Deck 6: Air Pressure and Winds

Question 1

If the earth were not rotating,

A)all winds would cease.
B)Earth would lose its atmosphere.
C)air would move directly from high to low pressure.
D)atmospheric pressure would decrease.

Answer 1

C

Question 2

The maximum pressure range of the atmosphere is between:

A)660-1335 millibars.
B)720-1335 millibars.
C)870-1085 millibars.
D)975-1035 millibars.
E)0-1000 millibars.

Answer 2

C

Question 3

Which of the following would involve the greatest change in atmospheric pressure?

A)horizontal airplane flight of 200 miles
B)balloon ascent from sea level to 3 miles
C)travel from center of a low pressure system to center of a high pressure system
D)difference between the highest and lowest recorded pressure at any one weather station

Answer 3

B

Question 4

What is a limitation of an altimeter that pilots must account for?

A)It has a low battery life at high altitudes.
B)Its readings may be too low or too high if the temperature varies from the expected.
C)Corrections are not as accurate at low levels as they are at higher levels.
D)They can't ever be used to determine altitude - only pressure.

Question 5

The term pressure gradient refers to:

A)change in pressure at a weather station over 3 hours time.
B)change in pressure from the tropopause to sea level.
C)change in pressure along a horizontal surface.
D)highest and lowest pressures at a station.
E)change in wind speed at the same station.

Question 6

Who invented the mercury barometer?

A)Galileo
B)Bergeron
C)Toricelli
D)Celsius

Question 7

Divergence in the atmosphere is best defined as:

A)air moving out of an area.
B)air piling up in one area.
C)warm air moving away from cold air.
D)clouds separating and dissipating.

Question 8

It the Earth were not rotating:

A)all air would move in one direction only.
B)friction would be eliminated.
C)the Earth would lose its atmosphere.
D)air would move directly from high pressure to low pressure.

Question 9

What units of pressure are used when air pressure is reported to the public in the United States?

A)millibars
B)inches of mercury
C)kilopascals
D)Newtons

Question 10

If air pressure is reduced by one-half for every five-kilometer increase in altitude,what would be the air pressure at a height of 25 kilometers as a fraction of sea-level air pressure?

A)1/32
B)1/8
C)1/64
D)1/4
E)1/16

Question 11

Air pressure drops ________ with altitude in a column of cold (dense)air than in a column of warm (less dense)air.

A)equally
B)more slowly
C)less significantly
D)more rapidly

Question 12

If the National Weather Service converted to the metric system,they would most likely report air pressure in which units?

A)pascals
B)kilopascals
C)millibars
D)inches of mercury

Question 13

The primary force which causes all winds is:

A)centrifugal force.
B)Coriolis effect.
C)inertia force.
D)geostrophic force.
E)pressure gradient force.

Question 14

An altimeter is an adaptation of the:

A)aneroid barometer.
B)millibar.
C)mercurial barometer.
D)anemometer.

Question 15

The addition of water vapor will cause the density of air to:

A)decrease.
B)increase.
C)stay the same.
D)vary widely in a horizontal direction.

Question 16

What is the average sea level pressure in the United States?

A)29.92 mb
B)766 mb
C)1000 mb
D)1013 mb

Question 17

The best explanation for the cause of atmospheric pressure is:

A)weight of the air above.
B)air temperature.
C)air compression.
D)wind force.
E)air density.

Question 18

Which of the following has the smallest impact on winds?

A)pressure gradient force
B)Coriolis effect
C)humidity
D)friction

Question 19

Neglecting friction,the speed and direction of the horizontal wind are determined by:

A)temperature and humidity.
B)viscosity and turbulence.
C)pressure gradient and Coriolis.
D)gravity and humidity.
E)only gravity.

Question 20

The National Weather Service measures air pressure in the unit of a millibar,which is equivalent to:

A)10 Newtons per square meter.
B)100 Newtons per square meter.
C)500 Newtons per square meter.
D)1000 Newtons per square meter.

Question 21

The Coriolis effect influences the wind by:

A)decreasing the wind speed.
B)changing the direction of the wind.
C)increasing the wind speed.
D)starting the air motion.

Question 22

The Coriolis effect occurs because of this characteristic of the earth:

A)its magnetic field.
B)its atmosphere.
C)its rotation.
D)its dense core.

Question 23

The overall strength of a circulation system is determined by:

A)the latitude.
B)no one factor is more important than the others.
C)friction between the ground and the air.
D)its pressure gradient.
E)air temperature.

Question 24

The pressure gradient force is directed from higher to lower pressure:

A)only in the Northern Hemisphere.
B)only at the poles.
C)everywhere except the equator.
D)only at the equator.
E)everywhere.

Question 25

Horizontal variations in air pressure cause a force which makes the wind blow.These pressure variations are caused by:

A)warm temperatures in the stratosphere.
B)greenhouse effect.
C)non-circular shape of Earth.
D)Earth's rotation.
E)uneven heating of the earth's surface.

