Comment Section

Weak but clear magnetic cloud structre. Velocity profile shows gradual decline indicating expansion and magnetic field shows signs of rotation in both x and y directions. The solar counterpart for this event isn't obvious, but given the rather slow bulk speed at 1 AU (< 300 km/s) a Halo CME on the 19th is a possibility. (Hess)

Image Data

A combination of SWEPAM and MAG data from the ACE Satellite:

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The blue lines are an approximation of the CME cloud and the red line denotes the shock.