Fig. 1From: Geomagnetic secular variation violating the frozen-flux condition at the core surfaceSingular values λj (black dots) and their standard deviations (gray dots) of the matrix A for the MF models from (a) GRIMM (LMF = 12) at 2003.5 and (b) CM4 (LMF = 13) at 1980.0. The maximum number of non-zero singular values is 1079 and 1260 forBack to article page