Sporadic-E Radio Propagation

[hamateur 1953]

2 hours ago, Drax Spacex said:

I check the 6m band SSB calling frequency 50.125MHz a few times a week, and have called CQ a few times, but haven't heard anything from my location in several months.  I see the Boulder MUF rise to just over 40MHz a few days ago, but yeah will need a large boost in SFI for sustained MUF above 50MHz, something I have not experienced.  In the meantime, the 10m band has been really good for both domestic and international contacts, a benefit during the years of solar maximum!

Indeed @Drax Spacex  We are likely to get another year at least like this with flux hanging around 150-175 with occasional runs over 200.  I have never seen a twelve or thirteen mo smoothed 10.7 but 25 is so close to cycle 20 it’s kinda spooky as both @Philalethes and me have remarked before.    Across the Atlantic is nice with salt water for your lower loss first hop to be sure.  We still could get a wild peak over 250.  Never know,….. 73 Drax. Mike.   Edit. As you probably are aware we may get a chunk of spectrum around 40 mhz. Hams are making many contacts legally using the experimental callsigns in the United States. Parts of Europe have 8 metres as you probably know.   Couldn’t happen too soon for me!   

Edited March 5 by hamateur 1953
8 metres

[hamateur 1953]

On 3/27/2023 at 10:38 AM, KW2P said:

Great article. Finally got time to read it.

One thing that's clear is we shouldn't feel badly that it's taken 90 years to get close to an answer, and we still don't have it all. It's complicated.

As a ham radio guy I would someday like to have accurate forecasts of Es conditions, but that's still off in the future.

After reading the article I'm a bit puzzled about why the repeated reference to "metal ions".  Metals are conductive because the electrons in the outer shell are loosely bound and free to move. As a result, metals are easily ionized. But metals reflect radio waves regardless. It doesn't matter whether they're ionized or not. Why doesn't the article just say "metallic particles"?

Good points. @KW2P  What I would like to do this coming Es season is try to ascertain whether there is a coincidental occurrence of Es with flare activity.  A reasonable observation should also see whether there exists Es when we only have normal solar flux within 140-200 or so.  
I will be using dx maps daily at 50 mhz to keep an eye on activity and it may prove interesting as a general forecasting tool.  I’ve also read accounts where people have attempted this before and were frustrated, but this was forty years ago. Before we had as many tools available to the general public.  73  Mike N7ORL   Edit: another important factor to be considered is that the character or wavelength composition of each flare is probably unique. But for now, I am not going to worry too much about that.  Hams are only interested in results….  Any other ideas of monitoring or logging are most definitely welcomed by me incidentally either here or by PM. Mike 

Edited March 9 by hamateur 1953

[helios]

There's something that I don't understand. There are often areas where sporadic-e occurs more often than others. The influence from the sun or meteors isn't that localized.

In Europe there is an area between southern UK and Belgium where there are very frequent sporadic-E-clouds. At least it was like that until last fall. But since then, about half a year, it almost completely stopped. But instead it seems to be happening more frequent in North America.

I operate 24 receivers simultaneously to monitor the propagation 24/7, so I have somewhat empirical data. But it seems pretty much uncorrelated with anything. I guess that's the "sporadic" in sporadic-e.

Edited March 9 by helios

[hamateur 1953]

2 hours ago, helios said:

There's something that I don't understand. There are often areas where sporadic-e occurs more often than others. The influence from the sun or meteors isn't that localized.

In Europe there is an area between southern UK and Belgium where there are very frequent sporadic-E-clouds. At least it was like that until last fall. But since then, about half a year, it almost completely stopped. But instead it seems to be happening more frequent in North America.

I operate 24 receivers simultaneously to monitor the propagation 24/7, so I have somewhat empirical data. But it seems pretty much uncorrelated with anything. I guess that's the "sporadic" in sporadic-e.

