Fig. 2From: The BGS candidate models for IGRF-13 with a retrospective analysis of IGRF-12 secular variation forecastsExample along-track standard deviations for Swarm Alpha data during 2017, in the X, Y and Z vector components, from top to bottom. Data are smoothed for visualisation as the median of values binned in approximately 0.5\(^\circ \) equal-area tessera (empty tessera are white). Contours of geomagnetic dipole latitude are marked at 0\(^\circ \)and |55|\(^\circ \)Back to article page