气候变化领域集成服务门户(CCPortal): Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock

CCPortal

DOI	10.1029/2020GL087350
	Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock
	Romanelli N.; DiBraccio G.; Gershman D.; Le G.; Mazelle C.; Meziane K.; Boardsen S.; Slavin J.; Raines J.; Glass A.; Espley J.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:9
英文摘要	We perform the first statistical analysis of the main properties of waves observed in the 0.05–0.41 Hz frequency range in the Hermean foreshock by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Magnetometer. Although we find similar polarization properties to the “30 s” waves observed at the Earth's foreshock, the normalized wave amplitude (δB/\|B0\|∼0.2) and occurrence rate (∼0.5%) are much smaller. This could be associated with relatively lower backstreaming proton fluxes, the smaller foreshock size and/or less stable solar wind (SW) conditions around Mercury. Furthermore, we estimate that the speed of resonant backstreaming protons in the SW reference frame (likely source for these waves) ranges between 0.95 and 2.6 times the SW speed. The closeness between this range and what is observed at other planetary foreshocks suggests that similar acceleration processes are responsible for this energetic population and might be present in the shocks of exoplanets. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Magnetometers; Particle size analysis; Acceleration process; Frequency ranges; MErcury Surface; Particle acceleration; Polarization properties; Space environment; Ultra low frequencies; Wave amplitudes; Earthquakes; foreshock; frequency analysis; magnetometer; Mercury (planet); polarization; solar wind; wave climate
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170394
作者单位	NASA Goddard Space Flight Center, Greenbelt, MD, United States; CRESST II, University of Maryland, Baltimore County, MD, United States; Institut de Recherche en Astrophysique et Planetologie, UPS/CNRS, Toulouse, France; Department of Physics, University of New Brunswick, Fredericton, NB, Canada; Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States
推荐引用方式 GB/T 7714	Romanelli N.,DiBraccio G.,Gershman D.,et al. Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock[J],2020,47(9).
APA	Romanelli N..,DiBraccio G..,Gershman D..,Le G..,Mazelle C..,...&Espley J..(2020).Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock.Geophysical Research Letters,47(9).
MLA	Romanelli N.,et al."Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock".Geophysical Research Letters 47.9(2020).