ATM OCN 100 Exam 2
planet with no atmosphere
same ingoing and outgoing radiation (radiative equilibrium)
factors effecting average temperature
ocean currents, elevation above sea level, and proximity to water
stratus clouds
reflect incoming solar radiation (high latitude summer is characterized by this)
Greenhouse effect
retention of IR by the atmosphere
nothing in the atm absorbs...
visible light so it goes to Earth's surface
reflection
when a wave of electromagnetic radiation, incident upon an object at some angle of incidence, bounces off that object at the same angle
scattering
when light bounces off an object at any angle
radiative equilibrium
when the rate of absorption of solar equals the rate of emission of terrestrial IR
seasonal temperature lag
why the max radiation does not mean the temperature is the highest because of this (max radiation occurs but oceans take longer to heat up so the lag occurs)
speed =
(wavelength) x (frequency)
how is transfer accomplished?
- 30% latent heat (water evaporates in tropics) - 40% sensible heat (mid-latitude cyclones) - 30% ocean currents (warm poleward currents)
length of the day
- June 22, daylight is longer with increasing latitude - long path lengths allows for more absorption by particles and scattering
Venus
- clouds reflect almost all incoming solar - sulphuric acid clouds - greenhouse effect is prevalent
why does the earth have seasons?
- earth rotates on its axis every 24 hours - earth revolves around the sun once every 365 1/4 days a year
daily temp cycle
- lowest temp right after sunrise - highest temp a few hours after noontime
summer
- max radiation on June 21 - incoming > outgoing radiation so warm - temp increases until incoming = outgoing
winter
- min incoming radiation on Dec. 21 - outgoing > incoming radiation so cold - temp decreases until outgoing = incoming
max temperature
- most intense radiation occurs at noontime - warmest temp is when incoming = outgoing - 3-5 pm on a sunny breezy day
angle of incidence
- much bigger area in which radiation is spread when it is tilted more - intensity per area is less tho
scattering depends on
- size of the particles - size of the wavelength
our atm absorbs some
IR radiation but it is also transparent to some
radiative equilibrium
S= Ec
a small increase in the temp of an object can lead to...
a huge increase in its emitted radiation
frequency
a measure of how many wave crests pass a point in 1 second
what is the difference between a planet with an atmosphere and one without one in regards to temp?
a planet with selective absorbers is greater than the temp of a planet w/out an atm
radiation can be
absorbed, reflected, and transmitted
glass
absorbs IR and transmits visible
selective absorber
absorbs some wavelengths and transparent to others (the atmosphere)
longer path lengths means
all except longest wavelengths are totally scattered
black body
an object that is a perfect emitter and absorber
our atm is composed of selectively absorbing gasses
atmospheric windows
snow radiates lots of energy away during long nights
creates frigid arctic air masses in northern Canada and Alaska
how does radiant energy travel?
electro magnetic waves
what do objects above absolute zero do?
emit radiation
where never sees the sunset
everywhere above 66.5 degrees
short wave lengths =
high energy
summer solstice
highest angle of incidence and also the sun is directly above the northern hemisphere
Stefan-Boltzmann Law
how much energy is emitted by an object is based upon its temp
refraction
if a light wave is incident to an angle, the slowdown causes the wave to bend
Kirchoffs Law
if an object is a good emitter at a wavelength it is also a good absorber at that wavelength
refraction
if light passes through a less dense medium to a more dense medium at an angle it causes the wave to bend
earth emits almost all of its radiation at
infra-red wavelengths
earth's atm has a preference and does not act as a black body
it absorbs and emits IR radiation
if an object emits more radiation than it absorbs then..
it is colder
if an object emits less radiation than it absorbs then..
it is warmer
refraction in rainbows
light is refracted twice but reflected once
high wavelengths
little scattering
earth's radiation is known as
longwave
short wavelengths
lots of scattering
long wave lengths =
low energy
speed
measure of how far a wavecrest moves in 1 second (all electromagnetic waves have the same speed)
molecules in the atmosphere are (blank) and scatter (blank) best
selective scatters and scatter short wavelengths best
what wavelengths are refracted the most?
short wavelengths
sun's radiation is known as
shortwave
the amount of electromagnetic radiation depends on?
temp of the object
radiant energy
the energy transferred from the sun and your face is a version of this
the higher the objects temperature...
the faster the vibrations of electrons
where does radiative equilibrium exist?
the surface and top of the atmosphere
Wein's displacement law
the wavelength of max emission depends on temp.
if the atm absorbs some outgoing IR then..
there will be a presence of CO2 and H2O
planet with atmosphere
transparent to solar radiation translucent to infrared radiation
