Deck 8: Air Pressure and Winds

Question 1

It takes a larger column of cold, more-dense air to exert the same surface pressure as a taller column of warm, less-dense air.

Answer 1

False

Question 2

In the Northern Hemisphere, the average height of contour lines on an upper-level isobaric chart tends to decrease northward.

Answer 2

True

Question 3

An altimeter measures altitude but is calibrated to indicate pressure.

Answer 3

False

Question 4

One atmosphere of pressure is equivalent to 760 torr of pressure.

Question 5

The angle at which surface winds cross isobars depends upon surface friction, wind speed, and the height above the surface.

Question 6

Surface winds that blow over the ocean are closer to being geostrophic than those that blow over land.

Question 7

Flights from San Francisco to New York City take, on average, about 30 to 45 minutes less than the return flights.

Question 8

The pressure gradient force is non-existent at the equator.

Question 9

In middle latitudes, surface pressure changes are primarily the result of large high- and low-pressure areas that move toward or away from a region.

Question 10

Station pressure and sea-level pressure can never be the same value.

Question 11

If you (in the Northern Hemisphere)stand with the wind aloft to your back, Buys Ballot's law states that lower pressure will be to your right and higher pressure to your left.

Question 12

Newton's first law of motion states that an object at rest will remain at rest, and an object in motion will remain in motion (and travel at a constant velocity along a straight line)as long as no force is exerted on the object.

Question 13

The angle at which surface winds cross isobars is to a large degree dependent on the roughness of the terrain.

Question 14

Most of the time, the atmosphere does not approximate hydrostatic equilibrium.

Question 15

In the tropics, daily (diurnal)fluctuations of pressure appear to be due primarily to the absorption of solar energy by ozone in the upper atmosphere and by water vapor in the lower atmosphere.

Question 16

Net convergence of air would cause surface pressure to ____ and net divergence would cause surface pressure to ____.

A)increase; decrease
B)increase; increase
C)decrease; decrease
D)decrease; increase
E)remain the same; remain the same

Question 17

The Coriolis force is the force that causes the wind to blow.

Question 18

Surface pressure is affected by the relationship between upper-level divergence and surface convergence.

Question 19

The pressure gradient force has a direct effect on horizontal wind movements.

Question 20

Air pressure decreases with height more rapidly in warm air than in cold air.

Question 21

If two air parcels at sea level have the same size but different temperatures, the colder parcel of air will have ____.

A)a higher pressure but the same density as the warm parcel
B)the same pressure but lower density than the warm parcel
C)the same pressure but higher density than the warm parcel
D)a lower pressure but the same density as the warm parcel
E)the same pressure and the same pressure as the warm parcel

Question 22

The surface pressures at the bases of warm and cold columns of air are equal. Air pressure in the warm column of air will ____ with increasing height ____ in the cold column.

A)decrease; at the same rate as
B)decrease; more slowly than
C)increase; more rapidly than
D)increase; more slowly than
E)increase; at the same rate as

Question 23

A station at an altitude of 900 m (about 3,000 feet)above sea level measures an air pressure of 930 mb. Under normal conditions, which of the values below do you think would be the most realistic sea level pressure for this station?

A)840 mb
B)930 mb
C)1,020 mb
D)1,830 mb
E)1340 mb

Question 24

The amount of pressure change that occurs over a given horizontal distance is called the ____.

A)pressure tendency
B)Coriolis parameter
C)pressure gradient
D)potential gradient
E)slope

Question 25

On a 500 mb chart, ____ are drawn to represent horizontal changes in altitude which correspond to horizontal changes in pressure.

A)contour lines
B)isobars
C)isotherms
D)isotachs
E)isofiles

Question 26

Which of the following instruments measures pressure?

A)Barometer
B)Thermometer
C)Radiometer
D)Hygrometer
E)Densitometer

Question 27

The pressure gradient force is directed from higher pressure toward lower pressure ____.

A)only at the equator
B)at all places on Earth except for the equator
C)only in the Northern Hemisphere
D)only in the Southern Hemisphere
E)at all places on Earth

Question 28

Suppose a parcel of air has a given temperature, pressure, and density. If the parcel's size remains the same while its temperature increases, then the air pressure inside the parcel will ____.

A)decrease
B)decrease, but will not drop below 1,000 mb
C)increase
D)remain constant
E)decrease to well below 1,000 mb

Question 29

Horizontal pressure variations cause air to move from areas of _____ pressure to areas of ____ pressure.

A)high; low
B)low; high
C)low; low
D)high; high
E)high; higher

Question 30

Warm air aloft is associated with constant pressure surfaces that are found at ____ altitudes than normal and ____ normal atmospheric pressure aloft.

A)higher; higher than
B)higher; lower than
C)lower; higher than
D)lower; lower than
E)lower; the same as

Question 31

On an isobaric surface, ____.

