X5 class solar flare to start the new year

[Phil Erickson]

Hi all,

  The sun was a bit early for 0000 UTC but it celebrated the 2024 new year with another strong X5 class solar flare:

https://www.swpc.noaa.gov/news/x50-flare-closes-out-2023-year

  Impact time would have been about 2151 UTC +roughly 8 minutes on 2023-12-31.  Flare was on the limb.  It doesn't look like there was an associated Earth directed CME due to its location though.

  Do we have any early reports of D region absorption / HF propagation impacts in Grape or other networks?  This is really late in the day for US impacts - in fact, not sure there would be much of any since it was technically just at sunset - so maybe not.

73

Phil W1PJE

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Phil Erickson
phil.e...@gmail.com

[Ward Silver]

My station shows the antenna falling off for about a half hour :-)  Recovery took another half hour and then there was an interesting partial dropout that might have resulted from multipath cancellation as the various layers got themselves back together saying, "What the heck was that!!??"

Happy New Year, HamSCIsters!

73, Ward N0AX

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[Darrel]

Hi Phil,
   I caught the flare on 10 MHz, as did my colleague Henry, KB7NIE who lives about 10 miles south of me.  I'm in NE Tucson, AZ where it was still a couple of hours before sunset.  We're both using Grape receivers (both constructed by Henry).

Here is the 10 MHz data for the day from Henry.  His antenna is a half-wave dipole.  As usual, red is signal amplitude and black is Doppler.  The big flare just before 22h UTC is quite obvious.

From about 01h to 14h the MUF from Tucson to WWV drops below 10 MHz, so most of the signal that Henry sees then is WWVH, not WWV.

Below are my data.  It shows the flare equally well.  My antenna is a 2-element interferometer, phased to reject WWVH but peak on WWV at 10 MHz.  So, between about 01h and 14h Henry and my data are quite different, because I'm partially rejecting WWVH.


For reference, below I've plotted the GOES X-ray data for the day.

Cheers,
    Darrel, aa7fv.

[Graham c]

the peak of the flare occurred around 2023-12-31 21:50ut as noted on the Goes X-ray Flux page.

My local sunset ( Eastern Ontario, Canada ) was approximately 20 minutes earlier around 2023-12-31 21:30ut.

This is the plot of the data collect by my Grape1-drf system and clearly shows the significant drop in WWV 15MHz signal level and doppler shift of the carrier at that time:

cheers, Graham ve3gtc

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[Gwyn Griffiths]

Hi Phil

An illustrative measurement of D region absorption is through its effect on propagated-in noise level at sites with low local noise. The attached graphic shows this effect at 40, 30, 22, 20, 17 and 15 m at the Northern Utah SDR site KA7OEI-1.

At that site, 12 and 10 m are limited by local noise, so absorption not seen, but those two bands show what may be a solar noise burst.

73

Gwyn G3ZIL

[Jonathan]

Since this flare occurred towards the end of dusk at my location in PA (EST), there was minimal influence on strong VLF transmitters, namely NAA:

There was minimal impact on NAA's amplitude except for a small flare around 1900UT, but you can definitely see the shift in absolute phase at both the smaller flare and the big one! NML showed a similar effect:

Here, both the small and large X class flare are visible as a SID. Sferics also indicated D layer absorption. Below is a compressed spectrogram of sferics (and everything else in the VLF band) up to 16 kHz:

What is really interesting here is that you can see some noise bursts at ~5 kHz at the time of the small flare and a noise band from ~300 Hz to ~3 kHz at the time of the big flare with increased absorption of sferics between ~6-8 kHz. This is quite an interesting observation! The horizontal band at ~3.7 kHz is a pesky noise emitter somewhere in the local area, possibly synchronous to mains indicating it's some sort of switching power converter.

