Unequal heating of the atmosphere

Incoming radiation/insolation from the sun heats the Earth.

Insolation is not equal all over the Earth’s surface.

The amount of insolation depends on latitude and seasons.

Latitude

Latitude

Insolation is greater at the equator, therefore very hot and insolation decreases north- and southwards towards the poles.

Therefore heating of the earth is affected by latitude.

Heating of the Earth and it’s atmosphere is hotter in summer as in the winter.

The Earth’s axis is responsible for unequal heating and our seasons on Earth.

The Significance of the Earth’s Axis

The Earth rotates on its own axis. The Earth completes one rotation on its axis every 24 hours.

The part of the Earth that faces the sun and receives insolation in the 24 hours – is daytime and the other way around.

The earth’s Axis is tilted at 23.5˚and causes unequal heating at the Earh’s surface.

The Earth’s axis

During summer – Longer days and more heat.

During winter – shorter days and less heat.

Northern hemisphere is titled towards the sun – thus daytime.

Half of the earth facing the sun is experiencing day the other half facing away from the sun is experiencing night.

Half the Earth at the equator has day and the other half night. Therefore at the equator there is equal day and night.

• The Southern hemisphere that has more darkness than daylight is experiencing winter and Northern hemisphere summer – more daylight.

• The area between the Arctic circle and North pole has daylight all the time – sun never sets.

• The area between the Arctic circle and South pole has nighttime all the time – sun never rises.