Propagation news

Propagation news and other items:

First of all the spaceweather report, then scroll down for the RSGB's GB2RS weekly propagation report and other information.

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This page was updated 2017 July 21st 09:55 UTC.

The following data is from the Space Weather Prediction Centre.

Geophysical Alert Message wwv.txt

Issued 2017 July 21 0900 UTC

Solar-terrestrial indices for July 20 follow.

Solar flux 70 and estimated planetary A-index 7.

The estimated planetary K-index at 0900 UTC on 21 July was 3.

No space weather storms were observed for the past 24 hours.

No space weather storms are predicted for the next 24 hours.

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Solar Region Summary (Sunspots visible on the solar disc)

Issued 2017 July 21 0030z

Regions with Sunspots.  Locations Valid at July 20/2400z

Region Number.........Location...........Area..........Mag Type

None......................xxxxxx.............xxxx..........xxxx

xxxx.......................xxxxxx.............xxxx...........xxxxx

xxxx.......................xxxxxx.............xxxx...........xxxxx

Data courtesy of the Space Weather Prediction Centre

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Now the radio propagation report, compiled by G3SVW, G3YLA and G4BAO on Friday 21st July, for broadcast by GB2RS on Sunday, July 23rd

Last week spaceweather was dominated by sunspot number 2665 which was twenty times larger than any recent sunspot - the largest since number 2529 in April 2016. It disappeared on Wednesday as the sun’s rotation took it out of our view. Solar flux held at 92 before fading back to the low seventies.

Conditions were unsettled due to C2 and C3 flares. Strong geomagnetic storms occurred. The south-pointing Bz component of the interplanetary magnetic field reached a maximum negative value of minus 23 nanotesla.

Maximum useable frequencies rose briefly to just over 24 MHz for the longer paths. Stations in Japan were worked from Europe around mid-day on 18 MHz. European and Russian activity was plentiful on 28 MHz for most days in the week.

Many stations in the International Beacon Project network were copied on 14 and 18 MHz. It is always worth listening on their spot frequencies as indicators of conditions.

At 2300 UTC on Thursday the 14 and 18 MHz bands were still open to USA The W1AW Morse practice runs were copied on both bands. South America produced a contact from Peru on 14 MHz at 2330.

NOAA is forecasting more of the very low solar activity we have become used to. Propagation we may enjoy is likely to be disrupted by further flares. Moderate geomagnetic storms continue to threaten.

At the closing of this HF report there are no visible sunspots on our side of the sun and the solar flux is 70.

             

And now the VHF and up propagation news.

 Last week saw record breaking Tropo from South West UK down to the Canary islands with 144MHz and 432MHz QSOs and a claimed new 1.3GHz Region 1 record of 2662 km. At this time of year, fortunately placed stations in the South West can couple in to the ducts caused by the “Azores High” giving some super DX. The rest of the country did not fare as well but next week there may be some brief spells with a ridge of high pressure near to southern areas, but not looking like a strong feature. Tropo is an option, but relatively weak and typically found overnight and first half of the morning, before the sunshine warms out any overnight temperature inversion. A weak area of low pressure covers much of Britain at first with some scattered showers, possibly heavy and thundery will give options for more rain scatter on the GHz bands.

Sporadic E has found new legs recently with some good openings across Europe and beyond. It is still within the prime time for Es and should provide days of activity well into August. As usual the best times are late morning and late afternoon and early evening.

Moon declination is positive but falling and goes negative on Friday, with losses increasing as the week progresses. We are still a week or more away from Apogee so use the early part of the week for best results on EME.

 

And that’s all from the propagation team this week.

 

This report is by courtesy of the Radio Society of Great Britain and its Propagation Studies Committee.

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See current spaceweather data by following this link  http://www.swpc.noaa.gov/ Watch the solar wind change by the minute and see how the solar magnetic field within that wind is changing direction. What can disrupt propagation is a negative value for Bz, e.g. -4 nT. The unit nT is nanoTeslas. The more negative that parameter is, then the worst the propagation becomes.

 

Here is a link to a YouTube video showing some of the work of the SWPC: https://www.youtube.com/watch?list=UU9hQvMjzSxurMirYDgOMezw&v=JncTCE2NWgc

 

GB3WES beacon 5,290 kHz.

 

StratWarm - stratospheric warming. Does it have an effect on HF propagatiion? If it creates turbulence in the ionosphere and stirs the electron distribution, then surely it does.

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