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Geomagnetic Coordinate Calculator

Structural and dynamical features of the ionised and neutral upper atmosphere are strongly organised by the geomagnetic field, and several magnetic coordinate systems have been developed to describe this organisation. Here we provide a quasi-dipole geomagnetic coordinate calculator (Emmert et al, J. Geophys. Res., 2010) using coefficients for all spherical harmonic degrees (up to 13) of the 14th Generation International Geomagnetic Reference Field, and for comparison, a simple tilted dipole coordinate calculator using only the degree 1 coefficients of IGRF-14. Locations which have similar geomagnetic latitudes are likely to experience similar levels of magnetic disturbance. Local time and conductivity structures also influence magnetic disturbance levels.

These data are delivered under the Open Government Licence, subject to the following acknowledgement accompanying the reproduced BGS materials:

"Geomagnetic coordinates are determined using model calculations provided by British Geological Survey - Geomagnetism"

If you require further information, wish to report a problem, or have suggestions as to how we can improve our service, please contact BGS Enquiries.
km above surface (WGS84)
Range: 1900-2030
Click anywhere on map to show results

As this is based on a web service you can also obtain results in JSON format using an HTTP GET request. Fetch data here modifying the query string parameters as appropriate.

km above surface (WGS84)
Range: 1900 - 2030
Range: 1900 - 2030
Step size: 0.1 or greater
Decimal Degrees (> 0.01)
Decimal Degrees (> 0.01)
km above surface (WGS84)
Range: 1900 -2030

As this is based on a web service you can also obtain results in JSON format using an HTTP GET request. Fetch data here modifying the query string parameters as appropriate.

Learn More

The Earth's magnetic field is a vector quantity; at each point in space it has a strength and a direction. To completely describe it we need three quantities. These may be:

  • X, Y, and Z - three orthogonal strength components
  • F, D, and I - the total field strength and two angles
  • H, Z, and D - two strength components and an angle

The relationship between these 7 elements can be viewed at: INTERMAGNET

Secular variation (SV) is typically defined as the slow annual to decadal change of the Eath's magnetic field and is caused by the flow of liquid in the outer core, deep inside the Earth. The change of the field is not easily predictable due to the nature of the flow regime in the core and the mechanism by which the magnetic field is generated. However, an estimate of the instantaneous flow itself can be computed, if we make some assumptions about its nature and how it affects the magnetic field we observe at the surface. If we have a longer series of data we can compute the accelerated flow too.