DOI: 10.1029/2018JA025312
Scopus记录号: 2-s2.0-85050312067
论文题名: Thermal and Energetic Ion Dynamics in Ganymede's Magnetosphere
作者: Poppe A.R. ; Fatemi S. ; Khurana K.K.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 6 起始页码: 4614
结束页码: 4637
语种: 英语
英文关键词: exosphere sputtering
; Ganymede
; ion precipitation
; radiation belts
; surface weathering
英文摘要: Ganymede is the solar system's only known moon with an intrinsic, global magnetic field. This field is strong enough to stand off the incident Jovian magnetospheric flow to form a small, complex magnetosphere around the satellite. Ganymede's magnetosphere is thought to be responsible for variable surface weathering patterns, the production of a neutral exosphere, and the generation of UV aurorae near Ganymede's open-closed field line boundaries; however, the exact details and underlying mechanisms are poorly understood. We use results from three-dimensional hybrid models of Ganymede's magnetosphere and a three-dimensional particle tracing model to quantify the dynamics of thermal and energetic Jovian ions as they interact with Ganymede's magnetosphere and precipitate to the surface. We identify the formation of quasi-trapped ionic radiation belts in the model and variable surface weathering. Most of the particle precipitation occurs in Ganymede's polar caps, yet ions also precipitate onto Ganymede's equatorial region in lesser amounts due to particle shadowing of quasi-trapped ions in Ganymede's ionic radiation belts. Model results predict that within Jupiter's central plasma sheet, total ion fluxes to Ganymede's polar, leading, and trailing hemispheres are 50 × 106, 10 × 106, and 0.06 × 106 cm−2 · s−1, respectively. Finally, convolution of incident ions fluxes with neutral sputtering yields for icy bodies predicts neutral sputtered fluxes in Ganymede's polar, leading, and trailing hemispheres of 1.3 × 109, 4.8 × 108, and 1.2 × 108 neutrals cm−2 · s−1, respectively. Together, we estimate that Ganymede loses 7.5 × 1026 neutral particles per second, or assuming a mean mass of 18 amu, approximately 23 kg/s, half that estimated for Europa. ©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/113751
Appears in Collections: 气候减缓与适应
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作者单位: Space Sciences Laboratory, University of California, Berkeley, CA, United States; Swedish Institute of Space Physics, Kiruna, Sweden; Institute for Geophysics and Planetary Physics, University of California, Los Angeles, CA, United States
Recommended Citation:
Poppe A.R.,Fatemi S.,Khurana K.K.. Thermal and Energetic Ion Dynamics in Ganymede's Magnetosphere[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(6)