NASA Scientists predict that Solar cycle 24 will be the best ever with solar activity the highest ever experienced but cycle 25 which should peak around 2022 is expected to be the worst ever for radio propagation. The reason for this is a slowing of the Sun's Great Conveyor Belt, a massive circulating current of hot plasma inside the Sun.
The belt has two branches, in the north and south which normally move at about 1 metre per second. This means each belt completes a circuit in approximately 40 years.
Researches believe that the turning of this Conveyor Belt controls the sunspot cycle.
Recent measurements indicate that both the northern and southern branches of the belt have slowed to a crawl. This slowdown will affect future sunspot cycles, with cycle 25, peaking around the year 2022, predicted to be less than half the strength of Cycle 23.
Cycle 24 however, is predicted is to be one of the strongest sunspot cycles since the 1960's.
A full explanation of the Conveyor Belt can be found on the NASA website at http://science.nasa.gov/headlines/y2006/10may_longrange.htm