That is especially interesting to me @helios  24 receivers wow.  Anyway In the states it seems to always be present throughout the most of our summer months as noted.  I’m guessing that you are already aware of the main frequency range where we observe it occurring here. Typically 28-70 mhz.  Naturally with flux over 150 or so F2 comes into play regularly below 40 mhz or so.   What frequencies are you monitoring primarily?? 

Edited March 9 by hamateur 1953
Clarity

[Pom]

Heja all,

 

I'm freshly registered, however not new to the forum. I've been reading the forums for early aurora warnings for some years not to miss any VHF aurora propagation coming down to N52 E09 / JO42. Thank you all for the discussions on radio emissions, CMEs and halos!

My main interest is portable VHF DXing like ACS, tropo, MS, Es, aurora. I'm a keen SOTA OP having a crappy home shack and I appreciate getting reliable information on lift condx beforehand, as it's a 45 mins drive, another 30 mins ascent to a nearby summit and 15-30 mins of deploying my station depending on the setup I want to use. Long story short, I'm one of the guys getting excited by solar condx when HF radio amateurs moan about Mögel-Dellinger.

On topic, GM4FVM recently posted a decent summary of Es research on his blog. Nothing new in it, but it is a good sum-up of three important papers from the 21st century and helps well to understand how Es works.

5 hours ago, helios said:

At least it was like that until last fall. But since then, about half a year, it almost completely stopped.

Assuming you're located in Europe. Stay patient, Es season is on its way. Having operated exclusively on 28 megs (except my favourite band 144 MHz) for the past three months, I can see the hops are getting shorter while summer condx approaching. Euro stations came to my log rather seldom, only EA7, SV and F4WBN with his decent antennas and the Pyrenees in his back to central EU. For some weeks, EA3, CT and S5 have been logged now. Today even I3 and I was also able to hear weak signals from G-land, however too weak to complete QSO. So, hops are getting shorter and better for inter-EU Es contacts. Wait for May when Es in combination with F2 will make the upper HF bands the place to be. 🤩

 

Ahoi

Pom, DG7AC

Edited March 10 by Pom

[hamateur 1953]

20 minutes ago, Pom said:

Heja all,

 

I'm freshly registered, however not new to the forum. I've been reading the forums for early aurora warnings for some years not to miss any VHF aurora propagation coming down to N52 E090 / JO42. Thank you all for the discussions on radio emissions, CMEs and halos!

My main interest is portable VHF DXing like ACS, tropo, MS, Es, aurora. I'm a keen SOTA OP having a crappy home shack and I appreciate getting reliable information on lift condx beforehand, as it's a 45 mins drive, another 30 mins ascent to a nearby summit and at 15-30 mins of deploying my station depending on the setup I want to use. Long story short, I'm the one of the guys getting excited by solar condx when HF radio amateurs moan about Mögel-Dellinger.

On topic, GM4FVM recently posted a decent summary of Es research on his blog. Nothing new in it, but it is a good sum-up of three important papers from the 21st century and helps well to understand how Es works.

Assuming you're located in Europe. Stay patient, Es season is on its way. Having operated exclusively on 28 megs (except my favourite band 144 MHz) for the past three months, I can see the hops are getting shorter while summer condx approaching. Euro stations came to my log rather seldom, only EA7, SV and F4WBN with his decent antennas and the Pyrenees in his back to central EU. For some weeks, EA3, CT and S5 have been logged now. Today even I3 and I was also able to hear weak signals from G-land, however too weak to complete QSO. So, hops are getting shorter and better for inter-EU Es contacts. Wait for May when Es in combination with F2 will make the upper HF bands the place to be. 🤩

 

Ahoi

Pom, DG7AC

You won’t find a lot of moaning here Pom.  We are mostly excited about CMEs. I have a number of interests, Ham Radio only one.  The Es article you referred to in your post, would you share a link here if possible?  73 Mike N7ORL 

[helios]

2 hours ago, hamateur 1953 said:

What frequencies are you monitoring primarily?? 

