World Magnetic Model 2025 Released | News

The latest version of the World Magnetic Model (WMM), one of the key tools developed to model the change in the Earth’s magnetic field, has been released. The WMM is a spherical harmonic model of the Earth’s main magnetic field and its slow temporal change. WMM is key to global navigation and ensures that technological systems that rely on the Earth’s magnetic field function properly.

The World Magnetic Model 2025 (WMM2025) provides more accurate navigation data for all military and civilian aircraft, ships, submarines and GPS devices. This year, two versions of the model will be released. In addition to WMM2025, the release includes the first ever World Magnetic Model High Resolution (WMMHR2025), which includes an improved spatial resolution of approximately 300 kilometers at the equator compared to the standard spatial resolution of 3300 kilometers at the equator. Higher resolution provides greater directional accuracy. Users are encouraged to upgrade to this higher resolution model.

The blackout zones introduced in the previous version have been updated in WMM2025 to represent small shifts in their location. These zones, near the North and South Poles, indicate where the Earth’s magnetic field may be useless for navigation.

Model Cooperation

Because the WMM is critical to accurate navigation and the Earth’s magnetic field changes in unpredictable ways over time, especially over periods longer than a few years, the WMM is updated at least every five years. Compasses are affected by the Earth’s magnetic field, so having an up-to-date model ensures that navigational instruments give correct readings.

WMM is the standard model used by the United Kingdom and United States governments, including the US Federal Aviation Administration and the US Department of Defense, as well as organizations with an international remit, such as the North Atlantic Treaty Organization (NATO), and the International Hydrographic Organization and the UK Hydrographic Office . Smartphone and consumer electronics companies also rely on WMM to provide consumers with accurate compass apps, maps and GPS services.

Developed jointly by the NOAA National Centers for Environmental Information (NCEI) and the British Geological Survey (BGS), WMM is a joint product of the United States’ National Geospatial-Intelligence Agency (NGA) and the United Kingdom’s Defense Geographic Center (DGC). The model, associated software and documentation are distributed by NCEI on behalf of NGA and by BGS on behalf of DGC.

NCEI and WMM

NCEI, with support from the Cooperative Institute for Research in Environmental Sciences (CIRES), plays a critical role in the development, maintenance and distribution of WMM.

NCEI develops and distributes models of the geomagnetic field and maintains archives of geomagnetic data to advance the understanding of Earth’s magnetism and its dynamic changes. NCEI also provides tools and services to visualize, access, and use WMM and other geomagnetic data products and models.

NCEI collaborates with partners to conduct research to better understand the Earth’s magnetic field, its variations, and its potential impact on Earth and its technologies. This research helps improve the accuracy of the WMM and contributes to the scientific community’s broader understanding of the Earth’s magnetic field and its various sources, from the core to electrical currents in the near-Earth environment.

NCEI also participates in international initiatives, such as the International Association of Geomagnetism and Aeronomy (IAGA), to ensure that the WMM reflects a global and collaborative approach to understanding and predicting changes in the Earth’s magnetic field.

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