Figure 4

Validation of candidate DGRF and IGRF models against independent observatory data. Annual differences between the field at t+6 months and t-6 months (blue dots and lines) between quiet monthly means at the MBO and KOU observatories are compared to predictions of the candidate SV models. The DGRF parent SV model for 2010.0 is shown truncated at degree 13 (red crosses) and degree 8 (cyan circles). The IGRF parent SV model for 2015.0 is shown truncated at degree 8 (red X). The average SV over 2010.0 to 2015.0, computed from differences of the DGRF and IGRF main field candidates, are shown as red squares. The predictions by the series of SV models calculated in Chulliat and Maus (2014) are also represented as black lines.