PROPAGATION
A Quick Look at Current Cycle 24 Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, February 2020: 0
12-month smoothed, August 2019: 2
10.7-cm Flux:
Observed Monthly, February 2020: 71
12-month smoothed, August 2019: 70
Ap Index:
Observed Monthly, February 2020: 6
12-month smoothed, August 2019: 6
One Year Ago: A Quick Look at Solar Cycle Conditions
(Data rounded to nearest whole number)
Sunspots:
Observed Monthly, February 2019: 1
12-month smoothed, August 2018: 4
10.7-cm Flux:
Observed Monthly, February 2019: 71
12-month smoothed, August 2018: 70
Ap Index:
Observed Monthly, February 2019: 7
12-month smoothed, August 2018: 7
It is not news that the overall activity on our Sun is low. It is common knowledge that during this period of low sunspot activity, the ionosphere is not energized enough to support global propagation of signals much higher in frequency than, say, 20 meters. Don’t give up hope, though. There is a very high probability that activity can occur on these higher frequencies during May.
The annual summer Sporadic-E (Es) season begins around May 1 (sometimes during the last week of April). The activity is sparse during the first two weeks of May and then it picks up to about 60% of the days by the end of May. This is great news for 10-meter enthusiasts. Now is the time to send out your signals in hopes to catch some propagation.
During the first days of May, oxygen ions that are in the E region of the ionosphere are being excited more and more by the increasing closeness of the Sun. This causes them to recombine with metallic ions that are also present in the E region. During this E season, which should last through summer, thin layers of these energized ions form, making it possible to refract higher HF and low
