GB2RS Propagation News
Propagation News – 8 June 2025
Last week’s HF propagation was heavily influenced by unsettled geomagnetic conditions. This was caused by a combination of coronal mass ejections and a strong solar wind from a coronal hole. The coronal mass ejection, or CME for short, followed a solar flare from sunspot 4100 on the 31 May at 0005UTC. The explosion lasted more […]
Propagation News – 1 June 2025
Last week’s high-speed solar wind, from a massive coronal hole on the Sun, took its toll on the HF bands. However, this week has been little better. Another coronal hole running diagonally across the Sun has been emitting particles that have pushed the Kp index up to a maximum of 6.67 which puts us into […]
Propagation News – 25 May 2025
A high-speed solar wind, originating from a massive coronal hole, took its toll on HF this past week. During the weekend of the 17th and 18th, the Kp index was above four for nine of the three-hourly recording periods. Unfortunately, the feed from the Dourbes Digisonde failed over this period, so we can’t comment on […]
Propagation News – 18 May 2025
This week, you could be forgiven for thinking that the Solar Cycle 25 maximum is now over. With a reduced solar flux index, and an almost blank Sun, there was little to get excited about. By Thursday 15 May, the SFI was 122 but previously, on the 12 May, it had been down to 116 […]
Propagation News – 11 May 2025
Active region 4079 turned out to be not quite so bad as we had predicted. The sunspot was large, about ten times the width of our Earth, so we expected it to be more active. It was regions 4081 and 4082 that produced most of the flare activity last week. Two filament eruptions also occurred […]
Propagation News – 4 May 2025
After the previous week’s geomagnetic disturbances, as described in last week’s GB2RS, the last seven days have been relatively quiet. The Kp index has mostly been in the ones and twos, however the rise to a Kp value of four on Thursday 1 May could herald a return to unsettled conditions. The solar flux index […]
