Chapter 2 The Energy Cycle Greenhouse Gases Greenhouse Warming Heat Infrared Atmospheric Window Joule Kelvin Kinetic Energy Kirchhoff s Law Latent Heat Latent Heating LH of Condensation Deposition Fusion Melting Sublimation and Vaporization Longwave Radiation Ozone Hole Parcel of Air Perihelion Photo dissociation Potential Energy Power Radiation Radiant Energy Radiative Forcing Sensible Heating Shortwave Radiation Solar Constant Solar Radiation Solar Zenith Angle Solstices Specific Heat Stefan Boltzmann Law Sublimation Temperature Terrestrial Radiation Thermal Conductivity UV Light Visible Radiation Watt Wavelength Wien s Law Work Key Terms Acceleration Advection Albedo Amplitude Angle of inclination Aphelion Blackbody Calorie Celsius Conduction Convection Deposition Diurnal Electromagnetic Energy Energy Enhanced Greenhouse Effect Equinoxes Fahrenheit Force Greenhouse Effect Summary Conduction convection advection and radiation are important processes that transfer energy in the atmosphere Conduction moves energy by physical contact Convection and latent heating transfer heat over great distances through vertical motions and phase changes of water Advection by the wind moves heat horizontally Radiative processes transfer heat throughout the entire atmosphere and into space Radiation can be absorbed reflected or transmitted The sun powers Earth s weather and climate Solar energy streams through space as electromagnetic waves Most of this solar radiation has wavelengths between 0 2 and 4 microns The reason the sun emits radiation with short wavelengths is because according to Wien s Law the Sun is very hot Earth intercepts a portion of this solar energy The total amount intercepted is determined by the tilt of the Earth s axis and how far the Earth is from the Sun Although Earth is a little closer to the Sun in January than in July Northern Hemisphere temperatures are warmer in July because Earth s axis of rotation points toward the Sun in July The Earth s Tilt combine with its orbit around the Sun causes seasons Approximately 50 of the solar energy reaching the planet passes through the atmosphere and is absorbed by the surface of the Earth The surface albedo is about 30 of the incoming sunlight Because any object that has temperature emits radiation the Earth emits energy and is constantly losing energy to space as longwave radiation or terrestrial radiation This energy emitted to space has wavelengths of 4 to 100 microns Both the surface and atmosphere emit longwave radiation not shortwave radiation like the Sun because they are much cooler than the Sun Much of the energy that escapes from Earth to space is in the narrow band of 10 microns to 12 microns called the atmospheric window At other wavelengths the Earth s atmosphere absorbs much of the longwave radiation emitted by the Earth ad warms the Earth s surface in return This is known as the Greenhouse Effect and it keeps the Earth from freezing The atmosphere is always losing radiant energy and the Earth s surface has a surplus of radiation energy Conduction convection evaporation and condensation transfer energy from the surface of the Earth to the atmosphere Averaged over many years the tropical and subtropical regions of the planet gain more solar energy than these regions lose to space by longwave radiation Polar regions lose more longwave energy than they receive from the Sun over a given year This energy imbalance with net energy losses at the ole and net energy gains in the tropics is the driving force of weather and climate
View Full Document
Unlocking...