Propagation News for 3 March

| March 1, 2013

And now the solar factual data for the period from Friday the 22nd to Thursday the 28th of February, compiled by Neil Clarke, G0CAS on Friday the 1st of March.

At first solar activity was at low levels with five small C class solar flares taking place on the first three days. Solar activity then declined to very low levels. Normally, B class solar flares do not get a mention in this report but, on the 25th, a long duration B class flare took place and lasted for approximately nine hours. This took place from a large sunspot group that rotated out of view two days before. This flare would have been much stronger if it was on the Earth facing side of the Sun and the associated coronal mass ejection would have headed our way. Solar flux levels declined from 107 units on the 22nd to 95 by the 24th and the 25th. Levels increased slightly by the end of the period and the average was 101 units. The 90 day solar flux average on the 28th was 114 units, that’s one unit down on last week. X-ray flux levels varied little day to day and averaged B2.5 units. Geomagnetic activity was quiet everyday. The most disturbed day was the 22nd with an Ap index of 8 units. The average was Ap 5 units. Solar wind data from the ACE spacecraft saw slow solar wind speeds at first but towards the end of the period increased to around 400 kilometres per second. Particle densities were low at first but on the 25th increased to 46 particles per cubic centimetre and 25 on the 27th and 90 on the 28th. Bz varied between minus 3 and plus 2 nanoTeslas on the quietest day and between minus 8 and plus 7 nanoTeslas on the most disturbed day.
And finally the solar forecast for the coming week. There are a number of sunspot regions that will rotate into view during the coming week. Solar activity is expected to be mostly low, however, there is the possibility that activity could increase occasionally. Solar flux levels should be slightly around the 100 mark or maybe higher if any of the sunspots groups are large. No coronal hole activity is expected this week so geomagnetic activity is expected to be quiet everyday. As always, around sunspot maximum, a coronal mass ejection could head our way and increase activity due to a number of reasons. MUFs during daylight hours at equal latitudes should be around 25MHz for the south and 22MHz for the north. Darkness hour lows should be about 8MHz. Paths this week to India 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 the path will be between 1000 and 1300 hours UTC.

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

Category: GB2RS Propagation News