DOI: 10.1002/2017JA024865
Scopus记录号: 2-s2.0-85040738491
论文题名: Survey of the Favorable Conditions for Magnetosonic Wave Excitation
作者: Kim K.-C. ; Shprits Y.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 1 起始页码: 400
结束页码: 413
语种: 英语
英文关键词: magnetosonic equatorial noise
; proton ring distribution
; Van Allen Probes
英文摘要: The ratio of the proton ring velocity (VR) to the local Alfven speed (VA), in addition to proton ring distributions, plays a key factor in the excitation of magnetosonic waves at frequencies between the proton cyclotron frequency fcp and the lower hybrid resonance frequency fLHR in the Earth's magnetosphere. Here we investigate whether there is a statistically significant relationship between occurrences of proton rings and magnetosonic waves both outside and inside the plasmapause using particle and wave data from Van Allen Probe-A during the time period of October 2012 to December 2015. We also perform a statistical survey of the ratio of the ring energy (ER, corresponding to VR) to the Alfven energy (EA, corresponding to VA) to determine the favorable conditions under which magnetosonic waves in each of two frequency bands (fcp < f ≤ 0.5 fLHR and 0.5 fLHR < f < fLHR) can be excited. The results show that the magnetosonic waves in both frequency bands occur around the postnoon (12–18 magnetic local time, MLT) sector outside the plasmapause when ER is comparable to or lower than EA, and those in lower-frequency bands (fcp < f ≤ 0.5 fLHR) occur around the postnoon sector inside the plasmapause when ER/EA > ~9. However, there is one discrepancy between occurrences of proton rings and magnetosonic waves in low-frequency bands around the prenoon sector (6–12 MLT) outside the plasmapause, which suggests either that the waves may have propagated during active time from the postnoon sector after being excited during quiet time, or they may have locally excited in the prenoon sector during active time. ©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/114734
Appears in Collections: 气候减缓与适应
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作者单位: Division of Science Education, College of Education, Daegu University, Gyeongsan, Gyeongbuk, South Korea; Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany; Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany; Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, United States
Recommended Citation:
Kim K.-C.,Shprits Y.. Survey of the Favorable Conditions for Magnetosonic Wave Excitation[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(1)