Current
                Geomagnetic activity  
                 
                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,
                Aberdeenshire  
                 
                
                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
                Chart Explanation)    
                 
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