Deck 18: Air Pressure and Wind

Question 1

Upper air winds _____ .

A) are unaffected by the Coriolis force
B) are greatly influenced by friction
C) are generally faster than surface winds
D) both A and B

Answer 1

are generally faster than surface winds

Question 2

The force that generates wind is _____ .

A) Coriolis force
B) gravity force
C) pressure gradient force
D) centrifugal force

Answer 2

pressure gradient force

Question 3

Isobars are lines on a weather map representing what?

A) lines showing equal density of bars
B) lines of equivalent air speed
C) lines of equal elevation for the tropopause
D) lines of equal air pressure

Answer 3

lines of equal air pressure

Question 4

Ground friction does not_____ .

A) involve uneven topography
B) have a slowing effect on winds
C) influence upper level winds
D) cause winds to cross the isobars

Question 5

In the Southern Hemisphere, the winds associated with a low pressure system blow _____ .

A) counterclockwise and outward from the center
B) clockwise and toward the center
C) counterclockwise and toward the center
D) clockwise and outward from the center

Question 6

Closely spaced isobars indicate _____ .

A) low pressure gradient and weak gusty winds
B) high pressure gradient and high winds
C) high pressure gradient and likely gusty winds
D) geostrophic conditions

Question 7

Widely spaced isobars often indicate _____ .

A) variable winds
B) light winds
C) cyclonic winds
D) high winds

Question 8

The mercurial barometer was invented by_____ .

A) Torricelli
B) Newton
C) Watt
D) Galileo

Question 9

You are watching the local weatherman on TV. You live in mid- latitudes in North America, and the weatherman says the winds aloft are blowing toward the northwest. Is this reasonable?

A) It is not likely, as Northern Hemisphere winds aloft always move from west to east because of the Coriolis force.
B) Yes, northwest winds are common at mid latitudes in North America.
C) Yes, southeast winds are common at mid latitudes in North America.
D) No, mid- latitude winds always move from east to west because of the Coriolis force.

Question 10

Low air pressure systems are usually associated with _____ .

A) converging air, precipitation, and high pressure aloft
B) descending air and low pressure aloft
C) diverging surface winds and low pressure aloft
D) clear weather

Question 11

Where is the Coriolis force greatest?

A) anywhere air moves north or south
B) low latitude
C) intermediate latitudes
D) high latitude

Question 12

You might wonder why a millibar isn't exactly 1/1000^th of an atmosphere. The unit is actually related to the old CGS units because atmospheric pressure is close to this unit. In CGS units 1 bar = 1000 dynes/cm². Pressure is often incorrectly reported as kg/cm², which is neither a legitimate pressure unit nor a standard SI unit pressure is force/unit area, and kg are a mass unit, and SI units never mix kg and cm.. So let's straighten out your friends on these units. Standard air pressure in this incorrect unit is 1.034 kg/cm². The weight of a kg at the earth's surface is 980,000 dynes. So what is standard air pressure in millibars?

A) 1013 mb
B) 1143 mb
C) 750 mb
D) 890 mb

Question 13

Standard sea level pressure in inches of mercury is _____

A) 28.70 inches
B) 7.52 inches
C) 14.70 inches
D) 29.92 inches

Question 14

The Coriolis effect influences _____ .

A) only wind speed
B) only wind direction
C) both wind speed and wind direction
D) neither wind speed nor wind direction

Question 15

Inches of mercury is something that would only be used in America. Elsewhere in the world, the mercury height would be in millimeters, or about 760mm 76cm.. Mercury has a density of about 13.56 g/cm³, or in other words, each cm of mercury weighs about 13,300 dynes. So 760mm of mercury weighs 1,013,000 dynes. 1 mb is 1 dyne/cm², so what is the air pressure in mb?

A) 760 mb
B) 1013 mb
C) 1,000,000 mb
D) 1.013 mb

Question 16

A weather system is moving from west to east. You look at a weather map and see that you are in an area of closely spaced isobars with the center just to your east, but the spacing of the isobars increases to the west of you. What would you forecast for wind conditions?

A) Winds will increase.
B) Winds will decrease.
C) Winds will stay the same.
D) Winds will increase then decrease.

