[50mhz] Es season so far

[Bill VanAlstyne]

>From New Mexico, DM65, the season started out on 11 May with some strong
openings to the midwest and a strong albeit brief double-hop opening to the east
coast on 25 May (thanks for Delaware!). The propagation path decidedly shifted
around to favor a long and strong opening to CA on 30 May -- which might be
anticlimactic for some, but since I'm avidly trying to be the first claimant for
a 6M Worked All CA Counties award, it was great. Picked up six new ones! (Have
now worked 31 out of 58 on 6M. Still a long way to go.) Since then, it's been
pretty sparse, with a couple extremely brief openings lasting no more than 30 to
60 minutes.

One of the more interesting facts about this season's Es so far seems to be the
relative paucity of morning openings, in favor of evening openings. Based upon
E-layer ionization measurements taken by balloon in the late 1940s here in New
Mexico, the strongest ionization by far, at that time, occurred between 9 and 11
AM during May, June, and early July. I've seen almost no propagation that early
in the day so far this year. And propagation to the west (CA), where ionization
at the path midpoint would be earlier in the day, has been nonexistent. By the
same token, evening openings seem to be lasting longer into the night than they
used to, with propagation to the east sometimes lasting until midnight local
time. This would put the path midpoint ionization at somewhere around 1AM local
time, when E-layer ionization is, according to the 1940s measurements, supposed
to be almost back to baseline.

So very little of what's happening this year accurately fits the E-layer
ionization model derived 50-plus years ago. Is something changing? Hard to say
at this juncture. My completely non-scientific theory about sporadic-E is that
it is somehow related to the shifting magnetic field of the planet, which at
this time is rapidly decaying toward a long-overdue magnetic pole shift some
time within the next century or two. (This is the most widely accepted theory at
the moment to explain why the field is weakening so quickly.) If by some fluke
there is such a relationship between the planetary magetic field and sporadic-E
ionization, it might explain a few things.

Anyway, here's hoping for good propagation during the contest weekend!

Bill / W5WVO



John Geiger wrote:
> Wonder what other's experience has been with the 6
> meter Es season so far.  In SW OK (EM04) it seems to
> have taken a real nose dive.  Started out decently
> last month, but has been dead the past week or so on
> 6.  Lets hope things pick up for the contest. This is
> the worst late may/early June I have seen on 6 since
> starting on the band in 1992.
>
> 73s john NE0P
>
>
>
>
>
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