Interplanetary CME Shocks

Interplanetary CME Shocks

. As it moves away from the Sun (top left) a fast coronal mass ejection (CME, top right) pushes an interplanetary shock wave before it, amplifying the solar wind speed, V, and magnetic field strength, B (bottom). The CME produces a speed increase all the way to the shock front, where the windís motion then slows down precipitously to its steady, unperturbed speed. Compression, resulting from the relative motion between the fast CME and its surroundings, produces strong magnetic fields in a broad region extending sunward from the shock. The strong magnetic fields and high flow speeds commonly associated with interplanetary disturbances driven by fast CMEs are what make such events effective in stimulating geomagnetic activity.

Copyright 2010, Professor Kenneth R. Lang, Tufts University