The spin of the Earth creates the Coriolis "force". As air moves in the northern hemisphere, for example, it is deflected to the right. This causes the overall circulation to break into cells. For further assistance for studying, refer to the guide posted below.
Question 1 .1 out of 1 points
1. On a weather map, this front, drawn in blue, represents a region where colder air is replacing warmer air:
Correct Answer: B. cold front
2. The inter-tropical convergence zone (ITCZ) is a region where:
Correct Answer: B. northeast trades meet the southeast trades
3. Suppose you are a pilot who is flying from warm air into colder air. In the cold air, even though your altimeter is still indicating the same altitude as it did in the warm air, you would be flying:
Correct Answer: D. At the same altitude as you were before
4. The majority of the United States lies within which wind belt?
Correct Answer: A. westerlies
5. Would you expect the heaviest snowfall to occur on an unusually cold night or a night when the temperature was just a little below freezing? Explain.
As long as there is moisture in the air and a way for it to rise and form clouds, there can be snow, even in temperatures below zero. But very cold air doesn't have much moisture in it, and it is also dense and heavy, so clouds don't form unless the cold air rises up a mountainside or unless the cold air blows across a body of water and collects moisture. Most heavy snowfalls occur in temperatures 15 degrees Fahrenheit or above.
6. Which of the following is NOT an important factor in the production of rain by the collision-coalescence process?
Correct Answer: C. The number of ice crystals in the cloud
7. The strongest winds in a hurricane are found:
Correct Answer: B. in the eye wall
8. What type of air mass would be responsible for refreshing cool, dry breezes after a long summer hot spell in the Central Plains?
Correct Answer: C. cP
9. If an area is described as a "good air mass source region" what information can you give about it?
Good air-mass source regions are dominated by high pressure where subsidence forces air towards the surface. These high pressures also enable air to move outward from the source region.
10. Which below does NOT describe the polar front jet stream?
Correct Answer: D. is normally found at a higher elevation than the subtropical jet
11. The so-called "Tornado Belt" of the United States is located :
Correct Answer: B. in the Central Plains
12. The large semi-permanent surface anticyclone that is normally positioned over the ocean, west of California, is called the:
Correct Answer: E. Pacific high
13. The wind around a surface high pressure center in the Northern Hemisphere blows:
Correct Answer: C. clockwise and outward from the center
14. According to the three-cell general circulation model, at the equator we would NOT expect to find:
Correct Answer: B. a ridge of high pressure
15. Before the passage of a cold front the pressure normally _____, and after the passage of a cold front the pressure normally _____.
Correct Answer: B. drops; rises
16. Why do ordinary cell thunderstorms most frequently form in the afternoon? Explain.
****- This is because the land is heated during the day and in the afternoon the hot heated moist air rises, it rises high enough then condenses. The more rapidly it rises the better storm cloud you would get.
17. Buys-Ballot's law states that , "In the Northern Hemisphere if you were to stand with your back to the surface wind, then turn clockwise 30 degrees, lower pressure will be ______.
Correct Answer: B. to your left
18. A wind that blows at a constant speed parallel to curved isobars or contour lines is called a:
Correct Answer: D. gradient wind
19. On a clear, windy day, the depth to which mixing occurs above the surface depends upon:
Correct Answer: D. all of these
20. A wind reported as 45 degrees would be a wind blowing from the:
Correct Answer: A. NE
21. Why is large hail more common in Kansas than in Florida? Explain.
Florida has a maritime climate and Kansas has a continental climate. Cumulonimbus cloud bringing thunderstorm and hail can happen in both places. Kansas is more likely to see the pattern where mild and moist air from the south meet polar cold and dry air above. Those are the conditions needed to see very unstable air with super cell cumulonimbus and large hail.
22. Squall lines most often form ahead of a:
Correct Answer: A. cold front
23. A discharge of electricity from or within a thunderstorm is called:
Correct Answer: B. lightning
24. Why is it impossible on the earth for a Hadley cell to extend from pole to equator? Explain.
The spin of the Earth creates the Coriolis "force". As air moves in the northern hemisphere, for example, it is deflected to the right. This causes the overall circulation to break into cells.
25. The cold water observed along the northern California coast in the summer is due mainly to:
Correct Answer: C. upwelling
26. Why are haboobs more prevalent in Arizona than in Oklahoma? Explain.
Haboobs need clear dry regions and convection mixes with the wind, forming a dust devil. Arizona favors these conditions.
27. Hurricanes can't form along the equator because:
Correct Answer: B. the Coriolis force is too small along the equator
28. Why do heavy showers usually fall from cumuliform clouds? Why does steady precipitation normally fall from stratiform clouds?
Cumuliform clouds are generally a sign of unstable air and the presence of cold fronts. When you have precipitation in those conditions, it is often showery in nature. The unstable air also provides (generally) better visibility and puffier clouds.
However, Stratiform clouds are suggestive of stable air and possibly warm fronts. in those conditions, you generally have steady rain (not showers), calm winds, lower visibility, and flatter clouds.
