climatology (1-9) Flashcards
(121 cards)
1
Q
What are the latitudinal locations where mid-latitude cyclones are found?
A
Between 30° and 60° North latitude
Mid-latitude cyclones are also referred to as temperate cyclones.
2
Q
Where do mid-latitude cyclones typically form?
A
At the polar front
The polar front is where warm westerlies and cold easterlies meet.
3
Q
What season are mid-latitude cyclones most prominent?
A
Winter
They are particularly common in the Southern Hemisphere during this time.
4
Q
What are other names for mid-latitude cyclones?
A
- Moderate Cyclone
- Extratropical Cyclone
- Temperate Cyclone
- Frontal depression
These terms may be used interchangeably in meteorological contexts.
5
Q
What are the conditions necessary for the development of mid-latitude cyclones?
A
- Cold polar air mass
- Warm tropical air
The meeting of these air masses creates an imbalance in energy distribution due to temperature differences.
6
Q
What is the characteristic of the cold sector in a mid-latitude cyclone?
A
Area of cold air behind the cold front
The low pressure is located in the center of the system.
7
Q
What is the characteristic of the warm sector in a mid-latitude cyclone?
A
Area of warm air behind the warm front
In the Southern Hemisphere, air moves in a clockwise direction.
8
Q
What is the typical isobar pattern of a mid-latitude cyclone?
A
Oval
This pattern reflects the distribution of pressure around the system.
9
Q
What is the movement direction of a warm front in mid-latitude cyclones?
A
West to east
This movement is driven by strong westerly winds.
10
Q
What is the typical diameter range of mid-latitude cyclones?
A
Between 1500 km and 3000 km
This size range allows for significant weather impacts.
11
Q
What is the speed at which warm fronts typically move?
A
50 to 60 km/h
This speed can vary based on environmental conditions.
12
Q
What is the lifespan of mid-latitude cyclones?
A
4 to 14 days
Lifespan can vary depending on various atmospheric conditions.
13
Q
How do mid-latitude cyclones usually occur?
A
In families
This means that multiple cyclones can develop in a sequence.
14
Q
What is the typical pressure at the center of a mid-latitude cyclone?
A
About 996 hPa
This low pressure is indicative of the cyclone’s strength.
15
Q
What happens during the development stage of a mid-latitude cyclone?
A
A wave develops in the polar front
This wave formation is crucial for cyclone development.
16
Q
What occurs when a small mass of warm air extends into cold air?
A
It rises, causing low pressure in the center
This rising air is a key feature of cyclone formation.
17
Q
What are the latitudinal locations where mid-latitude cyclones are found?
A
Between 30° and 60° North latitude
Mid-latitude cyclones are also referred to as temperate cyclones.
18
Q
Where do mid-latitude cyclones typically form?
A
At the polar front
The polar front is where warm westerlies and cold easterlies meet.
19
Q
What season are mid-latitude cyclones most prominent?
A
Winter
They are particularly common in the Southern Hemisphere during this time.
20
Q
What are other names for mid-latitude cyclones?
A
- Moderate Cyclone
- Extratropical Cyclone
- Temperate Cyclone
- Frontal depression
These terms may be used interchangeably in meteorological contexts.
21
Q
What are the conditions necessary for the development of mid-latitude cyclones?
A
- Cold polar air mass
- Warm tropical air
The meeting of these air masses creates an imbalance in energy distribution due to temperature differences.
22
Q
What is the characteristic of the cold sector in a mid-latitude cyclone?
A
Area of cold air behind the cold front
The low pressure is located in the center of the system.
23
Q
What is the characteristic of the warm sector in a mid-latitude cyclone?
A
Area of warm air behind the warm front
In the Southern Hemisphere, air moves in a clockwise direction.
24
Q
What is the typical isobar pattern of a mid-latitude cyclone?
A
Oval
This pattern reflects the distribution of pressure around the system.
25
What is the movement direction of a warm front in mid-latitude cyclones?
