Propagation News – 26 October 2014

| October 24, 2014

As forecast, a large complex sunspot group rotated into view at the start of the period. This is the largest sunspot group since 1989. It had produced large solar flares several days before it had rotated into view. Solar activity increased to moderate levels on most days and high on the 19th, 20th and the 22nd. In total, 11 M class and two X class solar flares took place that produced sudden ionospheric disturbances on the daylight side of the Earth and some were associated with coronal mass ejections but none, as yet, were Earth directed. Solar flux levels increased much higher than expected and increased from 146 units on the 17th to 227 by the 23rd. The 90 day solar flux average on the 23rd was 138 units, that’s seven units up on last week. X-ray flux levels varied little day to day and averaged C1 units. Geomagnetic activity started at quiet levels but the increased on the 20th due to a recurring coronal hole. This disturbance lasted till late on the 22nd. The most disturbed day was the 20th with an Ap index of 26 units and the average was Ap 13 units. Solar wind data from the ACE spacecraft saw solar wind speeds increase from 400 to 680 kilometres per second. Particle densities were low except for an increase to 23 particles per cubic centimetre on the 18th. Bz varied between minus 10 and plus 8 nanoTeslas during the disturbance. Aurora and auroral-E took place for some UK operators on the evening of 20th and there was somewhat unseasonal 6m Sporadic-E to south-east Europe on the morning of 22nd. Also, the French Guyana 6m beacon was reported into south west England on the 23rd.

Now the solar forecast for the coming week. A very large complex sunspot region is expected to remain in view till next weekend. This week solar activity is expected to be moderate to high, M class solar flares are possible on some days with a slight chance of an X class flare taking place. Solar flux levels should be around the 230’s at first but then decline as the sunspot group rotates out of view. Geomagnetic activity is expected to be at quiet levels, however a warning, with the large sunspot group having rotated into the western solar hemisphere any coronal mass ejections stands a much better chance of heading towards Earth. If that happens then activity would increase.

It is exactly 20 years ago that Neil, G0CAS first started compiling the solar report for GB2RS and this will be his last report. He would like to thank everybody for their support during this time, the staff at RSGB HQ and the GB2RS newsreaders, Martin, G3USF for standing in while he was not available and finally to all the listeners who it is hoped found the reports interesting and informative. Neil says, “Whatever bands you work, I wish you the best of DX and best 73s.”

Category: GB2RS Propagation News