The Sun Powers Earth’s Climate System

The Balance of Energy on Earth Almost all energy on Earth comes from….. The Sun!

What happens when radiation from the sun once it reaches Earth??

Absorption of Energy from the Sun Upon interaction with particles of matter: Absorption – particle gains energy from radiation Transmission – energy moves through particle Reflection - off particles

Energy Balance? The sun has no off switch! So why doesn’t the Earth just keep getting hotter? The Earth surface emits lower- energy infrared radiation back out.

The result? Earth’s global temperature stays fairly constant.

= Energy absorbed by Earth and atmosphere Energy radiated back again by Earth and atmosphere =

How Does Latitude Affect Climate? Why is it warmer at the Equator than at the poles of the Earth?

At the equator, the sun shines overhead, is spread over a smaller area, and feels stronger.

Latitude and Climate Angle of radiation hitting the Earth. Depth of atmosphere the sun’s energy must pass through.

Latitude and Climate At the poles, more atmosphere means more absorption and reflection by the atmosphere, so less reaches the ground.

Albedo The proportion of radiation reflected by a surface. Example: ice has a high albedo because it reflects back most of the Sun’s radiation.

Albedo and Climate Albedo Comparisons: Snow and ice (80 – 85%) Forests (5 – 10%) Oceans (4 – 7%) Ice Dessert Forest Ocean

Albedo and Climate

Effects of Albedo If Earth’s average temperature rises slightly, more ice melts. The increased water absorbs more of the Sun’s radiation, and Earth’s temperature increases even more. ....and vice versa.....

Absorption Transmission Reflection Energy Balance Albedo Albedo Effect Vocabulary! Absorption Transmission Reflection Energy Balance Albedo Albedo Effect

Homework Pg. 329 # 1 – 6 Pg. 357 # 3