|MF4 is a field model representing the visible part of the crustal magnetic field. It is derived from almost 5 years of CHAMP measurements of the period 09-Aug-2000 to Apr-2005. The model is given as a spherical harmonic expansion of the scalar magnetic potential to degree 90. Coefficients 1-15 are set to zero, since these coefficients are masked by the main magnetic field with its source in the Earth's core.
See also the special model for ground level: MF4x
Improvements over MF3 (GFZ)
Data processing scheme for the MF4 model
|Available MF4 Downloads|
|SH coefficients||ASCII Table||0.2||6371.2 km||MF4 Model spherical harmonic coefficients (Schmid semi-normalized, as usual)|
|Graphic||0.5||6771.2 km||Image of Bz at average satellite altitude|
|Graphic||0.8||6429.2 km||Image of Bz at 50 km above surface|
|Graphic||0.7||6771.2 km||Image of total intensity anomaly (dT) at 400 km altitude|
|Graphic||0.7||6429.2 km||Image of total intensity anomaly (dT) at 50 km above surface|
|Graphic||0.6||6471.2 km||Image of analytic signal |grad(dT)| at 100 km altitude|
|Graphic||0.6||6771.2 km||Image of analytic signal |grad(dT)| at 400 km altitude|
|Data grid||ASCII Listing||20||6771.2 km||15' grid of Bz at average satellite altitude|
|Data grid||ASCII Listing||20||6771.2 km||Total intensity anomaly (dT) at 400 km altitude|
|Data grid||ASCII Listing||20||6429.2 km||Total intensity anomaly (dT) at 50 km above surface|
|Data grid||ASCII Listing||21||6471.2 km||Analytic signal |grad(dT)| at 100 km altitude|
|Data grid||ASCII Listing||22||6471.2 km||Northward derivative of dT at 100 km altitude|
|Data grid||ASCII Listing||22||6471.2 km||Eastward derivative of dT at 100 km altitude|
|Data grid||ASCII Listing||22||6471.2 km||Downward derivative of dT at 100 km altitude|
|Data grid||ASCII Listing||20||6429.2 km||15' grid of Bz at 50 km above surface|
|Animation||AVI||31||6471.2 km||Simple animation of a rotating sphere with MF4 crustal anomalies using Z at 100 km altitude, exaggerated as 3D and colored; the smaller greyish structures are only bumpmap overlays of a topographic/bathymetric map.
Runs in MS Powerpoint und Apple Quicktime 5.0.2, but not in MS Windows Media Player. Compression yields in a loss of image quality.
|= use with caution since noise is strongly amplified by downward continuation!|
Stefan Maus, Martin Rother.
Last modified: Wednesday, 27-Jun-2007 19:01:52 MDT