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 August 19th  07:04  UTC.

The following data is from the Space Weather Prediction Centre:

Geophysical Alert Message wwv.txt

Issued 2017 August 19 0600 UTC

Solar-terrestrial indices for August 18 follow.

Solar flux 80 and estimated planetary A-index 21
The estimated planetary K-index at 0600 UTC on 19 August was 4.

Space weather for the past 24 hours has been minor.
Geomagnetic storms reaching the G1 level occurred

Space weather for the next 24 hours is predicted to be minor.
Geomagnetic storms reaching the G1 level are expected.

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Solar Region Summary (Sunspots visible on the solar disc)

Issued 2017 August 19 0030z

Regions with Sunspots.  Locations Valid at August 18/2400z

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

2671......................N11E22.............0410...........Beta-Gamma

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

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

Data courtesy of the Space Weather Prediction Centre

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The GB2RS radio propagation report broadcast on Sunday, August 13th

Last week the solar flux index continued to be in the mid 70s, with a single sunspot group making its way across the visible disk.

Compare and contrast this with the same week last year when there were actually five sunspot groups visible. This confirms, as it we didn't know, that Solar Cycle 24 is still declining. The current estimates for sunspot minimum place it around 2019 to 2020, so get used to more of the same.

The good news last week was that conditions were more geomagnetically stable with the K index mostly around one after Monday the seventh.

This meant that there was DX to be had, including some short-lived openings to the Far East on 20 and 30 metres around 1800hrs. Milton ZP9CTS in Paraguay was also worked by Tony G4CJC on Tuesday using the new digital mode FT8 on 10 metres.

Next week may start off unsettled due to another solar coronal hole, which became Earth-facing on Wednesday. This suggests unsettled geomagnetic conditions could occur from Friday the 11th and run in to this weekend.

This could bring auroral conditions, but may ultimately result in depressed maximum useable frequencies.

Once the weekend is over, next week should be more settled and conditions may settle. Look for DX openings on 30, 20, and 17 metres, with occasional sporadic E openings on higher bands at times.

 

And now the VHF and up propagation news.

The big problem with multiple weather models is that they usually predict ridges of high pressure and troughs across the country at different times. It's best therefore, to provide generalised operating guidance for the different weather types.

This week, the ridges of high pressure will tend to favour the south of the country for Tropo, principally into the continent and across Biscay to Spain.

The troughs and lows usually bring rain scatter and there’s been some good examples with the heavy thundery downpours lately. Look for heavy rain, shown as bright colours on the many online rainfall radars, to get the best from any large storm events.

The Perseids passed their peak at the weekend, but activity will still be high for the next few days for meteor scatter enthusiasts.

Sporadic E is still hanging on into the last part of the season with a few openings on most days, but not necessarily reachable from the UK. It’s quite likely that the unsettled weather currently bodes well for Es , since the powerful upper atmosphere jet streams which drive the rainy weather are also good for Sporadic E.

The lunar cycle continues on it’s predictable way. Now, and for the next few years, lowest path losses are coinciding with highest declination in the Northern Hemisphere. This means that Moon windows are longest  when losses are at their lowest. This week should be good for EME with falling losses as we move towards perigee and maximum declination on Friday.

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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