Deck 4: Atmospheric Pressure and Wind

Question 1

Air pressure:

A)constantly changes in order to avoid equilibrium.
B)is the force exerted in all directions by a column of air rising upward from the point of measurement.
C)is exerted downward only.
D)is independent of the force of gravity.

Answer 1

B

Question 2

In the northern hemisphere,a low pressure system:

A)has clockwise flow in at the surface and out at the top of the system.
B)has clockwise flow in at the top of the system and out at the surface.
C)has counterclockwise flow in at the surface and out at the top of the system.
D)has counterclockwise flow in at the top of the system and out at the surface.

Answer 2

C

Question 3

The pressure at the bottom of the atmosphere is referred to as:

A)reference pressure.
B)sea level pressure.
C)lowest pressure system.
D)constant surface pressure.

Answer 3

B

Question 4

According to Newton's Laws,an air parcel can accelerate:

A)by speeding up.
B)by slowing down.
C)by changing direction.
D)all of the above

Question 5

Anticyclones:

A)have air spiraling into them at lower elevations.
B)have clockwise winds in the Northern Hemisphere.
C)do not have winds in the upper atmosphere that follow height contours.
D)are associated with subgeostrophic winds.

Question 6

Which of the following is a correct approximation of average sea-level atmospheric pressure?

A)1013.2 millibars
B)31 inches of mercury
C)99 kilopascals
D)20 pounds per square inch

Question 7

Vertical pressure changes ________ with height.

A)incrementally
B)uniformly
C)non-linearly
D)linearly

Question 8

The sea level pressure distribution across the world is:

A)randomly distributed.
B)disorganized and widely scattered.
C)organized into high and low pressure areas.
D)not well-known by scientists.

Question 9

Gravity is:

A)a force.
B)an acceleration.
C)an attraction between any two masses.
D)all of the above

Question 10

Northeast has an azimuth value of

A)90 degrees.
B)135 degrees.
C)45 degrees.
D)315 degrees.

Question 11

This is the only atmospheric variable that always decreases with distance above the ground:

A)wind.
B)temperature.
C)pressure.
D)moisture content.

Question 12

The difference between speed and velocity is that velocity additionally incorporates:

A)time.
B)distance.
C)mass.
D)direction.

Question 13

What is average sea-level pressure in pounds per square inch?

A)14.7
B)101.3
C)1.47
D)1013.2

Question 14

Which of the following measure wind direction and speed?

A)aerovane
B)anemometer
C)wind vane
D)all of the above

Question 15

The basic unit of pressure measurement for atmospheric pressure is:

A)millibar.
B)pascal.
C)kilopascal.
D)inches of mercury.
E)all of the above

Question 16

Cyclones:

A)experience Coriolis effects that deflect air to the right in the Southern Hemisphere.
B)are associated with low-pressure systems.
C)are associated with supergeostrophic winds.
D)are typically regions of fair weather.

Question 17

In the atmosphere,pressure decreases most rapidly in the:

A)upper part of the atmosphere.
B)middle part of the atmosphere.
C)lower part of the atmosphere.
D)It doesn't matter where you are, the pressure decreases with altitude is the same.

Question 18

Sea level pressure:

A)is usually less than surface pressure.
B)is used in the United States, but not in Canada.
C)is used to correct for elevation differences at different locations.
D)usually disregards the effect of temperature on air pressure.

Question 19

Which of the following units of pressure measurement is used by Canadian meteorologists?

A)inches of mercury
B)pounds per square inch
C)kilopascals
D)millibars

Question 20

Air pressure is:

A)measured in pascals by American meteorologists.
B)independent of the density of air.
C)independent of the temperature of air.
D)the sum of the partial pressures of its constituent gases.

Question 21

Aneroid barometers are so called because:

A)they use aneroids to measure air pressure.
B)they measure air pressure without using a liquid.
C)they are a hybrid pressure measuring device.
D)None of the above. There is no such thing as an "aneroid barometer."

Question 22

The Equation of State (Ideal Gas Law)gives a relationship between:

A)pressure and wind speed.
B)pressure, temperature, and wind speed.
C)pressure, density, and temperature.
D)pressure, moisture content, and density.
E)none of the above

Question 23

Which of the following connects points of equal atmospheric pressure?

