Propagation News for 10 March

| March 8, 2013

And now the solar factual data for the period from Friday the 1st to Thursday the 7th of March, compiled by Neil Clarke, G0CAS on Friday the 8th of March.

With numerous sunspot groups visible everyday, however, most were small and simple. Solar activity varied between very low and moderate levels. Activity was very low on four days with no C class solar flares taking place. On the 5th activity increased to moderate levels when the only M class solar flare of the period took place. Only four C class solar flares took place during the period. Solar flux levels increased from 111 units on the 2nd to 118 by the 5th. The average was 114 units. The 90 day solar flux average on the 7th was 115 units, that’s one unit up on last week. X-ray flux levels averaged B2.8 units and varied little day to day. Geomagnetic activity started at elevated levels with an Ap index of 30 units on the 1st and 12 on the 2nd. This was in response to a coronal hole disturbance. Activity then returned to quiet levels for the remainder of the period. The average was Ap 9 units. Solar wind data from the ACE spacecraft saw solar wind speeds decline from 690 kilometres per second to 300 by the 5th. Particle densities declined from 28 particles per cubic centimetre on the 1st to low levels for the remainder of the period. Bz fluctuated between minus 16 and plus 14 nanoTeslas on the 1st and between minus and plus 3 nanoTeslas on the quieter days. MUFs were comfortably reached almost everyday. An impressive visual aurora took place on the 1st but radio contacts were only reported from stations at high latitudes.

And finally the solar forecast for the coming week. This week the more active side of the Sun is expected to have just rotated into view. Monitoring this sunspot region for the last several days via the STEREO Behind spacecraft as shown that it has produced a number of large solar flares and coronal mass ejections. Solar flux levels will depend on how active and complex this region (and others) will be once in view. Possibly, solar flux levels could be around the 120′s or as low as 100 units. Geomagnetic activity is expected to be mostly quiet but an Earth directed coronal mass ejection would increase activity. MUFs during daylight hours at equal latitudes should be around 25MHz for the south and 22Mhz for the north. 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 in excess of 30MHz. The optimum working frequency with a 90 per cent success rate of about 27MHz. The best time to try this path will be between 1000 and 1600 hours UTC.

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

Category: GB2RS Propagation News