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GeomagneticModelData
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GeomagneticModelData

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returns the current magnetic field data for the current location.

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GeomagneticModelData[locationspec]

returns the current magnetic field data for a location.

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returns the magnetic field data for the specified time for the current location.

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GeomagneticModelData[locationspec,datespec]

returns the magnetic field data for the specified time and location.

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GeomagneticModelData[locationspec,datespec,component]

returns the component of the magnetic field for the specified time and location.

Details and Options

  • GeomagneticModelData[] makes use of $GeoLocation to determine your location and Now to determine current time.
  • The location loc can be specified as latitude and longitude coordinates {lat,long}, coordinates with a height {lat,long,h}, GeoPosition[…], or as a named Entity[…]. h can be input as a numeric object in meters or as a Quantity.
  • locationspec can also be a region as specified by a named Entity[…], or a listed pair of specific locations {locationspec1,locationspec2} or {locationspec1,locationspec2,h}.
  • For regions, results are returned as arrays or an Association of arrays of magnetic field components by default. Arrays are calculated at the height of a specific coordinate point of the grid above the reference datum unless otherwise specified. If that data is not available, it uses a default height of 0 meters.
  • The magnetic field is calculated for the current time using the World Magnetic Model or "WMM". The model is updated regularly to account for slow changes in the Earth's magnetic field. Historical magnetic fields use "WMM" if the date is within their range of validity. Otherwise, GeomagneticModelData uses the International Geomagnetic Reference Field ("IGRF") or, for pre-1900 dates, the "GUFM1" model.
  • datespec can be specified by DateObject or DateList.
  • Location and date can also be specified together as Association["Location"->locationspec,"Date"datespec].
  • Components include "NorthComponent", "EastComponent", "DownComponent", "HorizontalComponent", "Declination", "Inclination", and "Magnitude". Components are measured relative to the reference ellipsoid "WGS84Original".
  • "DownComponent" is measured relative to the perpendicular to the reference ellipsoid where positive values are downward. "HorizontalComponent" is the field parallel to the surface at that point. "Declination" is the angle from the direction of true geographic north to the horizontal component, measured clockwise. "Inclination" is the angle between the horizontal component and the vertical component. "Magnitude" is the total magnitude of the field. "Potential" is the magnetic potential.
  • Components and "Magnitude" are returned in nanoteslas. "Inclination" and "Declination" are returned in angular degrees. "Potential" is returned as nanovolt seconds per meter.
  • All magnetic field components are returned as an Association unless a specific component is requested.
  • GeomagneticModelData[component] returns the component for the current magnetic field at your location.
  • GeomagneticModelData[locationspec,component] returns the component for the current magnetic field at the specified location.
  • GeomagneticModelData[locationspec,component,func] and GeomagneticModelData[locationspec,datespec,component,func] are used to specify the format of output when extended locations are specified.
  • Possible settings for func include:
  • Allreturn all values for extended locations
    GeoVectorreturn components as a GeoVector object
    GeoVectorENUreturn components as a GeoVectorENU object
    Intervalreturn intervals for extended locations
    Maxreturn maximum values for extended locations
    Meanreturn mean value for extended locations
    Minreturn minumum values for extended locations
    StandardDeviationreturn standard deviation for extended locations
  • GeoVector and GeoVectorENU are not available for "Potential" or "Magnitude" components.
  • GeomagneticModelData also includes the following properties: "NorthGeomagneticPole", "NorthModelDipPole", "NorthModelDipPoleGeoElevation", "SouthGeomagneticPole", "SouthModelDipPole", and "SouthModelDipPoleGeoElevation". These can be used to find the respective poles for the current or historical times.
  • GeomagneticModelData takes the following options:
  • GeoZoomLevel Automaticlevel of resolution of the magnetic field array
    Method Automaticmethod for calculating magnetic field
  • Method has the suboption "Model", which allows you to specify what model to use. Available models include "WMM", "IGRF", and "GUFM1".
  • The spatial resolution of the requested gravitational field data can be selected with the option GeoZoomLevelzoom, where zoom is a positive or negative integer. The larger the integer is, the more points are used to construct the array of data.

Examples

open allclose all

Basic Examples  (2)Summary of the most common use cases

Find the magnetic field components at a geographic position:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-pp365g
Out[1]=1

Use Entity to specify a location:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-3y9x34
Out[1]=1

Find the magnetic field at a location and time:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-e5ie8g
Out[2]=2

Scope  (16)Survey of the scope of standard use cases

Location Specification  (6)

Find the magnetic field components for the current location:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-szl1pu
Out[1]=1

Provide location as a GeoPosition:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-6gyby6
Out[1]=1

Location can be given as a list of coordinates and local height:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-f02paq
Out[1]=1

Coordinates and height can be specified with Quantity:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-sgodzi
Out[2]=2

Find an array of magnetic vectors over a rectangular region defined by two points:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-pdj1fl
Out[1]=1

Points can be specified with GeoPosition or Entity:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-0ifbkn
Out[2]=2

Set the height at which the magnetic vectors will be calculated over the region:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-9pea9r
Out[1]=1

Calculate the magnetic field over the region defined by an Entity:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-nwmtjk
Out[1]=1

Include a reference height:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-1ov99d
Out[2]=2

Date Specification  (2)

Find the magnetic field components for historical times:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-2qq01z
Out[1]=1

Find the magnetic field component at a specific place and time:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-3cdjku
Out[1]=1

Component Specification  (3)