A)altitude is constant
B)temperature is constant
C)pressure is constant
D)precipitation is constant
E)cloud coverage is constant

Question 32

Isobaric surfaces are higher in ____ air and lower in ____ air.

A)warm, more-dense; cold, less-dense
B)warm, less-dense; cold, more-dense
C)cold, more-dense; warm, less-dense
D)cold, less-dense; warm, more-dense
E)nonexistent; stable

Question 33

To correctly monitor horizontal changes in air pressure, the most important correction for a mercury barometer is the correction for ____.

A)temperature
B)altitude
C)density
D)gravity
E)humidity

Question 34

On an upper-level chart the wind tends to be ____.

A)at right angles to the isobars or contour lines
B)parallel to the isobars or contours
C)at an angle between 10 and 30 to the contours and towards lower pressure
D)at constant speed
E)at an angle between 10 and 30 to the contours and towards higher pressure

Question 35

Which of the following pairs has the largest differences in air pressure between the two?

A)The ground floor of a house on the beach in Miami and the fifth floor of an apartment complex on the beach in Boston
B)The ground floor of a New York City skyscraper and the top floor of the same skyscraper
C)The ground floor of a house on the beach in New Jersey and the ground floor of a house on the beach in Seattle
D)The fifth level of a business in Denver and the condominium on the sixth level
E)A ground-level public park in Phoenix and the fourth level of a neighboring public utility office

Question 36

A surface low pressure center is generally associated with ____ on an upper level isobaric chart.

A)a trough
B)a ridge
C)zonal flow
D)convergence
E)divergence

Question 37

The unit of pressure most commonly found on a surface weather map is ____.

A)inches of mercury
B)millibars or hectopascals
C)pounds per square inch
D)atmospheres
E)torr

Question 38

The base value of an isobar is ____.

A)1,000 mb
B)100 mb
C)8 mb
D)4 mb
E)2 mb

Question 39

A ridge on an upper-level isobaric chart indicates ____.

A)higher-than-average heights
B)lower-than-average heights
C)average heights
D)a region with calm winds
E)a region with strong winds

Question 40

The contour lines drawn on a 500 mb chart are lines of constant ____.

A)wind speed
B)pressure
C)density
D)wind direction
E)temperature

Question 41

Surface winds blow across isobars at an angle and the pressure gradient force is balanced by the ____ force and the Coriolis force.

A)surface
B)pressure gradient
C)frictional
D)centripetal
E)gravitational

Question 42

Zonal wind-flow patterns go ___.

A)from either north to south or south to north
B)from north to south
C)from south to north
D)from west to east
E)from east to west

Question 43

What is considered standard sea-level atmospheric pressure in millibars?

A)101.25 mb
B)103.25 mb
C)1013.52 mb
D)1031.25 mb
E)1013.25 mb

Question 44

In an aneroid barometer, a general rule is that the higher the reading, the more likely ____ weather will occur, and the lower the reading, the better the chances are for ____ weather.

A)clear; inclement
B)inclement; clear
C)cold; warm
D)windy; still
E)snowy; rainy

Question 45

Upper-level winds in the middle latitudes of both hemispheres generally blow from ____.

A)the north
B)the east
C)the south
D)the west
E)changing directions

Question 46

Winds blow slightly inward ____.

A)around surface low pressure centers in the Northern Hemisphere only
B)around surface low pressure centers in the Southern Hemisphere only
C)around surface low pressure centers in the Southern Hemisphere only
D)at the poles in both hemispheres
E)at the equator

Question 47

The unit of pressure designated by the International System (SI)of measurement is the ____.

A)atmospheric pressure
B)millibar
C)bar
D)torr
E)pascal

Question 48

Which of the following produces the strongest Coriolis force?

A)Fast winds; low latitude
B)Fast winds; high latitude
C)Slow winds; low latitude
D)Slow winds; high latitude
E)Fast winds; intermediate altitude

Question 49

In the tropics, pressure rises and falls in a regular pattern twice a day, due to absorption of solar energy by ____.

A)ozone in the upper atmosphere and water vapor in the lower atmosphere
B)water vapor in the upper atmosphere and ozone in the lower atmosphere
C)ozone and water vapor in the upper atmosphere
D)ozone and water vapor in the lower atmosphere
E)None of these is correct.

Question 50

In middle latitudes, when an area of high pressure approaches a city, surface pressure usually ____. When it moves away, pressure usually ____.

A)remains the same; remains the same
B)remains the same; falls
C)remains the same; rises
D)falls; rises
E)rises; falls

Question 51

Zonal flow wind-flow patterns are associated with ____.

A)north-to-south flows
B)south-to-north flows
C)east-to-west flows
D)west-to-east flows
E)random directional flows

Question 52

In the Northern Hemisphere, assuming there is no wind, there is a pressure-gradient force directed ____.

A)northward
B)southward
C)eastward
D)westward
E)upward

Question 53

The winds aloft in the middle latitudes of the Southern Hemisphere generally blow ____.

