Comment Section

Pretty clear shock signature on the 21st along with what looks like a very strong shock on the 23rd, with another possible shock in between the two. The magnetic field shows signs of rotation, indicating a possible magnetic cloud. The high velocity following the event could mean that some of these signatures are CIR related. My initial thoughts are that this was a CME being pushed by a fast speed stream with a CIR compressing the flux rope (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.