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Joe from Kokomo[_2_] · September 10th 15, 01:24 PM posted to rec.radio.shortwave

On 9/9/2015 7:35 PM, wrote:

Most of the diehards are still around. But (very long pause) the
present solar cycle is really the worst according to the astronomers
... since 1750.

Yes, poor conditions that got even worse yesterday (9 Sept). The K index
was 6, a G2 radio blackout, some classified this as a "major storm".

With the sun so quiet, no coronal mass ejections, no sunspots, how could
radio conditions be so bad?

The quote from spaceweather.com below seems to have the answer:

Powered by fusion, the sun is a 1027-ton nuclear explosion contained
in one place only by the awesome force of its own gravity. How quiet
can such a thing be? Very. According to NOAA, solar activity has
been very low all week long. No sunspots are flaring, and the sun's
X-ray output has flatlined. The chance of a strong solar flare on
Sept. 10th is no more than 1%.

How can such a display [referring to auroral displays in the article but obviously affecting radio propagation] occur while solar activity is so low? The
answer has to do with the interplanetary magnetic field (IMF). On
Sept. 7th, the IMF tilted south, opening a crack in Earth's
magnetosphere. Solar wind (which exists even during times of quiet)
poured in to fuel the auroras [and mostly killed HF propagation].

The 20 meter ham band was marginally decent on the 7th and 8th (at least
for the digital modes, PSK and JT) but the bottom dropped out on the
9th. It was so quiet that my first thought was that the antenna fell
down. :-)