A recursive coronal hole
Last week, a large coronal hole played the leading part in the space weather news, just as it also did 27 days ago.
/ Version francaise
posted: March 18

On March 9, 2004 we could read in the space weather news broadcast by the SIDC the following:
'...The solar wind speed started to increase from 350 to 450 km/s. The recursive large coronal hole is pushing the velocity to higher levels. From Feb 10 on, we expect active to minor storm geomagnetic conditions.'
Exactly 27 days ago, on February 12, the SIDC sent out a similar message:
'...From midnight, the wind speed showed a steady increase. This is a clear sign that we are under the influence of a coronal hole....'

The EIT 284 picture on the left dates from Feb 12, while the picture on the right dates from March 10.
Click here for more graphs for tracking the behavior of the hole.