Observatory

The signature of an auroral substorm on the magnetometer.

The substorm 'onset' is at 21:05 UT and is indicated by the sharp decrease in the northward (x) component of the magnetic field.

You can also see the aurora and the riometer record for this event


A sudden storm commencement.The magnetosphere is compressed by the arrival at a shock at the magnetopause. The SSC is at 1231 UT. You can also see the riometer record for this event.