Deck 6: Air Pressure and Winds

Question 1

The scale on an altimeter indicates altitude, but an altimeter actually measures ____.

A) temperature
B) density
C) pressure
D) humidity

Answer 1

C

Question 2

Two air columns extend from sea level up to an altitude of 10 km. If one column is cold and the other is warm, the air pressure in the cold column will ____ the air pressure in the warm column.

A) decrease more rapidly with increasing height than
B) decrease less rapidly with increasing height than
C) increase more rapidly with increasing height than
D) increase at the same rate as

Answer 2

A

Question 3

A wind that blows at a constant speed parallel to curved isobars or contour lines is called a ____.

A) geostrophic wind
B) cyclonic wind
C) convergent wind
D) gradient wind

Answer 3

D

Question 4

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

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

Question 5

A wind blowing at a constant speed parallel to straight line isobars with the pressure gradient force (PGF) and the Coriolis force in balance is called a ____.

A) gradient wind
B) meridional wind
C) geostrophic wind
D) cyclostrophic wind
E) zonal wind

Question 6

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 at the poles
D) at all places on the earth

Question 7

Mercury is used in barometers primarily because of which one of the following properties?

A) Mercury is a good conductor of electricity.
B) Mercury doesn't freeze.
C) Mercury is a good conductor of heat.
D) Mercury has a high density.

Question 8

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

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

Question 9

Cyclonic flow means ____ in either the Northern or Southern Hemisphere.

A) clockwise wind flow
B) counterclockwise flow
C) circulation around a low pressure center
D) circulation around a high pressure center

Question 10

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 ____ than in the cold column.

A) decrease; more rapidly
B) decrease;, more slowly
C) increase; more rapidly
D) increase; more slowly

Question 11

A ____ usually indicates clearing weather or fair weather.

A) constant pressure
B) steadily rising pressure
C) steadily falling pressure
D) fluctuating pressure

Question 12

To obtain the station pressure you must normally make corrections for ____.

A) temperature and gravity
B) temperature and altitude
C) operator error and temperature
D) temperature and time

Question 13

On an upper-air chart, the wind aloft tends to blow ____.

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

Question 14

The winds aloft in the middle latitudes would not blow from the west if the ____.

A) earth's rotation slowed or increased slightly
B) tilt of the earth changed slightly
C) air over high latitudes became warmer than over the equator
D) direction of the moon's orbit around the earth were reversed

Question 15

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

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

Question 16

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

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

Question 17

The wind around a surface low pressure center in the Southern 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

Question 18

If the earth's gravitational force were to increase, atmospheric pressure at the ground would ____.

A) increase
B) decrease
C) remain the same
D) cause the atmosphere to expand vertically

Question 19

Atmospheric pressure changes ____.

A) more rapidly in the horizontal direction than in the vertical
B) more rapidly in the vertical direction than in the horizontal
C) at the same rate in the horizontal and vertical directions
D) more rapidly in the vertical direction over land than over the ocean

Question 20

A gradient wind blowing around the low-pressure center is constantly accelerating because it is constantly changing directions. This is called ____.

A) the pressure gradient force
B) the Coriolis force
C) centripetal acceleration
D) cyclonic flow

Question 21

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

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

Question 22

A wind profiler obtains wind information using ____.

A) an aerovane
B) a theodolite
C) an infrared radiometer
D) a Doppler radar

Question 23

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

Question 24

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 Northern and Southern Hemispheres
D) at the poles in both hemispheres

Question 25

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

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

Question 26

The force that causes the wind to deflect off its intended path is the ____.

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

Question 27

Suppose that the winds aloft are geostrophic and blowing from the north. With the same orientation of isobars at the surface, the winds would blow from the ____.

A) southwest
B) northwest
C) northeast
D) southeast

Question 28

Which of the following forces does not have a direct effect on horizontal wind motions?

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

Question 29

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

A) north
B) south
C) east
D) west

Question 30

The atmosphere around the earth would rush off into space if the vertical pressure gradient force were not balanced by ____.

A) the Coriolis force
B) the horizontal pressure gradient force
C) gravity
D) the centripetal force

Question 31

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 region that often has a slight breeze
D) in a region of moderate, steady winds

Question 32

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

A) rising; rising
B) rising; sinking
C) sinking; sinking
D) sinking; rising

Question 33

Suppose that the winds aloft in the Northern Hemisphere are geostrophic and blowing from the north. Low pressure is located to the ____.

