A coronal mass ejection
(CME) hit Earth's magnetic field at 0617 UT on Jan.
22nd. At first the impact did not appear to be a
strong one: the solar wind speed barely lifted itself
to ~400 km/s when the CME passed by. Now, however,
in the wake of the CME, a dense and increasingly
geoeffective solar wind stream is blowing arround
Earth, setting the stage for possible auroras on
the night of Jan. 22nd.
Reference:
Al Larson aka Hans Hannula, Astrophysics & Chaos (Mar 30 1999).
