Propagation News – 29 January 2023

| January 27, 2023

As of Thursday, we had a strange situation whereby all the current visible sunspots were in one hemisphere of the Sun. But this isn’t that unusual, as the two hemispheres usually peak at different times in the cycle.

In a couple of years, we may well have the reverse situation.

Nevertheless, the solar flux index declined and stood at 172 on the 26 January when this report was prepared. While there are plenty of sunspots, they are all relatively small, unlike a week ago when active region 3190 was on the visible face.

Last week saw the Sun being settled geomagnetically, with the Kp index not exceeding three. We have had some M-class flares, but nothing stronger.

NOAA predicts that the solar flux index will decline to 175 before increasing again at the beginning of next month. We can expect quiet geomagnetic conditions for a time, but NOAA predicts that the Kp index will rise again around the 1 February and then from the 7 to the 10 February.

Meanwhile, the 3Y0J Bouvet Island DXpedition, located at 54.42 degrees South, 3.36 degrees East, is getting closer to its final location. So, it’s time to start looking at propagation predictions for this sought-after entity. Bouvet lies almost exactly due south from the UK. If you have a beam point it at 180 degrees or 0 degrees for the long path.

The short path is likely to give you the best results, that is 80 to 100% reliability, with the 15m band open from 0800 to 2100UTC. There are shorter 12m and 10m openings during the day, with 10m open from 1200 to 1400UTC and again from 1700 to 1800UTC. 20m should give the best results overall from 1700 to 0200UTC, although it is likely to be the busiest band.

30m and 40m also offer up good propagation from 1700 to 0400UTC.

There is also a weaker long-path opening predicted on 17m from 1000UTC until 1600UTC with 50% probability. These were all calculated with VOACAP online and Proppy.

The UK appears to have good HF propagation to Bouvet overall but do make sure you are on the right band at the right time!

VHF and up

There has been some very focused tropo in the last week, especially on 70cm and 23cm digital modes around the edge of some high pressure from the UK into eastern Europe and the southern Baltic.

This shows the value of looking for paths along the edge of extensive highs, rather than across the centre, where the inversion dips lower and may duct the path into the ground.

The coming week offers further high-pressure systems, mostly over the Atlantic to the west of Britain or to the south. So, perhaps paths towards Spain or the Canary Islands are worth a look. The northern half of the charts will see deep lows, much stronger winds and rain or showers, so introducing rain scatter options and testing the antennas.

Other modes are available, of course, but the good practice of watching the clusters should keep everyone informed so that you don’t miss out.

It’s still worth a check for aurora, and random meteor scatter is always an option around dawn, even in the current meteor shower minimum period that lasts until the Lyrids in mid-to-late April.

With the Moon at peak declination on Thursday, this is a good week for EME with long Moon availability windows. That said, Moon apogee next Saturday means that EME path losses are high. 144MHz sky noise is moderate, reaching 500 Kelvin on Wednesday.

Category: GB2RS Propagation News