnetic energy is converted into plasma flows as well as heating and energization of plasmas within the Earth's magnetosphere. Magnetic reconnection occurs at two locations: one in the near-tail at a distance of 15-30 Earth radii and the other in the distant tail at 100-200 Earth radii. The near-Earth reconnection is explosive, creating high-energy charged particles that are responsible for the dynamic auroras in the upper atmosphere but also for damage to Earth-orbiting satellites. Near-Earth reconnection is largely associated with space weather events called magnetic storms and substorms. In contrast, the distant tail reconnection (about which much less is known) is envisioned to be steadier. It is not understood how the two reconnection sites interact. Of major importance for the present study, fast plasma flows are produced moving both Earthward and tailward from each of these reconnection sites. A satellite at lunar orbit (~60 Earth radii) between the two sites has the important advantage of being able to detect tailward flows from the near-Earth site, and earthward flows from the distant tail site. Thus the connection between the two, and the impact on magnetotail conditions of each, can be investigated from the same mid-tail vantage point. New insights into magnetic reconnection from the suggested study are valuable for research in planetary magnetospheres, as well as astrophysical and laboratory plasmas. The suggested work will provide important training for graduate students. It also includes public outreach and educational activities.
To accomplish the goals described above, the proposers will analyze observations from the Artemus (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun) satellites in lunar orbit at ~60 Earth radii using case and statistical studies to investigate the occurrence rates of reconnection outflows from both near- and distant-tail reconnection sites, their variations over a range of space weather conditions (quiescent to magnetic storming), the timing between them (i.e., which site activates first), as well as consequences to the mid-tail space environment, such as transient electric field enhancements, changes in the magnetic field geometry, and enhancements in high-energy particle fluxes. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92817
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Andrei Rounov. GEM: Magnetotail Reconnection Signatures at Lunar Orbit. 2016-01-01.
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