On one hand I am running broadband spectrographs. Two channels, 0-30 MHz and 30-60 MHz with 1028 bins each.
And then I'm logging FT8 and WSPR traffic on all amateur bands from 2200m to 6m simultaneously for statistical analysis of the propagation.

We had more frequent and more intense (higher foEs) Sporadic-E during solar minimum than now. So I'm not very convinced that there is a strong correlation between F10.7 and Es. Or perhaps there is even a negative one.

[Pom]

38 minutes ago, helios said:

Or perhaps there is even a negative one.

This!

 

 

 

59 minutes ago, hamateur 1953 said:

would you share a link here if possible?

Hej Mike,

it's already there. Just click on GM4FVM.

 

Ahoi

Pom

Edited March 10 by Pom

[hamateur 1953]

Thanks guys. @Pom and @helios

I agree completely with your perspectives on Es as far as 10.7 and its effects on our E layer goes.  Not sure if there is a negative effect when taking seasonal variations into consideration though.  As you guys are probably aware the E layer is only really affected by soft and hard X radiation anyway* Hard UV isn’t even going to get down to its level typically.  Appreciate the link.  It won’t stop me from investigating alternatives like M and X class flaring but was interesting nonetheless.  73. Mike N7ORL   I should add here that this is highly speculative and even if I do eventually discover a likely causative link, it probably is not the only reason for Es and likely requires other factors to be present.   * As a generalization and percentage, of course. 

Edited March 10 by hamateur 1953
Clarity

[helios]

A speculation:
During solar maximum, the Exosphere and Thermosphere are heating and extending further into space. Perhaps micro meteorites burn up at higher altitudes and do not reach the altitude of the E-layer. Respectively, only a fraction of them.

[hamateur 1953]

21 hours ago, helios said:

A speculation:
During solar maximum, the Exosphere and Thermosphere are heating and extending further into space. Perhaps micro meteorites burn up at higher altitudes and do not reach the altitude of the E-layer. Respectively, only a fraction of them.

Certainly plausible, hadn’t even considered this.  I had a funny fantasy you may get a kick outta. Many of us are dismayed when there is no ejecta hence no cme or geomagnetic storming with X flares.  Hams, particularly HF guys love it. Cuz all the radiation, no disruptions.   Anyway assuming my crazy idea has merit:  We see a massive X 15 or so, immediately the e layer is hit hard.  Predictive models set an arrival time at   48 hours,  plenty of time to log those rare grid squares until the geomagnetic storm of the century arrives. Haha. Later @helios  73. Mike   Edit: we had an interesting coincidence back in January in the states where we had nine M class flares over some eight hours. I was speculating that it might have been sufficient to give us a nighttime E layer as the Aug 4 1972 event did over Russia. I never expected it to really happen. @KW2P apparently observed this live, it was too far south for him or me to take advantage of it but he advised me later about it.  This fact definitely got me thinking about it, as you might imagine.  Another nugget of information I learned the other day:  we actually accumulate sixty tons of meteoric dust daily!  No kidding. As I noted elsewhere I have no idea who measured this. But it seems valid at present.  90 percent of which is iron or iron-bearing chondrite.  
  

Edited March 11 by hamateur 1953
Addendum

[hamateur 1953]

22 hours ago, helios said:

There's something that I don't understand. There are often areas where sporadic-e occurs more often than others. The influence from the sun or meteors isn't that localized.

In Europe there is an area between southern UK and Belgium where there are very frequent sporadic-E-clouds. At least it was like that until last fall. But since then, about half a year, it almost completely stopped. But instead it seems to be happening more frequent in North America.

I operate 24 receivers simultaneously to monitor the propagation 24/7, so I have somewhat empirical data. But it seems pretty much uncorrelated with anything. I guess that's the "sporadic" in sporadic-e.

