Published February 18, 2021 | Version v1
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GEOMAGNETIC FIELD CHARACTERISTICS REVEALED BY EMPIRICAL ORTHOGONAL FUNCTIONS

Authors/Creators

  • 1. "Sabba S. Ştefănescu" Institute of Geodynamics of the Romanian Academy, 19–21, Jean-Louis Calderon St., 020032 Bucharest, Romania, cristiana_stefan@geodin.ro

Description

Using COV-OBS.x1 (Gillet et al., 2015) main geomagnetic field model, covering the time span 1840–2020, we decomposed the geomagnetic field at Earth’s surface, namely the vertical and horizontal components, in oscillation modes at various timescales by means of empirical orthogonal functions (EOF). The EOF analysis shows that the first three oscillation modes of both components are characterized by periodicities of >100 years while modes 4 and 5 are characterized by dominant periodicities of 60–90 years. The first three EOF modes are responsible for more than 90% of the observed features of the vertical and horizontal components at Earth’s surface.

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