Probing the Earth's subdecadal core-mantle dynamics based on satellite geomagnetic field models
Final Report Abstract
From the recent magnetic field model C3 FM2 for 1957.0 to 2008.0, we have derived a number of core flow models while changing the inversion setting systematically, in an effort to assess the subsequent estimations of the core angular momentum (CAM) variation. These estimations are examined simply in the time domain. We have drawn some insights with regard to the specific features of CAM variation, the trend over the half century and the 6-year variation, as described below. • Magnetically estimate CAM trends are consistent with the observed LOD trend, when they are calculated from core surface flow models that are either large-scale and tangentially magnetostrophic, or intermediate-scale and tangentially geostrophic. • The above flow models correspond to the dynamo regimes discovered by previous numerical simulations. No clue to distinguish the two regimes from LOD observation has yet to be obtained. • The 6-year CAM variation is not detected robustly using C3 FM2 magnetic field model. Its phase is, however, relatively well determined by the large-scale field components.
Publications
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On magnetic estimation of Earth’s core angular momentum variation, AOGS 11th Annual Meeting, July 2014, Sapporo, Japan
Asari, S., Wardinski, I.
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On magnetic estimation of Earth’s core angular momentum variation, EGU General Assembly, April 2014, Vienna, Austria
Asari, S., Wardinski, I.
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On magnetic estimation of Earth’s core angular momentum variation, SPP1488 “PlanetMag” 4th Meeting, January 2014, Potsdam, Germany
Asari, S., Wardinski, I.
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On magnetic estimation of Earth’s core angular momentum variation. Journal of Geophysical Research: Solid Earth 120 (10), 6740-6757, 2015
Asari, S., Wardinski, I.