A)isohyets
B)isobars
C)isotherms
D)isotachs

Question 24

The relationship between air pressure and elevation is nonlinear because:

A)air is compressible.
B)air pressure changes with elevation.
C)the equation of state is an exponential function.
D)There is no clear relationship between temperature and elevation.

Question 25

Mercury barometers:

A)use mercury because it has a low density.
B)are more cumbersome than water barometers.
C)give direct measurements in millibars.
D)are inverted into a pool of mercury.

Question 26

According to the Ideal Gas Law,the pressure will increase if:

A)the air density and temperature decreases.
B)the air density increases while the temperature is held constant.
C)the air density and the temperature are held constant.
D)none of the above

Question 27

Regarding hydrostatic equilibrium and movements toward hydrostatic equilibrium,it is true that:

A)upward vertical movements are likely to occur more rapidly than downward movements.
B)air density has no effect on the up or down motion of air masses.
C)a sparse atmosphere feels a stronger gravitational pull than does a dense atmosphere.
D)the vertical pressure gradient force is no match for the force of gravity.

Question 28

Which of the following is true?

A)Surface pressure is always greater than the sea level pressure.
B)Surface pressure is always equal to sea level pressure.
C)Sea level pressure is always greater than surface pressure.
D)Surface pressure is almost always lower than sea level pressure.

Question 29

All other variables equal,humid air is less dense than drier air because:

A)water molecules are negatively charged and thus repel other molecules.
B)the molecular weight of water is less than that of either diatomic oxygen or diatomic nitrogen.
C)some of the water in humid air will condense, and the latent heat released will expand the air.
D)water molecules have a lower average velocity than does diatomic nitrogen.

Question 30

Wherever you find a mercury barometer,you'll also find a(n):

A)meteorologist.
B)anemometer.
C)thermometer.
D)home testing kit for mercury poisoning.

Question 31

A recording barometer is called a what?

A)sling psychrometer
B)barograph
C)hydrograph
D)meteorograph

Question 32

The horizontal pressure gradient force (pgf):

A)is solely responsible for air movement.
B)can affect the direction of wind flow.
C)is always directed from high pressure to low pressure.
D)is strongest where the temperature differentials are the greatest.
E)all of the above

Question 33

Pressure decreases with altitude by 50% with every increase in altitude of how much?

A)1 mile
B)1 km
C)5.5 km
D)10 km

Question 34

The difference between the highest and lowest sea level pressure in the continental United States typically differs by about:

A)24 mb.
B)100 mb.
C)9 percent.
D)14 percent.

Question 35

Mercury barometer readings must be corrected for all of the following factors,except:

A)temperature.
B)changes in the acceleration of gravity with latitude.
C)moisture content of the air.
D)elevation above sea level.

Question 36

The equation of state is not dependent upon this:

A)the density of the gas.
B)the composition of the gas.
C)the temperature of the gas.
D)the pressure of the gas.

Question 37

Regarding isobars,it is true that:

A)their spacing indicates the strength of the pressure gradient.
B)they are drawn at 10 mb intervals in the United States.
C)they depict areas having the same barometer reading.
D)you will not find them on Canadian pressure charts.

Question 38

The Sears Tower in Chicago is 110 stories tall.Atmospheric pressure is greatest at the

A)top of the building.
B)bottom of the building.
C)50th floor.
D)the pressure is equal on all floors.

Question 39

Horizontal pressure changes are ________ than vertical pressure changes.

A)greater
B)less than
C)about the same
D)None of the above. There are no horizontal pressure changes.

Question 40

Hydrostatic equilibrium occurs when:

A)the force of gravity and the vertical pressure gradient both act to push air upward.
B)the force of gravity and the vertical pressure gradient both act to push air downward.
C)the force of gravity and the vertical pressure gradient have equal value and oppose each other.
D)large air masses are moving either up or down.

Question 41

The layer in the atmosphere where friction is important in determining wind speed:

A)thermosphere.
B)ionosphere.
C)planetary boundary layer.
D)hydrosphere.

