Hi all,

It’s nice to have firsts!

 

Yesterday afternoon the planetary K index (https://www.swpc.noaa.gov/products/planetary-k-index) rose from a dormant Kp=1 to a healthy Kp=7. Kp characterises geomagnetic  storms.

 

In parallel, the aurora-predicting geomagnetic disturbance level went from green to amber and then red, breaching the 200nT threshold at about 15:30 UTC (https://aurorawatch.lancs.ac.uk/plots/?project=awn&site=sum&date=2021-05-12). 

 

So, I turned the newly installed 6 metre Yagi north. And there was a radio aurora in full swing with MM5DWW on Orkney working the world – or at least those north of 55 degrees. We exchanged 5/7 both ways and went on our way – him to work yet more, and me to listen to a couple of CW stations. There were also some ethereal voices that might – or might not – have been other SSB stations.

My Great Circle distance to Orkney is 400km, but the actual path length will have been significantly more to the scattering medium further north and back to Orkney. In an aurora, all stations generally beam north.

 

The radio aurora was gone by 16:30 and 6 metres reverted to its normal flat state.

 

I’d heard radio auroras as a teenager but never had the necessary kit to work them, so it was good to tick that box. I’ve now got a feeder run and Yagi to install for 2 metres, so next time I’ll be able to compare the bands. 

 

And next time I’ll remember to record the activity. The voices are heavily distorted by the Doppler shift caused by the movement of the free electrons in the auroral columns doing the reflecting. You’ve to listen hard. There’s no time for exchange of pleasantries.

Radio auroras are infrequent. Sometimes, they are intense enough and at a low enough latitude to support southern stations. If you're interested, install the AuroraWatch and SpaceWeatherLive apps.

Regards,

John, GM8JBJ

John Berry Mob. 07553 250 919 Email: john.berry@... Willowburn, Kirkton, Hawick, Scottish Borders, TD9 8QJ

Hi Berni. Certainly. Do put on the site.

Might also be worth adding copies of the Kp and disturbance graphs?

John

On Thu, 13 May 2021 at 11:58, M0XYF Berni <msars@...> wrote:

Thank you John. Well written and very interesting. May I post a copy on the website please?

Berni M0XYF

On 13/05/2021 09:09, G8JBJ John wrote:

Hi all,

It’s nice to have firsts!

 

Yesterday afternoon the planetary K index (https://www.swpc.noaa.gov/products/planetary-k-index) rose from a dormant Kp=1 to a healthy Kp=7. Kp characterises geomagnetic  storms.

 

In parallel, the aurora-predicting geomagnetic disturbance level went from green to amber and then red, breaching the 200nT threshold at about 15:30 UTC (https://aurorawatch.lancs.ac.uk/plots/?project=awn&site=sum&date=2021-05-12). 

 

So, I turned the newly installed 6 metre Yagi north. And there was a radio aurora in full swing with MM5DWW on Orkney working the world – or at least those north of 55 degrees. We exchanged 5/7 both ways and went on our way – him to work yet more, and me to listen to a couple of CW stations. There were also some ethereal voices that might – or might not – have been other SSB stations.

My Great Circle distance to Orkney is 400km, but the actual path length will have been significantly more to the scattering medium further north and back to Orkney. In an aurora, all stations generally beam north.

 

The radio aurora was gone by 16:30 and 6 metres reverted to its normal flat state.

 

I’d heard radio auroras as a teenager but never had the necessary kit to work them, so it was good to tick that box. I’ve now got a feeder run and Yagi to install for 2 metres, so next time I’ll be able to compare the bands. 

 

And next time I’ll remember to record the activity. The voices are heavily distorted by the Doppler shift caused by the movement of the free electrons in the auroral columns doing the reflecting. You’ve to listen hard. There’s no time for exchange of pleasantries.

Radio auroras are infrequent. Sometimes, they are intense enough and at a low enough latitude to support southern stations. If you're interested, install the AuroraWatch and SpaceWeatherLive apps.

Regards,

John, GM8JBJ

John Berry Mob. 07553 250 919 Email: john.berry@... Willowburn, Kirkton, Hawick, Scottish Borders, TD9 8QJ

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John Berry
TimelessTime Ltd
Tel: 07553 250 919
Tel: 01450 372 274

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