Propagation News – 11 January 2015

| January 9, 2015

As is usual this time of year we start with a retrospective look at 2014, and it looks like we passed the peak of Sunspot Cycle 24 in the spring. The peak solar flux index (SFI) for the cycle occurred on 23 October 2014 with 227, although there were plenty of other times when it bettered 200, including January and December.

On an annual basis, 2014 had the highest average daily sunspot numbers of any year since 2002, according to the ARRL, although the peak solar flux indices were higher in 2002, hitting 261 on 29 January that year.

What has been very apparent is the recent general increase in solar flares and coronal mass ejections, CMEs: this week the geomagnetic Kp index even hit eight at high latitudes. This has led to disturbed geomagnetic and radio conditions and is typical of the downward trail away from a sunspot maximum.

Over the next quarter we can expect to see overall sunspot numbers decline slightly, with solar flare and CME activity remaining high. Expect to see SFI numbers in the range 120-180, still good enough to provide good openings to DX on the higher bands.

We may well see the cycle rise again at times before it finally tails off over the next few years.

VHF and up propagation news

The weather pattern is likely to continue in to the New Year in unsettled form after a couple of brief enhancements at the start of the month. There will be a series of low pressure areas passing close to Britain this week bringing very windy weather at times and as a result mainly flat, VHF/UHF weather-driven propagation.

After last week’s Quadrantids meteor shower, we are now entering the seasonal lull in activity with no major showers until the April Lyrids, so there’ll be just random meteor scatter and the odd chance of aurora to provide any DX opportunities.

We are just a week away from the moon’s lowest declination and also from perigee so we’ll see shorter moon windows, with reducing losses as the week progresses.

For VHFers needing a challenge, some EME-equipped stations have recently made QSOs via reflection from the ISS, and aircraft reflection is easy with a moderate terrestrial system. Failing that there’s still amateur satellites to use, and just a moderate station can make QSOs via FUNcube, so there’s always something to try at VHF and up.

Category: GB2RS Propagation News