1 / 22

ENERGY (CH 2)

ENERGY (CH 2). The ability to do “Work”. UNITS : Joule (J). POWER: The rate at which energy is released, transferred, or received. UNITS : Joule/second (J/s). Types of Energy. Kinetic Energy Potential Energy. Look at figure 2-1 p.32. ENERGY. Transfer mechanisms. Conduction

mavis
Download Presentation

ENERGY (CH 2)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ENERGY (CH 2) The ability to do “Work” UNITS: Joule (J) POWER: The rate at which energy is released, transferred, or received UNITS: Joule/second (J/s) Types of Energy Kinetic Energy Potential Energy Look at figure 2-1 p.32

  2. ENERGY Transfer mechanisms Conduction Convection Radiation

  3. Heat transfer in the atmosphere • 1. Conduction—transfer of heat from molecule to molecule. • Works best in solid objects (molecules locked together) • Air is a poor conductor. Sun warms the Earth’s surface and the heat is conducted to a small layer of air Above the surface. (Think of heat waves off of blacktop)

  4. 2. Convection—transfer of heat by the mass movement of a fluid (currents). • Air near surface heats, becomes less dense, and rises. Cooler air above is brought down to the surface. • Most of the heating in the lower atmosphere comes from earth’s the surface (from below)

  5. Rising Warm Air--Thermals

  6. 3. Radiation • Electromagnetic radiation has a dual nature • It moves through the vacuum of space as a wave • It interacts with matter like a particle • Moves at the speed of light--186,000 miles/sec • Wavelength measured in micrometers (one millionth of a meter… μm) • Longer wavelengths carry less energy

  7. RADIATION Quantity and Quality Quality: the type of radiation This is measured by its wavelength Quantity: amount of energy transferred. measured by its amplitude

  8. RADIATION-Type FIG 2-6 p. 36 Shortwave carries more energy Than longwave radiation • Infrared radiation (IR): • emitted by The Earth & is • considered Longwave • (think…can you • Get a sunburn at night from • Heat emitted by earth?) • Ultraviolet (UV): emitted by • The sun is considered • Shortwave • Visible: emitted by both the • Sun and the Earth…we see • Colors because of this

  9. RADIATION Intensity and Wavelengths of emitted radiation • 1. Sun emits energy with shorter • Wavelengths than Earth • Sun is hotter than Earth and • Therefore radiates more energy.

  10. Infrared light is used in meteorology to view weather From space: white clouds are cold, dark areas are warm IR satellite image RADIATION

  11. FLIR (forward looking IR)(Time to change that flight suit…)

  12. Atmospheric Influences on Insolation: As solar radiation enters the atmosphere, not all of it makes it to Earth’s Surface…the following are the fates of solar radiation • Absorption • Reflection & Scattering • Transmission

  13. Absorption Atmospheric gases, particulates, and droplets all reduce the intensity of solar Radiation EFFECTS • The absorber gains energy and warms • The amount of energy delivered to the surface is reduced

  14. Reflection Reflection: radiation is redirected away from the surface without being absorbed Albedo: The percentage of visible light reflected • TWO TYPES: • Specular Reflection • Diffuse Reflection

  15. Scattering Disperse radiation in different directions 3 TYPES • Rayleigh • Mie • Nonselective

  16. Rayleigh Scattering Disperse radiation both forward and backward • Leads to blue skies on a clear day • The redness of sunsets and sunrises

  17. Mie Scattering Disperse radiation predominately forward • Effectively scatters all wavelengths therefore sky looks gray • Causes sunrises to be redder

  18. Nonselective Scattering Each wavelength is being refracted a different amount Creates Rainbows and Iridescence in clouds

  19. Transmission When solar radiation enters the atmosphere only a fraction Makes it to the surface

  20. Transmission & The Fate of Solar Radiation • 100 units available at the top of the atmosphere • Atmosphere absorbs 25 units • 7 units are UV radiation absorbed by ozone • Remainder is IR radiation absorbed by gases • Clouds reflect 19 units back to space • Gases and aerosols scatter 6 units back to space • 50 units reach the surface • 5 units scattered back to space

  21. Earth’s Energy Balance 5% reflected Back to space From Earth’s surface 19% reflected by clouds 6% scattered back to space By molecules 25% absorbed by gasses in atmosphere 45% absorbed By surface Surface Outgoing radiation = 30% Incoming radiation=70% 100% Planetary albedo=19%+6%+5%=30%!!!! Think about what would happen if this were higher or lower

  22. Earth’s Energy Balance Outgoing radiation = 30% Incoming radiation=70% Incoming > Outgoing Temperature rises Ex. equator Outgoing > Incoming Temperature decreases Ex. poles The primary principle of the energy budget is that Earth would like Incoming radiation to equal outgoing radiation, but since it doesn’t weather Happens to balance the surplus of heat at the equator and the deficit at the poles

More Related