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[DX] Es arvoitukset tuskin selviavat...
Attached an earlier list of comments and opinions,
Es comments by OH2LX
I'm reading the opinions and comments in '6 & 10' with greatest
interest, personally perceiving these discussions as a tribute to the
past work of my friend, late F8SH, Serge Canivenc, who as a long time
Region 1 Es studies coordinator produced enormous amounts of useful
material. As an acting Auroral studies coordinator I certainly believe,
it is not possible to contribute to so called auroral studies without
intensively taking part in Es observations.
In a two part article in QST Oct 97 and Nov 97, one of the worlds's
leading Es researchers, Dr David Whitehead concludes with five remaining
main problems with the wind shear theory:
1. The (much too) intense summer maximum. There is an enormous increase
in Es sometime in May/June (Nov/Dec in Southern hemisphere?) over what
happens in the equinoxes. As to the Es, Jokela continuous data does not
show a statistically clear pattern of good and bad calendar days as
suggested by Pocock et al. How different this can be in the different
parts of the world, is hard to define. There no doubt is much more Es in
Europe during September/October compared to March/April. I wonder how all
this could be related to the very sudden change of foF2 to higher
frequency conditions, sometimes called an 'October 15th effect'. During
maximum years this often means a sudden opening of 50 MHz.
2. The much higher than expected distribution over South East Asia.
Several individuals have suggested that it must have something to do with
the special Western Pacific climate. There is e.g. a report dated in 1950
by a radio operator/meteorologist working in China after the WW2.
3. There is the need for an ion reservoir to explain the lack of
correlation between Es and meteor showers. This seems to partly
contradict with otherwise good ideas by G Neil Spokes, AB4YK.
4. The Es layers descend only down to about 105 km while theory says that
metal ion layers should be carried down by the wind pattern to about 95
km. So, the apparently shorter Es single hop distances, suggested by
Steve should generally be due to denser Es layers, not so much to lower
altitude. The so called sequential Es, where the reflection height
spirals down from 150-200 km to 105-120 km is well known to Sodankyla
people. A good reference is Tauno Turunen's doctoral thesis
"Properties of the Sporadic E layer at Sodankyla" (1977).
5. The fifth problem is the thickness of Es layers. If ionized particles
are being compressed, rather than the metal ions themself, it would take
as long as a day to compress the layer fully.
PS
1986 FM-havaitsijoista oli jaanyt pois Marko (MB):
N: EN,
NW: JJS, PRI,
NE: HHH, OSY,
SW: AVA, EKL, JOE, JSB, KRA, PJP, PTN,
SE: BKL, IM, JOB, JUS, PSO, THAe,
HEL: JTK, KTU, MIE, MB, ML, TIL,
Terveisin Vaino (VKL) (11 July 2007)
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Ennakkotilaa WRTH 2007 nyt:
http://www.hard-core-dx.com/redirect2.php?id=wrth2007
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