EMAG2v3: Earth Magnetic Anomaly Grid (2-arc-minute resolution)

Description

EMAG2v3 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of the previous release of the Earth Magnetic Anomaly Grid. The resolution remains 2 arc-minutes, and the altitude of 4 km above the geoid is still supported, but an additional product, a grid that is observed at sea-level over oceanic regions, has been produced. New additions grid and track line data have been included, both over land and the oceans. Wherever available, the original shipborne and airborne data were used instead of precompiled oceanic magnetic grids. Interpolation between sparse track lines in the oceans was improved by using a kriging algorithm, which specializes in heterogeneous data distribution gridding, in order to create a compilation as true to the observed data as possible, and avoid using a priori information. The longest wavelengths (>300 km) were replaced with the latests satellite lithosphere magnetic field model, MF7.

Resources

Name Format Description Link
47 ASCII text file that contains format description of the EMAG2v3 CSV data file. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_readme.txt
0 https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.geophysical_models:EMAG2_V3/html
21 emag2.html http://www.ngdc.noaa.gov/geomag/emag2.html
34 PNG of EMAG2v3 as a poster at sea level over oceanic regions. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_SeaLevel_poster.png
34 PNG of EMAG2v3 estimates of the error in nanoTesla for each cell. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_Error_map.png
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
48 A georeferenced TIFF (GeoTIFF) for EMAG2v3, where the altitude is at sea level over oceanic regions, with a resolution of 2 arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_Sealevel.tif
0 Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
57 Zip file containing the comma delimited ASCII grid that contains i and j grid indicies, latitude and longitude cell centered location information, magnetic anomalies at a consistent 4km elevation, sea level over oceanic regions, anomaly source grid code, and an error estimate for each cell. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530.zip
34 PNG of EMAG2v3 as a poster at a consistent 4km altitude. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_UpCont_poster.png
25 KMZ plugin for Google Earth of EMAG2v3 as a poster at a consistent 4km altitude with data gaps filled with MF7 values. Requires installation of Google Earth. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_UpCont_MF7fill.kmz
34 PNG of EMAG2v3 codes to designate which grid is primarily responsible for the anomaly value for each cell. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_Code_map.png
0 A science paper about the construction and evaluation of the Earth Magnetic Anomaly Grid 2 Arc-Minute Resolution Version 3 https://doi.org/10.1002/2017gc007280
48 A georeferenced TIFF (GeoTIFF) for EMAG2v3, where the altitude is at a consistent 4km altitude, with a resolution of 2 arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point. https://www.ngdc.noaa.gov/geomag/data/EMAG2/EMAG2_V3_20170530/EMAG2_V3_20170530_UpCont.tif
0 Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords

Tags

  • nesdis
  • magnetic field
  • national geophysical data center
  • noaa
  • global
  • magnetic anomalies
  • u.s. department of commerce
  • earth science
  • geographic region
  • magnetic intensity
  • doc/noaa/nesdis/ngdc
  • solid earth
  • doc/noaa/nesdis/ncei
  • geomagnetism
  • national centers for environmental information

Topics

Categories