test 3 Flashcards

1
Q

Primary circulation

A

General worldwide atmospheric circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Secondary circulation

A

This consists of migration of high and low pressure systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Air mass thunderstorms

A

They are short lived and rarely produce severe weather

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Super cell thunderstorms

A

produces hail at least 3/4 of an inch in diameter and has surface wind gusts of 58 mph, or creates a tornado

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are surface winds generated?

A

When two regions have different temperatures, they soon begin to have different air pressures as well. Differences in air pressure allows air molecules to move from one place to another (which is what wind is)
synoptic scale: Across two latitudes
regional scale: Between two surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is pressure gradient force?

A

wind speed proportional to the pressure difference between high and low pressure regions. The greater the PDF, the greater the wind flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the corolis force?

A

This is the way that the wind flows due to the fact that it spins on an access..it does not have an effect on wind flows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why is the corolis force stronger at the poles than at the equator?

A

Because at the poles it is perpendicular to the earths surface but it is parallel at the poles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the corolis force affect the direction of the wind?

A

Wind is deflected to the right in the Northern hemisphere and to the left in the Southern hemisphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a geostrophic wind and how is it created?

A

This is when the wind has reached a constant flow. It is created by the pgf that acts on an air parcel and deflects it to the right. As the air parcel increases in speed, it gets closer and closer to the pgf. This is the point at which it is balanced and becomes constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Free atmosphere

A

This occurs when wind flow is above the level of friction . On average this is reached at about 1000m. Creates a geostrophic wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the impact of friction on wind flow?

A

Reduces wind speed and it alters the direction of the wind. The deflection of wind flow on the ocean is about 8 degrees while it is about 25 degrees on land

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Poleward air flow (western side)

A

air flow carries a lot of moisture. This affects continental margins of the US. Creates adibiatic cooling and condensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Equatorward air flow

A

air carries dryness because of strong air subsidence. This air cannot cool and condense. Many of the deserts are located on the eastern side of the subtropical high cells because of this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

polar front

A

the boundary between continental polar air mass (cold/dry) and tropical maritime air mass (warm/moist)… where frontal precipitations can take place. It seperates the polar easterlies from the westerlies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The westerlies

A

they are generated from substropical high pressure cells They take place between 30 degrees and 60 degrees and are more active in the southern hemisphere than in the northern because of the unbroken belt of oceans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens when tropical air mass carried by the westerlies collides with the polar front?

A

condensation, development of mid latitude cyclones, and frontal precipitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Polar easterlies

A

cold and dry wind flow moving from the polar regions. They have a greater velocity of Antarctica because of the strong polar high that develops at the south pole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Upper air circulation

A

It controls the movement of air masses at the surface and is responsible for the development of mid latitude cyclones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

zonal flow

A

fast moving wind from west to east. maintains air masses from within their natural boundaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Meriodinal flow

A

slow moving flow moving across the latitudes in both directions. allows very cold air from the arctic to move toward lower latitudes. also very warm air from the tropics to move north ward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is air mass

A

a large body of air whose physical properties (e.g., density, temperature, moisture) are more or less
uniform horizontally for hundreds of kilometers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why is weather variable in the mid latitude regions

A

It has to do with the traveling air masses and how they interact with one and other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

mE

A

maritime equtorial. warm oceans in the equatorial zone. warm and very moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

mT

A

maritime tropical. warm oceans in tropical zone. warm and moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

cT

A

Continental tropical. Subtropical deserts. warm and dry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

mP

A

maritime polar. Midlatitude oceans. cool and moist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

cP

A

contiental polar. Northern continental interiors. cold and dry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

cA

A

Continental arctic. Regions near north and south pole. very cold and very dry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what happens when an air mass starts to move?

