What’s Happening to the Sun?
For about 50 years from roughly 1650 to 1700, the Sun took a break from its typical sunspot activity. That phase of solar rest coincided with what we now refer to as “The Little Ice Age” — a period of cooling on the Earth that resulted in bitterly cold winters, particularly in Europe and North America. Scientists attribute the Little Ice Age to two main causes: increased volcanic activity and reduced solar activity.
Could it happen again? And are we headed there now?
The term “solar activity” refers collectively to sunspots, solar flares, and solar eruptions. Together, these phenomena make up the “space weather” that alters interactions between Earth and its atmosphere, causing potential disruptions to satellites, communications systems, and power grids. Varying levels of solar activity also cause significant changes in atmospheric circulation patterns, which can affect the weather and climate on Earth.
Solar cycles, which last an average of 11 years, are driven by the number, size, and placement of sunspots — cooler, darker spots on the Sun’s surface where intense magnetic activity occurs — on the Sun’s surface. Each cycle is marked by a solar minimum and a solar maximum, meaning the approximate time in the cycle when the least and greatest amounts of solar activity occurred. During the solar minimum, sunspot activity diminishes, and during the maximum greater numbers of sunspots appear. As one cycle winds down and another begins, sunspots from both cycles can be seen simultaneously.
By late 2007, Solar Cycle 23, which began in 1996, was decaying to low activity levels, and NOAA forecasters predicted that Solar Cycle 24 would begin in March 2008, plus or minus six months. Indeed, the new cycle’s first sunspot appeared in January 2008 — its high-latitude location a clear sign that it was part of the new solar cycle. But in the months that followed, there was a marked decrease in sunspot activity, spawning questions about whether we could be headed into another little ice age.