Fig. 5.
From: The CHAOS-3 geomagnetic field model and candidates for the 11th generation IGRF
First time derivative of the vector components, dX/dt, dY/dt and dZ/dt, at selected observatories. Symbols refer to observations (annual difference of revised monthly means in black, annual differences of traditional monthly means in light blue), whereas the solid curves indicate field estimates from the CHAOS-2s (red), “extended CHAOS-2s” (magenta), CHAOS-3α (green) and CHAOS-3 (blue) models. Green symbols indicate values used for CHAOS-3 (and the updated CHAOS-2s model), but not for CHAOS-3α.