[HQRP] Fwd: Solar update & Leonids

[Ed Manuel (N5EM)]

>Date: Wed, 17 Nov 1999 12:51:56 -0700 (MST)
>Reply-To: na5n@rt66.com
>Sender: owner-qrp-l@Lehigh.EDU
>From: "Paul Harden, NA5N" <na5n@rt66.com>
>To: "Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>
>Subject: Solar update & Leonids
>X-To: qrp-l@lehigh.edu
>X-Authentication-Warning: shell.rt66.com: na5n owned process doing -bs
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>
>
>THE SUN/PROPAGATION.
>Todays M7 flare was geoeffective, meaning the resulting coronal mass
>ejection (CME) will impact the earth, likely late on friday.  This will
>undoubtedly trigger at least a minor geomagnetic storm, and more likely
>a major to severe storm.  This will cause band conditions on 20M and
>below to be pretty rocky over the weekend with extreme noise levels and
>bursty static crashes.
>
>On the good side, it has elevated the solar flux, an extra dose of
>ionizing radiation, making the E and F layers very reflective.  The MUF
>is currently 40MHz over much of North America.  So 20 through 10M should
>be hopping.  (I hear plenty of signals on 10M right now, but no time to
>QSO ... shucks!).
>
>THE LEONIDS.
>The Leonid Meteor shower is the result of the earth plowing through the
>debris field from the Swift-Tuttle comet.  As a comet comes through our
>solar system and begins to be heated by our sun, it begins to shed lots
>of debris.  This debris, mostly small chunks of ice, is illuminated by
>our sun, forming the "tail" of the comet.  This tail of debris remains
>suspended in space for eons, and is relenished every time the comet makes
>a return trip.  In the case of the Swift-Tuttle comet, it comes along
>every 33 years.  However, the comet does not always cross the earths
>path with the same exact trajectory ... it can be a bit ahead of the
>original path, or perhaps a bit above or below the plane of the earths
>orbit.  Furthermore, the earth itself does not circle the sun on the
>exact path year after year.  Therefore, some years the earth will plow
>through the center of the comet's debris field for a spectacular meteor
>shower, and other years sorta of skim it, for an anemic display.  And
>predicting when a good year or bad year will occur is nearly impossible,
>since these pieces of debris are smaller than what can be detected by
>instruments.  In other words, we don't know exactly where the core of the
>debris field is located.
>
>Of the various methods used to estimate when we will plow through the
>thickest part of the debris field, most indicated that last year and/or
>this year will be the highest probability.
>
>For this Leonids, it is ESTIMATED the peak activity will occur on
>November 18 between 0200-0400 UTC.  Since the best display is where the
>earth goes through the debris between midnight and local sunrise, this
>indicated the best displays will be along Europe and Africa.  But, this 
>is not exact science, as we could encounter the debris field earlier or
>later than expected, and where we go through it could be narrower or
>wider than expected.
>
>Since last night was a dud, means we haven't gone through the debris
>field yet.  So it *will* be sometime tonight.  If we hit it when
>predicted (02-04Z), then that will be early evening on the east coast
>of the US, a shortly after sundown farther to the west.  If it persists
>for 6-8 hours, then it *could* produce a nice meteor shower for much of
>the evening.
>
>So the moral of the story is this evening is the ideal time to look for
>enhanced meteor activity.  It could be a few extra meteorites over normal,
>or perhaps a period of tremendous activity.  So you'll have to take your
>chances, as usual with these sorts of things, as to whether or not there
>will be a spectacular display.  Many people are predicting a very heavy
>meteor shower this evening, but they did last year as well :-(
>
>If you have the means to observe the skies tonight from a fairly dark
>location, it might be worth it.  But please don't pack up the kids and
>drive 50 miles into the country because I say so.  You must take your
>chances like the rest of us.
>
>But ... this year *does* coincide with the 33-year cycle of above normal
>meteor counts ... statistically at least.
>
>If nothing else, listen to a distant FM station and see if you notice
>the signal strength suddenly improving for 10-20 seconds now and again.
>If so, meteorites are entering and causing brief periods of ionizations
>(meteor scatter propagation ... and effect around 50MHz and above).
>
>72, Paul NA5N
>
>

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