{"title":"用旋转对流实验探索行星内部七十年","authors":"Alban Pothérat, Susanne Horn","doi":"arxiv-2409.05220","DOIUrl":null,"url":null,"abstract":"The interiors of many planets consist mostly of fluid layers. When these\nlayers are subject to superadiabatic temperature or compositional gradients,\nturbulent convection transports heat and momentum. In addition, planets are\nfast rotators. Thus, the key process that underpins planetary evolution, the\ndynamo action, flow patterns and more, is rotating convection. Because\nplanetary interiors are inaccessible to direct observation, experiments offer\nphysically consistent models that are crucial to guide our understanding. If we\ncan fully understand the laboratory model, we may eventually fully understand\nthe original. Experimentally reproducing rotating thermal convection relevant\nto planetary interiors comes with specific challenges, e.g. modelling the\ncentral gravity field of a planet that is parallel to the temperature gradient.\nThree classes of experiments tackle this challenge. One approach consists of\nusing an alternative central force field, such as the electric force. These\nare, however, weaker than gravity and require going to space. Another method\nentails rotating the device fast enough so that the centrifugal force\nsupersedes Earth's gravity. This mimics the equatorial regions of a planet.\nLastly, by using the actual lab gravity aligned with the rotation axis, insight\ninto the polar regions is gained. These experiments have been continuously\nrefined during the past seven decades. We review their evolution, from the\nearly days of visualising the onset patterns of convection, over central force\nfield experiments in spacecrafts, liquid metal experiments, to the latest\noptical velocity mapping of rotating magnetoconvection in sulfuric acid inside\nhigh-field magnets. We show how innovative experimental design and emerging\nexperimental techniques advanced our understanding and painted a more realistic\npicture of planetary interiors, including Earth's liquid metal outer core.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"15 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Seven decades of exploring planetary interiors with rotating convection experiments\",\"authors\":\"Alban Pothérat, Susanne Horn\",\"doi\":\"arxiv-2409.05220\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The interiors of many planets consist mostly of fluid layers. When these\\nlayers are subject to superadiabatic temperature or compositional gradients,\\nturbulent convection transports heat and momentum. In addition, planets are\\nfast rotators. Thus, the key process that underpins planetary evolution, the\\ndynamo action, flow patterns and more, is rotating convection. Because\\nplanetary interiors are inaccessible to direct observation, experiments offer\\nphysically consistent models that are crucial to guide our understanding. If we\\ncan fully understand the laboratory model, we may eventually fully understand\\nthe original. Experimentally reproducing rotating thermal convection relevant\\nto planetary interiors comes with specific challenges, e.g. modelling the\\ncentral gravity field of a planet that is parallel to the temperature gradient.\\nThree classes of experiments tackle this challenge. One approach consists of\\nusing an alternative central force field, such as the electric force. These\\nare, however, weaker than gravity and require going to space. Another method\\nentails rotating the device fast enough so that the centrifugal force\\nsupersedes Earth's gravity. This mimics the equatorial regions of a planet.\\nLastly, by using the actual lab gravity aligned with the rotation axis, insight\\ninto the polar regions is gained. These experiments have been continuously\\nrefined during the past seven decades. We review their evolution, from the\\nearly days of visualising the onset patterns of convection, over central force\\nfield experiments in spacecrafts, liquid metal experiments, to the latest\\noptical velocity mapping of rotating magnetoconvection in sulfuric acid inside\\nhigh-field magnets. We show how innovative experimental design and emerging\\nexperimental techniques advanced our understanding and painted a more realistic\\npicture of planetary interiors, including Earth's liquid metal outer core.\",\"PeriodicalId\":501270,\"journal\":{\"name\":\"arXiv - PHYS - Geophysics\",\"volume\":\"15 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Geophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.05220\",\"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 - Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.05220","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Seven decades of exploring planetary interiors with rotating convection experiments
The interiors of many planets consist mostly of fluid layers. When these
layers are subject to superadiabatic temperature or compositional gradients,
turbulent convection transports heat and momentum. In addition, planets are
fast rotators. Thus, the key process that underpins planetary evolution, the
dynamo action, flow patterns and more, is rotating convection. Because
planetary interiors are inaccessible to direct observation, experiments offer
physically consistent models that are crucial to guide our understanding. If we
can fully understand the laboratory model, we may eventually fully understand
the original. Experimentally reproducing rotating thermal convection relevant
to planetary interiors comes with specific challenges, e.g. modelling the
central gravity field of a planet that is parallel to the temperature gradient.
Three classes of experiments tackle this challenge. One approach consists of
using an alternative central force field, such as the electric force. These
are, however, weaker than gravity and require going to space. Another method
entails rotating the device fast enough so that the centrifugal force
supersedes Earth's gravity. This mimics the equatorial regions of a planet.
Lastly, by using the actual lab gravity aligned with the rotation axis, insight
into the polar regions is gained. These experiments have been continuously
refined during the past seven decades. We review their evolution, from the
early days of visualising the onset patterns of convection, over central force
field experiments in spacecrafts, liquid metal experiments, to the latest
optical velocity mapping of rotating magnetoconvection in sulfuric acid inside
high-field magnets. We show how innovative experimental design and emerging
experimental techniques advanced our understanding and painted a more realistic
picture of planetary interiors, including Earth's liquid metal outer core.