[HQRP] Fwd: X-class flare; rough days ahead

[Ed Manuel]

Time to build, not to operate :-(


>Delivered-To: directvinternet.com%edmanuel@directvinternet.com
>X-Received: 21 Aug 2002 21:13:22 GMT
>Date:   Wed, 21 Aug 2002 14:23:25 -0600 (MDT)
>Reply-To: pharden@aoc.nrao.edu
>Sender: owner-qrp-l@Lehigh.EDU
>From: Paul Harden <pharden@aoc.nrao.edu>
>To: "Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>
>Subject: X-class flare; rough days ahead
>X-To:   qrp-l@lehigh.edu
>X-Cc:   "Prof. Arnaldo Coro Antich" <inforhc@ip.etecsa.cu>
>
>Gang,
>The sun has been extremely active for the past few days, mostly due to
>active region 69 (10069), which is rotating towards the eastern limb of
>the sun - meaning any further flares will not highly effect the Earth
>in a couple more days onward.  Monday there were 18 C-class flares and
>4 M-class, tuesday there were 11 C class and 2 M-class flares, and today
>an M-class and an X-class (major) flare.  Most all of these flares have
>caused some sort of coronal mass ejection (CME), associated shock waves,
>and HF radio bursts.  The shockwaves from these flares are at different
>velocities, meaning they will be striking the earth every few hours over
>the next 2-3 days, keeping our geomagnetic field in a constant state of
>disturbances.  We have experienced minor to major geomagnetic storming
>almost continuously since tuesday afternoon, a bit quiet right now
>(wednesday afternoon) with more minor storming episodes to come.  Some
>of these disturbances have caused periods of HF blackout conditions.
>
>Today's X-class flare (X1) occured about 0530UTC with an estimated
>shock velocity of about 800 km/sec ... kinda small for an X-class flare,
>but it will impact earth late friday, likely triggering yet another
>minor geomagnetic storm.  It was also a "tenflare," meaning the flux from
>this flare was seen as high as 10cm (2880 MHz).  Since this is the
>frequency that the solar flux is measured at, it suggests that today's
>solar flux values (currently at 228) has been contaminated by the flare,
>and the real value is a bit lower.
>
>With the solar flux above 200, this indicates that there is plenty of
>solar energy to ionize our E and F layer for good propagation.  However,
>with the sun now dropping in latitude for autumn, it means the high
>MUF contours are now drifting south of us.  For example, the 21MHz
>contour for good propagation today just barely covers the southern
>tier of states (from Geogia to mid-California).  Thus, if you live in
>the northern U.S., you are probably not experiencing 15M openings, but
>are in the far south.  An ideal "DX location" right now for 15-10M would
>be Havana, Cuba.  (Hint: the U.S. embargo with Cuba does not cover HF
>radio signals!  Only because they probably didn't think of it).  MUF's
>in Canada are pathetically low (below 12MHz).  So while Jim AL7FS is
>listening to a dead radio right now, Arnie, CO2KK should be booming in!
>
>In short, the lower HF bands will be in very poor shape over the next
>3 days as the result of these arriving flare shock waves and the
>fluctuations in the solar wind speed and density as a result.  These
>shock waves and arriving protons from the flares keeps pumping protons
>and electrons into our polar regions, so auroral activity will likewise
>be potentially high over the next few evenings, although not likely to
>extend too far down into the northern US states.
>
>As always, these solar/propagation recaps are merely to inform you of
>what is going on and to learn a bit of the exciting world of solar
>physics from the privacy of your own home.  It is never meant to
>discourage anyone from getting on the air.  Your mileage may differ
>depending on a host of factors.  But if the bands sound dead, or your
>noise is S-9 (regardless of RF gain setting), etc., well, at least you
>know why.
>
>72, Paul NA5N
>
>National Radio Astronomy Observatory
>Socorro, New Mexico
>
>Home of the worlds largest radio telescope (or more precisely, the
>worlds largest variable multiple baseline interferometer for auto
>correlated synthesis imaging), or WLVMBIACSI (VLA for short).
>
>Sorry, a little (stress little) astronomy humor.


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