Fig. 4From: Applications for CryoSat-2 satellite magnetic data in studies of Earth’s core field variationsSV times series obtained from annual differences of revised monthly means (black dots) (Olsen et al. 2014), and 4-monthly Core Field GVOs derived from CHAMP (purple dots), CryoSat-2 (blue dots) and Swarm (red dots) data. Note the GVO estimates have been mapped from satellite altitude to ground in order to aid the comparisonBack to article page