NW7US Propagation Update 17 January 2005 - 2030 UTC The latest long-duration flare from active solar region 720 (the flare measured X3.8 and X4.1, officially recorded as X3.8 at 0659 UTC 17-I-2005), which took 2 hours to reach maximum, and had a long decay as well, unleashed such an intense amount of plasma, proton, and energy burst that many sensing equipment (satellites like ACE) have become unreliable and unusable. The solar wind speed exceeded 800 km/s, and the interplanetary magnetic field orientation was observed pointing southward, until the sensors 'shut down' under the influence of the proton bombardment. So, we don't really know how high the wind speed has been since, nor do we really know how the IMF is oriented.
What we know is that we are under a full onslaught of a proton storm. We are under the influence of a very strong solar wind. Massive amounts of plasma and a solar particle cloud is passing as the result of the coronal mass ejection from the X2-class flare of a few days ago. The planetary K index (Kp) has reached the level of 7 - a real geomagnetic storm. The CME-triggered storm will continue for at least the next 12 to 24 hours. But, with the arrival of what looks like a medium-sized coronal hole, as well as the arrival of a new coronal mass ejection on 18 January 2005, we are expecting the geomagnetic storm to increase to severe storm levels on the 18th. The X3.8 flare unleashed a very fast coronal mass ejection. This one is faster than the last two by over 300 km/s. It was measured at 1567 km/s, and was directed toward Earth. This means that it will arrive here sometime on 18 January 2005. This one is big. The long-duration of this event indicates a possibly very large cloud ejected over a longer period than the last two ejections. Again, that translates to a severe geomagnetic storm. Since the current strong (S3) radiation storm is expected to continue for several more days, we cannot be sure if the sensors will give us indication of when the shock wave arrives. Reports will therefore be spotty. Active region 720 has been amazingly eventful. Five large solar flares produced moderate (R2) to strong (R3) radio blackouts since 15 January. HF radio communications on the sunlit hemisphere of Earth experienced significant signal degradation during these solar flares, and the area around eastern Africa was totally shut down. Active Region 720 is a large and complex sunspot cluster. Further major eruptions are possible from this region before it rotates around the visible solar disk on 22 January. Continued radio blackouts, geomagnetic storms, and solar radiation storms will impact MW, HF, VHF communications. Aurora is a sure bet. 73 de Tomas, NW7US (AAR0JA/AAA0WA) : Propagation Editor for CQ, CQ VHF, Popular Communications : : Creator; live propagation center http://prop.hfradio.org/ : : Associate Member of Propagation Studies Committee of RSGB : : US Army Miltary Affiliate Radio Service (MARS) SMD AAA0WA : : 122.93W 47.67N / Brinnon, Washington USA CN87 CW/SSB/DIGI : : Website/software/database design http://newwebmakers.com/ : : 10x56526, FISTS 7055, FISTS NW 57, Lighthouse Society 144 : ---[Start Commercial]--------------------- World Radio TV Handbook 2005 is coming out. Preorder yours and support open communications for DXers: http://www.amazon.com/exec/obidos/ASIN/0823077942/hardcoredxcom ---[End Commercial]----------------------- ________________________________________ Hard-Core-DX mailing list Hard-Core-DX@hard-core-dx.com http://dallas.hard-core-dx.com/mailman/listinfo/hard-core-dx http://www.hard-core-dx.com/ _______________________________________________ THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed and/or modified under the conditions set down in the Design Science License published by Michael Stutz at http://dsl.org/copyleft/dsl.txt