Jonathan

KC3EEY

 

On Mon, Jan 1, 2024 at 11:26 AM Darrel <demers...@gmail.com> wrote:

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[jimwi...@gmail.com]

All,

 

Here are my WSPR spot observations from 80- to 10-meters on 20231231, with solar flare time approximately 21:50Z

 

80-meters was affected from 21:46 to 21:58 (blackout - no spots recorded).

 

 

40 meters was affected at distances from 669 [km] to 1590 [km] during the 21:56 cycle.

There is also an unrelated deep fade at around 16:30.

 

 

20-meters was affected at distances from 2000 [km] to 3500 [km] for cycles at 20:48, 20:58 and 22:08.

There is also an unrelated deep fade at around 16:00 and an unrelated shallow fade around 18:38.

 

 

15-meters was affected at distances from 3144 [km] to 3489 [km] for the cycle at 21:50.

 

 

 

10-meters was not affected.

 

 

 

73,

 

Jim KX4TD

--

[jimwi...@gmail.com]

Further to the effects of the flare:

 

Looking at the AUSTIN ionosonde for 20231231: Looking at the charts, in both the fo and hmE traces, readings were lost for twenty minutes starting at at time 2200Z and ending at time 2220Z. The most common reason for this is absorption in the D-region decreasing the signal to noise.

 

 

 

Conclusion:

 

The solar flare caused increased absorption in the D-region. This increased absorption led to a blackout on 80 meters and lesser degradation of HF propagation on the higher frequency bands.

 

The Austin ionosonde readings followed the same pattern with greatest effect on the E-layer, and little to no effect on the F-layers.

 

This pattern is consistent with the “absorption is proportional to the wavelength squared” rule of thumb.

 

73,

 

Jim KX4TD

[Ward Silver]

I forgot to include the graphs of the Grape data :-)

73, Ward N0AX

[Kristina Collins]

Adding Bill Blackwell's collected graphs to this thread. Quite a distinct signature in the frequency plot, as we've come to expect. I looked at the Grape plot, said "ooh, I bet that's an X-class flare" and then checked the NOAA data to confirm. There are some interesting antics in the power plot too, although I'm less attuned to those. 

Happy new year!

-KC

[Phil Erickson]

Hi Gwyn and Darrel,

  (Apologies to others for rewinding the thread a bit.). Gwyn mentioned:  "At that site, 12 and 10 m are limited by local noise, so absorption not seen, but those two bands show what may be a solar noise burst."

  My distinguished colleague Alan EE Rogers, whom I'm sure Darrel knows very well, operates the precisely calibrated EDGES system in the quiet western Australia desert.  EDGES has measured a fundamental high-redshift cosmological signature of the early universe in an observational tour de force:

https://www.haystack.mit.edu/astronomy/astronomy-projects/edges-experiment-to-detect-the-global-eor-signature/

  The system, EDGES-3, makes absolutely calibrated noise temperature measurements, averaged over the sky, in the bands just below commercial FM.  Antenna chromaticity is precisely accounted for and the frequency response is calibrated at the >1 part in 10,000 or better level.  The system actually continuously samples about 40 MHz to over 120 MHz, but calibration is not correct below 50 MHz and above the FM band (or at least Alan cautions).

  So I asked Alan and sure enough, on 31 December 2023, the system caught a spectacular signature of the radio burst associated with the X5 solar flare arrival.  This plot is the entire UT day in the main EDGES band from a bit below 50 MHz to 80 MHz:

  X axis is UTC, and Y axis is frequency in MHz.  Color represents absolute noise temperature in Kelvin.  The top line plot is average temperature across frequency in K.  The impulsive flare signature is quite obvious if you expand the plot.  For orientation, local time in western Australia is UTC + 8 so sunset occurs about 08 UTC and sunrise time is evident.  You can also nicely see some qualitative response below 50 MHz which is sporadic E at or after sunset reflecting low VHF transmissions into the antenna.

  Alan kindly zoomed in to the time of the flare and produced a wider < 50 to 120 MHz coverage:

  Note the presence of the commercial FM band - but these are not local stations, rather they are stations within 2000 km reflected by sporadic meteor trails!  (That's how sensitive EDGES-3 is.)

