| Project/Area Number |
23740334
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SAKURABA Ataru 東京大学, 理学(系)研究科(研究院), 助教 (50345261)
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| Project Period (FY) |
2011 – 2012
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| Project Status |
Completed (Fiscal Year 2013)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2012: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2011: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 地磁気永年変化 / 地球ダイナモ / 西方移動 / ジャーク / ねじれ振動 / 数値シミュレーション / 磁気不安定 / 地磁気西方移動 / 磁気流体波動 / 電磁流体力学 / 地磁気ジャーク / 地球電磁気 / 流体力学 / 地球磁場 |
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| Research Abstract |
I performed numerical simulations of convection and geomagnetic field generation processes in Earth's liquid metallic core to reproduce several characteristic geomagnetic secular variations. The numerical result exhibits torsional oscillations that are composed of traveling waves toward and out of the Earth's rotation axis, suggesting that they are created by turbulence in internal core convection. The result also shows clear westward drift in the core-surface magnetic field particularly in high-wavenumber components and in the low latitudes, and I pointed out existence of dispersion in the westward drift. In order to figure out this dispersion property, I conducted linear stability analysis of axisymmetric magnetic field in an inviscid rotating fluid sphere, and discussed possible relations between westward propagation of slow hydromagnetic wave and the geomagnetic westward drift.
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