Propagation News – 9 March 2014

Thirteen sunspot groups were visible on the 28th but this had declined to nine by the 6th. Some of these groups were complex enough to produce the occasional M class solar flares, except on the 4th and the 6th when solar activity was low with only C class solar flares taking place. Solar flux levels declined from 171 units on the 28th to 149 by the 5th and the 6th. The average was 159 units. The 90 day solar flux average on the 6th was 160, that’s two units up on last week. X-ray flux levels declined slightly from C1 units on the 3rd to B5.5 by the 6th, the average was B8.7 units. Geomagnetic activity was quiet every day and the average was Ap 6 units. Solar wind data from the ACE spacecraft saw solar wind speeds decline from 500 kilometres per second on the 28th to 330 by the 3rd. Particle densities were elevated on the 28th with 22 particles per cubic centimetre and 18 on the 3rd and the 4th. Bz varied between minus 10 and plus 9 nanoTeslas on the most disturbed day and between minus and plus 3 nanoTeslas on the quietest day. The HF bands were in good shape with 28MHz open to all continents during the period, also, 50MHz saw openings to South Africa on the 4th and Mauritius on the 6th.

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 at mostly low levels but a chance of a larger solar flare taking place is still possible. Solar flux levels should decline and be around the 130s during the second half of the week. Geomagnetic activity should be unsettled today and tomorrow due to a coronal hole disturbance. Activity should then decline to quiet levels for the rest of the week. MUFs during daylight hours at equal latitudes should be around 30MHz. Darkness hour lows are expected to be about 10MHz. Paths this week to the Middle East should have a maximum usable frequency with a 50 per cent success rate of around 31MHz. The optimum working frequency with a 90 per cent success rate will be about 24MHz. The best time to try this path will be between 1000 and 1500 hours UTC.

Category: GB2RS Propagation News