exam 2

Question 1

radiant energy

Answer 1

energy transferred from the sun; travels in the form of waves that release energy when they’re absorbed by an object

Question 2

electromagnetic waves

Answer 2

waves that share properties of electricity and magnetism

Question 3

wavelength

Answer 3

a measure by which different forms of electromagnetic waves are distinct from each other

Question 4

speed

Answer 4

the measure of how far the wave crest moves in 1 second

Question 5

frequency

Answer 5

the number of wave crests passing a fixed point in 1 second

Question 6

visible light

Answer 6

wavelengths ranging from .4 to .7 microns

Question 7

ultraviolet light

Answer 7

wavelengths less than .4 microns

Question 8

infra-red light

Answer 8

wavelengths more than .7 microns

Question 9

radiative equilbrium

Answer 9

when an object radiates and absorbs energy at equal rates; an object’s temperature won’t change

Question 10

kirchoff’s law

Answer 10

an object’s efficiency of absorption of a certain wavelength of energy is exactly equal to its emission efficiency at the same wavelength

Question 11

black body

Answer 11

any object that is both a perfect emitter and absorber

Question 12

radiative equilibrium temperature

Answer 12

when the amount of shortwave solar radiation absorbed at the surface is exactly equal to the amount of infra-red radiation emitted from the surface

Question 13

selective absorber

Answer 13

any object that absorbs and emits only some wavelengths; transparent to others

Question 14

atmospheric windows

Answer 14

regions in the spectrum in which none of the gases absorb radiation

Question 15

atmospheric greenhouse effect

Answer 15

carbon dioxide absorbs nearly all infra-red radiation; any surface temperature is much higher than its radiative equilbrium temperature

Question 16

positive feedback

Answer 16

an increase in water vapor content exacerbates the warming instigated by the increase in carbon dioxide

Question 17

angle of incidence

Answer 17

the angle at which the light/radiation is exposed to the surface

Question 18

summer solstice

Answer 18

where the northern hemisphere is pointed maximally towards the sun; June 22

Question 19

land of the midnight sun

Answer 19

everywhere above 66.5 degrees north never see the sunset

Question 20

autumnal equinox

Answer 20

not pointed towards/away from the sun, everywhere on Earth gets the same length of day; September 21

Question 21

winter solstice

Answer 21

the northern hemisphere is pointed away from the sun; the sun never goes up at the north pole nor down at the south pole; December 22

Question 22

vernal equinox

Answer 22

axis not tilted towards/away from the sun; everyday is the same length; March 21

Question 23

sensible heat

Answer 23

the transfer where the tropics are made cooler and the higher latitudes are made warmer; accounts for the redistribution of radiative energy

Question 24

radiation iversion

Answer 24

temperature inversion where the temperature is lowest at the ground than in the air; the ground is more efficient at radiating energy

Question 25

albedo

Answer 25

fraction of incident solar radiation that’s reflected back into space

Question 26

stefan-boltzmann law

Answer 26

objects w/ very high temperatures emit energy at a greater intensity than objects at lower temperatures; E = (constant)(temperature to the power of four)

Question 27

wein’s displacement law

Answer 27

states that the wavelength of max emission of an object is related to the object’s temperature; Lambda = 3000/Temp