'Sunspots are temporary phenomena on the surface of the Sun (the photosphere) that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection, forming areas of reduced surface temperature. Although they are at temperatures of roughly 3,000–4,500 K, the contrast with the surrounding material at about 5,780 K leaves them clearly visible as dark spots, as the intensity of a heated black body (closely approximated by the photosphere) is a function of T (temperature) to the fourth power. If the sunspot were isolated from the surrounding photosphere it would be brighter than an electric arc. Sunspots expand and contract as they move across the surface of the sun and can be as large as 80,000 km (50,000 miles) in diameter, making the larger ones visible from Earth without the aid of a telescope. ' – Wikipedia

What relationship do they have with Amateur Radio Operations?
'Sunspot activity actually can help ham radio reception because the increased radiation causes the atmosphere to bend higher radio frequencies back toward Earth. The increase in radiation that accompanies a solar flare is a theoretical health hazard to spacewalking astronauts, crew and passengers in high-flying aircraft, but there isn't any evidence that people have actually gotten sick from such exposure' - HowStuffWorks.com

What is a Sunspot Cycle?
'Sunspot cycle (or solar cycle)--an irregular cycle, averaging about 11 years in length, during which the number of sunspots (and of their associated outbursts) rises and then drops again. Like the sunspots, the cycle is probably magnetic in nature, and the polar magnetic field of the Sun also reverses each solar cycle.' - NASA

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