DOI: 10.1002/2014GL062555
论文题名: Confirmation of existence of the small-scale field-aligned currents in middle and low latitudes and an estimate of time scale of their temporal variation
作者: Iyemori T. ; Nakanishi K. ; Aoyama T. ; Yokoyama Y. ; Koyama Y. ; Lühr H.
刊名: Geophysical Research Letters
ISSN: 0094-9087
EISSN: 1944-8818
出版年: 2015
卷: 42, 期: 1 起始页码: 22
结束页码: 28
语种: 英语
英文关键词: acoustic gravity wave
; atmospheric wave
; field-aligned current
; ionospheric dynamo
; magnetic field
; middle latitudes
Scopus关键词: Gravity waves
; Magnetic fields
; Orbits
; Plasma flow
; Time measurement
; Acoustic-gravity waves
; Atmospheric waves
; Field aligned currents
; Ionospheric dynamo
; middle latitudes
; Magnetism
; estimation method
; gravity wave
; latitude
; magnetic field
; statistical analysis
; temporal variation
; timescale
英文摘要: The magnetic data obtained by the SWARM (the Earth's Magnetic Field and Environment Explorers) satellites in middle or low latitudes during the initial 2 months after launch were analyzed, when they flew nearly on the same orbit with variable time separation ranging from 5 to 100 s. It was confirmed that the small-scale magnetic fluctuations having period around 10-30 s are the manifestation of spatial structure of small-scale field-aligned currents along the orbits. From the statistical relation between correlation coefficients and two satellite separation in time, the typical time scale of temporal variation of the field-aligned current system is estimated to be around 200 s for meridional component and 340 s for zonal components of the magnetic fluctuations, respectively. Existence of shorter time scale around 30-50 s was also found. These results suggest that the main source of current generation is the acoustic mode of atmospheric gravity waves. Key Points Confirmation of existence of the small-scale FACs in midlatitude/low latitude Temporal scale of variation of the FACs is estimated by a new method Acoustic mode of gravity waves is suggested to be the source of FACs ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921820127&doi=10.1002%2f2014GL062555&partnerID=40&md5=f113b5a8bcab9aedb98d6b2ae36f256c
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8703
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Graduate School of Science, Kyoto University, Kyoto, Japan
Recommended Citation:
Iyemori T.,Nakanishi K.,Aoyama T.,et al. Confirmation of existence of the small-scale field-aligned currents in middle and low latitudes and an estimate of time scale of their temporal variation[J]. Geophysical Research Letters,2015-01-01,42(1).