| Propagation |
| And now the solar factual data for the period from the 12th to the 18th of July, compiled by Neil Clarke, G0CAS on the 19th of July. Solar activity was very low to low. C class solar flares occurred on the 13th, 14th and the 17th. Solar flux levels declined from 80 units on the 12th to 76 by the 15th. Levels then increased again back to 79 units. The average was 78. The 90 day solar flux average on the 18th was 74 units, that’s one unit down on last week. X-ray flux levels varied little day to day and averaged A9.3 units. Geomagnetic activity started at quiet levels but on the 14th and the 15th a small coronal hole disturbance took place. The Ap index for both days were 11 and 10 units respectively. The average was Ap 5 units. Solar wind data from the ACE spacecraft saw solar wind speeds increased from 290 kilometres per second on the 14th to 500 by the 15th. However, by the end of the period had declined back to 290 kilometres per second. Particle densities were low throughout except for a brief increase to 16 particles per cubic centimetre during the 14th. Bz varied between minus and plus 16 nanoTeslas on the 14th for a short time just after the disturbance arrived. On the quieter days Bz varied between minus and plus 2 nanoTeslas, for example on the 17th and the 18th. And now the solar forecast. This week the quiet side of the Sun is expected to be looking our way. Solar activity should be at very low levels. Solar flux levels are expected to be in the low 70’s for most of the week. Geomagnetic activity for the next few days could be unsettled due to a recurring coronal hole. Activity is then expected to return to quiet levels from midweek. MUFs during daylight hours at equal latitudes should be around 18MHz for the south and 15MHz for the north. Paths this week to the Middle East should have a maximum usable frequency with a 50 per cent success rate of around 20MHz. The optimum working frequency with a 90 per cent success rate will be about 15MHz. The best time to try this path will be between 1200 and 1900 hours UTC. Sporadic-E is expected to take place most days during the coming week. The Middle East could occasionally be possible to work on 50MHz via double hop sporadic-E. And that’s all for this week from the propagation team.  Go back...  |
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Page last updated 28 July 2010 at 12:19
