DOI: 10.1002/2017JA024804
Scopus记录号: 2-s2.0-85046769384
论文题名: The Generation of Saturn's Aurora at Lower Latitudes by Electrostatic Waves
作者: Tripathi A.K. ; Singhal R.P. ; Singh O.N. ; II
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 5 起始页码: 3565
结束页码: 3579
语种: 英语
英文关键词: diffuse aurora
; electrostatic waves
; H and H2 emissions
; pitch angle diffusion
; Saturn's magnetosphere
英文摘要: In the present paper we have modeled diffuse auroral emissions, which have been observed at lower latitudes as compared to the main auroral arc at Saturn. It is generally accepted that these emissions are generated by precipitation of hot population of magnetospheric electrons on the closed field lines. We have considered the pitch angle diffusion by electrostatic electron cyclotron harmonic waves as the mechanism to diffuse trapped electrons into the atmospheric loss cone. Electrons are thereby precipitated into the atmosphere and excite the neutral atmospheric constituents producing auroral emissions. Calculation of ultraviolet emission intensities has been performed at two L-shells 5.35 and 7.0. Observed hot electron distribution functions and observed electrostatic electron cyclotron harmonic wave characteristics have been used in the study. Intensities of Lyman-alpha emission from excitation of atomic H and Lyman-alpha produced from dissociative excitation of H2 have been calculated, obtaining the values 20.1 R (1.8 R) and 1.6 kR (0.29 kR), respectively, for both L-shells 7.0 (5.35).Further, intensities of Lyman and Werner bands of H2 are also calculated. These have the values 7.50 kR (1.43 kR) and 7.52 kR (1.49 kR), respectively, for L-shells 7.0 (5.35). It is observed that the volume excitation rates of these four excitations peak at an altitude of about 2,000 km. From the range-energy relation in H2 gas it is estimated that the electrons producing these excitations should have energies less than about 250 eV. ©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/113916
Appears in Collections: 气候减缓与适应
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作者单位: Department of Physics, Indian Institute of Technology, Banaras Hindu University, Varanasi, India
Recommended Citation:
Tripathi A.K.,Singhal R.P.,Singh O.N.,et al. The Generation of Saturn's Aurora at Lower Latitudes by Electrostatic Waves[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(5)