[CQ-Contest] Update - Propagation today, tomorrow, and the next
day...
Tomas (NW7US)
nw7us at hfradio.org
Fri Oct 24 12:26:14 EDT 2003
Howdy, fellow HFer.
I just finished a long conversation with NOAA's Bill Murtagh, the solar
forecaster on duty. We discussed several things, including the press' obsession
with the current solar conditions. Here is a summary of our discussion.
1) NASA released a press release regarding a historical solar sunspot back in
the 1800's. ( See http://science.nasa.gov/headlines/y2003/23oct_superstorm.htm )
Many journalists and news outlets (like Fox News) did not get very much past the
headline. They joined the press release with the current sunspot group, and
incorrectly thought that we are in for a massive, historical storm.
This is not going to be the case. While the Kp readings might reach 7, or at
most 8, this initial CME shock has already hit, and will subside by tomorrow
(early, we think). The Kp will fall to about 4, maybe 5. Sometime on Sunday,
another CME might glance us. This will not cause excessive, record-breaking
massive geomagnetic storminess. It will just be stormy. Like it has been many
times in the last few years.
On the other hand, what is significant is the flaring activity. As I write
this, for example, we are under the influence of a long-lasting, slowly
declining M-class flare. Not just a quick, "hello" flare, this one is dragging
out. This is causing radio blackouts over the sunlit side of the ionosphere.
These radio blackouts are somewhat regional (at least on the sunlit side), and
possibly short-term (unless, like with this M-class flare, it lasts for a long
while). Geomagnetic storms, on the other hand, will degrade propagation for all
locations, generally speaking (night and day side).
Now, what's the outlook for HF propagation over the weekend? My original
forecast holds some theoretical plausibility - the geomagnetic storminess should
subside during Saturday. The higher flux (180 or so) should help balance out
conditions on the higher frequencies, and the lower frequencies will fare well.
Unless.... yes, unless... the flaring continues. There is a great chance that
we will have issues because of the continual flare activity. At least those who
are trying to make contacts or SWL those areas where the signal path is through
daylight regions will see a degradation of propagation. Low band DXing
(especially at night) should be fair to good, however, when the Ap/Kp falls.
This was not something we could see coming down the pike. Normally, we could
take a 27-day solar cycle and make a reasonable forecast on how conditions might
be. Based on 27 days ago, we should have had a GREAT weekend. Now, at best, we
will have a good weekend. Most likely, a fair weekend.
Or, a terrible weekend.
And, as Bill and I agreed, it is hard to assess because we don't have enough
data to create a working model, yet, we cannot for certain say who will have a
great weekend, and who will have a lousy weekend. Conflicting reports tend to
come in after such a chaotic event. Some find that these conditions don't
degrade THEIR working conditions, while others report a complete loss of signal.
And, there's no real pattern. I find that has held true in the past contests
when conditions were rough. Some said that they had record-breaking results,
even so. Others said that they decided that it was a waste of their contesting
energy. So, go figure.
One thing I came away with from this discussion with Bill is that we amateur's
really need to become more scientific in our data collection process. We need
to record more information about our working conditions, our QSO's, and the
other details that, when gathered together into a database, would allow us to
begin to unlock the secrets of propagation, such that we can begin to forecast
better how these events will affect us.
Bill is hoping that by the end of this current solar cycle, enough new data is
collected that we can begin to make correlations about these events with
something of a pattern and model things more accurately.
At the moment, the data shows the Bz is positive. Can we trust that reading?
Kp readings of 7 have been recorded. Is that in keeping with a positive Bz?
How can Kp be so high, if the Bz is positive? This is another question Bill and
his group are asking right now.
In the end, my forecast remains a bit more conservative, only because of the
flaring that might cause radio blackouts. Otherwise, I feel that the
geomagnetic forecast should hold true.
I will certainly continue to review this event and report on it in future e-
mails. I hope to hear from many of you about real-world conditions from your
perspective.
Oh, one more thing: Because of the unwarrented press due to the miss-reading of
the NASA press release and its timing with the current sunspot activity, NOAA
website resources are overwhelmed. Tell folks that they can relax. On the
other hand, Bill chuckled at the idea that maybe all this press is helpful when
they go for the hearing on October 31, 2003, regarding the funding they need to
stay alive. (See http://prop.hfradio.org for a look at this hearing).
More to follow, as new information becomes available...
73 de Tomas, NW7US (AAR0JA/AAM0EWA)
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