Saturday, 23 February 2008

Propagation Report March 2008

During the second half of February, the Solar flux has remained at a constant 72, and is likely to remain the same until at least 17th March, which would suggest that we may at last have reached sunspot minimum at the start of Solar Cycle 24.
The A index rose to 12 on February 21st, and dropped back to 5 the next day. The next disturbance will be on Feb 28th, to March 3rd with the index at 15 and the K at 4 followed by another disturbance 8-13th with the A index peaking at 15 on the 8th and 9th. The A index will then rise again to 10 by the 16th for at least 2 days.
In conclusion, the best days for HF reception will be March 4th 5th 14th and 15th with the A index at 5 and the K index at 2, the worst days being the 1st, 8th 9th and 15th.
The National Oceanic and Atmospheric Administration and the US Air Force have predicted the solar flux to remain at 72 from March 1st continuing into April. (From:
Maunder Minimum?

It has been suggested that we may be entering another Maunder Minimum, which is the name given to the period roughly from 1645 to 1715, when sunspots became exceedingly rare, as noted by solar observers of the time. It is named after the solar astronomer Edward W. Maunder (1851–1928) who discovered the dearth of sunspots during that period by studying records from those years. During one 30-year period within the Maunder Minimum, for example, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000–50,000 spots. See:

However, Tad Cooke of ARRL, after seeking the opinion of Dr. Kenneth Tapping of the Herzberg Institute of Astrophysics in Penticton, British Columbia recently wrote:
"I think we can relax about any possible upcoming 70-year period of a quiet Sun. We cannot say that it could not happen, but in fact there is nothing unusual about the current Solar Cycle minimum, and really no known method of predicting such a period."
Thanks to Mike Terry and Ken Fletcher for regular updates. Related links can be found at

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