Question 17

In a mercurial barometer increased air pressure will make the mercury level_____ .

A) stay the same
B) fluctuate
C) go up
D) go down

Question 18

Which of these instruments is not used to measure air pressure?

A) anemometer
B) mercurial barometer
C) aneroid barometer
D) barograph

Question 19

A steep pressure gradient_____ .

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

Question 20

An altimeter is an adaptation of the_____ .

A) barograph
B) aneroid barometer
C) mercurial barometer
D) anemometer

Question 21

In the Northern Hemisphere, the winds associated with a low pressure system cyclone. blow_____ .

A) clockwise and toward the center
B) clockwise and outward from the center
C) counterclockwise and toward the center
D) counterclockwise and outward from the center

Question 22

A Santa Ana or Chinook or Foehn. wind is a _____ .

A) very dry, warm wind flowing down a mountain slope
B) cold, damp wind blowing off a snow field
C) wind that is common to the world's deserts
D) wind associated with a blizzard

Question 23

Consider the below image: What would you expect to happen in terms of air flows wind.?

A) They will flow towards the L horizontally.
B) They will spin downward and dissipate.
C) They will flow vertically upward from the L.
D) They will flow away from the L horizontally.

Question 24

When are upper air winds fastest?

A) in summer
B) in winter
C) whenever the temperature gradient is weak
D) These winds maintain roughly the same speeds throughout the year.

Question 25

Why do storm systems move from west to east in mid latitudes of the Northern Hemisphere?

A) The storms are steered by approximately west to east winds aloft that are approximately geostrophic winds produced by Coriolis forces.
B) The prevailing wind is from the east, and the storm systems move toward the surface flow.
C) The prevailing wind is from the west.
D) The continents break up air flow that would normally be south to north and the Coriolis force turns the storms to the right, or toward the east.

Question 26

If stormy weather were approaching, the pressure tendency would probably be_____ .

A) steady
B) falling
C) rising
D) none of these

Question 27

High air pressure systems are usually associated with _____ .

A) diverging winds
B) clear weather
C) descending air
D) all of these

Question 28

Most of the United States is situated in which zone of prevailing winds?

A) westerlies
B) trade winds
C) subpolar easterlies
D) doldrums

Question 29

Which state might you expect to have the most variable wind direction patterns? For example, sometimes wind coming from the west and sometimes from the east, indicating proximity to a directional change zone.

A) Kansas
B) Florida
C) Ohio
D) Colorado

Question 30

Tropical cyclones produce the most intense low- pressure systems on earth. To develop and maintain this low pressure, what must happen aloft in this type of storm?

A) The storm must push the tropopause far into the stratosphere to maintain the low pressure.
B) Rain must fall to force thunderstorms to collapse to keep the air circulation going.
C) A strong divergent flow outflow. aloft must keep up with, or exceed, the inflow near the surface.
D) A strong jet stream flow must be present to maintain the inward flow.

Question 31

Fast moving currents of air found near the top of the troposphere are called_____ .

A) El Niño
B) mesocyclones
C) jet streams
D) chinooks

Question 32

Another name for the area low pressure in the equatorial region is the_____ .

A) horse latitudes
B) westerlies
C) subpolar easterlies
D) doldrums

Question 33

The subpolar low polar front. is _____ .

A) a zone where the trade winds meet
B) the forward edge of the Antarctic ice cap
C) the boundary between frozen and liquid
D) a zone where the polar easterlies and the westerlies converge

Question 34

You are on a boat in a fiord in Glacier Bay, Alaska. It is a clear sunny day with temperatures near 20°C with no wind. Within 5 minutes the sky is still clear but the wind is blowing at 30 knots down valley, the sea is filled with whitecaps, and the temperature drops to 5°C. What just happened?

A) A storm front must have passed.
B) You experienced an afternoon sea breeze, blowing cold air off the ocean.
C) You experienced a valley wind, caused by cold air spilling off an ice cap down the valley.
D) You experienced a Chinook wind.

Question 35

Tropical cyclones aka hurricanes in the Atlantic. are intense low- pressure systems characterized by heavy rain and high winds. When a tropical cyclone passes an area, however, there are generally several days of clear, dry weather. Why might this occur?

