Name:
Earth & Environmental Systems Science
Atmosphere Unit
Review for Quiz 2
Atmosphere Study Guide – Quiz 2
Water in the Atmosphere
1. What is the difference between air temperature, dew point temperature, and humidity?
Air Temperature – is the dry temperature taken by a thermometer and a direct measurement of the kinetic
energy of the molecules.
Dew Point – the temperature air needs to be lifted and cooled to in order to reach saturation and water
vapor condenses to form clouds in the sky or dew on the grass.
Humidity – is percent of water vapor in the air.
2. What does it mean to say that evaporation is a cooling process and condensation is a warming process and
be able to relate it to cloud formation?
Evaporation cools the surface it is on because it is stealing energy from the surroundings (causing a cooling
effect) in order to turn a liquid in to a gaseous state (speed up the kinetic energy).
Condensation warms a surface because it is releasing energy to the surroundings (causing warming) in
order to turn from a gas to a liquid (slowing down the kinetic energy).
3. What is saturation?
When the relative humidity is 100% and the parcel of air cannot hold any more water – full of water.
4. What is the humidity if air is saturated?
humidity = 100%
5. Summarize the procedure that you used in the humidity lab to find humidity and dew point.
a psychrometer is dampened and then spun until the wet-bulb reaches the same moisture content as the
air. As the wet bulb experiences evaporation, it has a cooling effect on the thermometer. The dry
temperature is subtracted by the wet bulb temperature, this is called the depression. This number is
compared to the dry air temperature on a chart to determine the humidity and dew point. The closer the
wet bulb is to the dry bulb temperature, the less evaporation that had to occur, which means the air
surrounding is pretty wet or humid. Not a lot of cooling will be needed in order for the air to reach the dew
point and clouds to condensate.
6. What is a psychrometer and what are its different parts:
wet - bulb dry-bulb
7. Why does the temperature of the wet bulb drop as you spin it around?
the wet bulb is experiencing evaporation a cooling process.
8. What type of humidity is associated with low air pressure and high air pressure?
Low pressure – high humidity
High Pressure – low humidity
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Atmosphere Unit – Quiz 2 Study Guide
Name:
Earth & Environmental Systems Science
Atmosphere Unit
Review for Quiz 2
Humidity
9. What does it mean to say that evaporation is a cooling process and condensation is a warming
process and be able to relate it to cloud formation?
Evaporation occurs when a liquid form of water changes to a gas by stealing energy from the environment
in order to speed up the particle’s kinetic energy  thus cooling the surroundings. Water must evaporate
in order for water vapor to enter into our atmosphere.
Condensation occurs when a gas form of water changes to a liquid droplet by giving away energy to the
environment in order to slow down the particle’s kinetic energy  thus warming the surroundings. Water
condensates in the air after it is lifted and cooled to its dew point forming clouds.
10. What is saturation?
Saturation is when the air is full of water vapor and cannot hold one more drop – if one more drop is
added, the cloud will rain.
11. What is the humidity if air is saturated? 100 %
12. What type of humidity is associated with low air pressure and high air pressure?
Low Pressure  lifting forming clouds and sometimes rain - higher humidity
High Pressure  sinking air – dry low humidity
Clouds and Precipitation
13. What are three things that causes air to rise in the atmosphere?
Convective cooling – hot air less dense, rises and cools
Forceful (Orographic Lifting) – as winds blow they push air up mountains where it cools
Air Masses and Fronts
14. What is the adiabatic lapse rate and how does it relate to cloud formation?
Comparison of dry and wet (dew point) cooling rates as air is lifted – when they are equal or dry is
cooler than wet clouds form.
Dry = -1 oC every 100 m
Wet = -.2 oC every 100 m
15. The upward movement of the atmosphere causes the temperature of the air to decrease
(decrease/increase) and become closer (closer to/further from) the dew point.
16. If air has a high humidity are the temperature and dew point close in value or really far apart?
very close together
17. What is the name given to the height in the sky when clouds will start to form?
Condensation Level
18. What is the dust called in the atmosphere that is needed for water to condense and cling to?
Condensation Nuclei
19. Any water that falls from clouds is called precipitation.
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Atmosphere Unit – Quiz 2 Study Guide
Name:
Earth & Environmental Systems Science
Atmosphere Unit
Review for Quiz 2
Insolation Budget
20. Define the term insolation.
Radiation and energy that is given off by the sun
21. How much of the sun’s energy reaches Earth?
51% absorbed by surface
22. What happens to the other 49% of the sun’s energy that doesn’t reach Earth?
19% absorbed by Atmosphere; 30% reflected (6% atmosphere, 20% clouds, and 4% Earth’s surface)
23. Because the bottom layer of our atmosphere is in contact with the ground it is directly heated by
the ground in which of the processes listed below?
a. Convection b. Conduction
c. Radiation
24. What is albedo?
The percentage of Radiation that is reflected back.
25. Describe a surface that would absorb and radiate incoming solar radiation.
Dark in color and rough in texture (land)
26. Describe a surface that would have a high albedo to incoming solar radiation.
Light in color and smooth in texture (water)
27. Compare land and water’s absorption/radiation and reflection rates.
Land absorbs the most energy in the shortest amount of time, but it also re-radiates this energy
(cools) at a very fast rate.
Water does not absorb energy as fast as land, but it does not re-radiate the energy either –
maintains a very constant temperature.
28. What creates the imbalance of the oxygen/carbon dioxide cycle?
Burning fossil fuels
29. Describe the Greenhouse Effect and how it is different from global warming.
Greenhouse Effect is the natural absorption of energy (from the sun and the Earth’s surface) by
certain gases in our atmosphere. It is natural to have the gases in our atmosphere and allows life
to be sustainable and a natural cycle of interglacial and glacial periods about every 50,000 years.
By burning fossil fuels, we are adding extra greenhouse gasses to out atmosphere and are
increasing the greenhouse effect, in turn increasing the rate of the natural climate cycle.
30. What type of radiation is trapped by the greenhouse effect?
Infrared Energy (energy re-radiated by the Earth’s surface)
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Atmosphere Unit – Quiz 2 Study Guide