Magneto-hydrodynamic interaction between planetary inner and outer cores

• Project/Area Number: 25610139
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Kyoto University
• Principal Investigator: Takehiro Shin-ichi 京都大学, 数理解析研究所, 准教授 (30274426)
• Co-Investigator(Kenkyū-buntansha): YAMADA MICHIO 京都大学, 数理解析研究所, 教授 (90166736)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2013: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
• Keywords: 内核外核境界 / 相変化 / ジュール熱 / ダイナモ過程 / 核マントル境界 / 安定成層 / アルフベン波 / 貫入距離 / ダイナモ作用 / 内核外核相互作用 / 地球磁場 / 地球内核外核境界 / 表面変位

Outline of Final Research Achievements

In order to elucidate fundamental characteristics of fluid motion in
planetary cores, magneto-hydrodynamic interaction between planetary inner and outer cores is investigated theoretically and numerically. First, inner core flows induced by Joule heating of the magnetic field penetrating from the outer core are obtained analytically and numerically. Second, penetration of fluid motions into the upper stably stratified layer near the top of the outer core is examined and the analytical expressions of penetration distance are derived. These expressions are validated by numerical calculations of magneto-hydrodynamic thermal convection in a rotating spherical shell. Finally, numerical experiments of the whole planetary central cores with a coupled inner-outer cores magneto-hydrodynamic fluid model are performed. It is shown that the inner core flows with upward and downward in the equatorial and polar regions respectively emerge.