  To the point of this thread, it's clear that there was a broadband solar associated noise burst at the X5 impact time all the way up to VHF and beyond; the top attenuation is the antenna system cutting off response.  So I think Gwyn's analysis is correct for 12 and 10 meters.

 Note:  EDGES-3 data is available in numerical form for those who wish to probe it; contact me and I'll put you in touch with Alan to further explore.  There is an amazing amount of ionospheric information buried in these plots (sporadic E reflections from over the horizon signals, etc. etc.) and he is interested in anyone who wants to use it for science.

73

Phil W1PJE

  

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[Fung, Shing F. (GSFC-6750)]

Hi Phil and All,

 

I’ve been reading the postings by the HamSCI group about this New Year Eve flare event with interest. Please know that the same event has also generated a lot of interest among the Radio JOVE group (cc’d). When I first saw the question raised about the possibility of solar radio bursts occurring during this flare/SID interval, I had hoped that someone from Radio JOVE would respond.  Hopefully without stealing someone’s thunder, with your latest message I’d like to at least point out that several Radio JOVE observers did report the detection of small groups of radio bursts (15-30 MHz) during the interval with the stronger bursts observed at 21:47:20 UT.   This might be a good opportunity for HamSCI and Radio JOVE to collaborate.

 

Shing

 

 

 

From: <ham...@googlegroups.com> on behalf of Phil Erickson <phil.e...@gmail.com>
Reply-To: "ham...@googlegroups.com" <ham...@googlegroups.com>
Date: Friday, January 5, 2024 at 5:43 PM
To: "ham...@googlegroups.com" <ham...@googlegroups.com>
Subject: [EXTERNAL] [BULK] Re: [HamSCI] X5 class solar flare to start the new year

 

CAUTION: This email originated from outside of NASA.  Please take care when clicking links or opening attachments.  Use the "Report Message" button to report suspicious messages to the NASA SOC.

Hi Gwyn and Darrel,

 

  (Apologies to others for rewinding the thread a bit.). Gwyn mentioned:  "At that site, 12 and 10 m are limited by local noise, so absorption not seen, but those two bands show what may be a solar noise burst."

 

  My distinguished colleague Alan EE Rogers, whom I'm sure Darrel knows very well, operates the precisely calibrated EDGES system in the quiet western Australia desert.  EDGES has measured a fundamental high-redshift cosmological signature of the early universe in an observational tour de force:

 

https://www.haystack.mit.edu/astronomy/astronomy-projects/edges-experiment-to-detect-the-global-eor-signature/

 

  The system, EDGES-3, makes absolutely calibrated noise temperature measurements, averaged over the sky, in the bands just below commercial FM.  Antenna chromaticity is precisely accounted for and the frequency response is calibrated at the >1 part in 10,000 or better level.  The system actually continuously samples about 40 MHz to over 120 MHz, but calibration is not correct below 50 MHz and above the FM band (or at least Alan cautions).

 

  So I asked Alan and sure enough, on 31 December 2023, the system caught a spectacular signature of the radio burst associated with the X5 solar flare arrival.  This plot is the entire UT day in the main EDGES band from a bit below 50 MHz to 80 MHz:

 

 

  X axis is UTC, and Y axis is frequency in MHz.  Color represents absolute noise temperature in Kelvin.  The top line plot is average temperature across frequency in K.  The impulsive flare signature is quite obvious if you expand the plot.  For orientation, local time in western Australia is UTC + 8 so sunset occurs about 08 UTC and sunrise time is evident.  You can also nicely see some qualitative response below 50 MHz which is sporadic E at or after sunset reflecting low VHF transmissions into the antenna.

 

  Alan kindly zoomed in to the time of the flare and produced a wider < 50 to 120 MHz coverage:

 

To view this discussion on the web visit https://groups.google.com/d/msgid/hamsci/CAAZaqEvwhME62man0V8kBRuQ-8E-M%2Bsfk3TFAmZkF%3DVktAoRWQ%40mail.gmail.com.

