Magnetometer readings can provide an indication of
ongoing geomagnetic activity.
Graph to left shows real-time data for today from SAMNET's
magnetometer at Crooktree, Near Torphins,
The graph shows the North-South (H) component of
the magnetic field as a black line, with a typical quiet day
shown in blue. The difference between the current field and a
quiet day is plotted as a colour-coded bar chart: green for
quiet, orange for active and red for stormy.
Times are in UT. (More