A) north
B) south
C) east
D) west

Question 34

The surface air around a strengthening low pressure area normally ____, while, above the system, the air normally ____.

A) diverges; diverges
B) diverges; converges
C) converges; converges
D) converges; diverges

Question 35

When the upward-directed pressure gradient force is in balance with the downward pull of gravity, the atmosphere is in ____.

A) hydrostatic equilibrium
B) unstable equilibrium
C) geostrophic balance
D) isobaric balance

Question 36

In the vertical, the pressure gradient force points ____ and gravity points ____.

A) toward the earth; away from the earth
B) toward the earth; toward the earth
C) away from the earth; away from the earth
D) away from the earth; toward the earth

Question 37

If upper-level divergence exceeds surface convergence, the air pressure at the center of the low will ____, and the isobars will become ____ tightly packed.

A) decrease; less
B) decrease; more
C) increase;, less
D) increase; more

Question 38

Which of the following combinations produces the strongest Coriolis force?

A) fast winds and low latitude
B) fast winds and high latitude
C) slow winds and low latitude
D) slow winds and high latitude

Question 39

The net force acting on air which is blowing parallel to straight contours at constant speed is ____.

A) in the direction of wind motion
B) to the right of the wind's motion in the Northern Hemisphere
C) zero
D) in a direction opposite the wind's motion

Question 40

An object is falling at constant speed. The net force is ____.

A) upward
B) downward
C) horizontally directed
D) zero

Question 41

Instructions: Choose one answer from each pair of selections. If the air pressure were to increase, the height of the column in a mercury barometer would INCREASE | DECREASE.

Question 42

What is a prevailing wind?

Question 43

When the flow of air is purely geostrophic, how can the wind speed be described and how is this represented on an isobaric map?

Question 44

Upper-level winds blow from west to east in both the Northern and Southern Hemispheres.

Question 45

Instructions: Choose one answer from each pair of selections. If upper-level divergence exceeds surface convergence, surface winds will INCREASE | DECREASE.

Question 46

Instructions: Choose one answer from each pair of selections. If you look in the direction the upper-level wind is blowing in the northern hemisphere, low pressure will be to your RIGHT | LEFT.

Question 47

Instructions: Choose one answer from each pair of selections. Surface winds blow in toward the center of LOW | HIGH pressure areas.

Question 48

Instructions: Choose one answer from each pair of selections. Wind direction is given as the direction TOWARDS | FROM which it is blowing.

Question 49

Instructions: Choose one answer from each pair of selections. Air pressure at the top of a mountain is ALWAYS | NEVER greater than the air pressure at its base.

Question 50

Instructions: Choose one answer from each pair of selections. Rising air motions are associated with surface centers of HIGH | LOW pressure in the Northern and Southern Hemispheres.

Question 51

Two parcels of air with the same volume and temperature will also always have the same pressure.

Question 52

Briefly describe the friction layer and how it affects wind speeds.

Question 53

Instructions: Choose one answer from each pair of selections. Pressure decreases most rapidly with increasing altitude in WARM | COLD air because the air has high density.

Question 54

Instructions: Choose one answer from each pair of selections. Would you expect to hear MILLIBAR or INCHES OF MERCURY pressure units used on a television weather report?

Question 55

What is the Coriolis force and how is it influenced by wind speed?

Question 56

Instructions: Choose one answer from each pair of selections. The horizontal movement of CIRRUS | FOG clouds is more influenced by friction.

Question 57

What does it mean when air is said to be in hydrostatic equilibrium?

Question 58

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

Question 59

An altimeter is often just an aneroid barometer that has been calibrated to indicate altitude.

Question 60

The Coriolis force will change the wind's direction, but cannot change its speed.

Question 61

Although many scientists have contributed to our understanding of why the wind blows, who stands out as making particularly significant contributions? When did this scientist live? Describe the two most important laws of motion proposed by this scientist.

Question 62

How can wind direction and pressure patterns aloft be estimated visually from the ground?

Question 63

Discuss the pros and cons of harnessing wind energy using wind turbines, and whether you think this is a viable solution for meeting the energy demands of people.

Question 64

Define prevailing wind. Give an example of how they can affect a region's climate. How can prevailing winds influence city planning and residential construction?

Question 65

Explain why and how altitude corrections are made to barometer readings.