A) The cyclone has sucked up all the moist air around it, leaving dry air behind.
B) The spiral arms of the hurricane are storm fronts, and each carries descending air behind it.
C) The hurricane carries a cold front with it, which carries dry air.
D) The cyclone must have an outflow aloft, which feeds descending air surrounding the storm.

Question 36

In the Northern Hemisphere, winds associated with a high pressure system blow_____ .

A) clockwise and outward from the center
B) clockwise and toward the center
C) counterclockwise and toward the center
D) counterclockwise and outward from the center

Question 37

The Sahara and Australian deserts among others. are associated with the_____ .

A) subtropical high
B) subpolar low
C) polar high
D) equatorial low

Question 38

If "fair" weather were approaching, the pressure tendency would probably be _____ .

A) rising
B) steady
C) falling
D) none of these

Question 39

This pressure zone is associated with abundant precipitation and warm temperatures.

A) polar high
B) subtropical high
C) subpolar low
D) equatorial low

Question 40

Asia has an intense monsoon, but North America also experiences a low- intensity monsoon. What causes monsoons?

A) The horse latitude high pressure system breaks down in summer, leading to monsoon moisture in desert locations like southwestern North America and India.
B) The oceans warm faster than the continents during the summer and spawn cyclonic storms that move toward the continents.
C) Heating of the polar regions in summer due to long days causes air to flow toward the poles in summer, drawing moisture from warm ocean dominated air masses.
D) The heating of the continent during the summer produces a persistent low pressure over the continent that draws warm moist air masses from adjacent oceans.

Question 41

Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern.

A) subtropical high
B) equatorial low
C) trade winds
D) polar front

Question 42

Why is the Santa Ana wind a danger signal in southern California?

A) It is a warm, dry wind that can quickly dry out brushlands and spread fires.
B) It is a warm, humid wind from Mexico that signals El Niño conditions and high potential for flooding.
C) It drives people crazy with the howling winds, so crime goes up.
D) It is a cold, dry winter wind that brings danger of hypothermia to people like the homeless living on the streets.

Question 43

Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern.

A) jet stream
B) friction
C) Coriolis effect
D) pressure gradient force

Question 44

What is the Southern Oscillation?

A) the 10- year cycle in winter storm activity in the temperate zone of the Southern Hemisphere
B) the intermittent switch from El Niño to La Niña conditions in the equatorial Pacific
C) the periodic intense cyclonic storms from Antarctica
D) the weather pattern that changes tropical cyclone activity in the southern ocean

Question 45

A sea breeze usually originates during the _____ .

A) evening and flows toward the land
B) day and flows toward the water
C) evening and flows toward the water
D) day and flows toward the land

Question 46

When someone says we have a southeast wind, what direction would you look to face into the wind?

A) east
B) west
C) northwest
D) southeast

Question 47

The Amargosa Valley in eastern California desert often experiences a cold evening wind that blows downvalley. Which of the following might explain this phenomenon?

A) Moist Pacific air rising over the Sierra Nevada Mountains produces mountain precipitation, and as this air spills off the eastern escarpment, it forms the valley wind.
B) Night time cooling upvalley produces a cold, unstable air mass that is funneled down the valley to produce a valley wind.
C) It is a nighttime land breeze and there should be an accompanying daytime seabreeze up valley.
D) Daytime heating causes a local low pressure that causes air to rush in by evening.

Question 48

Which of the following devices measures both wind direction and speed?

A) wind sock
B) anemometer
C) wind vane
D) None of these can measure both wind speed and direction.

Question 49

Consider the below diagram: What does the diagram show?

A) More commonly the wind blows from the Northwest.
B) The wind often blows to the North, but is very gentle when it does so.
C) The dominant wind direction is from the Southeast.
D) The wind is always blowing in the same direction in Australia.

Question 50

Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern.

A) trade winds
B) polar easterlies
C) westerlies
D) Chinook

Question 51

If you live in southwestern North America and are experiencing drought conditions, what do you hope will happen?

A) The temperatures will decrease in the eastern equatorial Pacific.
B) A La Niña period will begin.
C) An El Niño period will begin.
D) Conditions will return to a normal, with neither La Niña nor El Niño.