29. Hurricanes dissipate when:
Correct Answer: D. all of these
30. The turning of the water with depth is known as:
Correct Answer: B. the Ekman Spiral
31. In the general circulation of the atmosphere, one would find the region called the doldrums:
Correct Answer: B. at the equator
32. A surface low-pressure center is generally associated with _____ on an upper level isobaric chart.
Correct Answer: A. a trough
33. Lake-effect snows are best developed around Great Lakes during:
Correct Answer: B. late fall and early winter when cold, dry polar air moves over the relatively warm water
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34. You are in Florida; explain why it is often windy at the beach. What forces are responsible, and how do beachfront conditions differ from conditions farther inland? Explain.
The main reason is due to friction. When the wind comes from the sea the beach only has the sea in front of it. Further inland, trees, buildings, hills cause blockages to the wind flow, which causes the wind to be less. The beach has more exposure to the wind than inland.
35. Which of the following is NOT considered a semi-permanent high or low-pressure area?
Correct Answer: E. Icelandic high
36. It is summer. What type of afternoon weather would you expect from an air mass designated as mT? Explain.
This air mass produces very warm weather in summer, mild in winter, with high relative humidity throughout the year. It often has low clouds and fog with poor visibilities during the early morning hours, then hazy sun into the afternoon as clouds develop. Some of these cumulus clouds may build into cumulonimbus clouds, commonly known as thunderheads. This air mass brings most of the moisture into the nation.
37. Chicago, Illinois (latitude 42 degrees North) is located in the _____.
Correct Answer: C. westerlies
38. A true blizzard is characterized by:
Correct Answer: E. All the above
39. Just before a storm becomes fully a developed hurricane, it is in the _____ stage.
Correct Answer: B. tropical storm
40. One would expect a cP air mass to be:
Correct Answer: A. cold and dry
41. We can generally expect the air to be _____ above areas of surface low pressure and _____ above areas of surface high pressure>
Correct Answer: B. rising; sinking
42. Ice nuclei may be:
Correct Answer: D. All of the above
43. Radar gathers information about precipitation in clouds by measuring the:
Correct Answer: C. Amount of energy reflected back to the transmitter
44. The force that would cause a stationary parcel of air to begin to move horizontally is called the:
Correct Answer: B. Pressure gradient force
45. The main reason Santa Ana winds are warm is because:
Correct Answer: B. sinking air warms by compression
46. Surface winds are generally strongest and most gusty:
Correct Answer: A. in the afternoon
47. Will a valley breeze or a mountain breeze produce clouds? Explain.
Valley breezes form when the sun heats the side of a mountain more than the valley below it. As the air adjacent to the mountainside heats up it becomes less dense and rises. As this rising air cools it may saturate leading to cloud formation.
48. A wind flow pattern that takes on a more or less north-south trajectory is
Correct Answer: D. meridional flow
49. Lines connecting points of equal pressure are called:
Correct Answer: A. Isobars
50. Rain which falls from a cloud but evaporates before reaching the ground is referred to as:
Correct Answer: B. Virga
51. Which cloud would most likely produce drizzle?
Correct Answer: A. Stratus
52. An offshore wind:
Correct Answer: A. blows from land to water
53. Explain the relationship between the general circulation of air and the circulation of ocean currents.
The wind influences the flow of current. As the wind blows over the ocean it causes the surface water to drift along with it. The moving water gradually piles up creating pressure differences within the water itself.
54. On an upper-level chart, normally we find warm air associated with _____ pressure, and cold air associated with _____ pressure.
Correct Answer: B. high; low
55. The initial stage of an ordinary thunderstorm is the:
Correct Answer: C. cumulus stage
56. Which of the features below could indicate prevailing wind direction?
Correct Answer: D. all of these
57. Lightning may occur:
Correct Answer: D. all of these
58. At any given time, only one jet stream can be found in the atmosphere.
Correct Answer: False
59. Streamlines on a weather map depict:
Correct Answer: C. wind flow
60. A weak trough of low pressure found in the tropics, along which hurricanes occasionally form, is called:
Correct Answer: B. an easterly wave
61. During the summer along the coast, a sea breeze is usually strongest and best developed:
Correct Answer: A. in the afternoon
62. Freshly fallen snow __________ sound waves.
Correct Answer: B. Absorbs
63. A wind rose describes:
Correct Answer: B. the percent of time the wind blows from different directions
64. The heat from a chinook wind is generated mainly by:
Correct Answer: A. compressional heating
65. A group of thunderstorms which develop in a line one next to the other, each in a different stage of development, are called:
Correct Answer: C. a multicell thunderstorm
66. Average winter temperatures in Great Britain and Norway would probably be much colder if it were not for the:
Correct Answer: B. North Atlantic Drift
67. What can cause the air pressure to change at the bottom of a column of air?
The downward force exerted by overlying air causes greater pressure at the bottom of the atmosphere. Air molecules are actually "squeezed" by the weight of the air above. A
Another way of expressing this is that air pressure is inversely related to altitude, meaning change of altitude will cause a change of air pressure at the bottom of column of air.
