SUNSPOTS VANISHING FASTER THAN EXPECTED
Sunspots are becoming scarce. Very scarce. So far in 2018, the sun has been blank almost 60% of the time, with whole weeks going by without sunspots. Today's sun, shown here in an image from NASA's Solar Dynamics Observatory, is typical of the featureless solar disk:
The fact that sunspots are vanishing comes as no surprise. Forecasters have been saying for years that this would happen as the current solar cycle ("solar cycle 24") comes to an end. The surprise is how fast.
"Solar cycle 24 is declining more quickly than forecast," stated NOAA's Space Weather Prediction Center on April 26th. This plot shows observed sunspot numbers in blue vs. the official forecast in red:
"The smoothed, predicted sunspot number for April-May 2018 is about 15," says NOAA. "However, the actual monthly values have been lower."
"Official" forecasts of the solar cycle come from NOAA's Solar Cycle Prediction Panel–a group of experts from NOAA, NASA, the US Air Force, universities and other research organizations. They have been convening at intervals since 1989 to predict the timing and intensity of Solar Max. The problem is, no one really knows how to predict the solar cycle. The most recent iteration of the panel in 2006-2008 compared 54 different methods ranging from empirical extrapolations of historical data to cutting-edge supercomputer models of the sun's magnetic dynamo. None fully described what is happening now.