Sunspots
Also called: Sunspot cycle, Solar cycle · Topic: Climate Change: Causes, Evidence and the Global Response · NCERT: Class 11, Ch 11 "World Climate and Climate Change"
Meaning
Sunspots are dark patches on the Sun's surface. They look dark because they are cooler than the area around them. Their number rises and falls in a cycle of about 11 years. Some meteorologists link more sunspots to cooler, wetter and stormier weather. Class 11 says these findings are "not statistically significant". Solar output has been flat or slightly falling since 1950 while temperatures rose, so sunspots cannot explain recent warming.
Example
Solar Cycle 25 began in December 2019 and peaked around 2024–25. India's solar mission Aditya-L1 was launched on 2 September 2023 and has studied the Sun from the L1 point since 6 January 2024. L1 is a spot in space between the Earth and the Sun where a spacecraft can stay in a steady position.
Don't confuse with
- Maunder Minimum: a spell with very few sunspots (1645–1715), linked to the Little Ice Age. It was a long gap in sunspots, not the regular 11-year cycle.
- Milankovitch cycles: changes in Earth's orbit and tilt over tens of thousands of years. Sunspots are changes on the Sun itself.