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  • X11-class flare 29-X-2003

    From nw7us@nw7us@hfradio.removethispart.org (Tomas) to alt.ham-radio.hf,alt.ham-radio.ssb on Wed Oct 29 21:31:25 2003
    From Newsgroup: alt.ham-radio.ssb

    Quick update:

    At least an X10 or X11 class flare just occurred, peaking at 2049Z
    29-X-2003, adding to the already dead HF conditions due to the CME passage
    and the Kp >= 7. This one is a short-lived flare. Quick recovery is
    expected. I don't know, yet, what CME might be associated, if any.
    Details, soon.

    At the moment, most of the HF spectrum is "closed" to propagation, not
    because of the flare. I'm have not been hearing signals here in the
    Pacific Northwest on most of the HF, before the X11 flare. On many e-mail reflectors, I am reading some folks as saying, "Wow, that X17 flare sure
    has shut down the bands." Actually, it is not that solar flare that messed
    up the bands, today. Flares tend to cause radio blackouts that might last
    from a half hour to a number of hours. On the otherhand, major geomagnetic storms will cause HF radio propagation degradation because of
    "recombination."

    Today's general outage is due to the passage of one of the fastest moving coronal hole mass ejections on record. It caused the highest Kp index - a level 9 geomagnetic storm. Since it hit us, the Kp index has remained at
    or higher than 7. This is a severe geomagnetic storm. During a
    geomagnetic storm, the ionosphere experiences "recombination" - much like
    what happens at night. The maximum usable frequencies fall - sometime no
    HF propagation is possible, because the ionosphere is completely
    recombined... this is what is happening at this moment. Most of the HF spectrum is "shut down."

    Now, added to this geomagnetic storm and the general closure of the HF spectrum, we have this new X11-class flare from 2049Z. I don't yet know if
    a CME was associated with this one.

    More as details become available...


    73 de Tomas, NW7US (AAR0JA/AAM0EWA)
    --
    : Propagation Editor, CQ/CQ VHF/Popular Communications Magazines :
    : http://hfradio.org/ -- http://prop.hfradio.org/ -- Brinnon, WA :
    : 122.93W 47.67N - CW / SSB / DIGITAL / DX-Hunting / Propagation :
    : A creator of solutions -- http://accessnow.com/ -- Perl Rules! :
    : Washington State MARS Emergency Operations Officer - (AAM0EWA) :
    : WA State Army MARS Webmaster for http://wa.mars.hfradio.org/ :
    : 10x56526, FISTS 7055, FISTS NW 57, A.R. Lighthouse Society 144 :
    --- Synchronet 3.21b-Linux NewsLink 1.2
  • From Dan/W4NTI@w4nti@get rid of this mindspring.com to alt.ham-radio.hf,alt.ham-radio.ssb on Wed Oct 29 23:03:17 2003
    From Newsgroup: alt.ham-radio.ssb

    Can't help but wonder. If HF is shut down how come I can hear lots of
    signals on 75/40/20 meters ??

    Sure the polar routes are gone...but.....

    And if it is so bad, where is the aurora propagation on VHF? Ain't heard a peep yet.

    Dan/W4NTI

    "Tomas" <nw7us@hfradio.removethispart.org> wrote in message news:3fa03174.20096710@news.donobi.net...
    Quick update:

    At least an X10 or X11 class flare just occurred, peaking at 2049Z
    29-X-2003, adding to the already dead HF conditions due to the CME passage and the Kp >= 7. This one is a short-lived flare. Quick recovery is expected. I don't know, yet, what CME might be associated, if any.
    Details, soon.

    At the moment, most of the HF spectrum is "closed" to propagation, not because of the flare. I'm have not been hearing signals here in the
    Pacific Northwest on most of the HF, before the X11 flare. On many e-mail reflectors, I am reading some folks as saying, "Wow, that X17 flare sure
    has shut down the bands." Actually, it is not that solar flare that
    messed
    up the bands, today. Flares tend to cause radio blackouts that might last from a half hour to a number of hours. On the otherhand, major
    geomagnetic
    storms will cause HF radio propagation degradation because of "recombination."

    Today's general outage is due to the passage of one of the fastest moving coronal hole mass ejections on record. It caused the highest Kp index - a level 9 geomagnetic storm. Since it hit us, the Kp index has remained at
    or higher than 7. This is a severe geomagnetic storm. During a
    geomagnetic storm, the ionosphere experiences "recombination" - much like what happens at night. The maximum usable frequencies fall - sometime no
    HF propagation is possible, because the ionosphere is completely recombined... this is what is happening at this moment. Most of the HF spectrum is "shut down."

    Now, added to this geomagnetic storm and the general closure of the HF spectrum, we have this new X11-class flare from 2049Z. I don't yet know
    if
    a CME was associated with this one.

    More as details become available...


    73 de Tomas, NW7US (AAR0JA/AAM0EWA)
    --
    : Propagation Editor, CQ/CQ VHF/Popular Communications Magazines :
    : http://hfradio.org/ -- http://prop.hfradio.org/ -- Brinnon, WA :
    : 122.93W 47.67N - CW / SSB / DIGITAL / DX-Hunting / Propagation :
    : A creator of solutions -- http://accessnow.com/ -- Perl Rules! :
    : Washington State MARS Emergency Operations Officer - (AAM0EWA) :
    : WA State Army MARS Webmaster for http://wa.mars.hfradio.org/ :
    : 10x56526, FISTS 7055, FISTS NW 57, A.R. Lighthouse Society 144 :


    --- Synchronet 3.21b-Linux NewsLink 1.2