Earth's Energy and Radiation By: May-Lynn Fortune & Maesey Phillips

Earth's Radiation Solar energy travels from the sun to the earth and by a process call radiation. Radiation is energy that has atoms or molecules that give off energy in the form of electromagnetic waves. These wave carry the energy through space and only release the energy when they interact with a type of matter for example: the ground, water, or air. The radiation has different wavelengths the react different when they reach the earth.

Solar radiation waves There are seven types of solar radiation waves: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays, and gamma rays. The longer wavelengths have low energy and the shorter wavelengths have high energy

The Biosphere When energy from the sun gets to the earth and this energy reacts with the thin layer of air, land and water on the earths surface and this is called the biosphere. The Biosphere is made up of three parts: The atmosphere, lithosphere and hydrosphere The atmosphere (air) is a mixture of nitrogen, oxygen, and other gasses that covers more than 700km above the earths surface. The first 12km of the atmosphere, called the troposphere is where all weather takes place The lithosphere (land) is made up continental crust above sea level and oceanic crust at the ocean bottom.

The hydrosphere (water) is the water on the earth's surface The hydrosphere (water) is the water on the earth's surface. It includes liquid water, solid water and vapour water in ocean, river, streams and lakes.

Incoming and outgoing radiation The earth's land and ocean absorbs about 49 percent if the solar energy that enters the earth's atmosphere. 42 percent of the solar energy is absorbed, reflects and scatters which is caused by clouds, gases and aerosols. The last 9 percent is reflected by the earth's surface. Solar energy is reflected back into space by clouds and earths surface. Blue daytime sky and red/orange sunset sky is caused by dust particles and gases like water vapour spread sunlight.

In space there is less dust and gas that spreads sunlight which causes the black sky. It doesn't matter if solar energy is absorbed, reflected or spread, all the solar energy eventually ends back into space.

Factors Affecting Absorption of Energy The amount of energy that is absorbed depends on the color of the earths surface. Dark surfaces absorb energy and light surfaces reflect energy. The name used for reflecting energy is albedo. The type of substance also has an effect on how much energy is reflected or absorbed. A good example is when water takes in energy, it heats up and cools down at a more slower rate then air. Specific heat Capacity is the property of a substance which includes how it absorbs and releases energy. Land and air has less heat capacity then water does which causes water to have a better heat sink.

Heat sink is any substance which can absorb and retrain energy and not change its state. Water is a big influence on the weather because there is so much water on earth and water is a good heat sink.

How the earth keeps a stable temperature The earth keeps a stable temperature by being in radiative balance between the incoming short wave solar radiation and the outgoing long wave infrared radiation. Each of these short wave and long wave are controlled by clouds, the atmosphere and the earth's surface that a balance is created.

Greenhouse effect These energy absorbing gases include water vapour, carbon dioxide and methane Greenhouse gases absorb infrared radiation that reflects off and goes back to the earth's surface This radiation warms the surface of the earth and the atmosphere before going into outer space. The greenhouse gasses in the Earth's atmosphere acts as a heat sink

Which causes the troposphere(where all weather happens) to have more heat than it would if the gases were not there

What the earth would be like if it didn't have an atmosphere The atmosphere protects us from harmful radiation from the sun and the temperatures would be constantly changing so if the earth didn't have an atmosphere it would be very difficult for humans to live on earth because we would be exposed to high amounts of UV radiation and it would very hot during the day and very cold during the night which would make it hard to survive.

Earth without oceans When the heat energy from the sun hits the ocean, the ocean stores the heat. When the precipitation falls then the ocean releases the stored heat energy into the atmosphere.95% of the heat add to the environment over the last 50 years has gone into the oceans. So Without oceans it would always be cold because when the precipitation would fall there would be no heat energy being released into the atmosphere to but the precipitation back up.

Why coastal areas are warmer in the winter and cooler in the summer Coastal areas are warmer in the winter and cooler in the summer because in the winter the ocean holds more heat and in the summer the ocean absorbs more heat.