DOI: 10.1016/j.epsl.2019.115879
论文题名: Characterising Jupiter's dynamo radius using its magnetic energy spectrum
作者: Tsang Y.-K. ; Jones C.A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 530 语种: 英语
中文关键词: anelastic convection
; dynamo region
; Jupiter
; Lowes–Mauersberger spectrum
; magnetic energy spectrum
英文关键词: Hydrogen
; Magnetism
; Spectroscopy
; Anelastic convections
; Core-mantle boundary
; Electrical conductivity
; Jupiters
; Magnetic energies
; Metallic hydrogen
; Molecular hydrogen
; Temperature and pressures
; Interactive devices
; core-mantle boundary
; electrical conductivity
; geodynamo
; Jupiter
; magnetic field
; magnetic property
; numerical model
英文摘要: Jupiter's magnetic field is generated by the convection of liquid metallic hydrogen in its interior. The transition from molecular hydrogen to metallic hydrogen as temperature and pressure increase is believed to be a smooth one. As a result, the electrical conductivity in Jupiter varies continuously from being negligible at the surface to a large value in the deeper region. Thus, unlike the Earth where the upper boundary of the dynamo—the dynamo radius—is definitively located at the core-mantle boundary, it is not clear at what depth dynamo action becomes significant in Jupiter. In this paper, using a numerical model of the Jovian dynamo, we examine the magnetic energy spectrum at different depth and identify a dynamo radius below which (and away from the deep inner core) the shape of the magnetic energy spectrum becomes invariant. We find that this shift in the behaviour of the magnetic energy spectrum signifies a change in the dynamics of the system as electric current becomes important. Traditionally, a characteristic radius derived from the Lowes–Mauersberger spectrum—the Lowes radius—gives a good estimate to the Earth's core-mantle boundary. We argue that in our model, the Lowes radius provides a lower bound to the dynamo radius. We also compare the Lowes–Mauersberger spectrum in our model to that obtained from recent Juno observations. The Lowes radius derived from the Juno data is significantly lower than that obtained from our models. The existence of a stably stratified region in the neighbourhood of the transition zone might provide an explanation of this result. © 2019 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165315
Appears in Collections: 气候变化与战略
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作者单位: School of Mathematics, University of Leeds, Leeds, LS2 9JT, United Kingdom
Recommended Citation:
Tsang Y.-K.,Jones C.A.. Characterising Jupiter's dynamo radius using its magnetic energy spectrum[J]. Earth and Planetary Science Letters,2020-01-01,530