Magnetic North Pole shift brings updates to World Magnetic Model 2025
The World Magnetic Model (WMM) 2025 was released by the NCEI and the BGS on Tuesday, December 17, 2024. The release forecasts changes in Earth’s magnetic field for the next 5 years as the magnetic north pole keeps moving faster leading to important improvements in global navigation systems.
A stereographic map showcasing the Arctic region's magnetic declination (D) for the World Magnetic Model 2025. The map highlights declination contours, the position of the north magnetic dip pole, and blackout zones with horizontal field strengths indicated. Image credit: NOAA/NCEI and CIRES
- The WMM2025 and WMMHR2025 provide improved accuracy with updated magnetic field predictions for 2025 to 2029.
- Enhanced spatial resolution in WMMHR2025 improves navigation reliability for military and civilian systems.
- Adjustments in magnetic blackout zones reflect changes near Earth’s poles, ensuring precise global navigation.
The updated WMM 2025 was officially released by the Environmental Information (NCEI) and British Geological Survey (BGS) this month. The model predicts Earth’s magnetic field shifts from 2025 to 2029, enabling accurate global navigation.
2 versions of the model are:
- WMM2025: Standard model with a spatial resolution of 3 300 km (2 050 miles) at the equator.
- WMMHR2025: A high-resolution model with an improved spatial resolution of approximately 300 km (186 miles), offering enhanced directional accuracy.
“We’re delighted to join with NOAA and BGS to publish WMM2025 and WMMHR2025, and we encourage users, where possible, to transition to the higher resolution model,” Mike Paniccia, a geodetic Earth scientist and the program manager for the World Magnetic Model (WMM) at the National Geospatial-Intelligence Agency (NGA), stated.
The updates also refine the “blackout zones” near the North and South poles, regions where the magnetic field becomes unreliable for navigation. The zones have been slightly adjusted to reflect the field’s latest changes.
Understanding the magnetic North Pole
The magnetic North Pole differs from the geographic North Pole, which remains fixed. The geographic North Pole marks the Earth’s rotational axis, while the magnetic North Pole is where the planet’s magnetic field lines converge perpendicularly into the ground.
The magnetic North Pole has been drifting at an accelerated pace, shifting tens of kilometers annually due to the motion of molten iron in Earth’s outer core. It has moved from the Canadian Arctic toward Siberia over recent years. The changes are a result of Earth’s magnetic field, which is asymmetrical and complex.
Why does Earth have magnetic field?
Earth’s magnetic field is generated in its outer core, a layer of liquid iron located 2 890 to 5 000 km (1 800 to 3 100 miles) beneath the surface. The movement of this electrically conductive iron through an existing weak magnetic field produces electric currents.
The currents generate a magnetic field creating a self-sustaining process known as the geodynamo.
“If you had a hot cannonball and you put it on the table, it would gradually cool. [The heat] would diffuse away and essentially go back to ambient. The same is true with the magnetic field. If you’re not sustaining it by these fluid motions, it will gradually decay away and disappear,” Bruce Buffett, a geophysicist at the University of California, Berkeley, explained.
This geodynamo has been active for billions of years, ensuring the planet retains its magnetic field.
Role of WMM
The WMM is a mathematical model predicting the difference between magnetic north and true north across the globe. It combines data from satellite missions like Swarm of the European Space Agency (ESA) and high-precision ground-based magnetometers.
The model supports navigation systems for aircraft, ships, and smartphones, ensuring their compasses remain accurate.
“Your smartphone or GPS system has a magnetometer, effectively a digital compass built into it. It measures the direction of the magnetic field where you are, and it enters your position into the World Magnetic Model software to tell it what the magnetic field should look like. And then, by comparing what I measured and what I should have got, you can work out which direction you’re facing,” William Brown, a geophysicist at BGS, explained the integration.
Scheduled updates and irregular changes
The WMM is updated every 5 years to maintain accuracy. The magnetic field’s chaotic nature makes predictions difficult, necessitating periodic revisions.
“Typically, about five years is when the accuracy of the model starts to get to the point where it’s not as good as we would like it. So we make a better prediction with five years more information to work from, and just update the prediction going forward,” William Brown noted.
An off-schedule update was issued in 2019 due to an unexpected acceleration in the northern magnetic field’s movement. Such deviations show the unpredictable behavior of the geodynamo.
Applications and global importance
The WMM serves as the navigational standard for organizations like the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO), the International Hydrographic Organization, etc.
Its civilian applications include airplane navigation systems, GPS devices, and smartphones. Millions of users depend on the WMM for accurate orientation, ensuring seamless global navigation.
Technical advances with WMMHR2025
The introduction of WMMHR2025 marks a leap in magnetic field modeling. Its higher resolution delivers improved directional accuracy, benefiting important operations like aviation, shipping, and military applications.
Enhanced precision also supports scientific research into Earth’s magnetic dynamics.
Scientific collaboration and research
The WMM is a collaborative product of the U.S. National Geospatial-Intelligence Agency (NGA) and the U.K.’s Defence Geographic Centre (DGC), jointly developed by NCEI and BGS. Research for the model incorporates international efforts to study geomagnetic changes.
NCEI, supported by the Cooperative Institute for Research in Environmental Sciences (CIRES), archives geomagnetic data and conducts research to understand Earth’s magnetic variations. The research improves model accuracy and expands scientific knowledge of geomagnetic phenomena.
The WMM 2025, including its high-resolution version, reflects advancements in predicting Earth’s magnetic field changes. The WMM ensures continued reliability for navigation systems by providing updated data and tools, enhancing both military and civilian applications. Scientists and users can adjust to changes in Earth’s magnetic field over the next 5 years with these updates.
References:
1 World Magnetic Model (WMM) – NCEI – Accessed on December 18, 2024
2 World Magnetic Model 2025 Released – NCEI – December 17, 2024
Rishika holds a Master’s in International Studies from Stella Maris College, Chennai, India, where she earned a gold medal, and an MCA from the University of Mysore, Karnataka, India. Previously, she served as a Research Assistant at the National Institute of Advanced Studies, Indian Institute of Science, Bengaluru, India. During her tenure, she contributed as a Junior Writer for Europe Monitor on the Global Politics website and as an Assistant Editor for The World This Week. Her work has also been published in The Hindu newspaper, showing her expertise in global affairs. Rishika is also a recipient of the Women Empowerment Award at the district level in Haryana, India, in 2022.
One question. Does the 2025 update have a latitude and a longitude for the two geomagnetic poles?
Yes, the WWM 2025 update provides the latitude and longitude for the geomagnetic poles.
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