Question 26

Upper air winds:

A)are greatly influenced by friction.
B)are generally faster than surface winds.
C)are unaffected by the Coriolis force.
D)do not influence surface weather.

Question 27

A plane takes off from City A headed for City B,located directly to the north.The pilot flies directly north,but arrives at a city some distance to the west of City B.What can be said of the airplane?

A)It probably has a broken compass.
B)It was blown off course by upper atmospheric winds.
C)It was flying in the Northern Hemisphere.
D)It was flying in the Southern Hemisphere.

Question 28

Refer to the map above.Which of the following areas has the highest pressure gradient?

A)Southwestern Texas
B)Southern California
C)Southern Florida
D)Lake Michigan/Southeastern Wisconsin

Question 29

What do isobars represent on a map?

A)lines connecting points of equal air pressure
B)the lowest pressures on the map
C)the highest pressures on the map
D)areas of convergence in the upper atmosphere

Question 30

Refer to the map above.What best explains the high wind speeds found immediately around the low pressure center (L)?

A)the dramatically lower temperatures in the area
B)increased friction
C)the comparatively high pressure gradient in the area
D)the higher humidity associated with low pressures

Question 31

Refer to the map above.The black lines on the map are called ________ and they represent lines of equal ________.

A)isobars;pressure
B)isotherms;temperature
C)isotherms;pressure
D)isodrosotherms;humidity

Question 32

With respect to the Coriolis force,which association is NOT correct?

A)Northern Hemisphere - deflection to the right of the wind's original direction
B)North Pole - strongest deflection
C)Low wind speeds - strongest deflection
D)deflection - always at a 90 degree angle to the direction of air flow

Question 33

The Coriolis effect is important only for motions that:

A)do not involve a pressure gradient.
B)cover short distances.
C)are slow.
D)are near the earth's surface.
E)cover long distances.

Question 34

A steep pressure gradient:

A)produces light winds.
B)produces strong winds.
C)is only possible in the tropics.
D)would be depicted by widely spaced isobars.

Question 35

Which of these factors influence the magnitude of the Coriolis force?

A)wind direction
B)latitude
C)wind speed
D)both wind speed and latitude

Question 36

Meteorologists convert all atmospheric pressure data to the equivalent sea-level air pressure in order to:

A)make sure all of the data is measured in millibars.
B)correct for the effects of the Coriolis force.
C)remove the effects of elevation.
D)unify the pressure gradient force at all locations.

Question 37

Circulations in the earth's atmosphere are fundamentally caused by:

A)heating of the ozone layer.
B)frontal storm systems.
C)ocean currents.
D)gravity.
E)temperature contrasts between different locations.

Question 38

As seen by an observer on Earth,the Coriolis effect is an illusion;no deflection can actually be measured.

A)false
B)false,but only near the poles
C)true,but only near the poles
D)true

Question 39

Refer to the map above.Which of the following areas is most likely to be experiencing rain or other significant weather?

A)the Great Lakes region
B)the Southwest
C)Western Canada
D)the Pacific Northeast

Question 40

The force that generates wind is:

A)pressure gradient force.
B)friction.
C)gravity.
D)Coriolis force.
E)centrifugal force.

Question 41

High air pressure zones are usually associated with:

A)converging winds.
B)stormy weather.
C)ascending currents.
D)relatively dry conditions.

Question 42

The wind speed normally increases with height in the layer of air next to the ground.This illustrates the fact that:

A)friction is present only close to the ground.
B)the lowest part of the atmosphere is turbulent.
C)temperature decreases with height.
D)pressure decreases with height.
E)density decreases with height.

Question 43

Identify the choice above that represents low pressure center.

A)graph a
B)graph b
C)graph c
D)both a and b
E)none of these

Question 44

You would expect vertical airflow in an anticyclone to result in:

A)convergence aloft.
B)divergence aloft.
C)convergence at the surface.
D)clouds.

Question 45

When geostrophic conditions exist in the atmosphere,the net force on the moving air is:

A)called a centrifugal force.
B)zero.
C)large when the wind speed is slow.
D)called a centripetal force.
E)large since the wind speed is fast.

Question 46

Which option above is generally associated with "fair" weather?

A)graph a
B)graph b
C)graph c
D)both a and b
E)none of these

Question 47

The geostrophic wind concept is most like the real atmospheric winds:

A)in an anticyclone.
B)near the surface.
C)near the equator.
D)in a cyclone.
E)at high altitudes.

Question 48

What does Buys Ballot's Law state?

A)If you stand with your back to the wind,there is low pressure on your left and high pressure on the right.
B)If you stand with your back to the wind,there is low pressure on your right and high pressure on your right.
C)If you stand with your back to the wind,there is low pressure directly in front of you.
D)If you stand facing into the wind and you are facing north,the wind is geostrophic.

Question 49

In the southern hemisphere,anticyclonic winds flow:

A)outward and clockwise.
B)inward and clockwise.
C)outward and counterclockwise.
D)inward and counterclockwise.

