Hi all. Last nights plot from Steve was very interesting. Despite his
reduction of the "gain" by some 10dB, DCF39 showed the highest recorded
levels so far around 0600z.
This is despite an small increase in the Kp recently. I think this probably
indicates that the geomagnetic disturbance only produced the same effect as
would be seen normally many days after a major storm. We have had a very
quiet period through late December and into January. I believe that under
these conditions a small increase in the ionisation in the D-layer due to a
small number of precipated electrons from the minor disturbance has lead
some multipath propagation, and some constructive interference. ( Of course
I could be totally wrong !! ) I did suggest that the rise in the Kp to 4
would manifest itself by Tues/Wed , but I suggested increased absorption and
deep troughs. There is little evidence of absorption but there are some
sharp fading troughs, which would be expected when the different path phases
This is a "good omen" for the coming solar minimum !! It indicates to me
that with a quiet sun, a small geomagnetic disturbance can be beneficial to
long distance propagation. I believe that some coronal hole activity will
continue through the quiet years whilst there may be few sunspots and
flares. (I do need to try and check on this).
It will be interesting to see the results from tonight (22/23rd) and
tomorrow night as the Kp rose to 5 just after midnight on the 20th, and has
had some further periods at 4.
Cheers de Alan G3NYK