-------- Original Message -------- Subject: Re: [QRP-L] X5 flare 6Mar 1730MST Date: Tue, 06 Mar 2012 19:03:17 -0700 From: <n...@zianet.com> To: Jim Miller <j...@jtmiller.com> CC: QRP-L <qr...@mailman.qth.net>
Jim Miller writes: > technically speaking....that's a biggun!! Yes, and so it this: > ALERT: Type II Radio Emission > Begin Time: 2012 Mar 07 0017 UTC > Estimated Velocity: 2273 km/s Our current solar wind is 374 km/sec, not much above the static (minimum) solar wind. The above NOAA Type II radio alert means the CME resulting from this flare, escaping the sun, produced type II radio sweeps, which is used to measure the velocity of the CME as it punches through the sun's magnetic field lines. In this case, a whomping 2273 km/sec., or a little over half-million miles per hour. This shock wave will lose some speed on it's way to earth, but will still be a significant "blast" of solar wind when it arrives compared to the present 374 km/sec. The X5 solar flare came from region 1429, which is approaching the center of the sun. Therefore, we won't get a direct hit from this approaching shock wave, but we'll likely get far more than a "glancing blow." This, of course, can produce a major geomagnetic storm when it arrives in about 3 days. Region 1429 is a very active region with strong and organized magnetic field lines. If it continues to grow in size, it could produce more M and X class flares over the next few days. And as others have noted, a few flares here and there always raises the daily solar flux. I'd keep an eye on solar activity on the following NOAA website: http://www.swpc.noaa.gov/today.html Top chart shows the solar x-ray flux. You can see the X5 flare right at the beginning of Mar. 7 UTC. The second chart shows the proton flux (currently elevated, though not due to the flare) and the K-index. Currently, the K-index is<4 (green bars) meaning a quiet geomagnetic field. When the shockwave arrives, the K-index will quickly change to storm status, yellow or red bars. HF propagation is usually highly degraded (and noisy) during a geomagnetic storm, which lasts in the orders of several hours. General rule of thumb (not exact science): There will be a radiation storm following an M or X class flare on the sunlit side of the planet. This will cause QRN on HF for a few tens of minutes after the flare. Once the short-lived radiation storm ends, this radiation also ionized our ionosphere and the E and F layers for enhanced propagation and raising the MUF into the higher bands (15 and 10M). Therefore, shortly after a major flare to local sundown, enhanced HF propagation becomes very conducive to QRP signals. About 3 days later, if the shock wave hits Earth, it will likely trigger a geomagnetic storm that last several hours. Working HF is difficult for the duration of the geomagnetic storm. Keep an eye on ol' sol. She's waking up, but who knows for how long. 72, Paul NA5N ______________________________________________________________ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:qr...@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
