GEM: Magnetotail Reconnection Signatures at Lunar Orbit

GSTDTAP

项目编号	1503097
	GEM: Magnetotail Reconnection Signatures at Lunar Orbit
	Andrei Rounov
主持机构	University of California-Los Angeles
项目开始年	2016
	2016-03-01
项目结束日期	2019-02-28
资助机构	US-NSF
项目类别	Continuing grant
项目经费	90104(USD)
国家	美国
语种	英语
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.
来源学科分类	Geosciences - Atmospheric and Geospace Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/69179
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Andrei Rounov.GEM: Magnetotail Reconnection Signatures at Lunar Orbit.2016.