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Futoshi Takahashi Last modified date:2019.06.12

Associate Professor / Dynamics, Structure and Evolution of Earth and Planets
Department of Earth and Planetary Sciences
Faculty of Sciences


Graduate School
Undergraduate School


E-Mail
Homepage
http://seis.geo.kyushu-u.ac.jp/
Deep Earth Physics Lab. .
Academic Degree
Dr of Science
Field of Specialization
Earth and planetary magnetism, Lunar and planetary exploration
Research
Research Interests
  • Numerical simulation of the geomagnetic field
    Ancient lunar core dynamo
    Lunar magnetic anomaly
    Planetary magnetic fields
    keyword : geomagnetic field, dynamo, planetary magnetic field, moon, planetary exploration
    2014.03.
Academic Activities
Papers
1. Futoshi Takahashi, Hisayoshi Shimizu, Hideo Tsunakawa, Mercury’s anomalous magnetic field caused by a symmetry-breaking self-regulating dynamo, Nature Communications, doi: 10.1038/s41467-018-08213-7, 10, 2019.01, 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..
2. Futoshi Takahashi, Testing a toroidal magnetic field imaging method at the core-mantle boundary using a numerical dynamo model, Earth, Planets and Space, 10.1186/s40623-014-0157-z, 66, 157, 2014.11.
3. Futoshi Takahashi, Hideo Tsunakawa, Hisayoshi Shimizu, Hidetoshi Shibuya, Masaki Matsushima, Reorientation of the early lunar pole, NATURE GEOSCIENCE, 10.1038/NGEO2150, 7, 6, 409-412, 2014.06, 月がかつて地球と同じようなコアのダイナモによる双極子型のグローバル磁場を持っていたかどうかは、月の起源や進化史を理解するうえで不可欠な情報である。本研究では周回衛星から得られた月地殻磁場のデータを解析することにより、月にかつてコアのダイナモによって双極子磁場が存在していたこと、そしてそれが逆転を起こしていたことを示し、更に、月が極移動を経験していたことを明らかにした。.
Presentations
1. Futoshi Takahashi, On the origin and evolution of the lunar core dynamo, SELENE Symposium, 2017.09.
2. F. Takahashi, Dynamos driven by double diffusive convection with a stably stratified layer and inhomogeneous core-mantle boundary heat flow, SEDI Symposium, 2016.07.
3. Futoshi Takahashi, Numerical dynamo simulations and magnetic field observations of the Earth, Moon and planets to infer core dynamics, 26th IUGG General Assembly, 2015.06.
4. Futoshi Takahashi, Hideo Tsunakawa, Hisayoshi Shimizu, Hidetoshi Shibuya, Masaki Matsushima, An ancient core dynamo and true polar wander on the early Moon deduced from the lunar magnetic anomalies, The 14th Symposium of Study of the Earth's Deep Interior, 2014.08.
5. Futoshi Takahashi, Double diffusive convection in the Earth’s core and the morphology of the geomagnetic field, The 14th Symposium of Study of the Earth's Deep Interior, 2014.08.
Membership in Academic Society
  • SGEPSS
  • JpGU
  • AGU
Awards
  • Study on the magnetic fields of the Earth and Moon.
Educational
Educational Activities
Classes of basic physics, mathematics and solid Earth science. Research guidance of undergraduate and graduate students.