A comparison of the total field for three Oersted main field models (OIFM, IPG-Paris and Florida State) with the Magsat field (M102389) from degrees 15-19 at 600 km altitude.

Oersted and Magsat Magnetic Models

In contrast to the Magsat model, all three Oersted models exhibit North-South features of alternating polarities in the South Atlantic and South America coincident with the South Atlantic Anomaly (SAA). These features are not associated with any known lithospheric anomaly and are likely to be an artifact. In the Florida State (FSU) model these extend across much of the low to mid southern latitudes. These artifacts are of smallest areal extent in the OIFM model and only slightly more extensive in the IPGP model.

A Comprehensive Model of the Near-Earth Magnetic Field: Phase 3 (CMP3 model)


Oersted  Initial  Field Model (OIFM)


IGRF 2000


Back to Terrestrial Magnetism Home Page

Responsible NASA official:Dr. Herbert Frey
Web Curator: Katia Nazarova (Raytheon)
Email katianh@geomag.gsfc.nasa.gov with comments or suggestions
Last modified on May 15, 2001