[K3PZN-List] Propagation - Lookout Below !

[Curt Milton]

FYI - Paul works among experts who watch how the sun
is behaving.  He posts as he gets a chance to the
QRP-List.  I hope we see some visible aurora!  73,
curt


Gang,
Solar region 0808 released another major flare, an
X5.4 at 2052 UTC, 8 
SEP.
Fortunately, the area is right on the limb of the sun,
such that the 
resulting CME will not impact earth.  We will not
experience a 
geomagnetic 
storm from this flare, or the X17 yesterday.  However,
a solar/radio 
storm 
is in progress causing a near total HF blackout.  This
is caused by the 
x-ray and ionizing radiation penetrating our
ionosphere down to the 
D-layer. 
Right now, the D-layer is highly ionized, meaning it
is absorbing HF 
energy 
and preventing it from passing on to the E/F layers. 
The flare was a 
relatively short-duration flare, lasting from
2052-2106 UTC.  The 
ionizing 
radiation from this flare has since ended, which will
allow the D-layer 
to 
recover quickly, probably by 2400 UTC. 

Instruments that measure the D-layer show very high
absorption right 
now up 
to around 20MHz over the western U.S..  The eastern
U.S. should see 
14MHz 
recovering fairly shortly, the western U.S. around
2400 UTC (1800 MDT).  
Once we slip into nighttime, the lower bands will be
back to normal.  
This 
is not a long term effect. 

Yesterday, our servers were down for outgoing mail
while they were 
installing a new OS-12 line (whatever that is), so was
unable to post 
about 
the X17 flare.  Although, it seemed to get plenty of
immediate 
attention on 
qrp-l, the news, Art Bell, etc.  I noticed several
people posted their 
opinion of the flare, basically it was on the limb of
the sun, won't 
cause a 
geomagnetic storm, the HF blackout is temporary, etc. 
Your early 
analysis 
of the flare was "right on." There is no doubt in my
mind the QRPers on 
this 
group are amongst the best informed hams.  Inspite of
all the hysteria 
on 
the news about yesterday's "massive X17"
end-of-the-world kill-shock 
flare, 
the geometry and physics of the event was quickly
analyzed and posted 
by a 
few of you properly, indicating it was not a
hysterical thing and bands 
would be back to normal soon.  I'm proud of ya! 

However, I would keep an eye on this region.  It's a
hot one, now on 
it's 
third solar rotation still producing major flares.  In
a few more days 
of 
rotation towards the center of the sun, future X-class
flares from this 
region WILL impact earth to trigger major to severe
geomagnetic storms.  
Yesterday's X17 CME shockwave was 2,000 km/sec.  If
that were to hit 
the 
earth, it would cause an extreme K=9 storm, possible
power grid 
failures and 
probably blow aurora down to the Gulf of Mexico.  The
next week and 
half 
could be exciting as this region rotates into a more
favorable position 
to 
directly impact earth. 

72, Paul NA5N 


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