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Enhanced Magnetic Model 2010

browse graphicDeclination Comparison of WMM and EMM
The Enhanced Magnetic Model (EMM) extends to degree and order 720, resolving magnetic anomalies down to 56 km wavelength. The higher resolution of the EMM results in significantly improved pointing accuracy than the World Magnetic Model (WMM), which uses spherical harmonic representation to degree and order 12, resolving the magnetic field at 3000 km wavelength. The EMM model provides the magnetic field vector at any desired location and altitude close to and above the Earth's surface.

Cite as: National Geophysical Data Center (2009): Enhanced Magnetic Model 2010. National Geophysical Data Center, NOAA. doi:10.7289/V5HH6H0D [access date]

Search and Download
  • EMM2010_Sph_Windows_Linux.zip (download)
    Enhanced Magnetic Model (EMM2010) and software using the spherical harmonic approach for Windows and Linux environments. High CPU requirements (use the faster Mesh software for large number of points), very low RAM requirement (7.5 MB). For use with years 2000 to 2015.
  • EMM2010_Mesh_Windows_Linux.zip (download)
    Enhanced Magnetic Model (EMM2010) with software with rapid field calculation using 3D mesh interpolation for Windows and Linux environments. Low CPU requirements, High (1.4 GB) RAM requirement. Only works for years 2010-2015, for 2000-2010 please download the spherical harmonic version above.
  • EMM2010_Dec-15-09.zip (download)
    Enhanced Magnetic Model (EMM2010) with software for point and grid calculation.
  • EMM-720_V3p0.tar.gz (download)
    Enhanced Magnetic Model with software for rapid field calculation using 3D mesh interpolation.
  • EMM-720_V3p0_static.cof.gz (download)
    Enhanced Magnetic Model. Spherical Harmonic Coefficients of the static internal field at 2010.0.
  • EMM-720_V3p0_secvar.cof.gz (download)
    Enhanced Magnetic Model. Spherical Harmonic Coefficients of the estimated secular variation 2010-2015.
  • EMM-06.tar.gz (download)
    Software for the Enhanced Magnetic Model (EMM-06), including main field, secular variation, NGDC-720-V1 crustal field, magnetospheric field, and induced field. The package includes a simple single-point program and a thread-safe multi-processor application which can be adapted to produce large grids and time series.
Distribution Formats
  • EMM2010_Sph_Windows_Linux.zip (Version: 4)
  • EMM2010_Mesh_Windows_Linux.zip (Version: 3)
  • EMM2010_Dec-15-09.zip (Version: 1)
  • EMM-720_V3p0.tar.gz (Version: 3)
  • EMM-720_V3p0_static.cof.gz (Version: 3)
  • EMM-720_V3p0_secvar.cof.gz (Version: 3)
  • EMM-06.tar.gz (Version: 3)
Distributor DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Point of Contact NGDC Geomagnetic Modeling Team
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
geomag.models@noaa.gov
Documentation links not available.
Originator
  • NGDC Geomagnetic Modeling Team
    DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publisher
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Date(s)
  • publication: 2009-12-15
Edition: 3
Data Presentation Form: mapDigital
Dataset Progress Status Complete
Data Update Frequency: As needed
Purpose: Magnetic anomaly maps provide insight into the subsurface structure and composition of the Earth's crust. Over continental areas, magnetic anomalies illuminate geologic, tectonic, and geothermal evolution of crust and lithosphere. In the world's oceans, anomalies trending parallel to the isochrons (lines of equal age) reveal the temporal evolution of oceanic crust. Magnetic maps are widely used in the geological sciences and in resource exploration.
Use Limitations
  • While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
  • Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.
Time Period: 2000-01-01  to  2014-12-31
Spatial Reference System: urn:ogc:def:crs:EPSG::4326
Spatial Bounding Box Coordinates:
N: 90
S: -90
E: 180
W: -180
Spatial Coverage Map:
Themes
  • EARTH SCIENCE > Solid Earth > Geomagnetism > Magnetic Field
  • EARTH SCIENCE > Solid Earth > Geomagnetism > Magnetic Intensity
  • EARTH SCIENCE > Solid Earth > Geomagnetism > Magnetic Declination
  • EARTH SCIENCE > Solid Earth > Geomagnetism > Magnetic Inclination
  • EARTH SCIENCE > Solid Earth > Geomagnetism > Magnetic Anomalies
Data Centers
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Places
  • Geographic Region > Global
Use Constraints
  • Cite as: National Geophysical Data Center (2009): Enhanced Magnetic Model 2010. National Geophysical Data Center, NOAA. doi:10.7289/V5HH6H0D [access date]
Fees
  • None
Source Datasets
  • CHAMP Satellite Data
  • ORSTED Satellite Data
  • INTERMAGNET Observatory Data
  • GEODAS magnetic data
    • Description of Source: Trackline magnetics observations hosted on GEODAS at the National Geophysical Data Center (NGDC).
    • Spatial extent used:   N: 90   S: -90   E: 180   W: -180
Lineage Statement Lineage statement not available.
Processor
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Processing Steps
  • Measurements during daytime and during periods of strong solar activity are contaminated by external current systems, which are difficult to accurately model. Therefore, only nighttime data during magnetically quiet periods were used in estimating the WMM coefficients.
  • Some contributions to the measured magnetic field, such as the diamagnetic effect of ionospheric plasma (L?hr et al, 2003) or motional induction by tidal ocean currents (Kuvshinov and Olsen, 2005; Maus, 2007), can be accurately modeled and were corrected for prior to the estimation of the WMM main field coefficients.
  • To account for the contributions that have not been removed in the previous steps, an extended set of model parameters is co-estimated with the WMM model coefficients. These account for smaller-wavelength internal magnetic field contributions (spherical harmonic degree larger than 12), second time derivatives (secular acceleration) and contributions from currents external to the Earth. The set of WMM coefficients plus the extended model parameters is called a parent model of the WMM. Two different parent models were produced, reflecting different modeling strategies employed by NGDC for the main field model and BGS for the secular variation model.
  • Satellite, marine, and aeromagnetic measurements were compiled into an ellipsoidal degree-720 magnetic model of the Earth's lithosphere. This model accurately represents the crustal field down to wavelengths of approximately 56 kilometers. This results in a higher pointing accuracy.

Metadata Last Modified: 2014-05-29

For questions about the information on this page, please email: Brian.Meyer@noaa.gov