Chapter 10, Section 2 Chapter 22, Section 2

Solar Energy Key Terms: Create a flashcard for each. The words can be found starting on page 555 or use the glossary. If you finish early, study your new words! Electromagnetic Spectrum Albedo Greenhouse effect Conduction Convection

Solar Energy Heat in the atmosphere comes from the absorption of the sun’s rays by gases in the atmosphere and indirectly as the ocean and land surfaces absorb solar energy and then give off that energy as heat.

Radiation Radiation= all forms of energy that travel through space as wave. Visible light is a form of radiation the human eye can see UV rays, x-rays, radio waves are also radiation Electromagnetic Spectrum= all of the frequencies or wavelengths of electromagnetic radiation

INTERACTIVE

The Atmosphere and Solar Radiation As solar radiation passes through the atmosphere: 30% is reflected back into space 20% absorbed by clouds, dust, and gases 50% absorbed by Earth’s surface

Scattering Clouds, dust, water droplets, and gas molecules in the atmosphere disrupt the paths of radiation from the sun and scatter them. This deflection causes the rays to change direction and some reflects back to space.

Why is the sky blue?? As light travels through the atmosphere the smaller wavelengths (Blues) hit small particles of gas and dust, which then scatter the blue light in all directions across the sky. Longer wavelength light (Reds) usually pass straight through the sky, however when the sun is low in the sky (sunset), only the reds can get through so we see only shades of red, not blue. Demo

Reflection When solar energy reaches the surface it is either absorbed or reflected. The fraction of solar radiation that is reflected = albedo Amount of energy absorbed or reflected depends on color, texture, composition, volume, mass, etc.

INTERACTIVE Tell me about the GREENHOUSE EFFECT

Greenhouse Effect The Earth’s atmosphere allows radiation to pass through but it slows the escape of energy the radiates from the Earth’s Surface Car example… Generally the amount of solar energy that enters the atmosphere is equal to the amount that escapes into space Human activities may change this balance (CO2 has increased, which prevents energy from leaving the atmosphere)

BrainPop GreenHouse Effect

Conduction and Convection Conduction: Transfer of energy as heat through direct contact of one object to another Convection: Movement of matter (liquids and solids) due to different densities and temperature differences, which as a result transfers heat Cool air sinks, warm air rises

Assessment/INTERACTIVE Greenhouse Activity