|Solar activity - what can be expected|
|posted: Jan 23, 2012|
The Sun has again an activity revival since Jan 16, not an extra ordinary revival, but high. No records were broken.
There was a series of plasma ejections, not straight to Earth, but glancing blows from above. The most dangerous aspect up to
now is the ongoing proton event.|
For aurora-watchers: the chance for aurora in Belgium is very small.
The event of Jan 23 was the strongest of the last days. The Sun showed off with a combination of three sorts
of energy releases. Speaking in terms of x-ray radiation, the Jan 23 flare reached the M8.3 level. The speed
of the mass ejection of Jan 23 was relatively speaking high compared to the ones of the previous days: 1400
km/s compared with 700 km/s at most. What differs from the previous mass ejections, is that the component
that intersects with the ecliptic - and pass along the Earth - is stronger. The event triggered a proton storm: particles with relativistic speeds
fly through space into the direction of Earth. They harm satellites, eventually disrupting their pointing,
attacking their solar cells, ... Those particles can intrude the Earth's magnetosphere through the north/south polar
door. This is the strongest proton storm since May 2005. At this very moment (Jan 23, 20:00UT), the
proton event continues.|
The ejected mass did not yet arrive at Earth. At arrival, the magnetosphere might be disturbed. We speak about a geomagnetic storm causing unwanted effects on satellites and their performances. A geomagnetic storm can alter also the features of the ionosphere, a layer which is crucial for signals transmitted to satellites or from an earth transmitter to an earth receiver. This list of failures is not exhaustive. However, we don't forecast an extra ordinary geomagnetic show. For Belgium, this means that the chance for aurora is almost nihil.
With the figures below, you can reconstruct what kept us busy since Jan 16. Orange stands for events on the solar disk, blue stands for the situation a few solar radii away from the Sun, while green describes the situation near Earth.