A

it will gain (or lose) heat and gain (or lose) moisture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Secondary air masses

A

these are created because of thermodynamic and dynamic changes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Thermodynamic change

A

Takes place when a cold air mass is moving south over areas where the land mass is warmer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

dynamic change

A

Takes place when an air mass has to go over a topographic barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

mid latitude wave cyclone

A

a common situation along the polar front in the continental United States

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

3 phases of mid laittude wave cyclone

A
  1. ) Frontogenesis and cyclogenesis stage
  2. ) Mature (or open) stage
  3. ) Occluded (or dying) stage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

frontogensis

A

this is the first stage that refers to the creation of fronts delimiting air masses with different physical properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

stationary front

A

develops at the surface when two air masses remain in the same place. (typical of zonal flow conditions aloft)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Frontal waves

A

Frontal waves at the surface indicate that the upper air flow is starting to enter a meridional phase. Warm air mass is starting to move above the ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

warm front

A

created when warm air mass starts to glide on top of the cool air

40
Q

cold front

A

created when the cold air mass is pushing warm air aloft

41
Q

Cyclogenesis

A

adiabatic cooling takes place, condensation is reached, and a low pressure forms at the apex of the two fronts. (creation of mid latitude cyclones)

42
Q

The Mature stage

A

The storm is fully developed and precipitations are generated. Cold front travels faster than the warm front as it is pushing the warm front aloft. intense rain is happening near the front

43
Q

What happens with frontal passage?

A

Changes in temperature, wind speed, wind direction, cloudiness, and moisture take place

44
Q

what is overrunning?

A

this occurs when the air is very moist and unstable, and if the vertical rise of the warm air mass to the horizontal distance is 1km to 100km (or less)

45
Q

What are the weather conditions associated with an occluded front?

A

it is often the most intense part of the storm. (as far as rainfall is concerned) but there is no longer any warm or moist air. As the storm continues, central air pressure starts to rise.

46
Q

When does a storm dissipate when talking about an occluded front?

A

when all the warm air that is used at the surface is moved aloft

47
Q

Cold-type occlusion

A

In this type of occlusion, the cold front is catching up to the warm front and eventually takes over. eventually the warm air is moved aloft

48
Q

warm-type occlusion

A

This occurs mostly on the western side of the United States. The cold air mass coming from the pacific overruns the colder air mass which is pushed upward

49
Q

What are hurricanes?

A

A large scale storm (500-600 miles in diameter) that have speeds from 75 to 200 mph

50
Q

When is hurricane season in the Atlantic?

A

June through November

51
Q

What are the 6 conditions required for a tropical storm to turn into a hurricane?

A
  1. Warm sea surface temps (81%)
  2. Westward trajectory maintaining the storm over warm water
  3. No topographic obstacles islands?
  4. Creation of spinning cortex
  5. Little or no vertical wind shear
  6. Divergence of air aloft must exceed the convergence of air at the surface
52
Q

Why does the water need to be warm for the development of a hurricane?

A

this allows there to be sufficient convective motion and latent energy transfer

53
Q

why does there need to be no vertical wind shear in order for there to be a hurricane?

A

This allows there the be eye wall formation

54
Q

The eye of a hurricane

A

The eye of the equator is where air subsidence takes place. Usually reaches a span of about 30-50 miles wide

55
Q

Saffir-Simpson scale

A

This is the scale that explains that weak hurricanes are category and strong are category 5.

  1. wind speeds of 74-95 mph
  2. wind speeds greater than 155 mph
56
Q

Storm surge

A

a lot of sea water pushed inland by strong winds that is associated with a hurricane during landfall

57
Q

Where is the most dangerous part of a hurricane upon landfall?

A

The right front quadrant

58
Q

why does a hurricane lose strength after hitting land?

A

It no longer has the latent heat flux that is available over the warm ocean surface

59
Q

Can tornados form within a hurricane?

A

yes. they are very common and happen a lot in the right front quadrant of a hurricane

60
Q

What is the difference between a hurricane watch and warning?

A

issued when a hurricane will make landfall within the next 24 hours while a hurricane watch is when there is a possibility that a hurricane could hit land in the next 24-48 hours

61
Q

What three landscape settings are most at risk with hurricanes?

A
  1. ) Densely populated deltas
  2. ) Isolated Island groups
  3. ) Highly populated coasts in highly populated countries
62
Q

Why must warm air be moist in order to form a thunderstorm?

A

That way condensation (latent heat transfer) can be reached more quickly

63
Q

What are the main physical mechanisms that can generate a thunderstorm?

A

Frontal lifting 1 2 and 3. And non frontal generated thunderstorms

64
Q

Front lifting one

A

this occurs because of a cold front

65
Q

frontal lifting 2

A

occurs due to overrunning

66
Q

frontal lifting 3

A

Moisture front (dry line) lifitng

67
Q

Why is the frequency of Thunderstorms higher in Southeastern USA. Why is it low on the West coast?

