Martin Armstrong has noted the sunspot activity effecting earthquakes, volcanos, climate, etc...cyclic...remember the year without summer? June 1816 I believe....Washington DC to Maine had 2-3 feet of snow, Armstrong documents these many occurrences and ties them all with the cyclic sun spot activity. Of course the global warming idiots will deny anything other than C02. We are heading into a mini ice age.
https://www.almanac.com/extra/year-without-summer
The Farmers Almanac uses sunspot activity in many of its forecasts. They note 1816 had the lowest sun activity ever recorded ( yes, they kept records of solar activity back then).
I think that coinsides with Tambor eruption .