Geomagnetism

Magnetic Field Model MF7

Satellites in low-Earth orbit (LEO) provide the most effective means of mapping the long wavelengths of the magnetic field caused by the magnetization of the Earth's crust. The MF7 model was produced using CHAMP measurements from May 2007 to April 2010. The modeling methodology remained largly unchanged from the previous version MF6. MF7 resolves the crustal magnetic field to spherical harmonic degree 133, corresponding to length scales down to 300 km.

Fig.1: (click to enlarge) Fig. 1: Vertical component of the MF7 crustal magnetic field at the Earth surface, overlain with the isochrons of an ocean-age model inferred from independent marine and aeromagnetic data by Muller et al. (2007) and plate boundaries by Bird (2003).

Available MF7 Downloads
	Type	Format	Mbyte	Ref. Radius	Contents
	SH coefficients	ASCII Table	0.3	6371.2 km	MF7 Model spherical harmonic coefficients (Schmid semi-normalized, as usual)
	Graphic	PDF	1.0	WGS84	Image of vertical component (Z) at WGS84 ellipsoid altitude.
	Listing	GZ	42	WGS84	MF7_Z_0.xyz.gz 6 arc minute ascii grid of vertical component (Z) at WGS84 ellipsoid altitude.
	Graphic	PDF	1.0	WGS84	Image of the anomaly of total intensity at WGS84 ellipsoid altitude.
	Listing	GZ	42	WGS84	MF7_dF_0.xyz.gz 6 arc minute ascii grid of the anomaly of total intensity at WGS84 ellipsoid altitude.
	Listing	GZ	660	WGS84	MF7_dF_2.5.xyz.gz 1.5 arc minute ascii grid of the anomaly of total intensity at 2.5 km altitude above the WGS84 ellipsoid. This grid is intended for use in the World Digital Magnetic Anomaly Map project for the 2011 revision. Please be aware of the large file size (660 MB) of this grid.
	Graphic	PDF	1.0	WGS84	Image of the analytic signal at WGS84 ellipsoid altitude.
	Listing	GZ	6	6771.2 km	MF7_0_as.xyz.gz Ascii grid of the analytic signal at WGS84 ellipsoid altitude.
	Listing	GZ	6	6771.2 km	MF7_0_dFdx.xyz.gz Ascii grid of the northward derivative of the total intensity anomaly at WGS84 ellipsoid altitude.
	Listing	GZ	6	6771.2 km	MF7_0_dF_dy.xyz.gz Ascii grid of the eastward derivative of the total intensity anomaly at WGS84 ellipsoid altitude.
	Listing	GZ	6	6771.2 km	MF7_0_dFdz.xyz.gz Ascii grid of the downward derivative of the total intensity anomaly at WGS84 ellipsoid altitude.

2010-Aug-19, Stefan Maus