Grape Flares

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Dr. Nathaniel A. Frissell Ph.D.

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Aug 10, 2022, 2:07:48 AM8/10/22
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Hi everyone,

 

I know a lot of you have been asking to see results from the data you have been collecting. Kristina, myself, and a few others are working on a paper right now where we are trying to look at the data collected so far as a whole and show a few of the neat things the Grape can do.

 

Here is a figure I just worked up that shows the response on 10 MHz to both an X1 and a C4.9 class solar flare from October 28, 2021. The top panel shows the NOAA GOES X-ray flux data that is used to identify the onset of the flare in space, the second panel is the Doppler shift, and the third panel is the Grape Received power. Grapes are color-coded by longitude, with darker colors being more west and brighter colors being more east.

 

The X1 flare generates a very strong response in the Doppler shift. It is interesting that you do not see the Doppler response at the peak of the Solar Flare, but rather as the flare is ramping up. You can also see that the most Eastward stations have the strongest response… they are the stations closest to local noon and receiving the brunt of the solar flare impact. All stations (except W3LLA), see a decrease in received power due to the absorption caused by the flare.

 

While the X1-class flare is cool, I think it is really neat that these Grapes can sense much weaker solar flares as well. Take a look at the response of the Doppler shift due to the C4.9 class flare that occurs as 1738 UT. It is impressive we can measure that effect!

 

You can see there is one station that has almost 0-Hz Doppler shift and very little change in received power throughout the whole plot. That is Maxwell Moran W3LLA, who is in Fort Collins, CO practically line-of-sight of WWV. Therefore, his station serves as a control and does not see the larger ionospheric variations.

 

As we write this paper, we are posting all data that has been submitted to a public Zenodo repository and creating a set of python-based analysis tools to create these plots. Once I get things more stable with them, I’ll give a demo at one of the Thursday telecons so others can use the tools as well.

 

73 Nathaniel W2NAF

 

-----------------------------------------------

Dr. Nathaniel A. Frissell, Ph.D., W2NAF

HamSCI Lead / Assistant Professor
Department of Physics and Electrical Engineering
University of Scranton
(973) 787-4506

 

grape_flare_20211028.png

Steve Cerwin

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Aug 14, 2022, 1:15:14 PM8/14/22
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Nathaniel
I really liked your data presentation showing alignment of the GOES-17 and Grape data sets. Here is one more correlation for you. It is the Boulder Ionosonde hmF2 records for the day of the flare (10/28/2021) overlaid with control days from the day before and the day after. The hmF2 record shows a 14-20 km lowering of layer height at the time of the flare compared to the days before and after. The three ionosonde records show a lot of variability but do show a rapid 20 km initial drop in layer height followed by a recovery period. It might be interesting to make similar overlays for other ionosondes around the country.
73, Steve WA5FRF
Solar Flare-Boulder Ionosonde.pdf

Dr. Nathaniel A. Frissell Ph.D.

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Aug 14, 2022, 1:42:12 PM8/14/22
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Hi Steve,

Thank you! I agree, that is also a very good correlation. I think this sort of analysis would be useful for a more detailed study.

73 Nathaniel W2NAF

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<Solar Flare-Boulder Ionosonde.pdf>

Jonathan

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Jan 23, 2023, 8:57:48 AM1/23/23
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Hi All,

There was an M-class on January 15th, 2023 that was seen in my VLF transmitter plots NAA and NAU. Does anyone have the HamSCI code running that can produce such a plot: 
grape_flare_20211028.png
The code and instructions can be found at https://github.com/HamSCI/hamsci_psws
I'm having some FreeBSD Python dependency issues. For anyone who has the code running, can you pull the Grape and GOES data for January 15th, 2023, from 13:00UT to 16:00UT for the Grape stations listed in the plot and run the plotting code for that duration? Here are the NAA and NAu plots for reference:
1-15-2023 NAA.png
1-15-2023 NAU.png
Thanks!

Jonathan
KC3EEY

Graham c

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Jan 23, 2023, 10:32:10 AM1/23/23
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Jonathan,

I am not running the hamsci-grape software but I am monitoring CHU on 7850kHz using my custom GPS disciplined DC receiver and Spectrum Lab ( Win10 ).

I keep several days of files on Dropbox here:  https://www.dropbox.com/sh/hxnldv0iurucfd9/AADhaQZqW6YxKpGVLnNqaEpQa?dl=0

All of my data for 2023-01-15 is in it's own folder not surprisingly called CHU_7850KHz_20230115

screen captures are .jpg files at half hour intervals with each capture being approx 1 hour 15 minutes duration.  There is one .txt CSV file called chu_7850KHz_20221215.txt which contains the calculated FFT data used to create the plotted data; the first line of which provides details and header for the data. 

