Thanks for posting that article Patrick.
Another HUGE factor is the Bz - as Bz drops below zero, the Earth's
interplantary magnetic field orients South and becomes more susceptible
to energetic particles which can lead to aurora. As Bz rises above zero
the Earth's interplanetary magnetic field reverses to North, the
opposite occurs, and cndx improve noticeably - especially on the high
bands, but also impacting 40 -160.
Changes in the Bz orientation and magnitude can occur very rapidly, in
seconds to minutes with very dramatic changes in propagation. In
CQWWSSB 2021 I was noticing many 2 - 5 s-units swings in signal strength
in seconds to a few minutes on 10 and 15 all weekend. Like someone was
rotating the AF Gain knob back and forth on their radio!
There were similar but less dramatic swings in signal strengths on EU
signals on 40 - 160 over extremely short time periods as the Bz moved
from negative to positive and back again. These signal strength
changes were not the usual QSB.
I'm sure that if Carl were updating his article in 2022 (his original
article written in 2008) he would include Bz and discuss its importance.
Bz direction and magnitude is one of the more important factors in 160
propagation as well as on 80 - 10.
73
Bob, KQ2M
On 2023-01-11 08:36, W7TMT - Patrick wrote:
Lower solar wind speed perhaps?
Carl, K9LA has an interesting article linking solar dynamic
pressure/solar wind speed to 160M propagation predictions.
It is found here: https://k9la.us/Predicting_160m_Propagation.pdf
Based on the historical data for the last 7 days found on the NOAA
Space Weather Center site it appears that the wind speed numbers have
been trending down, with the exception of a cluster of short spikes,
over the last few days of reported improved propagation.
The historical data can be viewed here:
https://www.swpc.noaa.gov/products/real-time-solar-wind
Patrick. W7TMT
-----Original Message-----
From: Topband <topband-bounces+w7tmt=outlook.com@contesting.com> On
Behalf Of Roger Kennedy
Sent: Wednesday, January 11, 2023 03:32
To: topband@contesting.com
Subject: Topband: Good Conditions
As someone commented, maybe we should complain about poor conditions
more often, as the band was in good shape for DX last night!
I came on for a while from around 0300Z, and worked 22 NA stations in
18 different States . . . best DX was Texas.
Good to hear so many stations on 160m, both sides of the pond.
I'm still suffering with a high noise level, so apologies if you were
one of the stations calling me that I couldn't quite copy. OFCOM have
shut down one of my local noise sources . . . they are coming back up
here tomorrow to hopefully shut down the other one. (they have located
the source, but the offending business was closed)
73 Roger G3YRO
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