Request specific components of the magnetic field:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-u5eibl
Out[1]=1
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-1cnmhn
Out[2]=2

Find the derived components of a magnetic field:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-7wjuvu
Out[1]=1

Calculate the magnitude of the magnetic field:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-ftng51
Out[1]=1

Format Specification  (2)

Find the range of the east component for an extended region:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-evvli9
Out[1]=1

Obtain the maximum or mean value of a component for a region:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-cnzm38
Out[1]=1
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-53nrn3
Out[2]=2

Association Specification  (2)

Date and location can be specified together using Association:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-gwhag8
Out[1]=1

Association specification works with component arguments:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-qm2t4j
Out[1]=1

Poles  (1)

Find the properties of GeomagneticModelData:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-4icpiy
Out[1]=1

Find the north geomagnetic pole:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-olimcw
Out[2]=2

Calculate the position of the southern dip pole in 1943:

In[3]:=3
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https://wolfram.com/xid/0g359xr4k9hpvys7m-ivrihn
Out[3]=3

Options  (2)Common values & functionality for each option

GeoZoomLevel  (1)

Control the size of the array produced for an extended region using GeoZoomLevel:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-r3h41l
Out[1]=1
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-paankw
Out[2]=2

Method  (1)

Use the Method option to compare the IGRF and WMM models:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-2xzh4m
Out[1]=1

Applications  (5)Sample problems that can be solved with this function

Find the magnitude of the magnetic field at a location:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-i0tyo8
Out[1]=1

Calculate the angle to the vertical:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-le089a
Out[2]=2
In[3]:=3
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https://wolfram.com/xid/0g359xr4k9hpvys7m-lz95n7
Out[3]=3

Find the Lorentz force on an electron in a hydrogen atom traveling perpendicular to the vertical:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-tzau1n
Out[1]=1
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-of8dvb
Out[2]=2

Calculate how declination varies with latitude:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-799qtq
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-yuav4o
Out[2]=2

Explore how the geomagnetic field changes with time:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-8p1770
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-z7gyds
Out[2]=2

Track the location of a perpendicular magnetic field or dip pole over time:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-542tsp
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-lh2zku
Out[2]=2

Possible Issues  (3)Common pitfalls and unexpected behavior

Coordinates must be in the correct dimensions:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-sq79e3
Out[1]=1

The geomagnetic models are only valid near the Earth's surface:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-8f1zok
Out[1]=1

Historical models have a limited range of validity:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-h3gmva
Out[1]=1

For the World Magnetic Model, this is even more limited:

In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-dfvuzd
Out[2]=2

Neat Examples  (2)Surprising or curious use cases

Examine the magnitude of the geomagnetic field across the entire planet:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-16eo5j
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-zpbyek
In[3]:=3
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https://wolfram.com/xid/0g359xr4k9hpvys7m-4mqx93
Out[3]=3

Explore the change in declination across the globe:

In[4]:=4
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https://wolfram.com/xid/0g359xr4k9hpvys7m-ueac37
In[5]:=5
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https://wolfram.com/xid/0g359xr4k9hpvys7m-h6i21u
Out[5]=5

Examine how the Earth's magnetic field changes over time:

In[1]:=1
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https://wolfram.com/xid/0g359xr4k9hpvys7m-pkvwml
In[2]:=2
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https://wolfram.com/xid/0g359xr4k9hpvys7m-ya5zpl
Out[2]=2
Wolfram Research (2015), GeomagneticModelData, Wolfram Language function, https://reference.wolfram.com/language/ref/GeomagneticModelData.html (updated 2019).
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Wolfram Research (2015), GeomagneticModelData, Wolfram Language function, https://reference.wolfram.com/language/ref/GeomagneticModelData.html (updated 2019).

Text

Wolfram Research (2015), GeomagneticModelData, Wolfram Language function, https://reference.wolfram.com/language/ref/GeomagneticModelData.html (updated 2019).

✖
Wolfram Research (2015), GeomagneticModelData, Wolfram Language function, https://reference.wolfram.com/language/ref/GeomagneticModelData.html (updated 2019).

CMS

Wolfram Language. 2015. "GeomagneticModelData." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2019. https://reference.wolfram.com/language/ref/GeomagneticModelData.html.

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Wolfram Language. 2015. "GeomagneticModelData." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2019. https://reference.wolfram.com/language/ref/GeomagneticModelData.html.

APA

Wolfram Language. (2015). GeomagneticModelData. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/GeomagneticModelData.html

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Wolfram Language. (2015). GeomagneticModelData. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/GeomagneticModelData.html

BibTeX

@misc{reference.wolfram_2025_geomagneticmodeldata, author="Wolfram Research", title="{GeomagneticModelData}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/GeomagneticModelData.html}", note=[Accessed: 29-March-2025 ]}

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@misc{reference.wolfram_2025_geomagneticmodeldata, author="Wolfram Research", title="{GeomagneticModelData}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/GeomagneticModelData.html}", note=[Accessed: 29-March-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_geomagneticmodeldata, organization={Wolfram Research}, title={GeomagneticModelData}, year={2019}, url={https://reference.wolfram.com/language/ref/GeomagneticModelData.html}, note=[Accessed: 29-March-2025 ]}

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@online{reference.wolfram_2025_geomagneticmodeldata, organization={Wolfram Research}, title={GeomagneticModelData}, year={2019}, url={https://reference.wolfram.com/language/ref/GeomagneticModelData.html}, note=[Accessed: 29-March-2025 ]}