Propagation News

| November 4, 2012

And now the solar factual data for the period from Friday the 26th of October to the 1st of November compiled by Neil Clarke, G0CAS on Friday the 2nd of November.

Only four new sunspots groups appeared during the week, these, like the other visible sunspot groups, were mostly quiet, with only occasional small C class solar flares taking place on some days. On the 29th, 30th and the 1st, solar activity was at very low levels, with no C class solar flares taking place. Solar flux levels declined every day from 131 units on the 26th to 98 by the 1st. The average was 112 units. The 90 day solar flux average on the 1st was 120, that’s two units down on last week. X-ray flux levels declined from B5.1 units on the 26th to B2.2 by the end of the period. The average was B3.9 units. Geomagnetic activity was quiet every day, except for the 1st when activity increased due to a coronal mass ejection that departed the Sun on the 29th. The Ap index on the 1st was 24 units. The average was 7 units. Solar wind data from the ACE spacecraft saw solar wind speeds decline to a slow 260 kilometres per second by the 30th. Wind speeds then increased to 380 kilometres per second on the arrival of the disturbance. Particle densities were low but increased to 60 particles per cubic centimetre on the 31st. Bz varied between minus 3 and plus 2 nanoTeslas on the quiet days and between minus and plus 12 nanoTeslas during the disturbance. A weak radio aurora took place during the afternoon of the 1st, which extended down to northern Scotland during the afternoon.

And finally the solar forecast for the coming week. This week the quiet side of the Sun is expected to be looking our way. Solar activity is expected to be low, however, activity could decline further to very low levels on some days. Solar flux levels should be at their lowest for the next few days and be in the 90’s but later in the week levels should increase. Geomagnetic activity could be unsettled at first due to a small coronal hole disturbance, but by midweek quiet levels should return. MUFs during daylight hours at equal latitudes should be above 30MHz, especially early in the week until the coronal hole disturbance arrives, when MUFs could decline. Darkness hour lows should be around 9MHz. Paths this week to South Africa should have a maximum usable frequency with a 50 per cent success rate of around 35MHz. 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 1100 and 1500 hours UTC.

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

Category: GB2RS Propagation News

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