[HCRA] Fw: [CQ-Contest] Geomagnetic Storms, Aurora, and propagation

[Mike DeChristopher]

My apology to those subscribed to both lists...but if you are wondering what
happened to your radio, well.......

73', Mike DeChristopher KB1FWN
http://kb1fwn.home.comcast.net

----- Original Message -----
From: NW7US, Tomas <nw7us at hfradio.org>
To: SWL <swl at mailman.qth.net>; SW - TheBasicsOfShortwave
<thebasicsofshortwave at yahoogroups.com>; SWARL <SWARL at yahoogroups.com>; SWBC
<swbc at topica.com>; SWL and Ham DX Club
<hamradioandshortwavedxclub at yahoogroups.com>; VHF <vhf at w6yx.stanford.edu>;
<rtty at contesting.com>; CQ_Contesting <CQ-Contest at contesting.com>
Sent: Sunday, July 25, 2004 4:13 PM
Subject: [CQ-Contest] Geomagnetic Storms, Aurora, and propagation


> NW7US Propagation Bulletin - 25-VII-2004 / 1500Z
>
> We are in the middle of a very strong geomagnetic storm.  The estimated
> planetary K index (Kp) reached a level of 8, with the Bolder, Colorado K
> reading a level 7.  We have been seeing the geomagnetic activity increase
> on a steady climb since yesterday.  As I had predicted in my last NW7US
> Propagation Bulletin, we have been experiencing a geomagnetic storm since
> Thursday.
>
> Right after my last bulletin went out, the Kp rose to the level of 6.  For
> most of Friday, the Kp stayed at or above 5, until the end of the UTC
> day.  As Saturday progressed, the geomagnetic field again became highly
> active and reached storm levels.  It has continued to get more intense and
> we've now reached very high storm levels.
>
> All of this activity is caused by several concurrent influences.  During
> the last week, we have had moderate to high solar activity, with a steady
> occurrence of moderate flares (M-class).  Some of these have had coronal
> mass ejections associated with them.  In addition, there are two coronal
> holes that have enhanced the solar space wind.  The steady elevated wind
> speed and pressure, combined with the Interplanetary Magnetic Field's
> southward orientation in relationship with the Earth's Magnetosphere, has
> caused great disturbances in our geomagnetic fields.
>
> At the time of writing this bulletin, the Solar Wind Speed is 528
> kilometers per second.  That's not as high as during other major
> geomagnetic storms, where we've seen it as high as 800 km/s.  However, the
> IMF has been consistantly southward in its orientation for several days.
> (This is shown in the Bz index, where a negative number indicates the
> southerly orientation. The higher the negative index, the more southward
> the IMF's orientation).  This allows a strengthening of the interaction
> between the two magnetic fields.  And, with that, a "window" opens in our
> Earth's natural sheilds through which solar plasma can "rain" down into
> the Auroral ovals at our poles.  This causes an increase in the Auroral
> activity.  We are seeing an Auroral Activity index maxed out right now at
> a level of 10.
>
> The results of all of this continual geomagnetic storminess is the
> degradation of world-wide ionospheric conditions.  Geomagnetic activity
> causes the ionosphere to "recombine," much like what happens during the
> hours of darkenss.  Geomagnetic activity can cause the ionosphere to
> become "depressed" by ten to thirty percent from normal levels.  This
> lowers the maximum usable frequency over any given path.  We also see the
> increase in Aurora propagation (AU).
>
> I have seen reports already of AU openings.  If you are not on the air,
> don't waste any time!  Check out VHF weak-signal propagation via aurora.
> Check out shortwave -- during aurora some interesting HF propagation can
> be experienced.
>
> I expect to see the geomagnetic storms to continue for a number of days.
> There are two coronal holes still influencing the solar wind, and we are
> seeing a steady series of M-class flares, some of which may cause a
> glancing blow of coronal mass ejections.  However, I do expect the level
> of the storms to slowly decrease.  With that, we'll see the solar activity
> decrease a little until the next sunspot group rotates into view.
>
> Until next time, happy DXing!
>
> --
>
> 73 de Tomas, NW7US (AARØJA/AAAØWA)
>
> : Propagation Editor for CQ, CQ VHF, and Popular Communications :
> : Quarterly Propagation Columnist for Monitoring Times Magazine :
> : Creator of live propagation center - http://prop.hfradio.org/ :
> : Member, US Army Miltary Affiliate Radio Service (MARS) AARØJA :
> : 122.93W 47.67N / Brinnon, Washington USA - CN87 - CW/SSB/DIGI :
> : Website, software, database design - http://newwebmakers.com/ :
> : Washington State Army MARS, State Army MARS Director - AAAØWA :
> : 1Øx56526, FISTS 7Ø55, FISTS NW 57,  AR Lighthouse Society 144 :
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