Research Products

• [Journal Article] Bifurcation structure of two-dimensional viscous zonal flows on a rotating sphere (2015)
  • Author(s): Eiichi Sasaki, Shin-ichi Takehiro and Michio Yamada
  • Journal Title: Journal of Fluid Mechanics Volume: 774 Pages: 224-244
  • DOI: 10.1017/jfm.2015.262
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Regeneration cycle and the covariant Lyapunov vectors in a minimal wall turbulence (2015)
  • Author(s): Masanobu Inubushi, Shin-ichi Takehiro, and Michio Yamada
  • Journal Title: Physical Review E Volume: 92 Issue: 2 Pages: 023022-023022
  • DOI: 10.1103/physreve.92.023022
  • NAID: 120005672620
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Reconstruction of chaotic saddles by classification of unstable periodic orbits: Kuramoto-Sivashinsky equation (2015)
  • Author(s): Yoshitaka Saiki, Michio Yamada, Abraham C.-L. Chian, Rodrigo A. Miranda and Erico L. Rempel
  • Journal Title: Chaos Volume: 25 Issue: 10 Pages: 103123-103123
  • DOI: 10.1063/1.4933267
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Influence of surface displacement on solid state flow induced by horizontally heterogeneous Joule heating in the inner core of the Earth. (2015)
  • Author(s): S.Takehiro
  • Journal Title: Physics of The Earth and Planetary Interiors Volume: 241 Pages: 15-20
  • DOI: 10.1016/j.pepi.2015.02.003
  • NAID: 120005575265
  • Peer Reviewed / Open Access
• [Journal Article] Penetration of Alfven waves into an upper stably-stratified layer excited by magnetoconvection in rotating spherical shells. (2015)
  • Author(s): S.Takehiro
  • Journal Title: Physics of The Earth and Planetary Interiors Volume: 241 Pages: 37-43
  • DOI: 10.1016/j.pepi.2015.02.005
  • Peer Reviewed / Open Access
• [Journal Article] Waves and linear stability of magnetoconvection in a rotating cylindrical annulus (2014)
  • Author(s): Hori, K., Takehiro, S., and Shimizu, H.
  • Journal Title: Physics of the Earth and Planetary Interiors Volume: 236 Pages: 16-35
  • DOI: 10.1016/j.pepi.2014.07.010
  • Peer Reviewed
• [Journal Article] A spherical shell numerical dynamo benchmark with pseudo-vacuum magnetic boundary conditions (2014)
  • Author(s): Jackson, A., Sheyko,A., Marti, P., Tilgner, A., Cebron, D., Vantieghem, S., Simitev, R., Busse, F., Zhan, X., Schubert, G., Takehiro, S., Sasaki, Y., Hayashi, Y.-Y., Ribeiro, A., Nore, C., Guermond, J.-L.
  • Journal Title: Geophysical Journal International Volume: 196 Issue: 2 Pages: 712-723
  • DOI: 10.1093/gji/ggt425
  • Peer Reviewed
• [Journal Article] Full sphere hydrodynamic and dynamo benchmarks (2014)
  • Author(s): Marti, P., Schaeffer, N., Hollerbach, R., Cebron, D., Nore, C., Luddens, F., Guermond, J.-L., Aubert, J., Takehiro, S., Sasaki, Y., Hayashi, Y.-Y., Simitev, R., Busse, F., Vantieghem, S., Jackson, A.
  • Journal Title: Geophysical Journal International Volume: 197 Issue: 1 Pages: 119-134
  • DOI: 10.1093/gji/ggt518
  • Peer Reviewed
• [Journal Article] Effects of latitudinally heterogeneous buoyancy flux conditions at the inner boundary on MHD dynamo in a rotating spherical shell (2013)
  • Author(s): Sasaki, Y., Takehiro, S., Nishizawa, S., Hayashi, Y.-Y.
  • Journal Title: Phys. Earth Planet. Inter. Volume: 223 Pages: 55-61
  • DOI: 10.1016/j.pepi.2013.07.003
  • Peer Reviewed
• [Journal Article] Stability and bifurcation diagram of Boussinesq thermal convection in a moderately rotating spherical shell allowing rotation of the inner sphere (2013)
  • Author(s): Kimura, K., Takehiro, S., Yamada, M.
  • Journal Title: Phys. Fluids Volume: 25 Issue: 8
  • DOI: 10.1063/1.4819140
  • Peer Reviewed
• [Presentation] 2D Navier-Stokes equations on a sphere (2016)
  • Author(s): Yamada, M.
  • Organizer: Naruto Workshop on Vortex Dynamics
  • Place of Presentation: Hotel Ad Inn Naruto
  • Year and Date: 2016-01-16
  • Int'l Joint Research / Invited
• [Presentation] 微生物の運動と帆立貝定理 (2015)
  • Author(s): 山田道夫
  • Organizer: 数学協働プログラム「生命ダイナミクスの数理とその応用：理論からのさらなる深化」
  • Place of Presentation: 東京大学大学院数理科学研究科大講義室
  • Year and Date: 2015-12-10
  • Invited
• [Presentation] 球面上の 2 次元 Navier-Stokes 流 (2015)
  • Author(s): 山田道夫
  • Organizer: 共共拠点研究会 RIMS1963-IMI2013
  • Place of Presentation: 九州大学マス・フォア・インダストリ研究所
  • Year and Date: 2015-12-07
  • Invited
• [Presentation] Penetration of steady fluid motions into an outer stable layer excited by MHD thermal convection in a rotating spherical shell (2015)
  • Author(s): Takehiro, S., Sasaki, Y.
  • Organizer: Japan SEDI symposium 2015
  • Place of Presentation: 東京大学地震研究所
  • Year and Date: 2015-09-25
  • Int'l Joint Research / Invited
• [Presentation] Penetration of magneto-hydrodynamic disturbances into a strongly stable outer layer caused by MHD dynamo in a rotating spherical shell (2015)
  • Author(s): Sasaki, Y., Takehiro, S.
  • Organizer: Japan SEDI symposium 2015
  • Place of Presentation: 東京大学地震研究所
  • Year and Date: 2015-09-25
  • Int'l Joint Research
• [Presentation] On extremum statistics in dynamical systems and two dimensional flows (2015)
  • Author(s): Takehiro, S., Yamada, M.
  • Organizer: 8th International Congress on Industrial and Applied Mathematics(ICAIAM)
  • Place of Presentation: Beijing
  • Year and Date: 2015-08-11
  • Int'l Joint Research
• [Presentation] Stability of one-directional flow on a rotating sphere (2015)
  • Author(s): M.Yamada
  • Organizer: ICIAM2014
  • Place of Presentation: Beijing
  • Year and Date: 2015-08-11
  • Int'l Joint Research / Invited
• [Presentation] ジュール加熱により引き起こされる地球内核中の流れについて (2015)
  • Author(s): 竹広真一
  • Organizer: 日本地球惑星科学連合 2015 年大会
  • Place of Presentation: 幕張メッセ国際会議場
  • Year and Date: 2015-05-27
• [Presentation] ２次元流の渦力学と帯状流 (2015)
  • Author(s): 山田道夫
  • Organizer: 研究会「渦を知る」
  • Place of Presentation: 京都大学数理解析研究所
  • Year and Date: 2015-04-17
  • Invited
• [Presentation] 上層に安定成層を伴う回転球殻中の磁気対流により引き起こされるアル フベン波 (2014)
  • Author(s): 竹広 真一
  • Organizer: 2014 年日本流体力学会年会
  • Place of Presentation: 東北大学川内北キャンパス
  • Year and Date: 2014-09-16
• [Presentation] Influence of surface displacement on fluid motions induced by horizontally heterogeneous Joule heating in the inner core of the earth (2014)
  • Author(s): Takehiro, S.
  • Organizer: The 14th symposium of SEDI
  • Place of Presentation: 湘南国際村センター
  • Year and Date: 2014-08-03 – 2014-08-08
• [Presentation] Propagation of Alfven waves in an outer stably stratified layer excited by MHD thermal convection in a rapidly rotating spherical shell (2014)
  • Author(s): Takehiro, S.
  • Organizer: The 14th symposium of SEDI
  • Place of Presentation: 湘南国際村センター
  • Year and Date: 2014-08-03 – 2014-08-08
• [Presentation] Penetration of magneto-hydrodynamic disturbances into an outer strongly stable layer caused by MHD dynamo in a rotating spherical shell (2014)
  • Author(s): Sasaki, Y., Takehiro, S.
  • Organizer: The 14th symposium of SEDI
  • Place of Presentation: 湘南国際村センター
  • Year and Date: 2014-08-03 – 2014-08-08
• [Presentation] ジュール加熱により引き起こされる地球内核中の流れに対する表面変位の影響 (2014)
  • Author(s): 竹広 真一
  • Organizer: 日本地球惑星科学連合 2014 年大会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-04-30
• [Presentation] 回転円筒内の磁気対流の線形安定性と波動 (2014)
  • Author(s): 堀 久美子, 竹広 真一, 清水 久芳
  • Organizer: 日本地球惑星科学連合 2014 年大会
  • Place of Presentation: パシフィコ横浜
  • Year and Date: 2014-04-28
• [Presentation] Influence of surface displacement on fluid motions induced by horizontally heterogeneous Joule heating in the inner core of the earth
  • Author(s): 竹広真一
  • Organizer: pre-SEDI 2013
  • Place of Presentation: 湘南国際村センター
  • Invited