Fig. 6.From: Testing IGRF-11 candidate models against CHAMP data and quasi-definitive observatory dataAnnual differences of the Y component at MBO (a) and of the Z component at KOU (b), from definitive monthly means (blue dots) and quasi-definitive monthly means (red dots). The secular variation calculated from models at these two observatories is shown as black lines and circles (CHAOS-2 model, Olsen et al., 2009) and colored marks (IGRF-11 candidates, see the legend).Back to article page