DOI: 10.1029/2017JA024618
Scopus记录号: 2-s2.0-85046450866
论文题名: One-Hertz Waves at Mars: MAVEN Observations
作者: Ruhunusiri S. ; Halekas J.S. ; Espley J.R. ; Eparvier F. ; Brain D. ; Mazelle C. ; Harada Y. ; DiBraccio G.A. ; Thiemann E.M.B. ; Larson D.E. ; Mitchell D.L. ; Jakosky B.M. ; Sulaiman A.H.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 5 起始页码: 3460
结束页码: 3476
语种: 英语
英文关键词: 1-Hz waves
; group-standing waves
; low-frequency whistler waves
; Mars
; MAVEN
英文摘要: We perform a survey of 1-Hz waves at Mars utilizing Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft observations for a Martian year. We find that the 1-Hz wave occurrence rate shows an apparent variation caused by masking of the waves by background turbulence during the times when the background turbulence levels are high. To correct for this turbulence masking, we select waves that occur in time intervals where the background turbulence levels are low. We find that the extreme ultraviolet flux does not affect the wave occurrence rate significantly, suggesting that the newly born pickup ions originating in the Mars's exosphere contribute minimally to the 1-Hz wave generation. We find that the wave occurrence rates are higher for low Mach numbers and low beta values than for high Mach numbers and high beta values. Further, we find that a high percentage of 1-Hz waves satisfy the group-standing condition, which suggests that a high percentage of the waves seen as monochromatic waves in the spacecraft frame can be broadband waves in the solar wind frame that have group velocities nearly equal and opposite to the solar wind velocity. We infer that the wave occurrence rate trends with the Mach number and proton beta are a consequence of how the Mach numbers and beta values influence the wave generation and damping or how those parameters affect the group-standing condition. Finally, we find that the 1-Hz waves are equally likely to be found in both the quasi-parallel and the quasi-perpendicular foreshock regions. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113922
Appears in Collections: 气候减缓与适应
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作者单位: Department of Physics and Astronomy, The University of Iowa, Iowa City, IA, United States; NASA Goddard Space Flight Center, Greenbelt, MD, United States; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, United States; IRAP, University of Toulouse, CNRS, UPS, CNES, Toulouse, France; Space Sciences Laboratory, University of California, Berkeley, CA, United States
Recommended Citation:
Ruhunusiri S.,Halekas J.S.,Espley J.R.,et al. One-Hertz Waves at Mars: MAVEN Observations[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(5)