The 2011 10-Meter Spring/Summer Es Season
By Art Jackson KA5DWI
Background:
The following documentation is a summary of the 2011 Spring/Summer Es season based upon PropNET captures and identified fragments received at the home QTH of Art Jackson, KA5DWI, maidenhead grid square EM12ju located near Fort Worth, Texas. All of the data analyzed and displayed in this summary was accumulated by the software PNP (formally known as PropNETPSK, written and maintained by Jeff Steinkamp, N7YG. All captures logged were of the mode PSK31 from other participants of PropNET (
www.propnet.org) and others located near the 10-Meter operating frequency of 28.1188 MHz. No other frequency, bands or modes of communication were used in this synopsis. Data using PropNET captures of KA5DWI transmissions are used for comparison purposes only and captures of non-PropNET participants were used for probability measurements and non-Es propagation phenomena.
On occasion I will make references to past years in this summary. A 5-Year, followed by a 6-Year study of 10-Meter Es was written and published in 2010 and 2011 (Central States VHF Society Conference Proceedings). The data used in this analysis will be added to a 7-Year study in the future.
Any opinions and theories expressed in the summary are independent thoughts of my own and not to be construed from those members and officials of PropNET. My personal thanks go out to everyone involved and participated in PropNET for both the current and the past 8 years.
Operating:
QTH - North Richland Hills, Texas (Grid Square EM12ju), a northeastern suburb of Fort Worth, Texas in a 35+ year old neighborhood surrounded by trees and in a creek valley. A ridge of hills between 1/3 and 1/2 mile away and no lower than 60 feet higher than the tops of my antennas runs from northeast to east of the QTH.
Equipment :
Primary Rig – 20+ year old Yaesu FT-747GX, running 10 watts.
Secondary Rig – Radio Shack HTX-10 (not used for transmitting, called Lurker mode in PropNET)
Antennas:
Primary – 3-Element Yagi @ 30 feet.
Secondary – 102 inch Whip Ground Plane @ 10 feet for severe weather conditions.
Operating Schedule:
Transceiver Mode – Operated 24 hours a day for most the season.
Lurking Mode – Operated a few Sunday evenings and Monday mornings and while on vacation (7/07-7/13) or whenever severe weather was expected or occurring.
Data Statistics (April 20–August 28, 2011):
First identified partial or capture – 23:39 UTC on April 20, 2011 (KP3FT FK68qa)
Last identified partial or capture – 23:47 UTC on August 28, 2011 (KP3FT FK68qa)
Total Captures and identified partials (April 25 until August 14) – 9,453 PropNET Captures and Identified Partial/Fragments, plus 1,528 Non-PropNET Captures in which calls and grid square were identified.
Total KA5DWI Captured by other PropNET stations – 5,676 (Data not used in analysis)
The Year’s Challenges:
1. Computer – I continued to run PNP on a Windows XP Home P4 1.8-GHz 648-Meg RAM Dell Desktop. It did not run as well as it had in past years. The best I could determine was that running the newest version of PNP along with a memory and CPU hungry antivirus software were totally incompatible. On the third day of vacation, PNP failed to connect to LiveX, ran and read very poorly. I had a few short-lived power outages early in the season.
2. Software - I used PNP Version 4.5.2.0 for the season on the XP Desktop and at times the XP Pro 3 Gig Dell Desktop. After much pleasure with the 4.3.X.X version, the new version software was a disappointment. It may have been due to a CPU hog antivirus program, but at the same time changes in the settings of both the software, and what appeared to be quirkiness with LiveX added frustration to a disappointing year in Es conditions. I had to manually recalculate several days of the measured season due to several minor incidents. The changes made to the settings and operations for both the software and LixeX were to enhance the Robot operations of the software, and in my opinion adversely affected the collection of propagation data for my purposes. I had to audit this year’s data much more than I had in past ones.
3. Weather – The weather was rather violent to begin the spring. We had 3 hailstorms in April. Beginning in July, one of the longest and worst heat-waves that have happened in history began. The lack of wind caused very high low temperatures, but helped keep down static.
4. Antennas – One end of the off-centered reflector on my 3-Element Yagi bent down about 30 degrees, but did not seem to affect overall performance. It is time to finally repair it.
Normal Operation:
Transceive Mode - Yaesu FT-747GX @ 10 watts into 3-Element Yagi pointed 60-110 degrees (80 usual) azimuth.
Lurker Mode – Radio Shack HTX-10 into the 3-Element Yagi or the vertical in bad weather.
Results – 2011 Spring/Summer 10-Meter Es Season @ KA5DWI EM12ju
By the end of 2010, I had compiled the data into a 6-year study and prepared it for publication. This year I was able to present it at the Central States VHF Society Conference in Irving, Texas. With the increase in solar activity, I felt that a 7th year of participation would be interesting.
