Deck 9: Wind - Small-Scale and Local Systems

Question 1

​The slowing of the wind due to the random motion of air molecules is called

A) ​eddy viscosity.
B) ​mechanical turbulence.
C) ​molecular viscosity.
D) ​convective turbulence.
E) ​kinetic viscosity.

Answer 1

C

Question 2

The difference in surface wind speed between morning and afternoon is typically greater on a clear, sunny day than on a cloudy, overcast day.

Answer 2

True

Question 3

​What is an example of mesoscale motion?

A) ​winds on a surface weather map of North America
B) ​winds on a 500 mb chart
C) ​winds blowing through a city
D) ​winds blowing past a chimney
E) ​average wind patterns around the world

Answer 3

C

Question 4

The shape of a sand dune reveals the prevailing wind direction that existed during its formation.

Question 5

Coastal areas can have heavy waves on a clear, nonstormy day.

Question 6

Strong winds blowing over vegetation results in rapid water loss in the plant.

Question 7

Chinook winds are a common phenomenon on the east side of the Appalachians.

Question 8

Clear air turbulence often occurs near a boundary of high wind shear.

Question 9

Friction is not restricted to solid objects; it occurs in moving fluids as well.

Question 10

Wind direction and speed can be determined with an aerovane.

Question 11

Prevailing offshore winds in summer carry moisture, cool air, and fog into coastal regions, whereas prevailing onshore breezes carry warmer and drier air into the same locations.

Question 12

In city planning, sewage disposal plants must be situated upwind from large housing developments.

Question 13

​Which association is most accurate?

A) ​microscale - chinook wind
B) ​synoptic scale - sea breeze
C) ​mesoscale - land breeze
D) ​planetary scale - lake breeze
E) ​universal scale - ocean breeze

Question 14

Thermal lows form in response to variations in surface air temperature.

Question 15

A valley breeze develops its maximum strength in the early afternoon.

Question 16

Microscale circulations range from a few kilometers to about a hundred kilometers in diameter.

Question 17

Thermal lows become stronger with increasing height.

Question 18

Sand ripples can indicate the prevailing wind direction in an area.

Question 19

​What is an example of microscale motion?

A) ​winds on a surface weather map of North America
B) ​winds on a 500 mb chart
C) ​winds blowing through a city
D) ​winds blowing past a chimney
E) ​average wind patterns around the world

Question 20

In the northeastern half of the United States, the prevailing wind in winter is northwest and in summer it is southwest.

Question 21

​A wind rose indicates

A) ​the wind speed at a location at a particular time.
B) ​the percentage of time that the wind blows from different directions.
C) ​observed wind speed and direction on a surface map.
D) ​spinning wind patterns caused by buildings or other obstructions.
E) ​a rose fossilized by wind.

Question 22

​Suppose the wind speed increased from 5 mph to 10 mph. We can conclude that the force exerted by the wind increased by a factor of

A) ​0.5.
B) ​2.
C) ​4.
D) ​5.
E) ​25.

Question 23

​Dust storms on Mars are generally

A) ​infrequent.
B) ​extremely large.
C) ​small.
D) ​nonexistent.
E) not able to be recorded.

Question 24

​The wind's speed generally increases with height above Earth's surface because

A) ​only the lowest layer of air rotates with Earth.
B) ​air temperature normally decreases with height.
C) ​wind instruments are not accurate at Earth's surface.
D) ​friction with Earth's surface slows the air near the ground.
E) ​air parcels expand and become less dense as they rise above the surface.

Question 25

​The nighttime counterpart of the sea breeze circulation is called

A) ​Chinook.
B) ​Santa Ana.
C) ​land breeze.
D) ​a night breeze.
E) ​foehn.

Question 26

​On a clear, windy day, the depth to which mixing occurs above the surface depends upon

A) ​wind direction.
B) ​surface heating.
C) ​precipitation type.
D) ​cloud coverage.
E) ​nuclei types in the atmosphere.

Question 27

​The most practical location for building a wind turbine would be

A) ​​in a region of strong, gusty winds.
B) ​on the downwind side of a mountain.
C) ​in a narrow valley.
D) ​in a region of moderate, steady winds.
E) ​anywhere on top of a mountain.

Question 28

​Surface winds are generally strongest and most gusty

A) ​in the afternoon.
B) ​in the early morning.
C) ​around midnight.
D) ​just after sunset.
E) ​just before sunrise.

Question 29

​An offshore wind blows

A) ​from land to water.
B) ​from water to land.
C) ​only at night.
D) ​only during the day.
E) ​a minimum distance of 100 miles away from the shore.

Question 30

​Thermal turbulence above the surface is usually most severe

A) ​immediately after sunset.
B) ​during maximum surface heating.
C) ​around midnight.
D) ​just before sunrise.
E) ​about midmorning, or soon after the minimum temperature is reached.

Question 31

​Suppose a west wind of 20 knots blows over a coastal region which is densely covered in shrubs. If this same wind moves out over the middle of a large calm lake, its speed and direction would probably be

A) ​greater than 20 knots and more northwesterly.
B) ​less than 20 knots and more northwesterly.
C) ​greater than 20 knots and more southwesterly.
D) ​less than 20 knots and more southwesterly.
E) ​less than 20 knots and westerly.