Another thought on your observations  Sporadic E and distances.  Typically the higher the ionisation the shorter the hops as you no doubt are aware. Also the higher frequencies are reflected or refracted whichever you prefer to believe.  A station in the UK might be able to be received in your location on 90mhz FM band but further up in the band because the angle of effective refraction is lower in angle it still takes place, however it literally skips over your location.  This is a definite possibility.  However it does seem to me that you are monitoring DC to light as we used to say, you probably don’t miss much either 😆

Edited March 10 by hamateur 1953

[Jim Sinclair]

In the 1960's I was active on 6 and 2 metres from the Adelaide, South Australia area. In early summer each afternoon there was usually a fairly regular activity between Adelaide area VK5's and Brisbane area VK4's. There was a sort of channel opened up between us which was specific to those two areas. Propagation was fantastic, signal strength was comparable to local contacts. At that time nobody knew anything about the solar wind, Van Allen radiation belts or a magnetosphere but we all assumed it was something due to ionization from the sun but we didn't know how it worked. We now know that the magnetosphere causes charged particles to circulate so it is entirely possible that charged particles of a particular atomic weight from a solar origin could end up on the dark side of the Earth.

 

[hamateur 1953]

Howdy @Jim Sinclair Two metres would shock most of us stateside guys.  Myself included.  Guessing you probably were on am phone.  Although I cannot recall now your license class requirements.  CW obviously would have been fine too.  I was recently reading some discussions on “ ion precipitation “. Or raining into our E layers by Aurora along our magnetic field lines.  So many things to try to visualize, it boggles the mind at times!!  Edit  I had to look up the air miles  1,000 miles or about 1,600 km  perfect for Es at 50 mhz   

73. Mike N7ORL

@Newbie might find this interesting too.  Not a ham though 

Edited March 11 by hamateur 1953
Air miles

[hamateur 1953]

On 3/9/2024 at 4:39 PM, Pom said:

This!

 

 

 

Hej Mike,

it's already there. Just click on GM4FVM.

 

Ahoi

Pom

I really enjoyed reading that summary, especially enjoyed reading “ everyone is entitled to waste their time as they see fit”. 🤣. Only a Ham would say that without fear of contradiction! 73 @Pom Mike N7ORL 

[Newbie]

13 hours ago, Jim Sinclair said:

In the 1960's I was active on 6 and 2 metres from the Adelaide, South Australia area. In early summer each afternoon there was usually a fairly regular activity between Adelaide area VK5's and Brisbane area VK4's. There was a sort of channel opened up between us which was specific to those two areas. Propagation was fantastic, signal strength was comparable to local contacts. At that time nobody knew anything about the solar wind, Van Allen radiation belts or a magnetosphere but we all assumed it was something due to ionization from the sun but we didn't know how it worked. We now know that the magnetosphere causes charged particles to circulate so it is entirely possible that charged particles of a particular atomic weight from a solar origin could end up on the dark side of the Earth.

 

It's interesting to hear about your experiences with sporadic E propagation in the 1960s.
The speculation about charged particles from a solar origin influencing ionisation on the dark side of the Earth aligns with the understanding we now have about the impact of solar activity on the ionosphere. It's great how empirical observations from the past contribute to our evolving knowledge of ionospheric phenomena.

N.

@hamateur 1953

The article provides a fascinating overview of the some of variables to consider when attempting to unravel the mystery that is sporadic e propagation.

Historically it was thought weather played a part, eg. thunder storms and lightning but that’s been debunked now which was mentioned in the article.

Some reasons for the regional variability of sporadic E may include:

Geographic Location: The latitude and geographic location of a region play a crucial role. Sporadic E events are more common at mid-latitudes, so areas closer to the equator or poles may experience them less frequently.

Solar Activity: The Sun's influence on the ionosphere is a significant factor. Changes in solar activity, including sunspot cycles and solar flares, can impact ionisation levels and contribute to sporadic E events. Sunlight and solar radiation can also be a factor.

