Drop in solar activity has potential effect for climate on earth.
The sun has reached a milestone not seen for nearly 100 years: an entire month has passed without a single visible sunspot being noted.
When the sun is active, it's not uncommon to see sunspot numbers of 100 or more in a single month.
Every 11 years, activity slows, and numbers briefly drop to near-zero.
Normally sunspots return very quickly, as a new cycle begins.
But this year -- which corresponds to the start of Solar Cycle 24 -- has been extraordinarily long and quiet, with the first seven months averaging a sunspot number of only 3. August followed with none at all. The astonishing rapid drop of the past year has defied predictions, and caught nearly all astronomers by surprise.
But will the rest of us? In the past 1000 years, three previous such events -- the Dalton, Maunder, and Spörer Minimums, have all led to rapid cooling. One was large enough to be called a "mini ice age". For a society dependent on agriculture, cold is more damaging than heat. The growing season shortens, yields drop, and the occurrence of crop-destroying frosts increases.
Meteorologist Anthony Watts, who runs a climate data auditing site, tells DailyTech the sunspot numbers are another indication the "sun's dynamo" is idling. According to Watts, the effect of sunspots on TSI (total solar irradiance) is negligible, but the reduction in the solar magnetosphere affects cloud formation here on Earth, which in turn modulates climate.
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