巨行星带状流磁场效应的数值模拟

Shanshan Xue, Yufeng Lin
{"title":"巨行星带状流磁场效应的数值模拟","authors":"Shanshan Xue, Yufeng Lin","doi":"arxiv-2408.01650","DOIUrl":null,"url":null,"abstract":"Jupiter and Saturn exhibit alternating east-west jet streams as seen from\nsurface. The origin of these zonal flows has been debated for decades. The\nhigh-precision gravity measurements by Juno mission and the grand finale of\nCassini mission have revealed that the zonal flows observed at the surface may\nextend several thousand kilometres deep and stop around the transition region\nfrom molecular to metallic hydrogen, suggesting the magnetic braking effect on\nzonal flows. In this study, we perform a set of magnetohydrodynamic simulations\nin a spherical shell with radially variable electrical conductivity to\ninvestigate the interaction between magnetic fields and zonal flows. A key\nfeature of our numerical models is that we impose a background dipole magnetic\nfield on the anelastic rotating convection. By varying the strength of the\nimposed magnetic field and the vigor of convection, we investigate how the\nmagnetic field interacts with the convective motions and the convection-driven\nzonal flows. Our simulations reveal that the magnetic field tends to destroy\nzonal flows in the metallic hydrogen and suppress zonal flows in the molecular\nenvelope, while the magnetic field may enhance the radial convective motions.\nWe extract a quantitative relation between the magnetic field strength and the\namplitude of zonal flows at the surface through our simulations, which roughly\nmatches the observed magnetic field and zonal wind speed of Jupiter and Saturn.\nThis discovery provides support from a new perspective for the scenario of deep\nconvection-driven zonal winds which are confined to the molecular hydrogen\nlayers in giant planets.","PeriodicalId":501209,"journal":{"name":"arXiv - PHYS - Earth and Planetary Astrophysics","volume":"28 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Numerical Simulations of Magnetic Effects on Zonal Flows in Giant Planets\",\"authors\":\"Shanshan Xue, Yufeng Lin\",\"doi\":\"arxiv-2408.01650\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Jupiter and Saturn exhibit alternating east-west jet streams as seen from\\nsurface. The origin of these zonal flows has been debated for decades. The\\nhigh-precision gravity measurements by Juno mission and the grand finale of\\nCassini mission have revealed that the zonal flows observed at the surface may\\nextend several thousand kilometres deep and stop around the transition region\\nfrom molecular to metallic hydrogen, suggesting the magnetic braking effect on\\nzonal flows. In this study, we perform a set of magnetohydrodynamic simulations\\nin a spherical shell with radially variable electrical conductivity to\\ninvestigate the interaction between magnetic fields and zonal flows. A key\\nfeature of our numerical models is that we impose a background dipole magnetic\\nfield on the anelastic rotating convection. By varying the strength of the\\nimposed magnetic field and the vigor of convection, we investigate how the\\nmagnetic field interacts with the convective motions and the convection-driven\\nzonal flows. Our simulations reveal that the magnetic field tends to destroy\\nzonal flows in the metallic hydrogen and suppress zonal flows in the molecular\\nenvelope, while the magnetic field may enhance the radial convective motions.\\nWe extract a quantitative relation between the magnetic field strength and the\\namplitude of zonal flows at the surface through our simulations, which roughly\\nmatches the observed magnetic field and zonal wind speed of Jupiter and Saturn.\\nThis discovery provides support from a new perspective for the scenario of deep\\nconvection-driven zonal winds which are confined to the molecular hydrogen\\nlayers in giant planets.\",\"PeriodicalId\":501209,\"journal\":{\"name\":\"arXiv - PHYS - Earth and Planetary Astrophysics\",\"volume\":\"28 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Earth and Planetary Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.01650\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Earth and Planetary Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.01650","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

摘要

从地表看,木星和土星呈现出东西交替的喷流。几十年来,人们一直在争论这些带状气流的起源。朱诺任务的高精度重力测量和卡西尼任务的压轴发现,在地表观测到的带状流可能深达数千公里,并在分子氢到金属氢的过渡区域附近停止,这表明带状流存在磁制动效应。在这项研究中,我们在一个具有径向可变电导率的球壳中进行了一组磁流体动力学模拟,以研究磁场与带状流之间的相互作用。我们的数值模型的一个主要特点是,我们在无弹性旋转对流中施加了一个背景偶极磁场。通过改变施加磁场的强度和对流的强度,我们研究了磁场如何与对流运动和对流驱动的带状流相互作用。我们的模拟结果表明,磁场往往会破坏金属氢中的纵向流动,抑制分子包络中的横向流动,而磁场可能会增强径向对流运动。我们通过模拟提取了磁场强度与表面带状流振幅之间的定量关系,这与木星和土星的观测磁场和带状风速基本吻合。这一发现从一个新的角度为仅限于巨行星分子氢层的深对流驱动带状风的设想提供了支持。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Numerical Simulations of Magnetic Effects on Zonal Flows in Giant Planets
Jupiter and Saturn exhibit alternating east-west jet streams as seen from surface. The origin of these zonal flows has been debated for decades. The high-precision gravity measurements by Juno mission and the grand finale of Cassini mission have revealed that the zonal flows observed at the surface may extend several thousand kilometres deep and stop around the transition region from molecular to metallic hydrogen, suggesting the magnetic braking effect on zonal flows. In this study, we perform a set of magnetohydrodynamic simulations in a spherical shell with radially variable electrical conductivity to investigate the interaction between magnetic fields and zonal flows. A key feature of our numerical models is that we impose a background dipole magnetic field on the anelastic rotating convection. By varying the strength of the imposed magnetic field and the vigor of convection, we investigate how the magnetic field interacts with the convective motions and the convection-driven zonal flows. Our simulations reveal that the magnetic field tends to destroy zonal flows in the metallic hydrogen and suppress zonal flows in the molecular envelope, while the magnetic field may enhance the radial convective motions. We extract a quantitative relation between the magnetic field strength and the amplitude of zonal flows at the surface through our simulations, which roughly matches the observed magnetic field and zonal wind speed of Jupiter and Saturn. This discovery provides support from a new perspective for the scenario of deep convection-driven zonal winds which are confined to the molecular hydrogen layers in giant planets.
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信