Mercury’s anomalous magnetic field caused by a symmetry-breaking self-regulating dynamo

Futoshi Takahashi, Hisayoshi Shimizu, Hideo Tsunakawa

研究成果: ジャーナルへの寄稿記事

3 引用 (Scopus)

抄録

The discovery of Mercury’s unusually axisymmetric, anomalously axially offset dipolar magnetic field reveals a new regime of planetary magnetic fields. The cause of the offset dipole remains to be resolved, although some exotic models have been proposed. Deciphering why Mercury has such an anomalous field is crucial not only for understanding the internal dynamics, evolutionary history and origin of the planet, but also for establishing the general dynamo theory. Here we present numerical dynamo models, where core convection is driven as thermo-compositional, double-diffusive convection surrounded by a thermally stably stratified layer. We show that the present models produce magnetic fields similar in morphology and strength to that of Mercury. The dynamo-generated fields act on the flow to force interaction between equatorially symmetric and antisymmetric components that results in north-south asymmetric helicity. This symmetry-breaking magnetic feedback causes the flow to generate and maintain Mercury’s axially offset dipolar field.

元の言語英語
記事番号208
ジャーナルNature communications
10
発行部数1
DOI
出版物ステータス出版済み - 12 1 2019

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Magnetic Fields
broken symmetry
Convection
Magnetic fields
Mercury
convection
planetary magnetic fields
magnetic fields
dynamo theory
Planets
causes
strata
Numerical models
planets
History
histories
dipoles
Feedback
interactions

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

これを引用

Mercury’s anomalous magnetic field caused by a symmetry-breaking self-regulating dynamo. / Takahashi, Futoshi; Shimizu, Hisayoshi; Tsunakawa, Hideo.

:: Nature communications, 巻 10, 番号 1, 208, 01.12.2019.

研究成果: ジャーナルへの寄稿記事

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