Propagation News – 20 September 2020
We had another uninspiring week with zero sunspots. However, there was DX to be had, with many Chiltern DX Club members reporting openings on 17 and 15 metres for well-equipped stations. Clive, GM3POI reported hearing India, Japan, Lebanon and South Africa on 17 metres and South Africa, Kenya, Oman and Kuwait on 15 metres. This was no doubt due to seasonal changes in the ionosphere and a very low Kp index, reflecting settled conditions.
The sporadic E season in the Northern Hemisphere has now finished so 10 metre openings are now few and far between. Tony, G4CJC, in his 10 metre band report, said that it was an “appalling week” on 28MHz.
The good news is that NASA and NOAA reported that Solar Cycle 25 has begun. During a media teleconference on 15 September, an international panel of experts found that the sunspot number hit rock bottom in December 2019. Since then, it said sunspot counts have been “slowly increasing”, with solar maximum expected in 2025. Nevertheless, NOAA predicts that the solar flux index will remain pegged at 70 next week, with quiet geomagnetic conditions and a maximum Kp index of two. However, things become more unsettled next weekend when the Kp index may rise to four or five due to the return of a coronal hole and its associated high-speed solar wind stream.
VHF and up
It seems that we are continuing to show a strong hand for tropo, since high pressure remains close by for much of the time until the end of the coming week. A small blemish this first weekend is the risk of some isolated showers over southern England with possible GHz bands rain scatter options. With similar results, we also have a weak cold front moving south midweek. Otherwise, it’s high pressure predominating in the second half of the week and offering further tropo opportunities.
With negative Moon declination, visibility windows will shorten as the week progresses, reaching a minimum on Thursday. Last Friday’s perigee means that path losses will steadily climb throughout the week. 144MHz sky temperatures are close to 3,000K on Wednesday and combined with the low Moon, EME conditions will be poor midweek. However it’s a good week to increase your satellite DXCC and square counts between the tropo events. There are plenty of LEO sats to choose from plus of course, QO-100 available 24/7.
There is one meteor shower this week—the daytime Sextantids. It has a radiant in the constellation of Sextans and is active until 9 October with the peak occurring on 27 September. The source of the meteor shower is asteroid 2005 UD.
Category: GB2RS Propagation News
