Propagation News – 7 October 2018

| October 5, 2018

There are signs that ionospheric conditions are improving as we head into autumn. This isn’t unexpected; as the ionosphere cools there is a chemical shift towards more monatomic species that are easier to ionise.

The 4U1UN New York, VE8AT Nunavut and ZS6DN Pretoria beacons on 14.100MHz were all audible at the same time on Wednesday, and we can expect transatlantic conditions to get better as the month progresses. Robert, G4TUK even reported working Mayotte in the Indian Ocean on 10 metres. So do make sure you make the most of the autumn DX openings if and when they occur.

Next week the solar flux index is predicted to remain around 68-70, so 14 and 18MHz are likely to be the main daylight DX bands, with the possibility of occasional openings on higher bands. However, the effects of a solar coronal hole may once again disrupt the ionosphere with Sunday, the seventh, and Monday, the eighth, predicted to see a raised Kp index of up to six.

Look for pre-auroral enhancements before or just after the solar matter hits the Earth. One way to do this is monitor the real-time solar wind at solarham.com. An increasing wind speed, increasing particle density and a south-facing interplanetary magnetic field or Bz are all indicators of an impending geomagnetic disturbance.

Wednesday, the 10th, and Thursday, the 11th, may also be disturbed, before we see a little respite later in the week.

VHF and up

It’s looking a bit mixed for the next week with high pressure nearby over southern areas, while we have occasional periods of low pressure to the north and west of Scotland. The high pressure in the south will mean that tropo will be a feature again this week. This is typical autumn fare, and there should be some good paths into the continent and across the southern North Sea to the Baltic. It will also be worthwhile checking paths to the south across Biscay to Spain and the Canaries.

The north-west of the British Isles will probably miss out on these tropo conditions since it will also be rather breezy with occasional rain or showers. A few options may present themselves for some rain scatter on the microwave bands.

Moon declination is positive until Monday night, so EME windows will shorten and losses will climb as the week progresses.

October is a busy month for meteor showers. Next Tuesday sees the peak of the Draconids, which favours temperate and far-northern latitudes. Look for increased activity from Sunday night.

Category: GB2RS Propagation News