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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:01 |
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Conference: Bucharest University Faculty of Physics 2012 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Evolution and characteristics of high-frequency ingredients of the geomagnetic field at core surface
Authors:
Cristiana STEFAN, Venera DOBRICA, C. DEMETRESCU
Affiliation:
Institute of Geodynamics, Romanian Academy, Bucharest, Romania
E-mail
cristiana_stefan@geodin.ro
Keywords:
secular variation, ~80-year variation at the core-mantle boundary
Abstract:
The aim of the paper is to analyze the evolution and characteristics of the ~80-year variation of the radial component of the Earth’s magnetic field at the core surface. The long-term changes of the main field, the so-called secular variation, are related to the processes occurring in the fluid outer core of the Earth. Therefore, the knowledge of the secular variation is important in understanding these processes. The presence of high-frequency ingredients of the secular variation in the radial component of the Earth’s magnetic field, at time scales of 22 and ~80-year, was demonstrated in case of the gufm1 (Jackson et. al, 2003) main geomagnetic field model for the core-mantle boundary. The main characteristics of these ingredients are discussed. In addition, the secular acceleration is analyzed. Time-longitude and time-latitude plots, constructed to better understand the movement of the features of the ~80-year variation on the surface of the core, showed a westward displacement in the equatorial region of the core surface of about 0.27 deg/yr.
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