Energy Ability to do work Many different forms Conservation of energy (Law) Transformed: example: – Radiant to Thermal – Kinetic to Thermal (friction)
Absolute Zero As low as you can go -273 degrees Celsius All particles stop moving
The Electromagnetic Spectrum
Light (medium wavelength) made up of several color components
Infrared (long wavelength) eg: Heat Escaping from People
UV (short wavelength) causes sunburn and skin cancer
X-rays (very short wavelength)
Insolation SOLAR RADIATION (radiation coming from the sun) – Includes different types of radiation (UV/Infrared) – Visible light makes up the majority of this radiation
Transmission, Absorption, and Scattering Transmission – Wave passes through matter Scattering Absorption – Wave and energy are absorbed – Waves absorbed and reemitted Diffuse scattering Reflection
Refraction
Scattering Scattering is the redirection (in all directions) of light by small particles and gas molecules in the atmosphere; The result is more light rays with weaker intensity.
Diffuse Scattering of Sunlight
Scattering of Light through Reflection
Absorption of Sunlight by Asphalt
17.2 Heating the Atmosphere
Conduction Conduction is the transfer of heat through matter by molecular activity; Energy is transferred through collisions from one molecule to another.
Convection Convection is the transfer of heat by the movement of a mass or substance; It can take place only in liquids and gases.
Radiation Radiation is the transfer of energy (heat) through space by electromagnetic waves.
Temperature Temperature is a measure of the average kinetic energy of individual atoms or molecules in a substance.
Heat Heat is thermal energy transferred from one object to another.
(Calories) Joules Unit of Energy Calories is used in the US Joules is metric unit
SPECIFIC HEAT The amount of energy needed to heat 1 gram of a substance by one degree celsius
Heat is the energy transferred from one object to another because of a difference in their temperatures.
Reflection Reflection is the process whereby light bounces back from an object at the same angle at which is encounters a surface and with the same intensity.
Three mechanisms of energy transfer as heat are conduction, convection, and radiation.
Unlike conduction and convection, which need material to travel through, radiant energy can travel through the vacuum of space.
When radiation strikes an object, there usually are three different results. 1.Some energy is absorbed by the object. 2.Substances such as water and air are transparent to certain wavelengths of radiation. 3.Some radiation may bounce off the object without being absorbed or transmitted.
All objects, at any temperature, emit radiant energy. Hotter objects radiate more total energy per unit area than colder objects. The hottest radiating bodies produce the shortest wavelengths of maximum radiation. Objects that are good absorbers of radiation are good emitters as well. How the atmosphere is heated:
Greenhouse Effect Greenhouse effect is the heating of Earth’s surface and atmosphere from solar radiation being absorbed and emitted by the atmosphere, mainly by water vapor and carbon dioxide.