Deck 10: Midlatitude Cyclones

Question 1

According to the polar front theory,

A)midlatitude cyclones create fronts in the polar regions.
B)midlatitude cyclones form in front of several large air masses.
C)midlatitude cyclones form along a boundary separating polar air and warmer air to the south.
D)midlatitude cyclones form along a boundary separating frigid Arctic air with slightly colder polar air.

Answer 1

C

Question 2

According to the polar front theory,the stationary front

A)will change into cold and warm fronts.
B)will change into a cold front.
C)will change into a warm front.
D)will persist until the cyclone dissipates.

Answer 2

A

Question 3

According to the polar front theory,cyclogenesis begins when

A)cold air begins to rise above the warmer air.
B)an occluded front is formed.
C)cold air begins to advance northward and warm air begins to advance southward.
D)cold air begins to advance southward and warm air begins to advance northward.

Answer 3

D

Question 4

________ are the "mixmasters" of the atmosphere.

A)Mid-latitude cyclones
B)Tornadoes
C)Gust fronts
D)Cold fronts

Question 5

The development of a Mid-latitude Cyclone is called

A)Frontolysis.
B)Frontogenesis.
C)Cyclogenesis.
D)Mid-latitude bombs.

Question 6

The warm front associated with a mid-latitude cyclone

A)causes a shorter duration of precipitation than does the cold front.
B)typically forms stratiform clouds.
C)is most likely to have intense episodes of precipitation.
D)often breaks off from the low-pressure area and heads south.

Question 7

Mid-latitude cyclones

A)typically last a month or more.
B)do not really have the characteristics and behavior ascribed to them by the theory of cyclogenesis.
C)rarely travel more than a few hundred kilometers.
D)often bring substantial changes in wind and temperature.

Question 8

According to the polar front theory,midlatitude cyclones

A)are born in the tropics.
B)form over large oceanic areas with uniform surface temperature.
C)last only one to three days.
D)cover large portions of a continent and bring precipitation to wide areas.

Question 9

In a mature mid-latitude cyclone

A)the fronts have occluded.
B)stratiform clouds are located near the cold front.
C)overall movement of the storm continues west.
D)clear skies exist between the warm front and the cold front.

Question 10

The polar front theory is remarkable because

A)it demonstrated the value of high-powered computers.
B)it fully explained the formation, growth, and dissipation of tropical cyclones.
C)the developers had to invent new mathematical methods in order to describe it.
D)it was developed with far less observational data than we have today.

Question 11

When was it discovered that storms move from place to place?

A)1600s
B)1700s
C)1800s
D)1900s

Question 12

Who was the first individual to figure out that storms in the mid-latitudes probably moved from place to place,and weren't stationary?

A)Carl Rossby
B)Benjamin Franklin
C)William Bjerknes
D)Jacob Bjerknes

Question 13

Vilhelm Bjerknes

A)helped develop a modern theory of the formation, growth, and dissipation of mid-latitude cyclones.
B)helped discredit the Norwegian cyclone model.
C)opposed polar front theory.
D)focused on tropical storm development.

Question 14

The area between the cold front and warm front in a Mid-latitude Cyclone is called the

A)warm sector.
B)storm sector.
C)kill sector.
D)chill sector.

Question 15

With reference to mid-latitude cyclones in the Northern Hemisphere

A)there are more and weaker cyclones than in the Southern Hemisphere.
B)there are more and stronger cyclones than in the Southern Hemisphere.
C)there are fewer and weaker cyclones than in the Southern Hemisphere.
D)there are fewer and stronger cyclones than in the Southern Hemisphere.

Question 16

Which of the following more accurately describes the precipitation patterns of a Mature Cyclone?

A)light precipitation
B)wide band of precipitation
C)intense precipitation
D)precipitation always in the form of snow

Question 17

Scientists document about ________ mid-latitude cyclones around the world each year.

A)100
B)1,100
C)10,000
D)318

Question 18

Vilhelm Bjerknes

A)helped discredit the Norwegian cyclone model.
B)founded the Norwegian Geophysical Institute.
C)developed the polar front theory in order to explain the occurrence of hurricanes.
D)was a tragic victim of the fighting in World War I.

Question 19

The polar front theory of midlatitude cyclones,developed around a century ago,

A)has long fell into disfavor among meteorologists.
B)has stood the test of time remarkably well.
C)was never accepted by the meteorological community.

Question 20

Midlatitude cyclones

A)are commonly experienced by all people living outside the tropics.
B)are commonly experienced by all people living within the tropics.
C)are rare events confined to the tropics.
D)are rare events confined to the middle latitudes.

Question 21

The warm sector between the warm and cold fronts is generally characterized by

A)southeasterly winds.
B)squall lines immediately to the west of the warm front.
C)clear conditions.
D)declining dew points.

Question 22

________ is credited with discovering that storms move.

Question 23

For a mature mid-latitude cyclone,precipitation is least likely at this point.

A)near the center of the low-pressure center
B)just outside the low-pressure center
C)the eastern edge of the cyclone
D)near the cold front just below the low-pressure center

Question 24

In and during the occlusion process,the mid-latitude cyclone accomplishes its major purpose which is

A)to bring rain to the mid-western United States.
B)to mix air of different temperatures.
C)to cause a massive amount of damage through tornadoes.
D)to usher in heat waves or cold air outbreaks.

