Energy- Radiation Flashcards
What is the temperature of the atmosphere regulated by?
Incident radiation by the sun, and then spatial redistribution.
What light is absorbed by the atmosphere?
Photons in the visible portion of EM spectrum.
How much infrared energy does Earth emit proportional to solar radiation it recieves?
Same amount.
What type of wave is infrared?
Long wave
Why does Earth remit infrared energy?
Earth is cooler than the sun, has less energy.
Spectrum
Intesnsity of light/radiation emitted by an object as a function of wavelength.
Blackbody Radiation
This is an object/system, absorbing all radiation incident upon it, re-radient energy characteristic of this radiating system only(independet of the type of incident radiation)
Wiens Displacement Law
States black-body radiation curve for different temperatures peak at different wavelengths that are inversely proportional to the tempertaure.
Why does WDL peak occur?
Planck radiation law
Plancks Law
Says that spectral density of ER emitted by a BB in thermal equilbrium at a given temperature, when no net flow of matter/energy between body and envrionment
Spectral Density
Describes distribution of power into frequency components composing that signal.
Simply what does placnks law mean?
ER from heated bodies is not continous, but as discrete units of quanta of energy, size determined by plancks constant.
Simply what does Wiens Displacement Law describe
That spectrum from increasing temperatures shifts towards shorter wavelenghts.
Wavelenght
Distance from crest of one wave to the next
Frequency
Number of wave cycles passing a particular point in a given time.
Velocity
The speed at which individual components of the wave propogate throuhg space.
What equation describes energy of a phootn?
E = hF
Denote E = HF
h is plancks constant whilst f is velocity of light.
What does E = hf tell you about energy of wavelenghts?
Photons have higher energies at shorter wavelenghts, drastically changing atoms they interact with.
What is the wavelength of x rays?
100 angrstom
Wavelength of extreme ultraviolet radiation?
100 and 2,500 angrstrom
Where is Extreme UV absorbed?
By Ozone
What is the ionsphere formed by?
Extreme UV interaction with ozone.
How does ionosphere form?
Light ejects electrons from their atoms, producing partially ionised region.
What wavelength is UV?
1250 to 3000 angstrom
What wavelength is visible poriton?
3000 and 7000
What wavelenght is infrared?
Greater than 7000
Why does infrared get trapped beneath the atmosphere?
Length of radiation absorbed by GHG
What is radiative flux balanced by?
Equal magnitude of infrared emission and radiatve energy asborption
What causes the greenhoiuse effect?
Infraed absorptive gases reflect infrared back to earths surface.
Solar Constant
The rate of which energy reaches earths surface from sun
