In 1815 a volcano erupted spewing billions of tons of ash into the sky. This ash "cloud" caused global annual temperatures to drop below normal, causing "a year without a summer" in 1816.Which sphere did this ash "cloud" affect to cause these changes? *

The Atmosphere

Explanation:

1816 was a year without summer because the billions of tons of ash that was spewed blocked radiation preventing it from reaching the surface of the earth.

A volcano is a break in the crust of planetary bodies like Earth that allows gasses, volcanic ash, and hot lava to escape. Volcanos are one of the major factors that cause climate changes on Earth mostly because of their cooling effect.

The ash, gasses and lava usually escape to the atmospheric layer of the earth with their cooling effect. And they cool the earth by blocking incoming solar radiation. This can go on for months or years depending on the components and severity of the eruption and can lead to "a year without summer" as witnessed in 1816.