Low Activity!

A record has been set for annual spotlessness in the sun.  More days in 2019 have been without spots than any other year since the beginning of the Space Age.  So far in 2019, the sun has been without spots for over 270 days, 77% of the year.  Currently, it is in a continuous stretch of 33 spotless days in a row.

According to Wikipedia, “Sunspots are temporary phenomena on the Sun’s photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity. Their number varies according to the approximately 11-year solar cycle.”

While sunspot frequency varies in an about 11-year cycle, the magnitude of the solar maximum — that point in the solar cycle where the average monthly number of sunspots is at its maximum — also varies. The sun is currently at the end of solar cycle 24, which had a solar maximum at a lower magnitude than previous cycles, as shown in the figure below, which also depicts the November 2019 prediction for cycle 25.

The figure below is updated monthly.  I expect that future updates will incorporate the predicted smoothed curve for cycle  25, probably in a similar fashion as the second image below, which is from 2007, which provided the ranges in which it was thought the sunspots in cycle 24 would appear.

There has been speculation and studies from some scientists indicating that the exceptionally low solar minimum and its extended duration may signal approaching global cooling conditions. Other scientists disagree. Unfortunately, the speculations and studies cannot be tested in a laboratory environment and computer modeling may not yet be adequate to predict such future solar impacts on the climate.

A Principia Scientific International article says:

As the Earth was completing Solar Cycle 24, sunspot counts and magnetic activity were expected cyclically fall from its high of over 100 in 2014 to a low of zero in 2022. But the sunspot count plunged to zero in mid-2018 and has remained substantially lower than forecast for Solar Cycle 25.

The data could indicate the onset of a super cycle ‘Maunder Minimum.’ The last Maunder Minimum period from 1645 to 1715 was a period with 7 percent fewer sunspots and global cooling, referred to as the ‘Little Ice Age.’

The Little Ice Age altered atmospheric circulation patterns across northern Europe, resulting in widespread crop failures, famine, disease, and increased child mortality.  London’s Thames River froze over most years during the period.

There is no doubt, I believe, that changes in the behavior of the sun have to impact the planet’s climate.  How much and when is something not fully understood.