West to east
## Footnote
This movement is driven by strong westerly winds.
26
What is the typical diameter range of mid-latitude cyclones?
Between 1500 km and 3000 km
## Footnote
This size range allows for significant weather impacts.
27
What is the speed at which warm fronts typically move?
50 to 60 km/h
## Footnote
This speed can vary based on environmental conditions.
28
What is the lifespan of mid-latitude cyclones?
4 to 14 days
## Footnote
Lifespan can vary depending on various atmospheric conditions.
29
How do mid-latitude cyclones usually occur?
In families
## Footnote
This means that multiple cyclones can develop in a sequence.
30
What is the typical pressure at the center of a mid-latitude cyclone?
About 996 hPa
## Footnote
This low pressure is indicative of the cyclone's strength.
31
What happens during the development stage of a mid-latitude cyclone?
A wave develops in the polar front
## Footnote
This wave formation is crucial for cyclone development.
32
What occurs when a small mass of warm air extends into cold air?
It rises, causing low pressure in the center
## Footnote
This rising air is a key feature of cyclone formation.
33
What happens during the mature stage of a weather system?
Low pressure intensifies and moves into the westerly wind belt, away from the polar front. A well-developed cold and warm sector develops.
34
What occurs with cold and warm air during the mature stage?
Cold dense air moves faster, forcing light humid less dense air in the warm sector to rise. The cold sector becomes larger than the warm sector as cold air moves and lifts warm air.
35
What happens to the warm sector during the mature stage?
The warm sector continues to narrow as the cold front overtakes the warm front, causing warm air to become isolated from the ground.
36
What is cold front occlusion?
Air ahead is slightly warmer than air behind. Warm air in front is uplifted along the cold front, causing rising air to cool, condense, and form nimbostratus clouds, resulting in rain.
37
What is warm front occlusion?
Air ahead is colder than air behind. Air behind fronts in the warm sector rises over cold air, leading to rising air cooling, condensing, and forming nimbostratus clouds, resulting in rain.
38
What are the weather patterns associated with a cold front?
Cold sector experiences a sudden increase in air pressure, gusty winds backing from west to south, and a rapid fall in temperature.
39
What are the weather patterns associated with a warm front?
Warm sector remains steady in air pressure, winds back from NW to west, and experiences a sudden rise in temperature.
40
What is the precipitation pattern during a cold front?
Heavy and later soft, persistent showers with very good visibility, but poor during showers.
41
What is the precipitation pattern during a warm front?
Continuous rainfall that is steady and quite heavy, often leading to poor visibility.
42
What impacts does winter rainfall have?
Winter rainfall determines the type of crop cultivated and replenishes water in dams.
43
What dangers can snow present?
Snow in mountains can be dangerous, leading to closed mountain passes.
44
What are the effects of extreme cold weather?
Extreme cold can cause power cuts and disruption of human activity.
45
What is the effect of berg winds?
Berg winds (hot and dry) may encourage the spread of veld fires.
46
What are the dangers of gale force winds?
Gale force winds can create stormy conditions over oceans, posing a danger to ships.
47
What visibility issues can heavy rain cause?
Heavy rain can lead to poor visibility and traffic accidents.
48
What happens as a cyclone approaches?
Cloud cover increases, and there is a steady decrease in temperature as warm air rises over approaching cold air.
49
What cloud types are associated with an approaching cyclone?
Cumulonimbus clouds form as cold air forces warm air to rapidly rise, along with high and thinner clouds like altostratus, cirrostratus, and cirrus.
50
What is the pressure trend before a cold front arrives?
Pressure decreases, reaching the lowest point before the cold front arrives.
51
What is the visibility trend as a cold front nears?
Visibility is good but decreasing with the nearing front.
52
Why is winter rainfall necessary?
Winter rainfall is necessary for the production of winter crops.
53
What is the relationship between winter crops and food security?
The production of winter crops contributes to food security.
54
What are the dangers of snow and extreme cold for agriculture?
