NW7US Propagation Bulletin 20 January 2005 - 1430 UTC At the time of this bulletin, active sunspot region 10720 (720) continues its flaring activity. Since the X3.8 flare of 17-I-2005 that peaked at 0954 UTC, we've seen three M-class flares (peaks at 1134 and 1549 UTC, 18-I-2005 and 1539 UTC, 19-I-2005), and two X-class flares (peaks at 0824 UTC, 19-I-2005, and 0659 UTC, 20-I-2005). The most recent X-class, the X7.1 level flare, has created a very strong proton storm. This proton storm has caused the saturation of sensors aboard various satellites which are used to monitor the solar wind speed, causing them to become unreliable.
Region 720 is near the edge of the solar disk, about to rotate off the visual side. The expolsion of coronal material will not be directed toward Earth in any significant way. However, we are expecting the arrival soon of the coronal mass ejection from the X1.3 flare from yesterday. This will be a glancing blow, but since it is riding a solar wind that is already somewhat elevated from the currently geo-effective coronal hole, we expect perhaps up to minor storm level geomagnetic activity. With the inability to monitor the solar wind, it will not be clear when and if the CME from the X1.3 flare hits. HF propagation today will be fair to good on low- and mid-latitude paths, until sometime after the CME hits. HF propagation via the polar routes will be poor, if propagation is even possible under this strong to severe proton storm. VHF propagation via AU will not be exciting, since we don't expect a strong geomagnetic storm at this time. 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
