Propagation News – 5 January 2020
After the two new solar cycle 24 sunspots that appeared last week, we now have another spot developing in the Sun’s south-west quadrant. Don’t get too excited though, as the last two spots soon disappeared and this one might not amount to much either. It is, however, a positive sign that the next cycle is coming, albeit slowly.
Conditions have been settled geomagnetically, which has been good for the ionosphere. Maximum usable frequencies have reached 18MHz at times, although 7 and 14MHz have been more reliable during the day. There have been more interesting signals on the lower bands—160, 80 and 40m—after dark. January is a good month for propagation on these bands, with the long periods of darkness meaning no D-layer absorption. DX can start to appear on 40m during late afternoon and may continue throughout the night if the MUF stays high enough. Propquest.co.uk—which shows the results from the Chilton ionosonde—suggests this may be possible at times. Otherwise, NOAA predicts that the solar flux index will remain in the range 70-72 this week, with the Kp index hitting a maximum of two, thanks to a lack of coronal hole activity. This means conditions should remain roughly similar to last week.
VHF and up
Tropo records tumbled last week with the D41CV team on Cape Verde working British Isles stations on 144 and 432MHz via FT8. On 31 December they had a world record 432MHz QSO with GM3SEK at 4621km, then on New Year’s Day worked GM0EWX at 4776km on 144MHz FT8 to break the 144MHz record. Irish Sea tropo coupled in to the Azores high tropo region to make the contacts possible. Love it or loathe it, FT8, combined with social media posting of activity has really made these super-tropo paths visible by making people more aware that something is happening.
This exceptional tropo weather has just taken a pause for now, but with high pressure remaining over the continent for much of the coming week, tropo should still be a feature although probably not of the scale of last weekend. The preferred directions will be from southern Britain into northern Europe and again across Biscay to northern Spain. The northern parts of the UK will be rather windy at times as low pressure drives a series of fronts across northern areas and occasionally down into southern Britain. This could provide some rain scatter on the microwave bands.
Moon declination is positive and reaches a peak on Friday so good Moon availability all week. Path losses are falling so EME conditions will improve throughout the week.
The peak of the Quadrantids shower is over but meteor activity will still be above normal, so keep looking for meteor scatter contacts on the VHF bands.
Category: GB2RS Propagation News