A)from west to east
B)from east to west
C)from north to south
D)from south to north
E)in any of the above directions

Question 54

The ____ force is an apparent force created by Earth's rotation.

A)pressure gradient
B)Coriolis
C)centripetal
D)gravitational
E)frictional

Question 55

A geostrophic wind is a wind that results from a balance between the ____ force and the ____ force.

A)pressure gradient; gravitational
B)pressure gradient; frictional
C)Coriolis; gravitational
D)Coriolis; frictional
E)Coriolis; pressure gradient

Question 56

If, at your home in the Northern Hemisphere, the surface wind is blowing from the northwest, the region of lowest pressure will be to the ____ of your home.

A)north
B)southwest
C)east
D)west
E)northeast

Question 57

The force that would cause a stationary parcel of air to begin to move horizontally is called the ____.

A)Coriolis force
B)pressure gradient force
C)centripetal force
D)frictional force
E)gravitational force

Question 58

On a sunny day, an aneroid barometer would indicate "____" weather when carried to the top of a hill or mountain.

A)fair
B)sunny
C)cold
D)wet
E)stormy

Question 59

The wind around a surface low pressure center in the ____ blows clockwise and inward toward the center.

A)Northern Hemisphere only
B)Southern Hemisphere only
C)Eastern Hemisphere only
D)Western Hemisphere only
E)None of these is correct

Question 60

The wind around a surface high pressure center in the Northern Hemisphere blows ____.

A)counterclockwise and outward from the center
B)counterclockwise and inward toward the center
C)clockwise and outward from the center
D)clockwise and inward toward the center
E)clockwise and parallel to the center

Question 61

A ____________________ barometer uses a transducer to detect the change in pressure exerted by the atmosphere on a precisely engineered surface, and the change in pressure is then converted into an electrical signal.

Question 62

Because of friction, surface winds move ____ winds aloft with the same pressure gradient.

A)more slowly than
B)at the same speed as
C)faster than
D)twice as fast as
E)at half the speed as

Question 63

If you live in the Northern Hemisphere and a region of surface low pressure is directly west of you, the surface wind direction at your home would probably be either ____________________ or _____________________.

Question 64

Because water is 13.6 times less dense than mercury, an atmospheric pressure of 76 cm (30 in.)of mercury would be equivalent to 1034 cm (408 in.)of water. Therefore, a water barometer resting on the ground near sea level would have to be read from a ladder over ____ tall.

A)5 m (16 feet)
B)10 m (33 feet)
C)15 m (49 feet)
D)20 m (66 feet)
E)25 m (82 feet)

Question 65

On an upper-level chart cold air aloft is generally associated with ____________________ pressure.

Question 66

Atmospheric air pressure always ____________________ with height.

Question 67

Newton's second law states that the force exerted on an object equals its ____________________ times the ____________________.

Question 68

The friction layer usually extends upward to an altitude near ____ above the surface.

A)100 m
B)200 m
C)1,000 m
D)1,500 m
E)2,000 m

Question 69

We can generally expect the air to be ____________________ above areas of surface low pressure and ____________________ above areas of surface high pressure.

Question 70

The ____ force acts at a 90-degree angle to the wind.

A)meridional
B)zonal
C)pressure-gradient
D)friction
E)Coriolis

Question 71

The vertical pressure gradient force is directed ____________________.

Question 72

If upper-level divergence exceeds surface convergence, the air pressure at the center of the surface low will ____.

A)be unaffected
B)double
C)triple
D)increase
E)decrease

Question 73

On an upper-level chart, normally we find warm air associated with ____________________ pressure, and cold air associated with ____________________ pressure.

Question 74

At sea level, standard atmospheric pressure is ____.

A)1,000 mb
B)10 mb
C)1 kilobar
D)1 hPa
E)29.92 inches of mercury

Question 75

If Earth did not rotate, the wind would blow directly from regions of ____________________ pressure toward regions of ____________________ pressure.

Question 76

A pascal (Pa)is the force of ____ acting on a surface area of ____.

A)1 Newton; 1 square meter
B)100 Newton; 1 square meter
C)1 Newton; 1 square foot
D)1 Newton; 1 square inch
E)10 Newton; 1 square foot

Question 77

Suppose that the winds aloft are geostrophic and blowing from the north. Low pressure is located to the ____________________.

Question 78

A rapid change in pressure over a relatively short distance is called a ____ pressure gradient .

A)sudden
B)rapid
C)weak
D)gentle
E)steep

Question 79

Warming and cooling of air creates density oscillations known as ____________________ that show up as small pressure changes near Earth's surface.

Question 80

The magnitude of the Coriolis force varies with ____ and ____.

A)wind speed; longitude
B)wind flow; precipitation
C)altitude; latitude
D)wind speed; latitude
E)wind direction; hemisphere