According to NASA, the sunspot cycle we are now passing through – Sunspot Cycle 24 – is the smallest such cycle since Cycle 14, which ended back in 1906.
That is incorrect, says reader J. H. Walker.
“The problem with NASA’s sunspot count is that these are inflated by every blemish and spot fragment due to the optics they use,” says Walker.
If you use the Landscheidt sunspot-counting method, which counts only those spots that can be seen by 40MM optics, you realize that the current count is less than Solar Cycle 5. That solar cycle began in May 1798 and ended in December 1810.
It also corresponded with the Dalton Minimum.
The Dalton Minimum, a period of low solar activity named after English meteorologist John Dalton, lasted from about 1790 to 1830, says Wikipedia.
Like the Maunder Minimum and Spörer Minimum, the Dalton Minimum coincided with a period of lower-than-average global temperatures. The Oberlach Station in Germany, for example, experienced a 2.0°c decline over 20 years.
The “year without a summer” also occurred during the Dalton Minimum.
“The NASA counting method bears no relationship to the methods used in previous Solar Minimums, says Walker. “Hence the comparison with 1906 SC14 rather than SC5 1798.”