Propagation News – 5 October 2014

Yet another week with large and threatening sunspot regions that failed to produce a number of large solar flare. Saying that, five M class solar flares took place. The largest solar flare was a M7 that occurred on the 2nd as a large sunspot group was rotating off the solar disc. Numerous C class solar flares took place every day. Solar flux levels increased from 170 units to peak at 181 units on the 27th and the 28th before declining to 149 by the 2nd. The average was 168 units. The 90 day solar flux average on the 2nd was 135 units, that’s one unit up on last week. X-ray flux levels varied little day to day and averaged C1.1 units. Geomagnetic activity was unsettled on the 26th and the 27th and again on the 30th and the 1st. A coronal hole was responsible for both events. Solar wind data from the ACE spacecraft saw solar wind speeds vary between 350 and 490 kilometres per second every day. Particle densities were low every day and Bz varied between minus 7 and plus 6 nanoTeslas on the most disturbed day.

Now the solar forecast for the coming week. This week solar activity is expected to be mostly at low levels with only C class solar flares taking place, however there is a chance of a stronger flare on the occasional day. Solar flux levels are expected to decline slightly and be in the 130s for most of the week. Geomagnetic activity is expected to be at quiet levels every day. MUFs during daylight hours at equal latitudes should be about 30MHz. Darkness hour lows should be around 11MHz. Paths this week to the east coast of North America should have a maximum usable frequency with a 50 percent success rate of around 27MHz. The optimum working frequency with a 90 percent success rate will be about 21MHz. The best time to try this path will be between 1600 and 1900 hours UTC.

Category: GB2RS Propagation News