Question 32

​The howling of wind on a blustery night is believed to be caused by

A) ​variations in air temperature.
B) ​winds blowing around a frozen surface.
C) ​snowflakes striking one another but not sticking together.
D) ​air flowing past obstructions.
E) ​wind lifting, then lowering small objects at the surface.

Question 33

​The size and shape of a turbulent eddy depends upon

A) ​the composition of the obstacle.
B) ​the size and shape of the obstacle.
C) ​the wind direction.
D) ​topography of the surrounding landscape.
E) ​elevation where the obstacle is located.

Question 34

​A sea breeze circulation will reverse direction and become a land breeze

A) ​once every few days.
B) ​at the beginning and the end of the summer.
C) ​several times per day.
D) ​once per day.
E) ​once a month.

Question 35

​In south Florida the prevailing winds are northeasterly. Because of this, the strongest sea breeze is usually observed on Florida's ____ coast, and the strongest land breeze on Florida's ____ coast.

A) ​east; west
B) ​west; south
C) ​east; south
D) ​east, east
E) ​west; east

Question 36

​Which of the below determines how high a wind wave will grow over the open ocean?

A) ​water quality
B) ​density of water
C) ​length of time the wind blows over the water
D) ​shoreline topography
E) ​geographical location

Question 37

​If huge waves pound against the beach communities of Southern California for several days during clear, calm weather, it is a good bet that

A) ​the winds are strong somewhere out over the Pacific Ocean.
B) ​an earthquake has occurred somewhere on the ocean floor.
C) ​it is raining offshore.
D) ​it is a period of high tides.
E) ​there is a large difference in water density between the shoreline of Southern California and the middle of the Pacific.

Question 38

​A wind reported as 45 $\degree$ would be a wind blowing from the:

A) ​NE.
B) ​S.
C) ​SW.
D) ​NW.
E) ​E.

Question 39

​A sea or land breeze is caused by

A) ​differences in humidity.
B) ​temperature differences.
C) ​the Coriolis force.
D) ​ocean tides.
E) ​strong surf conditions.

Question 40

​During the summer in humid climates, nighttime clouds tend to form over water during a

A) ​land breeze.
B) ​chinook wind.
C) ​sea breeze.
D) ​Santa Ana wind.
E) ​lake breeze.

Question 41

​The winter monsoon in eastern and southern Asia is characterized by

A) ​wet weather and winds blowing from land to sea.
B) ​wet weather and winds blowing from sea to land.
C) ​dry weather and winds blowing from sea to land.
D) ​dry weather and winds blowing from land to sea.
E) ​dry weather and Chinook winds.

Question 42

​On the eastern side of the Rocky Mountains, chinook winds are driest when

A) ​clouds form and precipitation falls on the upwind side of the mountains.
B) ​the air aloft is cold.
C) ​the Sun is shining.
D) ​the winds are blowing from the east.
E) ​surface friction is greatest on the downwind side of the mountain.

Question 43

​Which of the following conditions favor the development of dust devils?

A) ​hot, moist days
B) ​hot, dry days
C) ​cold, moist days
D) ​cold, dry days
E) ​moderate temperature, dry days

Question 44

​The synoptic scale describes circulations on the ____ scale.

A) ​micro
B) ​global
C) ​meso
D) ​macro
E) ​weather-map

Question 45

​What is a serious hazard to aircraft?

A) ​molecular viscosity
B) ​laminar flow
C) ​clear-air turbulence
D) ​longwaves in the westerlies
E) ​thermal lows

Question 46

​Thermally-generated eddies typically peak

A) ​at sunrise.
B) ​around midnight.
C) ​at sunset.
D) ​at noon.
E) in the afternoon.

Question 47

​A sea breeze is most likely to develop along a coastline when

A) pressure gradients between the land and sea are large.
B) pressure gradients between the land and sea are small.
C) ​it is raining.
D) ​it is foggy.
E) ​surface temperatures are high.​​

Question 48

​An ideal setting for a katabatic wind is

A) ​a valley that is near a large river.
B) a canyon that flows into the sea.
C) a large elevated lake with a forest nearby.
D) ​an area where the land and the shore meet.
E) ​an elevated plateau surrounded by mountains with a nearby downhill slope.

Question 49

​Wind gusts are caused by

A) ​turbulent eddies.
B) ​wind waves.
C) ​mesoscale circulations.
D) ​wind shear.
E) ​circulations on the synoptic scale.

Question 50

​Clouds and precipitation are frequently found on the downwind side of a large lake. This would indicate that the air on the downwind side is

A) ​converging and rising.
B) ​converging and sinking.
C) ​stable and rising.
D) ​diverging and sinking.
E) ​diverging and rising

Question 51

​When a sea breeze moving north meets a sea breeze moving south, they form a

A) ​land breeze.
B) ​sea breeze convergence zone.
C) ​katabatic wind.
D) ​valley breeze.
E) ​thermal low.

