Heating And Cooling Of The Atmosphere Flashcards
Define temperature:
the measure of the average molecular motion
What are (3) temperature scales?
What are their ranges?
Define heat:
(Bonus: unit measured in?)
The energy required to change the temperature or phase of a substance
- measured in calories
State the source of external heat recieved by the Earth:
It is Earth’s only external energy source and is the driving force of the atmosphere
Define insolation:
INcoming SOLar radiATION
*shortwave radiation
Define terrestrial radiation:
Longwave radiation radiated from Earth
Define specific heat (heat capacity):
Measured in calories
Explain why land areas heat up and cool down more rapidly than water areas due to heat capacity (specific heat):
Water areas heat up and cool down slowly because of water’s relatively high specific heat.
Describe the effect of latitude and reflection on the amount of electromagnetic radiation absorbed by the surface:
–latitude–
Earth’s pole to poke axis is tilted
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Different latitudes are exposed to differing amounts depending on the time of year
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The Angle of Incidence * of sun’s rays changes throughout the seasons m, which alters the unit area of solar radiation being intercepted by Earth’s surface
–reflection–
Shortwaves can be reflected off cloud tops or Earth’s surface, which would impact the amount of radiation absorbed
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Amount of reflection is dependant on the sun’s angle and the nature of the surface it strikes
Explain how and when the lower atmosphere is warmed through radiation and conduction:
The sun heats the ground, radiation,
the ground heats the air, conduction,
The warm air rises, convection.
Explain how and when the lower atmosphere is cooled through radiation and conduction:
At night, Earth’s cools by emitting longwave radiation (radiation cooling),
= Earth cools overnight!
Heat is then conducted from air down to the earth, which will continue radiate longwaves.
This process continues to cool the lower levels until there is a balance.
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Conduction is the transfer of heat energy from a high source to a lower source of energy, which creates balance.
State how low level radiation heating and cooling is affected by:
- topography
-soil type
-ground type
-water bodies
-wind
-cloud/fog coverage
-moisture content
-topography: (land elevation)
-air cools on top of hills flows downslope into low lying areas
-soil type: specific heats affect amount of heating and cooling
-ground type: different reflectivity affects amount of SW reflected
-water bodies: relatively high specific heat
(Heats/cools 5x faster/slower
-wind: affects temperature with turbulent motion that mixes surface air with air higher up (day= warm sfc +cool aloft air)(night = cool sfc air+warmer air aloft)
-cloud/fog coverage: Longwave Terrestrial Radiation is strongly absorbed by clouds and reradiated back to Earth (warmer night than if clear)
-moisture content: limiting factor of how much the air cools by conduction
(Air temperature drops to dew/frost point + cooling = fog, releasing latent heat and providing liquid water droplets that absorb longwave radiation from Earth.
Describe advective warming AND cooling AND give examples of when and where they occur:
Advection = the transfer of any element by horizontal motion of air
Cold Air Advection: moves cold air sideways
- if over a warm sfc = conductive warming = advective warming
Ex: fall/Winter + cold land by relatively warm water (Great Lakes / North Atlantic)
Warm Air Advection: moves warm air sideways
- if over a cold sfc = conduction cooling= advective cooling
Ex: spring (south of Nova Scotia where warm air is moving north meets the cold Labrador current
Name the (6) processes by which water changes phase and state AND whether
Briefly explain expansion cooling and compression warming + give atmospheric example:
All sinking air warms through compression
Ex: the East side of the Rocky Mountains (Chinook)
Why? Pressure decreases with height.
