Propagation News – 8 September 2013

| September 6, 2013

A small number of sunspot groups were visible every day, all were small and mostly quiet. Only two new sunspot groups appeared during the period. Solar activity was very low on the 2nd but on the remaining days activity was low with only one C class solar flare taking place each day except for the 4th when nine took place. Solar flux levels showed little variation day to day and averaged 107 units. The 90 day solar flux average on the 5th remained at the same level as last week at 114 units. X-ray flux levels averaged B2.8 units and varied little day to day. Geomagnetic activity started at quiet levels but on the 31st and 2nd increased to unsettled levels with an Ap index of 13 and 12 units respectively. The average was Ap 8 units. Solar wind data from the ACE spacecraft saw solar wind speeds vary between 330 and 500 kilometres per second. Particle densities were low except for the 30th when they increased to 40 particles per cubic centimetre and 21 on the 3rd. Bz varied between minus 10 and plus 8 nanoTeslas on the 30th and between minus 7 and plus 8 nanoTeslas on the remaining days.

And finally the solar forecast for the coming week. This week the more active side of the Sun is expected to be looking our way, however, don’t get too excited as solar activity is expected to continue at low levels with only a small chance of any stronger solar flares taking place. Solar flux levels are expected to increase but only to around the 120 mark. Geomagnetic activity is expected to start at quiet levels but around midweek a recurring coronal hole is expected to increase activity. Quiet conditions should return by next weekend. 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 the east coast of North America should have a maximum usable frequency with a 50 per cent success rate of around 22MHz. The optimum working frequency with a 90 per cent success rate will be about 17MHz. The best time to try this path will be between 1700 and 2100 hours UTC.

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

Category: GB2RS Propagation News

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