Daily Figures from the Beginning to End of the Es Season
A Year That Was a Paradox
Daily Captures:
The Spring/Summer Es season of 2010 was one of the most “on average” of the 6 years of the study. The capture trend-line for the season was amazingly “right on”. The trend line had a slight shift to the left, indicating an early active season. Solar activity continued to increase during the fall and winter of 2010-11. Solar flux had been near 130 prior to this year’s season and at the beginning was around 110. As in 2010, this year’s season began very strong very early. The season seemed to be off to an exciting beginning, but it was short-lived. The expected peak that is annually experienced on 5/09 was weaker than normal and this trend continued until the second week of June.
The deficit between this year and the average of the prior 6 was as much as 39% of normal. The peak of the trend occurred on 7/17. At this point, the season appeared to be the worst measured. Out of the blue, things picked up, the deficit declined and the season finished strong. The 2011 Spring/Summer season was only the second worst in the 7 years measured.
The first chart shows how the daily activity of 2011 compared to the prior 6 years of the Es study that I have compiled. The “Regression” line is a best fit for the 6 years of data. The “Poly (2011Total)” is the polynomial line of best fit for this year. Notice that from the start of the season afterwards that activity is well below the average levels experienced for past years and the regression line. Good or at least normal activity levels did not occur until mid-June. The best part of the season was actually from mid-July to early August and is strongly evident by the trend-line (black dashes) and peaked about 2 weeks after the summer solstice.
It was all about the strength of the openings this season. The number of active hours once again (3 years running) were better than average. What is most obvious in this analysis was that the beginning and ending of the season was much better than past years. The peak of the season was very close to past experiences.
In most other years, the first 2 weeks of the season are slow. But like last year, it started off fairly active. Most days of the season, active hours were especially good and about 3 hours better than average. This year, peak daily volumes failed to be above normal and lows (valleys) were quite common. The peaks in activity were generally one day events. There were very few multiple highly active days and is prime reason for the short-fall. July 17 was the turning point and the salvation of a bad season. The seasonal median (midpoint) for activity was on July 2, much later than other years. The seasonal median (midpoint) for active hours was on June 29, also later than other years.
Despite lower results in activity, there was at least one PNP capture each day from May 3 until August 19. This was consistent with other years measured. The active hour measurement clearly shows the late peak of the season. Although better than average years, there was only one excellent day in which there was at least 21 hours was active.
3 Day Averages:
The “3-Day Average” is an average of daily captures two days prior to the day measured and the day measured. It shows about 16 short-lived peak periods for activity and about 12 for active hours. The slow growth of the season is quite clear as well as the later peak. The most highly active period again was the 3rd and 4th week of July and not the Summer Solstice. There were never any extremely high activity periods, nor with high active hours.
6 Day Average:
The 6-Day average is the average number of captures 5 days prior to and including the day measured. It shows approximately 11 peak activity days during the season (consistent with past years). This also shows that the season was much more inactive, along with the later peak. The daily hour open hour rate did not peak as sharply as it had in past years, but remained higher throughout the entire season.
Weekly Statistics:
After 3 years of measurements, statistics show that the Spring/Summer Es season begins 8 weeks prior to the Solstice and ends 10 weeks after. This year, the charts look like reflections of last year’s. The first half of the season was slow, the second half improved, and the exact opposite of what occurred last year.
Hourly Calculations
Captures:
In 7 years of measuring, the following chart confirms each year that the most active period for Es occurs mid-mornings, followed by a less active second peak during the late afternoon approaching sunset. This year the second peak was less pronounced and twilight hour activity was non-existent.
This chart represents the actual number of captures for each hour of the day from April 25 to August 28. It is shown as a 3-hour average to centralize the activity to a specific hour. For example, the 6 AM (6) local hour is the average of 5, 6 and 7 AM. The dual-peaked diurnal (daytime) pattern matched what occurred from 2006 through 2010.
Also, the number of captures that occur each open hour during the season closely duplicates the results of the capture activity chart above. These trends occur year after year. The more likely an opening is to occur, the better the quality of the opening. This year’s decline in activity was obvious on this chart as well. The only hour that improved this year was 7 AM.
Non-PropNET Captures and Captures of This Station:
In the 4th Quarter of 2009, it was decided to change the operating frequency from 28.131 to 28.1188 MHz. Moving below .120 allowed us to capture some of the activity on that frequency. The routine setup by Dave Donnelly, KF6XA accepts user non-PropNET captures via LiveX, pulls QTH data from QRZ.com and shows them as NPN captures, as well as adds them to the database. The routine is very selective. “CQ Contest” and “CQ 10-10” does not work.
After a hot first season, this season’s total NPN activity was down as well, but impressive nonetheless. Only 2,200 captures were added. I captured 506 different calls (down 200+), 208 grid squares (only down 6) and 27 DXCC entities (way up!). I had 19 transatlantic Non-PropNET captures (also up).
