Card Set Information
lecture greenhouse effect
Earth's Global Average temperature
15 degrees celsius
measure of kinetic energy(bouncing around energy) of atoms
Heat transferred through
conduction, convection, and radiation.
Earth receives what percent of its energy from the sun
How/where is solarg energy created
in the core of the sun, and through nuclear fusion.
How many million tons of H to He does our sun fuse
600 million tons
How many tons is converted to energy
Newtons inverse square law:
solar flux isinversely proportionalto the square of the distance from the sun.
As energy moves away from the sun, it is spread over a greater area.
amount of solar radiation at the top of the atmosphere
amount of energy per unit area.
self propagating waves that have electric and magnetic fields.
Electro magnetic radiation is induced by
acceleration of electrons
Frequency: f =
moves through vaccum at
speed of light
range of electromatic radiation.
The peak electromagnetic radiation is inversely related to the temperature of a black body. A hot body will elecctromagnetic radiation at shorter wavelengths than cold one. lamda_max = B/T
Stefan-Boltzmann Law... F is what?
The total energy emitted by an object is proportional to its temperature.
F = σT^4
F: energy flux
describes the thermal emission spectrum- the power per unit area emitted at each wavelength
assumes energy balance, incoming energy equals outgoing radiation.
what happens when incoming and outgoing radiation arent in balance
earths temp will rise or fall.
energy received from the sun
reflectivity of a surface.
-some radiation is not absorbed usually expressed as a fraction of the total incident radiation.
Types / causes of albedo
Clear sky albedo
Total Sky albedo - actual observed albedo
clouds contribute significantly to albedo.
Earth's radiative temperature
Incoming radiation = S(1-alpha)piR^2
thermal radiation x outgoing area
for thermal radiation use boltmann law
outgoing area= spherical area.
earths radiative temperature = 255K
atmospheric gas that absorbs in the long wave spectrum
process by which radiation from earth's surface is absorbed by atmospheric gases then reemitted causing planetary warming.
atmosphere is almost transparent to solar radiation.
Major greenhouse gasses
water, carbon dioxide
Greenhouse effect big picture
exists because gasses are transparent to shortwave radiation, but absorb long wave radiation. it acts as a blanket insulating and warming the earth.