Question 52

​Chinook winds are

A) ​warm, dry downslope winds.
B) ​warm, moist downslope winds.
C) ​cold, dry downslope winds.
D) ​cold, moist downslope winds.
E) ​warm, dry upslope winds.

Question 53

​Cumulus clouds that appear above isolated mountain peaks are often the result of

A) ​katabatic winds.
B) ​mountain winds.
C) ​fall winds.
D) ​Santa Ana winds.
E) ​valley breezes.

Question 54

​The land/sea breeze, lake breeze, and mountain/valley breeze are examples of

A) ​thermal circulations.
B) ​mechanical circulations.
C) ​atmospheric longwave circulations.
D) ​thermal turbulences.
E) ​frictional processes.

Question 55

​While fly fishing in a mountain stream, you notice that the wind is blowing upstream. From this, you could deduce that the wind is a

A) ​chinook wind.
B) ​valley breeze.
C) ​Santa Ana wind.
D) ​mountain breeze.
E) ​katabatic wind.

Question 56

​The heat from a chinook wind is generated mainly by

A) ​compressional heating.
B) ​sunlight.
C) ​warm, ocean water.
D) ​friction with the ground.
E) ​forest fires.

Question 57

​An upper wind direction is reported as 315 $\degree$ . From what compass direction is the wind blowing?

A) ​north
B) ​south
C) ​northeast
D) ​east
E) ​northwest

Question 58

​During the summer along the coast, a sea breeze is usually strongest and best developed

A) ​in the afternoon.
B) ​just after sunrise.
C) ​just before sunset.
D) ​just before noon.
E) ​around midnight.

Question 59

​The summer monsoon in eastern and southern Asia is characterized by

A) ​wet weather and winds blowing from land to sea.
B) ​dry weather and winds blowing from land to sea.
C) ​wet weather and winds blowing from sea to land.
D) ​dry weather and winds blowing from sea to land.
E) ​wet weather and Chinook winds.

Question 60

​If you are standing directly south of a smoke stack and the wind from the stack is blowing over your head, what would be the wind direction?

A) ​north
B) ​east
C) ​south
D) ​west
E) ​northeast

Question 61

​Waves forming by wind blowing over the surface of the water are known as

A) ​ripples.
B) ​waves.
C) ​wind waves.
D) ​fetch.
E) ​surf.

Question 62

Santa Ana winds warm by ____________________ as they flow down an elevated desert plateau.

Question 63

​Wind blowing with sufficient force to rip the roof off buildings

A) ​is common.
B) ​is impossible.
C) ​is uncommon.
D) ​happens during every storm.
E) ​only happens during snowstorms.

Question 64

The macroscale combines the ____________________ and ____________________ scales.

Question 65

When sustained winds or frequent gusts reach 35 mi/hr, the blowing or falling snow can produce ____________________ conditions.

Question 66

​Eddies that form both close to the mountain and beneath each wave crest are called

A) ​mountain wave eddy.
B) ​wind shear.
C) ​clear air turbulence.
D) ​leeward eddy.
E) ​rotors.

Question 67

During hang-gliding, it is dangerous to enter the ____________________ side of the hill when the wind speed is strong.

Question 68

A(n) ____________________ is an instrument that indicates both wind speed and direction. It consists of a bladed propeller that rotates at a rate proportional to the wind speed. Its streamlined shape and a vertical fin keep the blades facing into the wind. When attached to a recorder, a continuous record of both wind speed and direction is obtained.

Question 69

To protect crops and soil from wind-related erosion, windbreaks-commonly called ____________________-are planted.

Question 70

​When wind blows over a snow field, and if the wind is sufficiently strong, the moving clumps of snow become cylindrical, often with a hole extending through them lengthwise. These snow ____ range from the size of eggs to that of small barrels.

A) ​rollers
B) ​waves
C) ​ripples
D) ​dunes
E) ​dunes

Question 71

Water waves that oscillate back and forth are called ____________________.

Question 72

A katabatic wind is a cold and ____________________ wind.

Question 73

Mesoscale circulations have a(n) ____________________ (longer/shorter) duration than microscale circulations.

Question 74

​Stationary storm systems, centered somewhere over the open sea, are capable of creating large waves with wave heights measuring over

A) ​11 m (36 ft).
B) ​21 m (69 ft)
C) ​31 m (100 ft)
D) ​41 m (134 ft)
E) ​51 m (167 ft)

Question 75

The friction of fluid flow is called ____________________.

Question 76

When wind encounters a solid object, a whirl of air, called a(n) ____________________, forms on the object's leeward side.

Question 77

When the slowing of a fluid-such as air-is due to the random motion of the gas molecules, the viscosity is referred to as ____________________.

Question 78

Blowing sand eventually comes to rest ____________________ obstacles, which can be anything from a rock to a clump of vegetation.

Question 79

The force of the wind on an object is ____________________ to the wind speed squared.

Question 80

​A pilot enters the weather service office and wants to know what time of the day she can expect to encounter the least turbulent winds at 760 m (2500 ft) above central Kansas. If you were the weather forecaster, what would you tell her?

A) ​at midnight
B) ​in the early morning
C) ​at noon
D) ​in the afternoon
E) ​at sunset