Sunspot activity may be entering a lull for the first time in almost 400 years, offering scientists a rare chance to gauge how solar conditions affect Earth’s climate. “This is highly unusual and unexpected” says Frank Hill, a researcher at the National Solar Observatory. Three new NSO studies suggest that the sun’s fluctuating magnetic field may soon become too weak to produce sunspots, those dark regions of gas on the solar surface that normally wax and wane every 11 years. The sun should reach the peak of that cycle next year, but its recent calm “weather” including slower surface wind patterns and fewer solar flares could signal it’s entering a period of relative dormancy. That would mean less solar radiation reaching the Earth.
The last time sunspots disappeared, in 1645, their absence lasted for 70 years, during which Earth experienced a frigid period known as the “Little Ice Age.” Hill says there’s not “enough evidence either way” to say whether that dip in the sun’s magnetic activity caused the Earth’s cooling. But he says the coming sunspot hiatus will be “a splendid opportunity” to figure out how the sun’s weather affects our climate.