ATMS 111 UW Midterm Test
With Complete Solution
Ein=Eout - ANSWER Energy balance equation (shortwave radiation in,
longwave radiation out)
λ max=b/T - ANSWER Wien's displacement law; Objects of different
temperatures emit different amounts of radiation at different wavelengths
Δ T=λ Δ F - ANSWER Climate sensitivity equation; Change in temperature
(Celcius) = climate sensitivity * radiative forcing (W/m2)
What is the difference between weather and climate? - ANSWER Weather: the
conditions of the day; what you actually get; individual storms
Climate: average weather over a period of time; what you expect
What sorts of things can influence regional climate? - ANSWER Topography
(mountain, etc.)
Latitudes (sunshine)
Proximity to ocean
Ocean currents
Vegetation
What lines of evidence do we have that tell us that climate is indeed
warming? - ANSWER Ice is melting dramatically outside of the interior of
Antarctica and Greenland
,The growing season is lengthening in the Northern Hemisphere, plants are
blooming earlier
Mosquitoes, birds, and other creatures are being forced to higher altitudes
and latitudes
Many marine animals are being forced poleward by warming oceans
Radiation from the sun v. radiation from the earth (shortwave v. longwave) -
ANSWER Shortwave: emitted by the sun; more energetic; combination of
visible light, "near infrared", and small amount of ultraviolet radiation; some
of this radiation is absorbed by the Earth and some is reflected back
Longwave: infrared radiation emitted by the Earth (how the Earth loses
energy)
Everything emits radiation— how much mostly depends on temperature, but
also on substance
The Earth is heated by the shortwave radiation from the sun, and the Earth
loses energy through longwave radiation emitted by Earth out to space
What are the relative amounts of radiation absorbed and reflected by Earth? -
ANSWER Average incoming solar radiation is 342 W/m2
20% absorbed into atmosphere
50% absorbed at surface
30% reflected back to space
Overall: 70% absorbed, 30% reflected back
What is albedo? What is the Earth's average albedo? What are some things
with high and low albedo? - ANSWER Albedo: fraction of incident light that's
, reflected away from Earth; reflectivity of an object/substance; ranges from 0
(no reflection) to 1 (all reflection); white things reflect, darker things absorb
Clouds, ice and snow have higher albedo
Forests and oceans have lower albedo
Cloud albedo: 0.2-0.7
Snow: 0.4-0.9
Ocean: <0.1
Forests: 0.15
Deserts: 0.3
Albedo reflection: 20% clouds, 5% surface, 5% atmosphere
What is the main reason the Earth experiences seasons? - ANSWER The tilt of
the Earth—directness of solar radiation
Winter is tilted away from the Sun (less direct sunlight, therefore colder) and
summer is tilted towards the sun
What is the relationship between wavelength of radiation emitted and the
temperature of the object doing the emitting? - ANSWER Higher temperature
= more radiation and more energetic (shorter wavelengths)
Also depends slightly on substances
Energy balance; what happens to Earth's temperature if it is out of balance -
With Complete Solution
Ein=Eout - ANSWER Energy balance equation (shortwave radiation in,
longwave radiation out)
λ max=b/T - ANSWER Wien's displacement law; Objects of different
temperatures emit different amounts of radiation at different wavelengths
Δ T=λ Δ F - ANSWER Climate sensitivity equation; Change in temperature
(Celcius) = climate sensitivity * radiative forcing (W/m2)
What is the difference between weather and climate? - ANSWER Weather: the
conditions of the day; what you actually get; individual storms
Climate: average weather over a period of time; what you expect
What sorts of things can influence regional climate? - ANSWER Topography
(mountain, etc.)
Latitudes (sunshine)
Proximity to ocean
Ocean currents
Vegetation
What lines of evidence do we have that tell us that climate is indeed
warming? - ANSWER Ice is melting dramatically outside of the interior of
Antarctica and Greenland
,The growing season is lengthening in the Northern Hemisphere, plants are
blooming earlier
Mosquitoes, birds, and other creatures are being forced to higher altitudes
and latitudes
Many marine animals are being forced poleward by warming oceans
Radiation from the sun v. radiation from the earth (shortwave v. longwave) -
ANSWER Shortwave: emitted by the sun; more energetic; combination of
visible light, "near infrared", and small amount of ultraviolet radiation; some
of this radiation is absorbed by the Earth and some is reflected back
Longwave: infrared radiation emitted by the Earth (how the Earth loses
energy)
Everything emits radiation— how much mostly depends on temperature, but
also on substance
The Earth is heated by the shortwave radiation from the sun, and the Earth
loses energy through longwave radiation emitted by Earth out to space
What are the relative amounts of radiation absorbed and reflected by Earth? -
ANSWER Average incoming solar radiation is 342 W/m2
20% absorbed into atmosphere
50% absorbed at surface
30% reflected back to space
Overall: 70% absorbed, 30% reflected back
What is albedo? What is the Earth's average albedo? What are some things
with high and low albedo? - ANSWER Albedo: fraction of incident light that's
, reflected away from Earth; reflectivity of an object/substance; ranges from 0
(no reflection) to 1 (all reflection); white things reflect, darker things absorb
Clouds, ice and snow have higher albedo
Forests and oceans have lower albedo
Cloud albedo: 0.2-0.7
Snow: 0.4-0.9
Ocean: <0.1
Forests: 0.15
Deserts: 0.3
Albedo reflection: 20% clouds, 5% surface, 5% atmosphere
What is the main reason the Earth experiences seasons? - ANSWER The tilt of
the Earth—directness of solar radiation
Winter is tilted away from the Sun (less direct sunlight, therefore colder) and
summer is tilted towards the sun
What is the relationship between wavelength of radiation emitted and the
temperature of the object doing the emitting? - ANSWER Higher temperature
= more radiation and more energetic (shorter wavelengths)
Also depends slightly on substances
Energy balance; what happens to Earth's temperature if it is out of balance -
