Studies of effects of rotational speed change on core convection and geodynamo

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740311
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: MIYAGOSHI Takehiro 独立行政法人海洋研究開発機構, 地球深部ダイナミクス研究分野, 主任研究員 (60435807)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 地球ダイナモ / 地球回転変動 / 地磁気変動 / 数値シミュレーション

Outline of Final Research Achievements

We performed numerical geodynamo simulations including rotational speed variation associated with climatic changes with ice and non-ice ages, and studied the effect of rotational speed variation on the core convection and geodynamo. We focused on the variation of about twenty thousand years (which is the magnetic diffusion time and nearly equal to one of the Milankovitch cycle). The magnetic field variation is caused by it, and we also found the process of the magnetic field variation. The Joule heating is important for the magnetic field variation. Also we found that the heat flux at the core-mantle boundary changes by rotational speed variation.

Free Research Field

地球内部ダイナミクス