Propagation News – 9 December 2018

| December 7, 2018

We had a new sunspot group, Region 2729, appear this week, although it is a member of the weakening Solar Cycle 24. The region formed fairly quickly in the sun’s southwest quadrant and at the time of writing was producing only very minor B-Class solar flares. It is unlikely to do too much for the solar flux index though, which was at 70 on Friday morning.

The Independent reported that the Northern Lights might be seen in the UK on Wednesday, the fifth, but this proved to be over-optimistic. Meanwhile, the Daily Express said the Earth could be “plunged into darkness, with the solar wind having the power to affect satellites, knocking out GPS navigation, mobile phone signals and satellite TV”. The reality is that the large solar coronal hole may cause the K-index to rise, but the effects were more likely to be felt late on Friday, the 7th, and the weekend. Next week, NOAA has the K-index at two, thanks to a lack of coronal holes, and the solar flux index at 68.

We’d like to reiterate that this is a good season for low-band propagation though, with 160 and 80 metres coming into their own. Even 40m can be open to longer distances, even before sunset, so do keep an eye on the lower bands.

VHF and up

The Es’Hail 2 satellite launch went well and the bird is slowly moving to its final geostationary slot at 26 degrees east. Stations are already reporting reception of the commercial beacons with amateur equipment so check social media and the AMSAT site for details.

The night of Thursday, the 13th, and morning of Friday, 14 December sees one of the largest meteor showers of the year, the Geminids. With a zenith hourly rate of around 120 the shower can give excellent meteor scatter reflections on the low VHF bands up to 144MHz, and for EME-class stations even on 432MHz. 144MHz stations with a small Yagi and a quiet site should be able to work plenty of stations using the MSK144 digimode.

The weekend starting this period off will have windy and unsettled weather, so there may be no tropo around. Active systems like these may provide a few heavy showers to add rain scatter to the propagation on offer. The glimmer of hope with the next week is likely to be the appearance of a weak ridge of high pressure until mid-week. The second half appears to be a slide back into low-pressure weather, especially in the northwest of Britain, although high pressure remains just to the east. This may allow paths across the North Sea for a few more days, but none of these indicative weather types look to be really stand-out affairs.

Meanwhile, the Moon is at minimum declination this Sunday and reaches apogee this Wednesday, so concentrate on meteor scatter rather than the short Moon windows and high losses that will characterise this week on EME.

Category: GB2RS Propagation News