[CQ-Contest] Some Updates on Space Weather Events

nw7us at hfradio.org nw7us at hfradio.org
Thu Jan 20 11:52:27 EST 2005

NW7US Propagation Bulletin Update
20 January 2005 - 1645 UTC

This latest X-class flare, the THIRD LARGEST of this solar cycle (Cycle  
23), was incredible.  It unleashed an extreme (and very sudden) proton  
event, that has nearly caused a complete white-out of various space  
weather satellite instruments.

Even so, it has been confirmed that a full-halo coronal mass ejection was  
associated with this large and impressive X7 proton flare.  Because of the  
incomplete data (due to the proton bombardment), it appears that this CME  
may be fairly well directed Earthward.  But, this could be wrong.  Many  
teams are working on this one.  If the CME is directed mostly Earthward,  
the impact could be quite strong.  If the orientation at that time of the  
interplanetary magnetic field is soutward, (a negative Bz), we could see  
the most significant geomagnetic storminess of this entire period of  
activity associated with active solar region 720.

The impact of such a CME would be within one to two day.  Do remember that  
we are also under the influence of a coronal hole.  And, we now believe  
that the CME expected sometime today has likely arrived just before this  
big X7 flare occurred.  The solar wind speed had a jump of over 200 km/s.   
The Bz, however, remained positive as the wind reached over 900 km/s by  
0700 UTC.  That's when the sensors became saturated and we lost the  
ability to monitor the wind's details.

I'll send out another update later when more details are confirmed.

73 de Tomas, NW7US (AAR0JA/AAA0WA)

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