Question 42

The Coriolis force:

A)determines the motion in which water will spiral down a drain.
B)causes a deflection to the right in the Southern Hemisphere.
C)has a greater effect the longer it acts.
D)operates independently of Newton's Second Law.

Question 43

Horizontal pressure gradients:

A)are typically quite large.
B)often range over distances of hundreds of kilometers when viewed in large scale.
C)are smallest when measured across a hurricane.
D)can be quite large when compared with the average value of the air pressure.

Question 44

Given that the circumference of a circle is 360 degrees,it follows that the earth rotates about this many degrees per hour:

A)10.
B)15.
C)36.
D)360.

Question 45

Which of the following is not an effect of friction?

A)slows airflow
B)increases the Coriolis effect
C)causes airflow to cross isobars rather than run parallel to them
D)none of the above

Question 46

The horizontal pressure gradient force is proportional to:

A)the speed necessary to achieve hydrostatic equilibrium.
B)the change in temperature expressed in Kelvin degrees.
C)the change in air density.
D)the spacing between isobars.

Question 47

An examination of a typical 500 mb height map shows that:

A)pressure surfaces can change dramatically over a short distance.
B)there is no usefulness in consulting height maps for other pressures.
C)upper-atmosphere gradients are typically small.
D)it takes strong gradients to produce strong winds.

Question 48

The Coriolis effect is strongest at this latitude:

A)90 degrees.
B)45 degrees.
C)15 degrees.
D)0 degrees.

Question 49

Upper-level pressure height charts are produced how many times a day by the National Weather Service?

A)one
B)two
C)three
D)four

Question 50

If a column of air is heated,it will:

A)have a lower pressure at its base.
B)become more dense.
C)have a smaller vertical pressure gradient.
D)contract.

Question 51

The Coriolis force:

A)is constant.
B)affects the direction of motion.
C)affects the speed of motion.
D)is caused by pressure gradient forces.

Question 52

The heights of the 500 mb surface in air column A is 5700 meters and 5640 meters in air column B.Choose the best answer from the following:

A)the wind is stronger in column A.
B)the temperature in air column B is higher.
C)the temperature in air column A is higher.
D)the density in air column A is lower.
E)both C and D

Question 53

Height maps for the United States:

A)are updated twice a week.
B)correspond to different approximate elevation levels.
C)are done for 500 mb only.
D)have little practical application in weather forecasting.

Question 54

Which of the following are true?

A)Vertical pressure gradients are similar to horizontal pressure gradients.
B)Vertical pressure gradients are slightly greater than horizontal pressure gradients.
C)Horizontal pressure gradients are slightly greater than vertical pressure gradients.
D)Vertical pressure gradients are very much greater than changes in horizontal pressure.

Question 55

This prevents wind from following the direction of the horizontal pressure gradient force:

A)friction with the ground.
B)the earth's magnetic field.
C)interaction with the solar wind.
D)the Coriolis effect.

Question 56

The pressure gradient force:

A)can be measured by knowing the sea level pressure of just one point.
B)creates wind if it is horizontal.
C)will not necessarily result in the movement of air.
D)is unrelated to the speed of air movement.

Question 57

The Coriolis Effect is zero at:

A)the Equator.
B)the Poles.
C)the upper atmosphere.
D)sunrise.

Question 58

The free atmosphere lies above what height?

A).5 km
B)1 km
C)1.5 km
D)3 km

Question 59

The Coriolis force would be strongest on a(n):

A)supersonic jet.
B)baseball pitcher's 100 mile-per-hour fastball.
C)flock of Canada geese migrating north.
D)alien spaceship the size of New York City that is flying above a north-bound freeway at the speed of traffic.

Question 60

The effect of friction on air:

A)increases wind speed.
B)increases with height.
C)increases the Coriolis force.
D)is relevant only within the planetary boundary layer.

