Fig. 8From: Towards probing Earth’s upper mantle with daily magnetic field variations: exploring a physics-based parametrization of the sourceMaps of the first, dominant mode for each period P = 24, 12, 8, 6, 4.8, and 4 h for PCA for the whole time series with an FT segment length of 72 h. Both real and imaginary parts are displayed. Scaling is normalized and unit-lessBack to article page