Three-Dimensional Unstructured Magnetization Vector Inversion and Modeling of Planetary Equivalent Toroidal Currents for Earth’s Magnetic Field Analysis

Abstract

This study introduces a pioneering methodology for modeling the Earth’s geomagnetic field, departing from traditional reliance on current loops by employing a three-dimensional (3-D) geometric equivalent toroidal current source. We propose a 3-D unstructured magnetization vector inversion method aimed at inverting the geomagnetic vector field data set to construct an equivalent magnetization source. Subsequently, this constructed source is utilized to solve for the distribution of equivalent toroidal currents. Our objective is to elucidate and analyze potential distributions of toroidal currents within the core space. Diverging from conventional practices that estimate only seven parameters for a current loop, our research undertakes the inversion of millions of current parameters across the entire 3-D core space. This strategy eliminates the need for presuppositions regarding the current’s positions or its topological characteristics, significantly enhancing our capability to depict the possible geometry of toroidal currents. These advancements show considerable promise for modeling the geomagnetic field with high precision, transforming complex equivalent sources into more comprehensible forms, and offering profound implications for our understanding of Earth’s magnetic environment.