Solar Radiation and Energy Balance Unit 3: Weather and Climate Geo 12 Ms. Thind

Key Terms Solar radiation, net radiation, global radiation balance, albedo, greenhouse effect

Solar Radiation Electromagnetic energy emitted by the sun Earth intercepts about ½ of 1 billionth of the suns total energy output The total amount of solar radiation or energy that leaves and enters the atmosphere is called net radiation (Rn) Solar radiation passes through the atmosphere and is subject to: 1. scattering 2. absorption 3. reflection

Solar Radiation cont.. 1.Scattering: - ray is turned away by a molecule and the direction is changed 2. Absorption: - rays are absorbed by surfaces 3. Reflection: - rays are reflected by molecules back into space

Absorption of Radiation As radiation moves through the atmospheric layers molecules cause radiation to be scattered, reflected, and absorbed. Absorption of radiation results in a rise in temperature What can affect the absorption of radiation?

Global Radiation Balance The process of energy flow between the earth and sun (what we just described) Let’s see what this looks like…

Absorption of Radiation Amount of absorption is related to the albedo of a surface Albedo: surface’s ability to reflect radiation Eg: land has a low albedo because its ability to reflect solar radiation is low (it absorbs radiation easily) In contrast, snow has a high albedo because it reflects solar radiation easily

Greenhouse Effect Solid earth absorbs rays, as it heats up, it begins to radiate heat itself. These long waves emitted by the earth are absorbed by the atmosphere this process is called: greenhouse effect The atmosphere acts like the glass outside a greenhouse  greenhouse effect