2013 Fiscal Year Final Research Report
Influence of core-mantle boundary heat flows on the present and ancient dynamos of terrestrial planets
| Project/Area Number |
24840017
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| Research Category |
Grant-in-Aid for Research Activity Start-up
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| Allocation Type | Single-year Grants |
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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 |
HORI Kumiko 東京大学, 地震研究所, 特任研究員 (30636858)
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| Research Collaborator |
WICHT Johannes マックスプランク太陽系科学研究所, 上級研究員
DIETRICH Wieland マックスプランク太陽系科学研究所, 大学院生
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| Project Period (FY) |
2012-08-31 – 2014-03-31
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| Keywords | 地球ダイナモ / 火星ダイナモ / 内核成長 / 永年冷却 / コア・マントル相互作用 / 古地磁気学 / 国際情報交換 |
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| Research Abstract |
I performed numerical experiments of self-consistent magnetohydrodynamic dynamos and magnetoconvection in rotating spherical shells. The implications are: (1) when solid inner cores did not start to grow, such as the ancient Earth and Mars, a smaller lateral heat-flux variation at the core-mantle boundaries (CMB) leads to boundary-induced structures and different field strengths. (2) The effect is much smaller for dynamos with an inner core being growing, e.g. the present Earth's core, and the impacts on the lateral variations at the inner core boundary (ICB) cannot be as large as a former study proposed. (3) The lateral phase relationship between CMB and ICB heterogeneities varies on the strengths of a background magnetic field and buoyancy. However, it becomes identical as convection is sufficiently vigorous, like in the present Earth's core.
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