Meteorology and Climate Review Sheet Answers
1.
Weather is the daily atmospheric conditions for a specific location at a specific moment
in time. Climate is the average atmospheric conditions for a location over the course of
many months or years.
2. The troposphere is the layer in our atmosphere that contains nearly all the water vapor.
It also has the greatest air pressure.
3. Air temperature decrease in the troposphere, but then rises in the stratosphere, then
decreases again in the mesosphere and then increases again in the thermosphere. As
altitude increase the pressure always decreases.
4. The ultimate driving source of all weather is energy from the SUN.
5. Isotherms connect lines of equal temperature. On a weather map they are usually drawn
as nearly horizontal lines with minor dips and rises with lower values of temperature
near the north and south poles and higher values near the tropics and the equator.
6. A thermometer is used to measure temperature and it works through conduction. As
molecule of the air collide with the bulb of the thermometer, energy is transferred. If
the air is cold the thermometer will lose energy and the mercury inside will contract
giving a lower reading. If the air is warm, the bulb will gain energy and the volume of the
mercury will increase giving a higher temperature reading.
7. As latitude increases, temperature decreases. This is because the equator receives a
higher intensity of insolation compared to the poles.
8. As altitude in the troposphere increases, air temperature decreases, this is because as
air rises in the troposphere it expands and cools.
9. Particulate matter such as smoke and volcanic ash will result in an overall cooling of the
global climate because the smoke and ash scatter the insolation back into space,
preventing it from reaching the earth’s surface. Note, there might be a short term
initial warming period initially following an erupts, but the long term effect is cooling.
10. During the day, clouds cause the air temperature to decrease because they scatter
sunlight and prevent the insolation from reaching the earth’s surface. During cloudy
nights, the relative humidity is high, the water vapor in the air acts as greenhouse gas
and trap the reradiated infrared (heat) energy, thus warming the air.
11. Dark and ruff surfaces absorb energy better, so the air above them will be warmer.
Light colored and smooth surfaces will reflect insolation, so the air above will be cooler.
12. The hottest time of day is 2-3 PM, it is later than the maximum insolation (noon)
because it takes time for earth to absorb and reradiate the energy.
13. The coolest time of day occurs about an hour after sunrise because it takes time for
the amount of insolation absorbed to equal the amount that is being reradiated.
14. The hottest time of year is July and August, it is later than the maximum insolation
(noon) because it takes time for earth to absorb and reradiate the energy.
15. The coolest time of year occurs in January/February because it takes time for the
amount of insolation absorbed to equal the amount that is being reradiated.
16. Radiative balance is when the amount of absorbed insolation equals the amount of
reradiated heat energy, this happens at the hottest and coolest time of day. When not
in radiative balance, the earth is either warming up or cooling down.
17. Adiabatic cooling is when air rises and cools due to expansion.
18. On the windward side of the mountain, wind forces air to rise up the side of the
mountain, this air expands, cools, and condenses to form clouds and precipitation on the
windward side. On the leeward side, dry air becomes dense and sinks, compresses and
warms. Cool humid climate exists on the Windward side, but dry, warm climate exists on
the leeward side.
19. The greenhouse effect is the idea that certain gases in our atmosphere allow visible
light to transmit, but do not allow reradiated infrared heat energy to escape, thus
keeping the earth warm. The greenhouse gases are: carbon dioxide, methane, ozone,
water vapor and chlorofloro carbons.
20. Humans can reuse, reduce, recycle, ride bikes or walk rather than use cars, shut lights
off in order to reduce the amount of Carbon dioxide.
21. Absolute humidity describes the actually amount of water in the air. Relative humidity is
a comparison between the amount of water in the air compared to how much the air can
hold.
22. A sling psychrometer is used to measure relative humidity.
23. Warm air can hold more water vapor
24. Saturated air is filled with water, humidity will be 100%, dewpoint will equal the
temperature.
25. The dewpoint temperature the temperature the air must decrease to in order to be
saturated and condense.
26. As the air temperature and dew point approach eachother the relative humidity
increases.
27. The wet bulb depression is the difference between the wet bulb and dry bulb
temperatures on a sling psychrometer. If the wet bulf depression is a big number that
means a lot of evaporation occurred so the air must be dry and the relative humidity is
low.
28. A cloud is made of liquid water. The process that forms clouds is condensation. Dew and
fog are also formed by this process.
29. Warm moist air rises due to it’s low density. As it rises, it expands due to less air
pressure. The air cools due to this expansion. When the temperature cools to equal the
dew point temperature, condensation will occur, but only if condensation nuclei are
present. In short: Warm moist air, rises, expands, cools and condenses to form a cloud.
No credit if the word condensation is not included in your explanation. It is the most
important step.
30. Evaporation is when the surface of a body of water vaporizes (turns into a gas) because
it has gain energy from the sun. It is a cooling process since the water absorbs energy
from the environment in order to turn from liquid to gas. The higher the temperature
the faster the evaporation. The higher the wind speed the faster the evaporation. The
greater the surface area the faster the evaporation. The dryer the air the faster the
evaporation.
