In 2004, I first dabbled with PropNET on 10-Meters, if I recall using UI-View and MultiPSK. Back then, a Catch report was generated to create an “hour by hour” – “day by day” historical record of captured PropNET PSK31 captured packets, as well as a listing of transmissions that failed to acquire a captured status. I was impressed with the results in 2004 and decided to do a full-time PropNET effort in 2005 for what I call the “Spring/Summer Sporadic Es” season.
I do not believe in Magic. Everything happens for a logical, mathematical and scientific reason. Given the right conditions and sampling of data, anything can be explained by numbers. So the quest to find to find answers to Sporadic Es began in 2005. The journey was worth it.
It is beginning to appear that in the modern day measurement of solar cycles are showing that most of them have dual peaks. Cycle 23 peaked in July 2000 and again September 2001. Cycle 24 peaked in November 2011 and once again in April 2014. As noted by the graphs, Cycle 24 was much weaker than Cycle 23. Maximum usable frequencies were rarely higher than 40 MHz and 6 Meter F2 propagation was extremely rare. Also, Cycle 23 declined for 9 years. The average decline is 7 years.
My total number of PropNET captures for 7 years was 88,195, about 12,600 per year.
In 2009, solar flux was at minimum levels (67). By 2010, it was slowly increasing. Solar flux began to surge during 2011 and peaked late that year. Solar flux remained high in 2012. Many thought the peak had occurred as it dipped in 2013, but resurged to the highest spring/summer level in 2014. It finally had begun its decline in 2015.
Background X-Ray flux is the average daily X-Ray flux experienced each measurement period. It is a numeric interpretation of Alpha/Numeric values (A0.0=0, B1.0=10, C1.0=19). The sun was spotless most of 2009.
The A-Indices indicate geomagnetic activity. As noted earlier for the past solar cycle, this activity tends to peak a couple of years after the final peak of solar flux.
At least one of these solar or geomagnetic indices increased year following the 2009 lull.
In 2009, PropNET 10M operations were on 28.131 MHz, 11 kHz above the majority of regular PSK31 activity. Late 2009, the operating frequency was changed to 28.1186 MHz, 1.4 kHz below the activity. Thanks to Dave Donnelly’s KF6XA routines, this allowed for the capture of Non-PropNET activity surrounding 28.120 MHz. Non-PropNET activity accounted nearly 20% more captures in 2010. Therefore if Non-PropNET captures had occurred in 2009, the total captures that year would be been near 90,000. My personal PropNET statistics showed a decline of PropNET captures of 6% between 2009 and 2010.
The next graph shows a steady decline of capture activity since 2009.
PropNET activity between June 1 and July 9.
For the above chart, 2009 and 2015 data was removed.
10-Meter PropNET activity declined from 2010 to 2015 at an “exponential” rate. For non-math people, in science and nature, growth and decline occurs exponentially. If the data precisely fits the trend-line equation, the coefficient of determination (R-Squared) value would equal to one (1). In this case, 0.9538 is not bad at all.
For both years, the number of sunspots was nil to just a few. Solar activity was very low. In 2010, solar flux increases showed that Cycle 24 had just begun.
When no sunspots are on the Sun, background X-Ray flux is zero (A0.0). So was the case in 2009. In 2010, the formation of new sunspots created a couple of spikes in the X-Ray flux.
Geomagnetic activity was also very low in 2009. In 2010 there were signs of a few minor disturbances.
The pattern of activity focused on the summer solstice was evident in 2009. In 2010 there was a surge around Independence Day. The trend-line showed that activity peaked at the solstice, normal for 2005-2008.
2011 – The Solar Cycle Gets Active
At the beginning of the measuring period, solar flux was high enough to promote F2 and TEP propagation. As the days passed, it dropped to fairly low levels.
Background X-Ray flux was much higher than 2010. Its value was B1.0 or higher for all but one day. This was probably the best indicator than it would be active in the fall.
Geomagnetic activity was not much different than 2010.
Total PropNET activity was over 50% less than the prior year. It was 27% lower at my QTH. There was little evidence of a peak at the Summer Solstice. Not noted on the graph, it was very inactive from July 9 through the end of the season.
Background X-Ray Flux 2012-2015
The movement of background X-Ray flux was similar to solar flux in that it was rising and declining steadily. There were really no major/extreme solar flares this solar cycle.
The Geomagnetic A-Index clearly shows that it peaked after Solar Flux was back into decline. 2015 was the most active year. As mentioned earlier like solar flares, there were fewer large Coronal Mass Ejections (CME) within this solar cycle. Although there were some disturbances, they were generally short-lived.
2011 was the last good year for activity and far less than the previous 2 years.
At the bottom of Cycle 23 and the early stages of 24, 2009 and 2010 were outstanding years.
The cumulative activity of 2011-2015 was not half of what was experienced in 2009-2011. The hour to hour pattern did remain the same, a dual peaked diurnal (mid-morning & late afternoon).
The last 4 years have been very poor and in total just equaled 2011.
When the solar cycle (solar activity) was its lowest, Es peak at the Summer Solstice.
Once solar activity increased, the day to day pattern reversed.
A note: F2 High frequency maximum usable frequency (MUF) actually declines slightly as the Summer Solstice approaches.
In 2010, there were ninety (90) 10-Meter PropNET catches per hour. In 2014 there were barely five (5) catches per hour. The trend-line decline between these years was as perfect a polynomial mathematical equation you can compute (exact equals 1).
These hourly charts show the decline across the day. Each hour of the day was affected equally. The increase between 2009 and 2010 is due to Non-PropNET catches from a change of frequency.
Whether we had great conditions or bad ones, this is the most active and intense hour of the day. The morning sun is visible across N. America.
It is just a theory, but I think the fact that this solar cycle was “anemic” might have been the culprit.
Notice the peaks of geomagnetic disturbances declined throughout the year.
Art Jackson KA5DWI/7