Question 25

A mid-latitude cyclone reaches its most intense stage when

A)the storm moves over water.
B)the storm moves over cold air.
C)the storm system undergoes occlusion.
D)the warm sector reaches its maximum strength.

Question 26

In a mid-latitude cyclone,________ clouds form just ahead of the cold front.

Question 27

This is the first step in classical cyclogenesis for a mid-latitude cyclone.

A)a low-pressure system develops
B)warm air starts to flow south
C)a polar front separates masses of warm and cold air
D)a distinct warm front forms

Question 28

The Bergen scientists developed the idea of ________ to explain the formation of mid-latitude cyclones.

Question 29

A "Rossby Wave" is also called a

A)short wave.
B)transitory wave.
C)long wave.
D)meridional wave.

Question 30

This midlatitude cyclone

A)has not yet begun to develop.
B)is beginning the process of cyclogenesis.
C)is in the mature stage.
D)is dissipating.

Question 31

Of the following steps in classical cyclogenesis of a mid-latitude cyclone,this happens last.

A)occlusion occurs
B)a warm front forms
C)a cold front forms
D)a region of low pressure is established

Question 32

Mid-latitude cyclones in the Northern Hemisphere typically travel primarily in this direction.

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

Question 33

This midlatitude cyclone

A)has not yet begun to develop.
B)is beginning the process of cyclogenesis.
C)is in the mature stage.
D)is dissipating.

Question 34

Describe the weather changes that would likely occur as a mid-latitude cyclone passes over a given location,beginning with the approach of the warm front.

Question 35

During cyclogenesis,cloud formation will be least intense here.

A)at the center of the low-pressure area
B)along the boundary of the cold front
C)just outside the center of the low-pressure area
D)along the boundary of the warm front

Question 36

The fronts in a wave cyclone often take on what type of shape?

A)inverted V-shape
B)linear
C)L-shape
D)none of these

Question 37

The Bergen scientists noticed that cyclogenesis commonly initiated at all of the following places,except

A)in the middle of areas with uniform temperatures.
B)near coastal regions.
C)near boundaries between warm and cold ocean currents.
D)where topographical features disrupted normal air flow.

Question 38

The passage of a mid-latitude cyclone over Saint Louis would probably begin with this.

A)cold air and intense precipitation
B)relatively cold and sunny conditions
C)relatively warm and sunny conditions
D)deepening cloud cover with possible light rain showers

Question 39

Which of the following is vorticity relative to the Earth's surface?

A)earth vorticity
B)absolute vorticity
C)relative vorticity
D)astronomical vorticity

Question 40

Discuss the life of a mid-latitude cyclone as described by cyclogenesis.

Question 41

Regarding vorticity,it is true that

A)relative vorticity is always conserved.
B)counterclockwise rotation in the Northern Hemisphere has positive vorticity.
C)Earth vorticity decreases with latitude.
D)vorticity changes in the upper troposphere do not affect surface pressures.

Question 42

This component describes the overall rotation of air.

A)absolute vorticity
B)relative vorticity
C)Earth vorticity
D)Rossby vorticity

Question 43

A surface low-pressure system that results from motions in the upper troposphere is called a ________.

Question 44

The relationship between vorticity and convergence is such that

A)angular momentum is not conserved.
B)changes in vorticity in the upper troposphere can lead to convergence, but not divergence, near the earth's surface.
C)increased convergence requires an increase in absolute vorticity over time.
D)an increase in one value necessarily means a decrease in the other.

Question 45

________ has two components,relative vorticity and Earth vorticity.

Question 46

Define these terms: relative vorticity,Earth vorticity,absolute vorticity.

Question 47

After the development of cyclogenesis theory by the Norwegians,this was the next major development in the expanding knowledge of mid-latitude cyclones.

A)the development of the theory of Rossby waves
B)the discovery of strong winds in the upper troposphere
C)the discovery that storm systems move
D)the development of the First and Second Laws of Thermodynamics

Question 48

Vorticity is a measure of

A)rotation.
B)wave angle.
C)electrical resistance in the atmosphere.
D)the earth's orbital wobble.

Question 49

Rossby waves

A)have troughs that develop behind surface cold fronts.
B)can have up to three troughs for every ridge, and vice versa.
C)have little effect on divergence aloft.
D)have little effect on surface pressure.

Question 50

Which of the following is caused by the localized heating of the air from below?

A)thermal low
B)cold core low
C)dynamic low
D)exchange low

Question 51

Describe how changes in vorticity in the upper troposphere can lead to changes in surface pressure.

Question 52

Earth vorticity

A)is greatest at the Equator.
B)does not affect absolute vorticity.
C)is a function of latitude.
D)is vorticity relative to the earth's surface.

Question 53

Upper level divergence coupled with lower level convergence

A)are the ingredients needed for strong storm systems.
B)cause strong upward vertical motions.
C)have a destabilizing effect on the atmosphere.
D)all of these

Question 54

Dynamic lows result from

A)localized heating of the air from below.
B)localized cooling of air from below.
C)upper-tropospheric motions.
D)lower-tropospheric motions.

