Propagation News – 12 March 2017

| March 10, 2017

In the last report we said the ongoing disturbed geomagnetic conditions may have settled, with a predicted K-index of two. Unfortunately, this didn’t happen as early as expected and the beginning of the week saw a K-index up as high as five. This had an adverse effect on maximum useable frequencies, with a very unsettled ionosphere. Daytime MUFs seldom allowed the bands much higher than 20 metres to be used. This was also not helped by an absence of sunspots.

The slightly better news is that on Thursday a look at the sun in extreme UV light showed there were no earth-facing coronal holes on the sun’s equator, although there are some around its poles. This means that we can hope for a few days of lower K-indices this weekend, and hopefully more settled HF conditions for the Commonwealth Contest.

NOAA predicts the solar flux index will be in the mid-70s next week. To put this in perspective, the solar flux index never gets below 65 at sunspot minimum, so conditions are not good. NOAA also predicts conditions may be geomagnetically unsettled again from midweek, with a potential maximum K-index of five either Wednesday or Thursday. So look for better DX conditions at the beginning of the week, and then the potential for a pre-auroral opening on the upper bands just as the K-index rises, although this is harder to predict.

VHF and up

It looks like the early part of this week could bring some tropo over the south and central part of the UK, extending in to the North Sea up to Norway, so keep an eye on the bands and put out some CQ calls to generate interest.  There is the possibility of VHF auroral activity mid week if the K-index rises as predicted.

The winter minimum in meteor activity continues until the April Lyrids, so stick to the best time for random meteor scatter contacts, around dawn, when the earth is rotating into the flux of meteoric particles.

The Moon’s declination goes negative on Monday so Moon windows are shortening. The Moon is also heading out to apogee next Sunday so losses will be high and increasing as the week progresses.

Category: GB2RS Propagation News