Magnetic Field Variations: The Earth's magnetic field varies across different regions, affecting how charged particles interact with the ionosphere. Magnetic anomalies may contribute to regional differences in sporadic E occurrences.

Seasonal Changes: Sporadic E events often show seasonal patterns. Certain times of the year, such as late spring and early summer, may see increased occurrences, while other seasons might experience fewer events.

Ionospheric Composition: Variations in the composition of the ionosphere, including the presence of metallic ions, can contribute to sporadic E.
The solar wind and meteor dust distribute particles into the ionosphere. This composition can vary across different regions. 

Understanding the complex interplay of all of these factors within the framework of the ionosphere, which is dynamic in nature, helps to explain why sporadic E events are not uniformly distributed globally. 
-.

[hamateur 1953]

On 3/9/2024 at 12:16 PM, helios said:

There's something that I don't understand. There are often areas where sporadic-e occurs more often than others. The influence from the sun or meteors isn't that localized.

In Europe there is an area between southern UK and Belgium where there are very frequent sporadic-E-clouds. At least it was like that until last fall. But since then, about half a year, it almost completely stopped. But instead it seems to be happening more frequent in North America.

I operate 24 receivers simultaneously to monitor the propagation 24/7, so I have somewhat empirical data. But it seems pretty much uncorrelated with anything. I guess that's the "sporadic" in sporadic-e.

I know little about our magnetic field lines other than the obvious fact that they exist and are obviously subject to becoming distorted by solar geomagnetic disturbances @helios  perhaps the preponderance of Es along a specific corridor exists due mainly to the magnetic agglomerations referred to in the link that @Pom supplied.  Makes sense to me conceptually at least.  Btw on the swelling of our atmosphere. This makes sense as well to me after some thought.  Sweeping up meteors higher up , that is.   Currently our SFI is tanking unfortunately but since the winter anomaly has mostly passed anyway F2 would typically dive regardless due to the higher losses of ions at F level during normal summer in northern hemisphere. Another Es season is coming our way, regardless. 73 Mike. N7ORL  

Edited March 11 by hamateur 1953
Clarity

[hamateur 1953]

11 hours ago, Newbie said:

Location

About the only thing that us radio amateurs observe with regard to location and E propagation that is actually fairly reliable is Transequatorial propagation.  Hams along our southern tier states are able to hop the equator on a pretty predictable basis and at 50 mhz ( six metres)  I live too far away to hit that zone of influence, but it is a pretty reliable thing as I have read   Suspected to be a chordal hop as no stations are worked in between  it also produces very strong signals characteristic of E layer reflection  

 

 

l

[hamateur 1953]

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JA029921    
 

I recalled @Drax Spacex posting some intriguing stuff about research being done in Antarctica awhile back. 
The link above is an abstract for those interested in E layer propagation. 73. Mike. @KW2P

Edited March 21 by hamateur 1953
Tagged KW2P in the event he might find it interesting

[KW2P]

On 3/20/2024 at 9:54 PM, hamateur 1953 said:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JA029921    
 

I recalled @Drax Spacex posting some intriguing stuff about research being done in Antarctica awhile back. 
The link above is an abstract for those interested in E layer propagation. 73. Mike. @KW2P

Thanks for posting. That's some serious reading for another day.

Just wanted to add a couple things on transequatorial propagation. My experience is the latitude matters a lot. When I operated from Southern Nevada, working South America on 10 meters with booming signals was pretty much a daily thing. It was so common and easy to work Chile, Argentina, Brazil it was almost boring.

From here in West Virginia, no. There are openings to SA from time to time and signals are never strong. Huge difference. I suspect my path to South America is F-layer or an F bounce plus an E bounce.

As an aside, it's my understanding that hams who live along the equator can easily and reliably work stations that are also along the equator, so directly east or west. This implies that whatever is doing the reflecting is concentrated near and along the equator.

