This web site is a copy of the NOAA IGRF web site
International Geomagnetic Reference Field (IGRF)
The International Geomagnetic Reference Field (IGRF) is a standard mathematical description of the Earth's main magnetic field. It is used widely in studies of the Earth's deep interior, crust, ionosphere, and magnetosphere. While this web page is officially hosted at NOAA/NCEI, the model itself is developed and maintained by the IAGA.
Data Access
14th Generation Release
The coefficients for the 14th generation of IGRF model were finalized by an IAGA task force in November 2024. The IGRF is the product of a collaborative effort between magnetic field modelers and the institutes involved in collecting and disseminating magnetic field data collected from satellites, observatories, and surveys around the world. Please review the Model Health Warning before using the IGRF.
Citation
International Geomagnetic Reference Field: the 13th generation, Alken, P., Thébault, E., Beggan, C.D. et al. International Geomagnetic Reference Field: the thirteenth generation. Earth Planets Space 73, 49 (2021). doi: 10.1186/s40623-020-01288-x
Access Methods
Data, Programs, and Software
NCEI provides access to IGRF 14 coefficients, as well as programs with the coefficients integrated into the source code.
-
Coefficients: Text File | Spreadsheet
-
Geomag 7.0 Software: Windows | IGRF14_Windows.COF Linux Tar File | IGRF14_Linux.COF
-
Python 3.7 Package
-
Fortran Program (provided by the British Geological Survey)
-
GitHub repository with Python code and Gauss coefficients from the IGRF candidate evaluation (maintained by the V-MOD working group)
IGRF 14 Calculators
NCEI and the British Geological Survey (BGS) created calculators to compute values for the geomagnetic field and secular variation for specific dates and coordinates.
Geomag 7.0 License and Copyright Information
The software code is in the public domain and not licensed or under copyright. The information and software may be used freely by the public. As required by 17 U.S.C. 403, third parties producing copyrighted works consisting predominantly of the material produced by U.S. government agencies must provide notice with such work(s) identifying the U.S. Government material incorporated and stating that such material is not subject to copyright protection.
Older Versions
| Model | Main Field | Secular Variation | Release Year |
|---|---|---|---|
| IGRF-1 | 1965.0 | 1975.0–1980.0 | 1965 |
| IGRF-2 | 1965.0–1975.0 | 1980.0–1985.0 | 1975 |
| IGRF-3 | 1965.0–1980.0 | 1980.0–1985.0 | 1980 |
| IGRF-4 | 1945.0–1985.0 | 1985.0–1990.0 | 1985 |
| IGRF-5 | 1945.0–1985.0 | 1985.0–1990.0 | 1987 |
| IGRF-6 | 1945.0–1990.0 | 1990.0–1995.0 | 1991 |
| IGRF-7 | 1900.0–1995.0 | 1995.0–2000.0 | 1995 |
| IGRF-8 | 1900.0–2000.0 | 2000.0–2005.0 | 2000 |
| IGRF-9 | 1900.0–2000.0 | 2000.0–2005.0 | 2003 |
| IGRF-10 | 1900.0–2005.0 | 2005.0–2010.0 | 2005 |
| IGRF-11 | 1900.0–2010.0 | 2010.0–2015.0 | 2010 |
| IGRF-12 | 1900.0–2015.0 | 2015.0–2020.0 | 2015 |
| IGRF-13 | 1900.0–2020.0 | 2020.0–2025.0 | 2020 |