Question 52

The most precise instrument for measuring wind speed is a _____ .

A) wind vane
B) cup anemometer
C) wet bulb/dry bulb thermometer
D) wind sock

Question 53

A land breeze usually originates during the _____ .

A) evening and flows toward the land
B) evening and flows toward the water
C) day and flows toward the land
D) day and flows toward the water

Question 54

If the barometer indicated 1020 millibars, air pressure would be considered _____ .

A) medium
B) low
C) high
D) normal

Question 55

Where was the El Niño phenomena first recognized?

A) Peru and Ecuador
B) Central America
C) the Caribbean region
D) California

Question 56

Standard sea level air pressure is_____ millibars.

A) 1006
B) 1028
C) 1000
D) 1013

Question 57

Standard sea level air pressure is_____ inches of mercury.

A) 28.38
B) 29.01
C) 29.92
D) 29.15

Question 58

Under normal conditions the predominant winds in the equator region go from and there is _____ water off the coast of South America.

A) west to east; cool
B) west to east; warm
C) east to west; cool
D) east to west; warm

Question 59

A_____ breeze originates over land because the pressure on land is at night over land than over the water.

A) land; lower
B) sea; lower
C) land; higher
D) sea; higher

Question 60

If you live on the east coast of Florida or the Gulf Coast, why might you hope for an El Niño year?

A) It will decrease the chances of heavy summer thunderstorms and floods.
B) It will produce a warmer summer, but with less rain than normal.
C) It will decrease the probability of tropical cyclones.
D) It will bring clear, cool summer conditions, albeit dry.

Question 61

Low pressure systems are usually associated with _____ weather.

A) stormy
B) clear
C) cold
D) warm

Question 62

A southwest wind blows toward the_____ .

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

Question 63

A surface low pressure system will not strengthen unless there is _____ pressure aloft.

A) low
B) high
C) no
D) medium

Question 64

The Coriolis effect is strongest at the_____ .

A) equator
B) Tropic of Capricorn
C) Tropic of Cancer
D) poles

Question 65

An isobar is a line connecting places of equal _____ .

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

Question 66

_____ invented the mercurial barometer.

A) Torricelli
B) Mercator
C) Richter
D) Curie

Question 67

Most deserts are associated with the_____ .

A) subtropical low
B) polar high
C) subtropical high
D) polar low

Question 68

Closely spaced isobars indicate _____ wind speeds.

A) no
B) medium
C) high
D) low

Question 69

In the Northern Hemisphere, winds blow_____ and _____ from the center of anticyclones.

A) counter- clockwise, outward
B) counter- clockwise, inward
C) clockwise, outward
D) clockwise; inward

Question 70

The ultimate cause of a sea breeze is the_____ heating of land and water.

A) equal
B) winter
C) unequal
D) summer

Question 71

High pressure systems are usually associated with_____ weather.

A) stormy
B) clear
C) cold
D) warm

Question 72

The _____ is the main driving force behind wind.

A) influence of friction
B) pressure gradient force
C) Coriolis effect
D) geostrophic force

Question 73

The Coriolis effect influences _____ .

A) neither wind speed nor wind direction
B) wind speed but not wind direction
C) wind direction but not wind speed
D) both wind direction and wind speed

Question 74

Most of the people living in the United States are under the influence of the wind belt known as the _____ .

A) southeast trade winds
B) polar easterlies
C) westerlies
D) northeast trade winds

Question 75

Cyclones are usually associated with_____ weather.

A) stormy
B) clear
C) cold
D) warm

Question 76

If Earth were_____ , there would be no Coriolis force.

A) cooler
B) not rotating
C) more humid
D) closer to the sun

Question 77

Anticyclones characteristically have winds blowing _____ from their centers.

A) outward
B) upward
C) downward
D) inward

Question 78

Horizontal movement of air is called _____ .

A) jet stream
B) the Coriolis effect
C) pressure gradient
D) wind

Question 79

Upper air winds are generally _____ than the surface winds directly below.

A) faster
B) fluctuating in comparison to
C) about the same speed as
D) slower

Question 80

The region where the trade winds meet is also called the _____ .

A) doldrums
B) dog latitudes
C) polar easterlies
D) Arctic front