These data consist of uniformized magnetic variation
data created by SuperMAG from data received from over 200 ground
observatories worldwide. Data are made into 1-min resolution, are
cleaned for errors and artifacts, are converted to a NEZ coordinate
system (N and E are local magnetic North and East, Z is vertical down),
and have their dominant and slowly varying Earth field components
(i.e., baselines) subtracted out. Thus the data are intended for
studies of effects of variable ionospheric and magnetospheric current
systems. Data are available as line plots, as northern and southern
hemisphere maps, and as underlying IDL saveset files. User registration
is required prior to data access.