Question 55

Which of the following statements is NOT true?

A)Air flow in the upper troposphere can influence surface pressure.
B)Air flow in the lower troposphere can influence surface pressure.
C)Surface cold fronts do not influence the upper troposphere.
D)Surface warm fronts do influence the upper troposphere.

Question 56

This occurs when air stretches out horizontally due to variations in wind direction: ________.

Question 57

Explain the discovery of the jet stream in the middle and upper troposphere.

Question 58

The difference between "mid-latitude" cyclones and "tropical" cyclones is that

A)tropical cyclones can only form over water.
B)mid-latitude cyclones can only form over land.
C)tropical cyclones occur only during the Northern Hemisphere summer.
D)tropical cyclones have only warm air while mid-latitude cyclones have three kinds of air.

Question 59

Which of the following statements is NOT true?

A)Upper-level divergence increases the strength of mid-latitude cyclones.
B)Rossby waves can generate upper-level divergence.
C)Rossby waves can generate upper-level convergence.
D)Upper level divergence causes high pressure at the surface.

Question 60

Which of the following are associated with the formation and intensification of surface mid-latitude cyclones?

A)upper-level convergence and lower-level convergence
B)upper-level convergence and lower-level divergence
C)upper-level divergence and lower-level convergence
D)upper-level divergence and lower-level divergence

Question 61

Temperature advection

A)is not a significant factor in the upper atmosphere.
B)is often detected through examination of the orientation of height contours and isotherms.
C)refers to the vertical movement of warm air.
D)always occurs simultaneously with temperature conduction.

Question 62

An atmosphere where there is no temperature advection is called ________,while an atmosphere with temperature advection is called ________.

A)dormant; active
B)stagnant; mixed
C)barotropic; baroclinic
D)peaceful; stormy

Question 63

Given the implications of the hydrostatic equation,we would expect that

A)pressure be independent of altitude.
B)cold, dense air would have a greater vertical pressure gradient than would warm, light air.
C)differences in temperature on either side of a cold front should not have any significant effect on upper-level pressure.
D)differences in temperature on either side of a warm front should not have any significant effect on upper-level pressure.

Question 64

It is true that

A)the surface level and upper level of the troposphere are two distinct layers.
B)the Bjerknes model of cyclogenesis gives the best explanation for the formation and life of mid-latitude cyclones.
C)upper-level divergence has little impact on the surface.
D)the temperature at the surface can affect air flow at upper levels of the atmosphere.

Question 65

Speed divergence

A)occurs when faster-moving air encounters slower moving air.
B)can occur when contour lines on an upper-level weather map come closer together.
C)gives the same result as confluence.
D)has little actual effect on weather patterns.

Question 66

Upper-level convergence

A)has no effect on convergence at any level.
B)is primarily an effect in the horizontal dimension.
C)does not result in pressure changes.
D)is not a response to pressure gradients.

Question 67

Cold,dense air will have a ________ vertical pressure gradient than will warm,light air.

Question 68

Explain the relationship between cold fronts and the formation of upper-level troughs.

Question 69

Explain the physical processes behind speed divergence,speed convergence,diffluence,and confluence.

Question 70

Zonal patterns

A)feed the formation of intense cyclones.
B)feed the formation of intense anticyclones.
C)create substantial regions of heavy weather.
D)show little north-south displacement between contour lines on a 500 mb map.

Question 71

Rising air is usually associated with a(n)________ while sinking air is usually associated with a ________.

A)trough; ridge
B)ridge; trough
C)high pressure system; low pressure system
D)inversion; neutral atmosphere

Question 72

Divergence and diffluence

A)are vastly different.
B)are complimentary.
C)cannot coexist.
D)are confusing to most forecasters.

Question 73

Describe how short waves can influence surface conditions.

Question 74

Short waves

A)are comparable in size to Rossby waves.
B)typically migrate upwind.
C)are formed through temperature advection.
D)always act to reduce local convergence.

Question 75

The hydrostatic equation is a relationship between

A)temperature, pressure, and density.
B)temperature, pressure, and height.
C)temperature, density, height, and pressure.
D)height, density, and pressure.

Question 76

As a cold front moves into a warm air mass

A)there is a substantial horizontal pressure gradient at heights of a kilometer or more above the surface of the two air masses.
B)the cold front has a smaller vertical pressure gradient than does the warm air.
C)the cold front slopes backward at a ratio of between 1:5 and 1:20.
D)the warm air subsides and is overrun by the cold front.

Question 77

The horizontal transport of warm air is known as

A)a short wave.
B)vorticity.
C)warm air advection.
D)diffluence.

Question 78

The horizontal transport of cold air is known as

A)convergence.
B)cold air advection.
C)a Rossby wave.
D)speed divergence.

Question 79

An upper level trough is an indication of ________ air while an upper level ridge is an indication of ________ air.

A)rotating; still
B)cold; warm
C)warm; cold
D)sinking; rising

Question 80

The two sources of relative vorticity are ________ and ________.