Question 50

A cyclone is generally defined by meteorologists as:

A)an area of high pressure.
B)an area of low pressure.
C)an intense,violent storm.
D)a tornado on the ground.

Question 51

According to researchers at University of Colorado Denver,what was the most important factor in the high number of home runs at Coors Field?

A)The predominant summer wind direction is in favor of the batter.
B)The thin air allows the ball to fly further.
C)The lower temperatures help athletes not to overheat.
D)The thin air allows the batter to obtain better auditory cues about the pitch.

Question 52

Identify the choice above that represents low pressure center in the Northern Hemisphere.

A)graph a
B)graph b
C)graph c
D)both a and b
E)none of these

Question 53

You would expect vertical airflow in a cyclone to result in:

A)divergence aloft.
B)convergence aloft.
C)divergence at the surface.
D)no cloud development.

Question 54

The geostrophic wind describes a situation where the air moves:

A)very fast.
B)upward.
C)from pole to equator.
D)very slowly.
E)parallel to the isobars.

Question 55

In the northern hemisphere,cyclonic winds flow:

A)inward and counterclockwise.
B)inward and clockwise.
C)outward and clockwise.
D)outward and counterclockwise.

Question 56

Instead of the air flowing straight out of a high pressure system,it spirals out in a clockwise direction.The cause of the clockwise spiraling motion is:

A)pressure gradient force.
B)centripetal force.
C)Coriolis force.
D)inertia.
E)turbulence.

Question 57

Anticyclonic flow is:

A)associated with low pressure.
B)associated with storms and rainy conditions.
C)associated with air converging at the surface.
D)in the opposite direction of Earth's rotation.

Question 58

The effect of friction on the wind alters its:

A)viscosity.
B)heat content.
C)density.
D)speed and direction.
E)speed only.

Question 59

Identify the choice above that represents high pressure center in the Southern Hemisphere.

A)graph a
B)graph b
C)graph c
D)both a and b
E)none of these

Question 60

Why do surface winds cross the isobars at an angle toward lower pressure (instead of blowing parallel to the isobars)?

A)Friction reduces the speed so Coriolis is weakened.
B)Pressure gradient becomes stronger near the surface.
C)It results from divergence in the surface wind.
D)Coriolis strengthens by combining with friction.
E)Convergence of upper level winds causes this.

Question 61

Standard sea level atmospheric pressure in the U.S.is approximately 29.92 inches of mercury.

Question 62

If "fair" weather is approaching,the pressure tendency would probably be:

A)falling.
B)steady.
C)rising.
D)Pressure tendency has nothing to do with forecasting good or bad weather.

Question 63

The country that produces the greatest amount of wind energy is:

A)Germany.
B)the United States.
C)China.
D)Italy.

Question 64

If you're cooking pasta for your big romantic date,you'd better allow a few extra minutes for it to cook once it comes to a boil if you're at a high altitude.

Question 65

Cyclonic airflow is characterized by:

A)divergence aloft and convergence at the surface.
B)convergence aloft and divergence at the surface.
C)divergence both at the surface and aloft.
D)convergence both at the surface and aloft.

Question 66

Consider the pressure data recorded at Albany International Airport on September 27,2011.What statement can you make about the weather Albany is likely to experience soon?

A)Winds at Albany will likely be calming down.
B)Albany is likely to experience rain or storms soon.
C)Albany should have clearing skies.
D)Albany will definitely have a tornado within the hour.

Question 67

When air moves from the ocean onto land:

A)curved flow is initiated.
B)converging winds and ascending air result over the land.
C)divergence and subsidence occur over the land.
D)the winds tend to increase their speed.

Question 68

The mercury barometer is larger and less portable than an aneroid barometer.

Question 69

During times of warmer temperature (summer),the atmospheric pressure is usually less.

Question 70

The inventor of the mercury barometer was Sir Francis Bacon.

Question 71

Winds from the north are associated with:

A)0 degrees.
B)90 degrees.
C)180 degrees.
D)235 degrees.

Question 72

At a given pressure value,the air density will be highest when the temperature is coldest.

Question 73

Weather reports of wind express only the horizontal motion of the air.The vertical component of the air motion is usually:

A)very much slower.
B)much faster.
C)only slightly slower.
D)about the same.
E)No general statement can be made.

Question 74

A wind rose is used to identify:

A)prevailing wind direction.
B)wind direction at a given moment.
C)locations with similar wind directions during a storm.
D)the approximate degree of Coriolis deflection at a specific location.

Question 75

Air pressure is exerted in all directions.

Question 76

The primary cause of wind is not atmospheric pressure but atmospheric pressure differences.

Question 77

Of the various elements of weather and climate,changes in air pressure are probably the most easily perceived by people.

Question 78

An aerovane is commonly used to measure:

A)wind direction only.
B)wind speed only.
C)both wind direction and wind speed.
D)pressure gradient force only.

Question 79

If the pressure were 1020 millibars,it would be considered higher than average.

Question 80

Under typical atmospheric conditions,gas molecules behave like very elastic balls.