The South African Spline Model is a regional magnetic field model for Southern Africa and covers the years from 1961 to 2001. The special characteristic of this model is the use of harmonic spline functions for the spatial description of the field components. Being rarely used up to now, those functions offer several advantages: The base functions are defined on the measurement locations and permit an interpolation between the data points. In addition, a well defined relation to a global field description exists, so that such a regional field can be implemented into a global model.

Over the Southern African Region, the magnetic field is very weak and changes rapidly. As global models fail to map this behavior, a regional model allows for a more accurate description of the field in this area. Moreover, a data base consisting of repeat station measurements and observatory data exists allowing for well resolved temporal and spatial modeling.

Here, we provide animations of the evolution of the main field and the secular variation.

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