[Phil Erickson]

Hi Shing,

  Thanks for the reply.  It would indeed be very good to hear from the RadioJOVE crowd and their observations - what did all of you see?  Could this group weld together a broad spectrum observing set of the solar burst properties?

73

Phil W1PJE

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Phil Erickson
phil.e...@gmail.com

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[Fung, Shing F. (GSFC-6750)]

Hi Phil,

 

Since you asked, I’ve taken the liberty of compiling some Radio JOVE and HamSCI data for comparison: 

1. The top and bottom spectrograms (~ 15-30 MHz) [courtesy of Tom Ashcraft (New Mexico) and Dave Typinski (Florida), respectively] and the middle two panels of KA7OEI-1 data [(courtesy of Clint Turner) taken from the message from Gwyn Griffiths to you on 1/1/2024] are aligned as best I could to the same time scale for the interval of interest (bounded by the green vertical lines) on 12/31/2023.  The red/green vertical lines show the specific times when features are aligned across all the panels.
2. The red lines mark the start, peak and end times of GOES X-ray flux increases.
3. The middle green line marks a time just before the strongest type III radio burst within the burst group so as not to conceal the difference in the lower frequency extents of the burst registered by the two Radio JOVE stations. Further studies (of instrumental effects vs. natural environment) is needed to understand the difference in the lower frequency cutoffs between the two observing stations.
4. The D-region absorption in 15-40 m waves seen in the KA7OEI-1 data generally matches the galactic radio background fadeout (SID) seen by Radio JOVE, except that the radio fadeout tended (understandably) to have started later and recovered sooner at higher frequencies.

 

 

It would be good if there are more HamSCI data from distributed stations, but they would also need to be cross-calibrated so that their absorption spectra can be quantitatively compared.

 

Thouhgts/comments?

 

Shing

[Nick Evetts FRAS 2E0LUN]

I was taking part in the Spaceweatherwoman New Years Eve party at the time, and Dr Skov showed us her Geochron and how the Southern Hemisphere Dayside was wiped out for the event.

 Nick Evetts FRAS 2E0LUN / KC2VWR

  에버츠 닉 エベッツ   ニック  

Albert George Childs Observatory  

앨버트 조지 차일드 천문대  アルバートジョージチャイルズ天文台

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[Gwyn Griffiths]

Hi Phil, Shing

I'm so pleased to see the 31 Dec 2023 solar noise burst in the EDGES-3 data. It spurred me to look at data at four sites, KPH, KFS as well as KA7OEI-1 and VK7JJ, Tasmania, WsprDaemon's closest station to the EDGES-3 site in Western Australia.

Graphs at 28.125 MHz, 24.925 MHz and 21.097 MHz and commentary are shown in an attachment.

While accepting the wild assumptions I would appreciate access to the EDGES-3 numerical data for this period so that I can attempt a system-level calibration for KPH, KFS and KA7OEI-1 as in the last point on my graphic. I attach an Excel file for the data I've used for these plots, as you may find it useful Shing. Note that all my times are the start times of 110 second averaging intervals.

Cross-calibration has proven difficult, but at least with KPH, KFS and KA7OEI-1 we have the combination of excellent low noise sites, highly committed individuals and the same type of antenna.

It would also be good to look out for SRBs this summer from the Devon Island EDGES installation to repeat the 'calibration'. The 17 August 2022 SRB observed at Devon Island (EDGES MEMO #397) was observed as a 2 dB rise in noise level at KPH at 14:42 UTC on 28.125 MHz.

At the risk of overload, I have produced crude maps of peak excess absorption at 7.04 MHz and 14.097 MHz from the signal level changes of WSPR spots at known low local noise receivers.  All paths were one-hop, checked by looking at frequency spread. The necessity for that frequency spread check is nicely illustrated at 10.14 MHz as an NVIS path reverted to non-ionospheric resulting in a flat-bottomed 40 dB dip. 

