Thursday, December 07, 2006

Major Solar Storm Disrupts HF

Solar active region 930 has produced several large X-ray flares, including an X6 which caused an immediate Short Wave Fadeout in the United States. An S3 level solar radiation storm is in progress, and saturation of the sensor on the ACE spacecraft has made solar wind readings unreliable.

An S3-level event is deemed unsafe to astronauts. Further events could complicate space station EVAs that are planned for next week, but the major concern is for more X-level flares in the short term. The probability is around 50% for the next 24 hours.

These flares did eject coronal mass, so there is an enhanced possibility of a Sudden Storm Commencement followed by auroral activity. As always, though, we will have to wait and see if coronal mass hits or misses the Earth's magnetosphere.

So far, HF conditions have remained relatively good, despite a planetary A index of 22, at least after the bands recovered from the initial hit to the ionosphere.

It is obvious that Cycle 23, while nearly at an end, still has a few surprises before going spotnil long enough to allow marking the offical start of Cycle 24.