68. Another name for a small, rotating whirlwind observed at the surface is:
Correct Answer: D. dust devil
69. What is the difference between freezing rain and sleet? Explain.
Freezing rain - is super cooled liquid drops and immediately freeze upon striking a cold object forming a thin veneer of ice.
sleet - is falling snow flakes that melts as falls into warmer air. The cold rain drops tun back to ice when it falls through a deep subfreezing surface.
70. In the Northern Hemisphere, ocean currents in the Atlantic and the Pacific Oceans move in a generally circular pattern. The direction of this motion is _____ in the Atlantic and _____ in the Pacific.
Correct Answer: C. clockwise; clockwise
71. Which below would NOT be considered an onshore wind?
Correct Answer: B. Santa Ana wind
72. If huge waves pound against the beach communities of Southern California for several days during clear, calm weather, it is a good bet that:
Correct Answer: A. the winds are strong somewhere over the Pacific Ocean
73. In a hurricane, the eye wall represents:
Correct Answer: D. a zone of intense thunderstorms around the center
74. The main difference between a cloud drop and a raindrop is its:
Correct Answer: B. Size
75. The greatest annual number of thunderstorms in the United States occurs in:
Correct Answer: D. Florida
76. The large thermally driven convection cell that is driven by convective "hot" towers along the equator is the ____.
Correct Answer: B. Hadley cell
Antitrade winds are the winds that blow high in the atmosphere (not at the surface) from the equator to about 30 degrees. They are a part of the Hadley Cell.
Chromosomes are aligned along with the equator of the cell in metaphase.
The rotation of the Earth and its spherical shape, and solar radiation
Hypothetically, if the Earth's surface was entirely composed of water, there would be a single convection cell where hot air rises and moves towards the poles, while cold air moves towards the Equator as wind, undercutting the hot air. This idea was proposed by Halley (1686) and developed by Hadley (1735). The existence of irregularities in the Earth's surface (land) results in three convection cells: Hadley, Ferrel and a weak Polar cell. Key words to investigate: tricellular model, Inter-Tropical-Convergence-Zone (ITCZ) (existing between the Northern and Southern Hemisphere Hadley cells), doldrums (weak winds experienced in the ITCZ) and jet streams.
Also known as the equatorial plate, a cell equator refers to the middle part of the cell. This is where chromosomes line up during the metaphase stage of mitosis
Antitrade winds are the winds that blow high in the atmosphere (not at the surface) from the equator to about 30 degrees. They are a part of the Hadley Cell.
The air around the equator is caught in the doldrums and the trade winds. The air closest to the equator flows upward and westerly until it reaches the border of the prevailing westerlies when it heads back toward the equator again.
Yes, warm, moist air rises at the equator and causes cool, dry downdrafts at the tropics (30°N/S).
hadley
Constant heating from the sun causes air to rise, then flow away from the equator. Sinking air in the subtropics spreads out and some of it flows toward the equator. This creates a "cell" (Hadley Cell) of circulation that constantly generates rising air at the equator and therefore low pressure.
Constant heating from the sun causes air to rise, then flow away from the equator. Sinking air in the subtropics spreads out and some of it flows toward the equator. This creates a "cell" (Hadley Cell) of circulation that constantly generates rising air at the equator and therefore low pressure.
A Hadley cell is a circulation pattern in the tropical atmosphere. They have a rising motion near the equator and a descending motion in the subtropics. Hadley cells are one of the three primary circulation cells.
hadley cell, ferrell cell, polar cell
Hadley cell, ferrel cell, polar cell.
All these can be explained by simple gear mechanism. You have to put three gears A B C in a row above the equator and below the equator. Above the equator westerlies move in anticlockwise direction and below it moves in clockwise direction. So two gears move in opposite direction. This is normal phenomena. Energy for this is provided by sun. As equator is hottest, air is bound to go upwards. It can go all the way to polar region and go down. But this does not happen and you have three cells. That means Hadley cell, Ferrel cell and polar cell. In Hadley cell at equator air moves upwards at equator. From there it moves towards polar direction and then at tropic of cancer and tropic of Capricorn it it goes downwards. As air from there has already travelled to equator. Then Ferrel cell behave against the natural law. That means air flows from hot to cold region. Energy for this abnormal movement is provided by Hadley cell as well as polar cell. Here both the cells provide 'equal' energy. Then you have polar cell. It is normal to move air from cold region to hot region. As air from hot region will go up. So it needs no explanation. So in trade winds air moves from tropic of cancer and Capricorn to equator, in north and south poles respectively. In Ferrel cells you have westerlies. Air flows from tropic of cancer and tropic of Capricorn to 60 latitude. And in polar cell you have air flowing from polar region to 60 latitude. It causes polar easterlies. So movements of winds are explained.
Hadley cell
Hadley cell