Propagation News

| November 25, 2012

And now the solar factual data for the period from Friday the 16th to the 22nd of November compiled by Neil Clarke, G0CAS on Friday the 23rd of November.

At the start of the period 9 sunspot groups were visible but on the 17th a new sunspot group emerged onto the solar disc and grew in size rapidly. By the 20th and the 21st. solar activity had increased to moderate levels, when two M class solar flares took place on both days. During the other days solar activity was low, with only C class solar flares taking place. There were 34 in total. However, on the 22nd no solar flares occurred and as a result solar activity was at very low levels. Solar flux levels increased slightly to peak at 141 units on the 18th and the 20th but then declined to 128 units by the 22nd. The average was 137 units. The 90 day solar flux average on the 22nd was 122 units, that’s three units up on last week. X-ray flux levels increased to B6.1 units by the 20th but then declined to B3.5 by the end of the period. The average was B4.5 units. Geomagnetic activity was quiet everyday except for the 20th which increased to unsettled levels with an Ap index of 13 units. The average was Ap 6 units. Solar wind data from the ACE spacecraft saw solar wind speeds vary between 370 and 480 kilometres per second for the period. Particle densities were low every day. Bz never varied more than minus 7 and plus 5 nanoTeslas for the period.

And finally the solar forecast for the coming week. This week the quiet side of the Sun is expected to be looking our way once an active sunspot group rotates out of view around midweek. Solar activity should be at low levels, however, there is a slight chance that activity could increase to moderate levels till midweek. Solar flux levels should decline and by next weekend should be slightly above the 100 mark. Geomagnetic activity is expected to be at quiet levels, but there is a slight chance that activity could increase if a coronal mass ejection heads our way. MUFs during daylight hours at equal latitudes should be around 28MHz for the south and 25MHz for the north. Darkness hour lows should be about 9MHz. Paths this week to the Middle East should have a maximum usable frequency with a 50 per cent success rate of around 27MHz. The optimum working frequency with a 90 per cent success rate will be about 22MHz. The best time to try this path will be between 0900 and 1400 hours UTC.

And that’s all for this week from the propagation team.

Category: GB2RS Propagation News

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