MISTA candidate magnetic field models for IGRF-14 derived from MSS-1, Swarm and observatory data

Abstract The International Geomagnetic Reference Field (IGRF) is a spherical harmonic model representing the large-scale Earth’s main magnetic field and its secular variation (SV). In 2024, the International Association of Geomagnetism and Aeronomy (IAGA) V-MOD Working Group called for candidate models for the 14th generation of IGRF (IGRF-14). Inspired by successful launch of the Macau Science Satellite-1 (MSS-1) on May 21, 2023, Macau Institute of Space Technology and Application (MISTA) and the MSS-1 team submitted three candidate models based on newly acquired magnetic data: a main field model for epoch 2020.0, a main field model for epoch 2025.0, and an average SV model for the period 2025.0–2030.0. The 2020.0 model was contributed by Swarm satellite and ground observatory data, while the 2025.0 and SV models incorporated the latest magnetic data from MSS-1, Swarm and global observatories. This paper describes the construction and evaluation of these candidate models. The results of the evaluation show strong consistency between the MISTA candidate models and the officially released IGRF-14 models, confirming the reliability of our candidate models and the high quality of MSS-1 magnetic data. We also assess the unique contribution of MSS-1 data. Our discussion emphasizes the complementary value of combining observations from polar-orbiting satellites like Swarm with those from low-inclination missions like MSS-1 to improve the resolution of Earth’s magnetic field model. Graphical Abstract