Propagation News – 5 June 2022

What a difference a week makes! Last week we were looking at a solar flux index of 137 and a mass of sunspots. This week the SFI is standing at 101 with only three active regions visible, and one of those is about to rotate out of view.

Geomagnetic conditions have been relatively stable, but a little unsettled with a maximum Kp index of three over the past few days as this report was being prepared. The solar wind stream remained elevated above 500km/s due to a coronal hole stream combined with possible weak Coronal Mass Ejections, or CME, effects. As a result, HF conditions have been a little lacklustre with the Chilton Ionosonde showing a critical frequency of between four and five Megahertz. This equates to a maximum usable frequency of around 18-21MHz over a 3,000km path. As we said, nothing to write home about.

But all is not lost as the experts feel this will be a short-lived decline in solar activity and normal service will soon resume! NOAA thinks the SFI will decline a little more by the end of this week, before coming back with a roar from around Tuesday the 7 June.

It predicts the SFI could be 110 on Tuesday the 7 June and then rise to 150 by the 14 June. So next week could see the bands opening up again, at least for a while.

Geomagnetic conditions are predicted to remain quiet with a maximum Kp index of two, at least until the 10th when it could rise to perhaps four or five.

It looks like the Jubilee weekend may offer fairly flat HF conditions, but this may improve as we head into next week.

VHF and up

There are no signs at the moment of really strong long-lasting areas of high pressure so any Tropo is likely to be temporary. On today’s forecast charts, the only one that shows up develops over Scotland during the holiday weekend but declines as the weekend finishes.

The rest of the weather story is focused upon showery activity and with the prospect of some being heavy and thundery, it bodes well for rain scatter, but could also play havoc with HF CW NFD static levels.

The early days of June are regarded as prime time for Sporadic-E, and with this season getting off to a slow start, it’s high time we saw some activity.

There are a few jet stream segments over Europe during the week to come, but nothing looking too strong. This may be compensated for by the increase in the background meteor input in this period and, hopefully, there will be plenty to celebrate.

After the excitement of last week’s “will they, won’t they” Eta Aquarids meteor shower, this week is going to be something of a back to normal situation.

June is usually a slow month for meteors with no major showers. However, the daytime Arietids, which is a minor meteor shower, may provide some useful radio reflections on the Tuesday and Wednesday, the 7 and 8 June.

Sky noise will be quite low this week with the Moon full next Tuesday, the 14 June. Declination reduces throughout the week as the moon moves towards perigee. Path loss for Moonbounce will reduce as the week progresses. Once again, low declination will favour stations with little or no antenna elevation, potentially increasing operation time beyond that around moonrise and moonset.

Category: GB2RS Propagation News