Propagation – 31st March 2013

And now the solar factual data for the period from Friday the 22nd to Wednesday the 27th of March, compiled by Neil Clarke, G0CAS on Thursday the 28th of March.

Yet another week when solar activity resembled solar minimum, rather than solar maximum. All the visible sunspot regions during the period were small and simple. Several small C class solar flares took place on the 22nd when solar activity was at low levels, but the remaining days’ solar activity was at very low levels. Solar flux levels declined from 101 units on the 22nd to 92 by the 26th. The average was 96 units. The 90 day solar flux average on the 27th was 115 units, that’s one unit down on last week. X-ray flux levels declined from B3.2 units on the 22nd to B1 by the 27th. The average was B1.6 units. Geomagnetic activity was quiet everyday except for the 23rd when the Ap index increased to 11 units. The average was Ap 7 units. Solar wind data from the ACE spacecraft saw solar wind speeds increase from 340 kilometres per second on the 23rd to 570 by the 27th. Particle densities were moderate most days, levels were up to 32 particles per cubic centimetre during the 23rd. Bz varied between minus 10 and plus 8 nanoTeslas on the most disturbed day and between minus 4 and plus 4 nanoTeslas on the quieter days.

And finally the solar forecast for the coming week. This week the more active side of the Sun is expected to be rotating into view. Saying that, activity is only expected to be at low levels with only a small chance of solar activity increasing any higher. Solar flux levels should increase and be around the 120 mark later in the week. Geomagnetic activity should be quiet everyday. MUFs during daylight hours at equal latitudes should be around 23MHz for the south and 20MHz for the north. Darkness hour lows should be about 10MHz. Paths this week to South Africa should have a maximum usable frequency with a 50 per cent success of around 33MHz. The optimum working frequency with a 90 per cent success rate will be about 27MHz. The best time to try this path will be between 1000 and 1500 hours UTC.

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

Category: GB2RS Propagation News