A

availability of warm and moist air from the gulf of Mexico all year around…Stagnant anticyclonic conditions are common

68
Q

Air Mass Thunderstorms

A

These are short thunderstorms that have an individual storm cell. There are three distinct stages of development

69
Q

Cumulus stage (initial stage)

A

The cloud grows and moist air continues to be lifted and the growing cell expands vertically and horizontally. The process of collision and coalescence is active

70
Q

Mature stage

A

This is the stage where rain begins to fall and the most intense part of the storm. The top of the cloud is anvil shaped. The downdraft is cutting the updraft in half which means the storm dissipates quickly

71
Q

Dissipating stage

A

starts about 15-30 minutes after the Mature stage starts. This stage happens because the downdrafts dominates the updraft and clouds start to disappear

72
Q

Severe thunderstorms

A

a thunderstorm that produces hail of 3/4 diameter and has surface winds that are 58 mph or greater

73
Q

Oridnary thunderstroms…

A

tend to form in a region where there is limited vertical wind shear. (wind speed and direction do not abruptly change with increasing height above the surface)

74
Q

What is overshooting?

A

This happens in super cell thunderstorms where updrafts are strong enough to push into the lower stratosphere. (60,000 ft)

75
Q

What is gust front?

A

The out-flowing boundary that forces warm moist air into the thunderstorm

76
Q

What is a shelf cloud?

A

This is a cloud that forms as warm moist air rises along the forward edge of the gust front

77
Q

What is a Multi-cell thunderstorm?

A

Thunderstorms that are composed of several individual single-cell storms. All in different stages of development

78
Q

What is a squall line thunderstorm?

A

composed of thunderstorms arranged in a line or a band. They occur along a boundary of unstable air and is a form of a multi-cell thunderstorm

79
Q

Mesoscale convective complex

A

A number of individual multicell thunderstorms occasionally grow in size and organize into a large circular convective weather system. They are not fronts

80
Q

When/How do Mesoscale convective complex happen?

A

In the summer and in regions where upper winds are weak and where intense heating at the surface favors strong convection

81
Q

What is dryline thunderstorms?

A

These are a lot like squall line thunderstorms except they are aligned along a moisture front and not a thermal front.

82
Q

What air mass is involved in dryline thunderstorms?

A

cT airmass

83
Q

Why does moist air rise above dry air?

A

Moist air has a lot of water vapor it. And water vapor is a light gas which will rise above a dry gas

84
Q

What is thunder

A

it is formed because of lightning that causes expand explosity. This creates a shock wave

85
Q

Sheet lightning vs cloud to ground lightning

A

Sheet: diffuse illumination of the parts in the cloud that a flash happened
cloud to ground: It accounts for 20% of the lightning and takes place when an electrical discharge occurs between the cloud and the earth’s surface

86
Q

where are tornados most common in the world and in the US?

A

The US is the most common place in the world for tornado activity.

87
Q

When is tornado season?

A

April to July

88
Q

What is a mesocycle

A

The updraft of a thunderstorm rotating. Which causes a tornado. As it starts stretching vertically, it shrinks horizontally. This accelerates the spinning motion

89
Q

What are multi vortex tornadoes?

A

These are tornadoes that have smaller swirls that rotate within the tornado

90
Q

What are the 5 stages to a tornado?

A
  1. Dust-Whirl stage
  2. Organizing stage
  3. Mature stage
  4. Shrinking stage
  5. Rope Stage
91
Q

Dust whirl stage

A

1st stage of a nado. Dust swirling upward from the ground indicates that the tornado has touched down

92
Q

organizing stage

A

2nd stage of the tornado. Funnel cloud has hit the ground and is picking up intensity

93
Q

Mature stage

A

This is the 3rd stage. the greatest damage is encountered during this stage

94
Q

Shrinking stage

A

4th stage of tornado. overall decrease in funnel’s width and the funnel starts to tilt. still capable of a lot of damage

95
Q

Rope stage

A

this is the final stage of a tornado. It is stretched into the shape of a rope and eventually dissipates

96
Q

Tertiary circluation

A

These are local winds

97
Q

Sea breeze vs Land Breeze

A

Sea breeze: happens during the day

Land breeze: happens at night