Magnetic Field Dynamics in MAAX Satellite's Circular Polar Orbit: A Magnetic Model Comparison

Abstract

Motivated by the unique high-altitude polar orbit of the NASA Magnetosphere Auroral Asymmetry eXplorer (MAAX) mission and its Magnetometer Array Distributed on MAAX (MADMAAX), we examine the high-altitude magnetic field environment and its response to solar wind conditions. Using a data set from the Polar satellite magnetometer, we investigate the variations in the external magnetic field along its highly elliptical orbit. To obtain the external magnetic field, we subtract the internal field, estimated using the IGRF-95 model, from the observed data. Additionally, we compare the Polar observations with four empirical magnetospheric magnetic field models (T89, T96, T01, and T04) along the satellite's orbit. Our comparison of the observed external magnetic field with the modeled fields finds that the T01 model provides the most accurate predictions, even near the satellite's perigee, outperforming the other models (T89, T96, T04) for the data set used. To extend our findings, we simulate an artificial circular polar orbit with a radius of 7 RE, matching the proposed MAAX mission trajectory, and calculate the magnetic field distribution along this orbit using the T01 model. The results demonstrate that the T01 model reliably approximates the magnetic field for such a high-altitude circular polar orbit, highlighting its utility for future mission planning. Our findings provide valuable insights into the dependence of the external magnetic field on solar wind conditions, offering a better understanding of geomagnetic variations in the high-altitude regions and supporting the design and data interpretation of future missions like MAAX.