73

Gwyn G3ZIL

[Fung, Shing F. (GSFC-6750)]

Hi Gwyn,

 

Thanks much for sending the data from various stations. There‘s much for me to learn about how to understand/interpret these data. Do you also have the location info (long & lat)  for the transmitter(s) and various receiving stations?

 

Thanks,

Shing

 

From: 'Gwyn Griffiths' via HamSCI <ham...@googlegroups.com>
Reply-To: "ham...@googlegroups.com" <ham...@googlegroups.com>
Date: Sunday, January 7, 2024 at 7:00 AM
To: HamSCI <ham...@googlegroups.com>
Subject: Re: [EXTERNAL] [BULK] Re: [HamSCI] X5 class solar flare to start the new year

 

CAUTION: This email originated from outside of NASA.  Please take care when clicking links or opening attachments.  Use the "Report Message" button to report suspicious messages to the NASA SOC.

Hi Phil, Shing

I'm so pleased to see the 31 Dec 2023 solar noise burst in the EDGES-3 data. It spurred me to look at data at four sites, KPH, KFS as well as KA7OEI-1 and VK7JJ, Tasmania, WsprDaemon's closest station to the EDGES-3 site in Western Australia.

Graphs at 28.125 MHz, 24.925 MHz and 21.097 MHz and commentary are shown in an attachment.

While accepting the wild assumptions I would appreciate access to the EDGES-3 numerical data for this period so that I can attempt a system-level calibration for KPH, KFS and KA7OEI-1 as in the last point on my graphic. I attach an Excel file for the data I've used for these plots, as you may find it useful Shing. Note that all my times are the start times of 110 second averaging intervals.

Cross-calibration has proven difficult, but at least with KPH, KFS and KA7OEI-1 we have the combination of excellent low noise sites, highly committed individuals and the same type of antenna.

It would also be good to look out for SRBs this summer from the Devon Island EDGES installation to repeat the 'calibration'. The 17 August 2022 SRB observed at Devon Island (EDGES MEMO #397) was observed as a 2 dB rise in noise level at KPH at 14:42 UTC on 28.125 MHz.

At the risk of overload, I have produced crude maps of peak excess absorption at 7.04 MHz and 14.097 MHz from the signal level changes of WSPR spots at known low local noise receivers.  All paths were one-hop, checked by looking at frequency spread. The necessity for that frequency spread check is nicely illustrated at 10.14 MHz as an NVIS path reverted to non-ionospheric resulting in a flat-bottomed 40 dB dip. 

 

73

Gwyn G3ZIL

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[Gwyn Griffiths]

Hello Shing

I've added the locations to the Summary tab. A revised sheet is attached.

regards

Gwyn G3ZIL

[Fung, Shing F. (GSFC-6750)]

Thanks! I’ll replace the old one.

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[Jonathan]

Hi Shing,

I just wanted to mention that Thomas Ashcroft is quite active in the VLF community and produces beautiful timestamped video recordings of TLEs and meteors. His HF spectrogram data is of high quality as well and he often provides it with discussions of solar events that have effects in both the HF and VLF bands.

Jonathan

KC3EEY

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[Fung, Shing F. (GSFC-6750)]

Hi Jonathan,

 

Thank you for your message. Tom Ashcraft is also one of our avid and productive Radio JOVE observers. Indeed, he often posts his high-quality observations to the Radio JOVE group.

 

Cheers,

Shing  

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[Jonathan]

Hi Shing,

Yes, he is quite active in the Radio JOVE community as well. I'm glad you are utilizing his data.

Jonathan

KC3EEY

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[Fung, Shing F. (GSFC-6750)]

BTW, if you’re interested in knowing more about Tom Ashcraft and his work, please see his profile on the NASA Citizen Scientists page: https://science.nasa.gov/people/thomas-ashcraft/

 

Shing

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[Jonathan]

Hi Shing,

Thank you for providing this!!

Jonathan

KC3EEY

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