Another personal observation is that Antarctica on 10 meters from Southern Nevada or Southern California was pretty easy with strong signals. From West Virginia, no. Working Antarctica is a struggle from here. I've never had strong signals from Antarctica or South America here in Wrst Virginia.

[hamateur 1953]

2 hours ago, KW2P said:

Thanks for posting. That's some serious reading for another day.

Just wanted to add a couple things on transequatorial propagation. My experience is the latitude matters a lot. When I operated from Southern Nevada, working South America on 10 meters with booming signals was pretty much a daily thing. It was so common and easy to work Chile, Argentina, Brazil it was almost boring.

From here in West Virginia, no. There are openings to SA from time to time and signals are never strong. Huge difference. I suspect my path to South America is F-layer or an F bounce plus an E bounce.

As an aside, it's my understanding that hams who live along the equator can easily and reliably work stations that are also along the equator, so directly east or west. This implies that whatever is doing the reflecting is concentrated near and along the equator.

Another personal observation is that Antarctica on 10 meters from Southern Nevada or Southern California was pretty easy with strong signals. From West Virginia, no. Working Antarctica is a struggle from here. I've never had strong signals from Antarctica or South America here in Wrst Virginia.

Agree completely on the F2 to South America. Even from my latitude in Western Washington I could hear the chirpy signal of 100 watt beacon PY2AMI nearly every single day! For two years during SC23. Ha. The 50 mhz paths naturally never opened up this far north.  73. Mike   Btw. Solar flux was much much higher and those times really happened during the “ winter anomaly” well known to us hams.   I’m a bit surprised now reading that WV is tougher hmmm have to think about that awhile. I’m around 42-43 N. I think.  Mike

Ten meter CW beacon PY2AMI is listed as still active to my surprise however I have not personally verified this. 😋

Edited March 23 by hamateur 1953
Afterthoughts

[KW2P]

17 minutes ago, hamateur 1953 said:

Agree completely on the F2 to South America. Even from my latitude in Western Washington I could hear the chirpy signal of 100 watt beacon PY2AMI nearly every single day! For two years during SC23. Ha. The 50 mhz paths naturally never opened up this far north.  73. Mike   Btw. Solar flux was much much higher and those times really happened during the “ winter anomaly” well known to us hams.   I’m a bit surprised now reading that WV is tougher hmmm have to think about that awhile. I’m around 42-43 N. I think.  Mike 

39.2 North here.

Being 2,000 miles west of here might also have made a difference.

The upside of being here in WV is Europe is pretty much my back yard, easy, especially Spain and France.

[helios]

Yes, around the Equator 10m works on regular F2 propagation.
Here's for example a VOACAP simulation for 100W SSB from Cuba to Peru.

[hamateur 1953]

57 minutes ago, helios said:

Yes, around the Equator 10m works on regular F2 propagation.
Here's for example a VOACAP simulation for 100W SSB from Cuba to Peru.

Cool Helios.  Only time I had a decent chance I was on vacation on the tiny island of Bonaire Netherland Antilles in 1979. But was vacationing there.  There are now a few Hams there too plus the most powerful MW station at 1,000,000 watts on 800 khz. Still operational ( I checked). Unfortunately we were just vacationing there only had time to take a fluorescent tube in both hands and walk along the feedlines to see the modulating signal.  Wife wasn’t interested in the least!  🤣🤣. Afterthoughts:  It is a shame that they don’t go above 30 mhz however digisonde data seems to correlate pretty well with the MUFs I have been observing over the last two or so years.  Highest was 44 on our east  coast so far. Hawaii hits 50 mhz  with regularity it seems to me.   Mike. 

Edited March 23 by hamateur 1953
Six meter woes. Typos

[KW2P]

23 hours ago, helios said:

Yes, around the Equator 10m works on regular F2 propagation.
Here's for example a VOACAP simulation for 100W SSB from Cuba to Peru.

Hmm, that's fascinating. I took the article I read at face value. It attributed it to E-layer.

That's quite a graph.