This plot shows the evolution of the horizontal magnetic field components
within the last four hours. Depending on the activity within the last hour,
green/yellow/red alerts are displayed in plot.
Alert criteria used in the above plot assess the last 60 minutes: |
Quiet geomagnetic conditions |
Disturbed geomagnetic conditionsons |
Considerable geomagnetic activity |
Within the last hour, less than ΔB<80 nT, corresponding to <K3 |
Within the last hour, less than ΔB<140 nT, corresponding to K4 |
Within the last hour, ΔB>140 nT, corresponding to K5 |