DOI: 10.1002/2013GL057837
论文题名: Nighttime vertical plasma drifts and the occurrence of sunrise undulation at the dip equator: A study using Jicamarca incoherent backscatter radar measurements
作者: Ambili K.M. ; Choudhary R.K. ; St.-Maurice J.-P. ; Chau J.L.
刊名: Geophysical Research Letters
ISSN: 0094-8414
EISSN: 1944-8145
出版年: 2013
卷: 40, 期: 21 起始页码: 5570
结束页码: 5575
语种: 英语
英文关键词: equatorial electrodynamics
; equatorial F region
; equatorial region
; Jicamarca
; sunrise undulation
Scopus关键词: Chemical effect
; Equatorial regions
; Field control
; Jicamarca
; Magnetic equator
; Plasma motion
; Production peaks
; sunrise undulation
; Altitude control
; Backscattering
; Electric fields
; Electrodynamics
; F region
; Photoionization
; Radar measurement
; Magnetoplasma
; altitude
; backscatter
; drift behavior
; electrical property
; ionization
; measurement method
; plasma
; radar
英文摘要: The absence of photoionization, in combination with sustained downward plasma motion at night, means that the F region can be severely depleted at the magnetic equator in the morning. As a result, at sunrise, there can be a sudden upward jump in altitude of the F region peak followed by a quick descent in association with the downward motion of the photoionization production peak. This constitutes what is known as the equatorial sunrise undulation. Its anecdotal existence has been reported over Jicamarca while it has been seen repeatedly over Trivandrum, India, during equinox conditions. By contrast, we find that the phenomenon is not as frequent at Jicamarca as at Trivandrum. Using incoherent backscatter radar data from Jicamarca, we show that the differences have an electrodynamical origin. The sunrise undulation gets masked when remnant plasma from the previous night does not move down to low enough altitude. The nighttime residual ion density and its altitude are found to be strongly influenced by the evening and nighttime electric field. There is a strong association between a strong plasma uplift at sunset and the appearance of an undulation at sunrise around the magnetic equator. Key Points Sunrise undulation in hmF2 at the dip equator is purely a chemical effect Nighttime zonal field controls appearance of sunrise undulation nighttime remnant density and altitude important for sunrise undulation. ©2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887286493&doi=10.1002%2f2013GL057837&partnerID=40&md5=7c5c9ef87fd713fae3976efb80e65b7b
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/5678
Appears in Collections: 气候减缓与适应
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作者单位: Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum, Kerala 695 022, India
Recommended Citation:
Ambili K.M.,Choudhary R.K.,St.-Maurice J.-P.,et al. Nighttime vertical plasma drifts and the occurrence of sunrise undulation at the dip equator: A study using Jicamarca incoherent backscatter radar measurements[J]. Geophysical Research Letters,2013-01-01,40(21).