Sunday, September 22, 2013

4-Year Analysis Spring/Summer Es Propagation from PropNET

The following charts and data are based on 10-Meter PropNET and Non-PropNET PSK31 captures of North American PropNET participants from April 25 through August 15 2010 - 2013.

A specific formula was used to distinguish Sporadic Es propagation from F2 or Trans-Equatorial propagation. Only PropNET participant data from North America and Hawaii was used in the study. Any questionable data was removed to the best of my ability.

This information is for the use Amateur Radio public.  Please reference PropNET Studies as the source.

Narrative will be added as time permits.

Enjoy.  This stuff is fascinating and I believe it answers many questions about Sporadic Es propagation from year to year.

After one of the longest lulls in the Solar cycle ever recorded, the sun finally started to get more active in 2011. Unfortunately the increased activity in Solar Flux peaked in 2012.  Many look for a second peak in 2013-14.
Once the 2012 Es season ended, solar flux hit levels approaching 180.  By the spring of 2012 it had begun a decline.
On the other hand, the actual number of sunspots has not declined that much.
The number of new sunspot regions have actually grown year to year since 2010.
Despite the growth in new regions, these do not last very long.
Their ability to produce intense flares has been impeded.

Solar activity actually has a steady increase since 2010.  Due to mistiming of the solar poles, there has been a less extreme rise in solar flux. New sunspot regions form, create instability but do not produce the high MUF to support F2 propagation.

In 4 years, North American PropNET participants captured almost 300,000 packets from other members or non-participants transmitting specific algorithms. 

These are the average daily captures by day six weeks prior to and after the Summer Solstice. The trend line produced by the data shows that peak activity occurs at or near the solstice.
The overall trend was highly affected by the volumes of 2010 and 2011.
2010 - The last year of low solar activity.
2011 - Solar activity picks up.  The season had a lull early, and then became active toward the latter half.
2012 - Solar activity has peaked.  What activity there is occurs in the first half with a large lull during the solstice period.
2013 - Solar activity remained high. The trend line was almost a duplicate of 2012.
Activity has drastically deceased since 2010.
The number of open hours each season has declined, but at a slower level.

As has been seen in most years, Es activity has a dual-peaked diurnal.  In 2010, it was a morning peak.  As solar activity increased, it became afternoon active.
11:00 UTC represents sunrise on the East Coast of North America.  Activity peaks 2 hours prior to noon in the center of the continent and again 2 hours before the sun begins to set.
When solar activity was low, the morning hours are most active. As solar activity increases, it shifts to afternoon.
This chart is based on an equal percentage breakdown.  The highest hourly percentage of day occurred late afternoon when solar activity was its highest.
As solar activity increased, active hours of Es declined.
As the season begins if an hour opens, intensity increases until the solstice and steadily declines afterward. 
This chart shows that once solar activity increases, intensity drops of at beginning and end of the season.
As noted on the chart, low solar activity has a great influence.

F2 and Trans-Equitorial:
As solar activity rises so does TEP open.  This was very prevalent in the last 3 years.

Population Changes in 4 Years:

PropNET captures were about 5 times greater than Non-PropNET captures.

Changes in the mixture of PropNET to Non-PropNET changes since 2010 have occurred, but are very slight overall.  For the past two seasons, PropNET to Non-PropNET are at 80% to 20%. The only real changes that were noticeable were around year 2011 and were no more than 5%.

 The decline became more extreme after 2011
 Non-PropNET declines more evenly in 4 years.
 The mix of Non-PropNET to PropNET does not change much.
The overall decrease since 2010 for PropNET captures is about 3.5% greater than Non-PropNET..

Comparing North To South:

I wondered if what happens in the southern half of the continent is different than the northern half.  I split the continent at the grid squares FMx7, EMx7, DMx7 and CMx7 to the north and measured the data by hour by year.  To my surprise there is little difference, other than there is more activity in the south.

There are more active southern participants in PropNET.

When the totals are broken down by percentage of day, the north sees more Noon activity, the south sees more sunrise and sunset activity.  Not much difference, but a little more noticeable the last couple of years.

More Directional Comparisons:

So how does Es propagation differ by direction.  Once again consistant North to South, East to West.  Only Northeast to Southwest, Northwest to Southeast show any differences. 

 There are little differences in these directions.
Most activity is to the North.

 Only Eastward conditions are more volumes found.
Northeast and Southwest show morning activity.
Northwest and Southeast show afternoon and evening activity.

As was expected, solar activity has a profound affect on Es propagation after the minimum has occurred. The peak should occur by the winter.  It will be interesting to see how these numbers change the next few years.  I think it will be on the way up.

More analysis to come...............

Art Jackson KA5DWI