On February 4, 2019 an updated World Magnetic Model will be rolled out. Jointly developed by NOAA’s National Centers for Environmental Information (NCEI) and the British Geological Survey, the World Magnetic Model (WMM) describes the seven components of the Earth’s magnetic field.
The WMM provides a five-year forecast of the magnetic field. It was last updated in 2015 and was scheduled to be next updated in 2020. The 2018 annual check by NOAA and the British Geological Survey to measure the WMM predictions against the actual state of the Earth’s magnetic field produced errors outside of the acceptable range . Two issues are creating the need to update the WMM to be more accurate. The Earth’s magnetic field is mostly generated by liquid churning within the core of the planet. First, a geomagnetic pulse beneath South America in 2016 create a lurch in the magnetic field not anticipated by planners. Second, an acceleration in the movement of the Earth’s magnetic North Pole, which is shifting from Canada to Siberia, created an urgent need for a faster update of the model. Since the mid-1990s, the pace of the shift has increased from 15 kilometers per year to around 55 kilometers per year.
An accurate WMM is a necessity for all modern navigation from onboard ship navigation to smartphone apps. NCEI notes that the “World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO) and the International Hydrographic Organization (IHO), for navigation, attitude and heading referencing systems using the geomagnetic field. It is also used widely in civilian navigation and heading systems.” The 2019 update to the WMM was developed using three years of recent data, including the 2016 geomagnetic pulse. This update will carry the WMM until the 2020 regular update. On February 4, 2019 a comprehensive rollout of “updated online calculator, software, maps and technical note” will be released.
Witze, A. (2019). Earth’s magnetic field is acting up and geologists don’t know why. Nature, 565, 143-144.