Propagation News 10 November 2013

| November 8, 2013

A new sunspot group rotated into view on the 2nd which allowed solar activity to continue at moderate to high levels. The largest solar flare of the period was an X3 on the 5th. In total nine M class solar flares took place along with numerous C class solar flares of varying strength every day. Only on the 4th was solar activity at low levels. Solar flux levels increased slightly from 142 units on the 2nd to 154 by the 6th. The average was 147 units. The 90 day solar flux average on the 7th was 120 units, an increase of 3 units from the previous week. A steady increase started at the beginning of October when the 90 day solar flux average was 110 units. The highest 90 day solar flux average for sunspot cycle was 146, which took place in November 2011. X-ray flux levels increased from B6.1 units on the 3rd to C1 by the 5th. The average was B7.6 units. Considering the number of large solar flares and associated coronal mass ejections, none headed our way and triggered a geomagnetic disturbance. However, on the 7th a weak disturbance took place from a coronal hole. The Ap index was in single figures every day except for the 7th, when the Ap index was 14 units. The average was Ap 6 units. Solar wind data from the ACE spacecraft saw solar wind speeds vary between 310 and 410 kilometres per second. Particle densities were low throughout except for a brief increase to 20 particles per cubic during the 6th and again on the 7th. Bz varied between minus 6 and plus 5 nanoTeslas except for the 7th that varied between minus and plus 10 nanoTeslas. The HF bands were in good shape throughout period. K9W, the Wake Island expedition was worked from the UK on bands up to 28MHz, one UK operator reporting good signals on his indoor dipole.

Finally, the solar forecast for the coming week. The current spell of increased solar activity is expected to continue with the return of a couple of sunspot regions around midweek that produced major solar flares on their last rotation. Solar activity should be moderate or even high on some days. Solar flux levels are expected to be in the 140′s for most of the week. Geomagnetic activity should be quiet every day, however, there is a reasonable chance that a coronal mass ejection could head our way and increase activity. MUFs during daylight hours at equal latitudes should be in excess of 30MHz. Darkness hour lows should be around 10MHz. Paths this week to the Middle East should have a maximum usable frequency with a 50 per cent success rate of around 32MHz. The optimum working frequency with a 90 per cent success rate will be about 26MHz. The best time to try this path will be between 0900and 1500 hours UTC.

Category: GB2RS Propagation News

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