Question 61

Mercury is used in mercury barometers because

A)it is very heavy - lighter fluids would require a much larger glass column
B)it is very heavy - lighter fluids would require a much shorter glass column
C)it is very light - heavier fluids would require a much larger glass column
D)it is very light - heavier fluids would require a much shorter glass column

Question 62

If surface pressure readings were plotted on weather maps,they would give a false representation of the atmosphere because

A)high elevations have higher surface pressures than low elevations, even if the sea-level pressures are the same
B)high elevations have lower surface pressures than low elevations, even if the sea-level pressures are the same
C)the surface pressure at high elevations is often greater than sea-level pressure
D)the surface pressure at high elevations is often the same as sea-level pressure

Question 63

Humid air is actually less dense than dry air because

A)lighter air molecules like O2 and N2 are replaced by heavier H2O molecules
B)heavier air molecules like O2 and N2 are replaced by lighter H2O molecules
C)the greenhouse effect is enhanced when the humidity is high
D)the greenhouse effect is reduced when the humidity is high

Question 64

According to the equation of state p = RT,

A)an increase in pressure requires an increase in density or temperature or both
B)an increase in pressure requires an increase in both density and temperature
C)an increase in pressure requires a decrease in density or temperature or both
D)an increase in pressure requires a decrease in both density and temperature

Question 65

At the equator,the altitude of the 500 mb level is always larger than it is at the north pole because

A)the air usually has higher pressure at the equator
B)the air is always denser at the equator
C)the air is always warmer at the equator

Question 66

A geostrophic wind:

A)follows the pressure gradient force.
B)curves around to flow toward its original source.
C)flows perpendicular to the pressure gradient force.
D)is usually not affected by the Coriolis force.

Question 67

Gradient flow:

A)undergoes constant acceleration.
B)is a geostrophic wind.
C)occurs when wind flows parallel to the pressure gradient.
D)maintains the same direction.

Question 68

Barometer readings must be corrected for the effect of elevation because

A)lower elevations are usually colder than higher elevations
B)the acceleration of gravity is smaller at higher latitudes
C)vertical pressure changes are much larger than horizontal pressure changes
D)vertical pressure changes are much smaller than horizontal pressure changes

Question 69

In the figure,winds at the 500-mb level are

A)stronger near the Atlantic coast because the height contours are farther apart
B)weaker near the Atlantic coast because the height contours are farther apart
C)weaker near the Atlantic coast because the height contours are closer together
D)stronger near the Atlantic coast because the height contours are closer together

Question 70

Barometric pressure is often expressed as the _______ of a column of mercury in a barometer.

A)weight
B)density
C)temperature
D)height

Question 71

What does a 500 mb height map tell us about pressure,pressure gradient force,and wind?

Question 72

Which of the following is true about the geostrophic flow?

A)Pressure gradient force equals the Coriolis force.
B)It occurs only in the upper atmosphere.
C)Friction is not present.
D)all of the above

Question 73

An increase in wind speed is caused by an increase in this force,the ________.

Question 74

Is the motion of water spiraling into a bathtub drain influenced by the Coriolis force? Explain.

Question 75

Geostrophic flow:

A)undergoes a constant, or near constant, acceleration.
B)occurs when the pressure gradient force equals the Coriolis force.
C)occurs in atmospheric levels with substantial friction.
D)can occur in all levels of the atmosphere.

Question 76

This occurs around a high-pressure system when the Coriolis effect exceeds the pressure gradient force,causing air to turn:

A)subgeostrophic flow.
B)geostrophic flow.
C)supergeostrophic flow.
D)non-gradient flow.

Question 77

According to the equation of state p = RT,

A)an increase in density requires an increase in pressure or a decrease in temperature or both
B)an increase in density requires an increase in both pressure and temperature
C)an increase in density requires a decrease in pressure but not temperature
D)an increase in density requires a decrease in both pressure and temperature

Question 78

Increasing the humidity

A)increases the density because humid air feels 'thick'
B)increases the density because winds are usually weaker when the humidity is high
C)decreases the density because humid air usually sinks
D)decreases the density because the molecular weight of water is less than the molecular weight of the other major constituents of air

Question 79

According to the equation of state p = RT,if pressure remained constant and the temperature increased

A)the density would have to remain constant
B)the density would have to increase
C)the density would have to decrease
D)the constant R would have to change

Question 80

In the upper atmosphere,

A)horizontal pressure gradients are smaller than vertical pressure gradients
B)horizontal pressure gradients are the same as vertical pressure gradients
C)horizontal pressure gradients are larger than vertical pressure gradients
D)pressure is relative constant