I have added this data to Open Hour, Distance and Directional statistics. Total capture activity charts remain PropNET data only. The hourly data rates were not strongly affected (about ¾ hour).
Throughout the season, non-PropNET captures favored morning times. There was no discernable dual peak. Again, many felt that Es were evening phenomena. It was due to most Hams operating in the evening not the morning.
The following charts are the PropNET captures, non-PropNET captures, and PropNET captures of KA5DWI during the season. The dual peak-diurnal pattern is evident in these charts and is much sharper than past years. Captures of my station were also much lower this year by 30%.
Results by Distance
As in all prior years, a vast majority of all 10-Meter PropNET captures occur at this QTH between 1251 and 1750 kilometers (770-1070 miles). This area encompasses Florida, Georgia, the Carolinas, onward to Michigan and the Southwest U.S. Much of thee captures longer than 2250 kilometers are Non-PropNET, except for KP3FT, Jeff in Puerto Rico. We lost Hawaii and gained back Puerto Rico.
New this year was a significant increase in Trans-Equatorial propagation over 5000 kilometers. Solar flux is still not high enough to support F2, and it is my opinion that Es are still a part of this propagation. From a presentation given by James Kennedy K6MIO/KH6 this July at the Central States VHF Society Conference, he associates much of our long distance multi-hop DX events in the Summer or Winter to a combination of Es and F2 influences.
Distances by Hour of the Day:
As mentioned before, the vast majority of PropNET captures at this QTH occur near the 1251-1750 kilometer mark. The dual-peaked diurnal pattern is evident at these distances and was similar to past years. Captures between 751-1250 kilometers also peaked in the late morning hours. Both distance groups declined this year.
Once DX occurs past 1750 kilometers, it becomes apparent that it strongly favored late afternoon to evening peaks. I have classified trans-equatorial captures separately in the next chart as it deserves special attention. Due to the loss of a PNP station in Hawaii and a gain of one in Puerto Rico, these distances shifted in activity this season.
These are new charts this season. It is the Trans-Equatorial propagation experienced this season compared to last year. Notice the significant increase from 2010.
The second chart is in 2,500 kilometer increments of the “TE” propagation. The shorter distance may be more Es than F2, the farther distances are more F2 like. In order by distance; northern South America, southern South America, and last New Zealand-Australia.
Hourly Directional Trends:
A way to determine what directions are best by the time of day is to separate all captures into directional half-groups.
The next chart divides the captures easterly (0-179.9 degrees azimuth) and those westerly (180-359.9 degrees azimuth). Each group is broken into the hourly percent of the daily total. This method eliminates skewing due to the differences in volume by each directional group. As noted in this year’s chart, easterly directions are best as the sun rises. Westerly opportunities peak 1 hour after easterly ones. The westerly second peak occurs quicker. The decline is slower after sunset to the west.
As then sun rises, northern activity rises quickly. By Noon, southerly ones catch up and continued to rise and drop quickly after sunset. Northern paths strongly favored morning hours, southerly ones favored afternoon.
Outside Affects on Es
I never want to say that I have all the answer to Es, but I am always curious to find what might affect them. I have determined that meteors do strongly influence them, and I also have identified that solar events have an effect.
This year was interesting again. In 2010 activity dropped significantly when solar flux began to rise. This year it appeared to do the opposite. As solar activity was high at the beginning of the season, PNP activity was above normal. When solar activity decreased, activity was way below normal. It never approached normal, or better than until solar activity increased in the later stages of the season.
There were slight increases in the K and A-Indices during rises in solar flux. There were no major long term extremes.
It goes to show you that it is hard to pinpoint solar influences on Es propagation.
Daily Capture Maps of KA5DWI EM12ju
There were very few “big” days this year. There were few good ones. I captured 50 non-local PropNET stations this year, down 4 from last year. Here are maps of outstanding days and overall coverage.
August 4, 2011. Best day for PNP & NPN captures.
June 12, 2011. The second best day this season.
July 27, 2011. The third best day this season
2011 Spring/Summer Es Season 10-Meter Grid Squares Captured
Summary:
I looked forward to see how a rise in the solar cycle affected Es. Overall it was a below average year and if not for the latter half surge, it would have been the worst. It appeared that the increase in solar flux may have had a southerly influence and put a lid on east-west propagation. Did the rise in the solar cycle deter Es?? The worst season was at the solar cycle minimum!! There is still a mystery for someone to figure out. Good luck.
73s,
Art Jackson
KA5DWI
2011 KA5DWI Capture List
Once again, Rich-WD4RBX, Bob-WB8ILI, Jesse-K4EPS, Jerry-K8VGL, and Robert-K4RKM top the list.
Thank you again one and all for participating in 10-Meter PropNET.
© 2011 Art Jackson - KA5DWI
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