Propagation News

| September 2, 2012

And now the solar factual data for the period from Friday the 24th to Thursday the 30th of August, compiled by Neil Clarke on Friday the 31st August.

All the visible groups were small and magnetically simple and with it solar activity was at very low levels. On the 30th though, a sunspot group started to rotate into view over the south-east limb and solar activity increased to moderate levels, when the only M class solar flare of the period took place. Solar flux levels increased from 104 units on the 24th to 128 by the 30th. The average was 113 units. The 90 day solar flux average on the 30th was 124 units, the same level as last week. X-ray flux levels increased from B1.6 units on the 24th to B6.7 by the 30th, the average was B3 units. Geomagnetic activity was unsettled from the 24th to the 26th due to a small coronal hole. Activity then decreased and the Ap index on the 30th was 3 units. The average was Ap 7 units. Solar wind data from the ACE spacecraft saw solar wind speeds increase from 350 kilometres per second to 700 by the morning of the 27th. Speeds then gradually declined to 400 kilometres per second by the end of the period. Particle densities were low, except for a brief increase to 14 particles per cubic centimetre on the 25th. Bz varied between minus 9 and plus 11 nanoTeslas during the disturbance and between minus 2 and plus 4 nanoTeslas on the 29th and the 30th.

And finally the solar forecast from Sunday the 2nd of September. A new sunspot group has just rotated into view in the last few days and this could be the source of any large solar flare activity taking place this week. Solar activity could be at moderate levels on some days. Solar flux levels should increase and be around the 140’s. Geomagnetic activity is expected to be at quiet levels most days. 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 11MHz. Paths this week to South America should have a maximum usable frequency with a 50 per cent success rate of around 30MHz. The optimum working frequency with a 90 per cent success rate will be about 24MHz. The best time to try this path will between 1200 and 1800 hours. With the summer Sporadic-E season just about over now, no more forecasts will be made in this report. However, occasional openings will take place for the next few weeks.

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

Category: GB2RS Propagation News