31. Condensation nuclei are dust and pollution particles suspended in the air, they provide a
surface for water to condense onto. Think of the phrase “It can’t appear out of thin
air”, this originates from the idea that water vapor can not condense without a surface
to condense on to.
32. Clouds form at frontal boundaries because when two airmasses with different
temperatures meet, the warm air mass will rise over the cold air mass, causing cloud
development and precipitation. Converging winds are due to rising air called a low
pressure system, the wind converge to replace the air that is rising, this rising air
expands cools and condense to form clouds and precipitation. On the windward side of
mountains, wind forces air up the sides of the mountain, where again it expands, cools
and condenses to form clouds.
33. Air is warmer in a cloud than the surrounding air because condensation is a warming
process since energy is released from the water as it turn from a gas to a liquid. (This is
the opposite of evaporation.)
34. Precipitation is when rain, sleet, snow or hail fall from a cloud. Precipitation cleans the
atmosphere because it removes pollution particles that serve as condensation nuclei.
35. Air pressure is the weight of the atmosphere pushing down on earth. A barometer is
used to measure air pressure. The units are millibars and inches of mercury.
36. A warm air mass is less dense and will rise, resulting in lower air pressure as air is lifted
off the ground. A cooler air mass is more dense and will sink, resulting in high air
pressure as the air pushes onto the ground.
37. As altitude increase, air pressure decrease, as less and less molecule are piled on top. It
similar to diving in the ocean, the deeper you go the more water molecules on top of you
so the more pressure, due to gravity. We live on the bottom of a giant ocean of air.
38. Moist/ Humid air exerts less pressure on the earth’s surface because water molecules
are lighter than nitrogen molecules. Also humid air is less dense, so it has a lower
pressure. Dry air is dense and heavy so it has a high pressure. Remember high and dry,
low and lousy.
39. Closely spaced isobars indicate a fast wind speed.
40. The typical interval for isobars are 4mb. Isobars are usually circular.
41. A cyclone is a low pressure system, air moves counterclockwise and toward the center
(convergent). Stormy, cloudy, lousy weather occurs here. (but remember it still can be
warm or cold outside, you can have storms in the winter and the summer)
42. An anticyclone is a high pressure system, air moves clockwise and away from the center
(divergent). They are associated with clear, calm, sunny weather with no clouds nor
precipitation. Again keep in mind can still be hot or cold outside, you can have a clear
sunny day in the winter that is still very chilly.
43. Wind is the horizontal movement of air along earth’s surface. An anemometer measures
wind speed and a weather vane measures wind direction. Winds are always named for the
direction they come from.
44. Winds blow from high pressure zones to low pressure zones.
45. Sea breezes occur during the daytime due to unequal heating of the land and water. The
land is hotter during the day so air rises above the land and sinks above the water,
creating wind blow from water to land. A land breeze occurs at night, when the water
retains more heat than the land due to it’s high specific heat. Air sinks over the land
and rises over the ocean causing winds to blow from the land to the sea.
46. Global winds follow a curved path due to the Coriolous effect, the curve right in the
northern hemisphere and left in the southern hemisphere.
47. The USA is located in the SW wind belt, meaning that storm system will be carried to
the Northeast
48. The equator, 60 N and 60 S are wet. The poles and 30 N and 30 S are dry.
49. Air is sinking at the poles because the air is dry, and dense.
50. Wind is converging at the equator to replace the warm and moist rising air.
51. An air mass is a body of air with similar temperature and moisture throughout because
that mass of air remained stationary over a location for long enough to gain the
properties of that location. Air masses are named for the temperature and humidity of
their geographic source region.
52. An air mass track is the path an air mass will take due to the influence of the planetary
wind belts.
53. Weather systems are moved to the north east in the USA due to the prevailing wind
belts.
54. A cP air mass would originate over land near the poles. An mT air mass would originate
over water near the equator.
55. cA
56. A front is the boundary between two different air masses; it is named for the air mass
that is advancing forward, since it is leading edge of the moving air. Clouds and
precipitation occur along fronts because the warmer air mass will always rise over the
cooler air masse, resulting in clouds.
57. A cold front has a steeper slope.
58. A cold front has short but intense precipitation such as thunder storms.
59. A warm front has warning clouds and produces long periods of extended precipitation.
60. Along an occluded front a cold front has caught up to and merged with an warm front,
resulting in all the warm air to rise above the cooler air, producing clouds and
precipitation.
61. A stationary front is when warm air and cool air are sitting next to each other but
neither is advancing , yet.
62-66 See worksheets and notpacket
67-68. See venn diagram made in class.
69. A hurricane will lose wind speed and die out as it moves to colder areas of the ocean
further north or when it moves onto land, far from it’s energy source, the water.
70. Hurricanes change their direction when they approach the USA because they enter a
different planetary wind belt, the prevailing westerlies.
Good luck studying! Do NOT forget to complete the McGuire Review work too! Check your
answers, keys are all posted on my web page!