My receive site is approx 38 kilometres almost due East of the CHU transmitter site.

cheers, Graham VE3GTC

Jonathan

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Jan 23, 2023, 10:41:00 AM1/23/23
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Hi Graham,

I'll need plots from Grape data for various reasons, but do your spectrograms or data show any influence of the M-class flare in question? I'm trying to see and show, if indicated, that HF propagation was affected by the solar flare.

Thanks.

Jonathan
KC3EEY

Graham c

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Jan 23, 2023, 10:43:38 AM1/23/23
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Graham c

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Jan 23, 2023, 10:47:51 AM1/23/23
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This is the spectrum plot centered around 2023-01-15 1400utc

cheers, Graham ve3gtc

chu_7850KHz_20230115_143000.jpg

Jonathan

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Jan 23, 2023, 10:56:19 AM1/23/23
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Graham,

See my NAU and NAA plots in my previous post. Initial onset was around 14:30UT.

Thanks.

Jonathan
KC3EEY

Dr. Nathaniel A. Frissell Ph.D.

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Jan 23, 2023, 11:02:49 AM1/23/23
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Hi Jonathan,

 

Yes, the code that produced that plot is available here:

https://github.com/HamSCI/hamsci_psws/blob/main/scripts/Grape%20V1%20Multiple%20Station%20Time%20Series.ipynb

 

The code for downloading the data should also be in there. We can talk about it on the telecon tonight if you like.

 

73 Nathaniel W2NAF

The code and instructions can be found at https://github.com/HamSCI/hamsci_psws

I'm having some FreeBSD Python dependency issues. For anyone who has the code running, can you pull the Grape and GOES data for January 15th, 2023, from 13:00UT to 16:00UT for the Grape stations listed in the plot and run the plotting code for that duration? Here are the NAA and NAu plots for reference:

Thanks!

 

Jonathan

KC3EEY

Graham c

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Jan 23, 2023, 11:04:32 AM1/23/23
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And this plot is centered around 2023-01-15 14:30utc



chu_7850KHz_20230115_150000.jpg

Jonathan

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Jan 23, 2023, 11:24:22 AM1/23/23
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Graham,

It looks like the flare did not affect propagation along your path. Did you notice any drop in amplitude to correlate with the doppler shift? The doppler shift is not that significant and looks like a normal variation.

Nathaniel,

Due to a Python FreeBSD dependency issue, I'm having trouble running the notebook on my system. I was hoping someone had a working notebook and up-to-date data to generate the plots to see if there was anything significant that would indicate a flare.

Jonathan
KC3EEY

Dr. Nathaniel A. Frissell Ph.D.

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Jan 23, 2023, 11:30:29 AM1/23/23
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Hi Jonathan,

 

I can probably run that code for you over the next week or so. Let’s chat about it tonight.

 

Nathaniel

 

From: hamsci...@googlegroups.com <hamsci...@googlegroups.com> On Behalf Of Jonathan
Sent: Monday, January 23, 2023 11:24 AM
Cc: hamsci...@googlegroups.com
Subject: Re: [hamsci-grape] Grape Flares

 

Graham,

The code and instructions can be found at https://github.com/HamSCI/hamsci_psws

I'm having some FreeBSD Python dependency issues. For anyone who has the code running, can you pull the Grape and GOES data for January 15th, 2023, from 13:00UT to 16:00UT for the Grape stations listed in the plot and run the plotting code for that duration? Here are the NAA and NAu plots for reference:

Thanks!

 

Jonathan

KC3EEY

Jonathan

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Jan 23, 2023, 12:24:03 PM1/23/23
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Hi Nathaniel,

Sounds good. I will see you tonight.

Jonathan

Graham c

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Jan 23, 2023, 2:26:04 PM1/23/23
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There does appear to be a "blip" on the plot around 2023-01-15 14:23utc.

In these spectrum plots the intensity of the spectra is indicated by colour. The scale is in the lower left corner of the plot ( in case you had not already noted ).

After staring at these types of spectrum plots for CHU on 7850kHz for quite some time, this does look like the effect of the m class flare. See annotated version of plot (attached).

For comparison, I have also attached annotated plots for a M5.8 flare which occurred on 2022-10-01 and another for a X1.9 flare on 2023-01-09.  Intuitively you might think that the stronger X1.9 flare would produce a more visible change in the spectrum plot versus the M5.8 flare but that is not always the case and in these two examples it was the opposite.

cheers, Graham ve3gtc  ( ancora imparo )

chu_7850KHz_20221001_m5.8_flare.jpg
chu_7850KHz_20230115_150000.jpg
chu_7850KHz_20230109_x1.9_flare.png
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