Snow and extreme cold are dangerous for crops and livestock.
55
What is the impact of berg winds on vegetation?
Berg winds cause damage to vegetation due to dry warm conditions.
56
How do gale force winds affect crops?
Gale force winds can damage crops.
57
What negative effects can heavy rain have on agriculture?
Heavy rain can lead to floods, which are negative for crops and livestock.
58
How does the production of winter crops benefit the economy?
The production of winter crops contributes positively to GDP.
59
What are the costs associated with protecting crops and livestock?
It is expensive for farmers to protect crops and livestock.
60
What are the economic impacts of floods?
Floods can damage crops, negatively affecting the economy.
61
What strategies can be employed to reduce agricultural impacts?
Strategies include monitoring developments, keeping livestock in barns, planting cold-resistant winter crops, and staying indoors for protection.
62
What are the characteristics of a tropical cyclone?
Tropical cyclones are intense circular storms that originate over warm tropical oceans.
63
What wind speeds are associated with tropical cyclones?
Tropical cyclones have maximum wind speeds exceeding 119 km/h along with heavy rains.
64
Where do tropical cyclones typically form?
Tropical cyclones typically form at latitudes 30° N and S.
65
What causes the development of tropical cyclones?
They develop due to the confluence of tropical easterlies.
66
Why don't tropical cyclones develop on the equator?
Tropical cyclones do not develop on the equator due to a weak Coriolis force that does not deflect wind.
67
What are other names for tropical cyclones?
Other names include hurricane and typhoon.
68
What conditions are necessary for the development of tropical cyclones?
Conditions include ocean temperatures warmer than 26.5°C and the presence of tropical oceans.
69
What creates unstable air that continues to rise?
Hot moist air creates unstable air that continues to rise, resulting in condensation which releases latent heat.
70
What happens during surface air convergence?
Surface air convergence forces air to rise, especially when it converges at a low-pressure system.
71
What is upper air divergence?
Upper air divergence occurs when moist air is drawn into a system at the surface as air diverges in the upper air.
72
How does the tropical jet stream enhance low-pressure systems?
The tropical jet stream enhances low-pressure systems by causing stronger surface convergence and convection in upper air divergence.
73
What role does the Coriolis force play in cyclones?
The Coriolis force is needed to cause spiraling winds, resulting in a cyclone's rotation.
74
What are the characteristics of an intense cyclone?
Intense cyclones have a pressure below 1000 hPa, occur in late summers and autumns over warm tropical oceans, and exhibit clockwise movement in the Southern Hemisphere.
75
What is the wind speed of intense cyclones?
Winds can reach up to 300 km/h.
76
In which direction do cyclones typically move?
Cyclones typically move from west to east within tropical easterlies.
77
What develops at the center of a cyclone?
An eye develops at the center of the cyclone.
78
What type of clouds form the eyewall of a cyclone?
High cumulonimbus clouds form the eyewall.
79
What are the effects of a cyclone?
Cyclones can cause heavy rainfall, hail, storm surges, and hurricane winds.
80
How are cyclones named?
Cyclones are given alphabetic names.
81
Where do cyclones typically affect land?
Cyclones affect the east coast of continents.
82
Where do cyclones develop and where do they die?
Cyclones develop over oceans and die over land due to friction and lack of moisture.
83
What occurs during the formative stage of a cyclone?
In the formative stage, there is convergence of air towards a low-pressure area, creating a vortex with air pressure around 1002 hPa and wind speeds up to 60 km/h.
84
What happens during the development stage of a cyclone?
In the development stage, the storm's intensity increases, air pressure drops below 990 hPa, wind speeds increase to 120 km/h, and an eye forms in the center.
85
What characterizes the mature stage of a cyclone?
In the mature stage, the storm reaches maximum intensity with pressure dropping to 950 hPa, wind speeds exceeding 180 km/h, and a fully developed eye.
86
What occurs during the decaying stage of a cyclone?
During the decaying stage, air cools down as it enters temperate latitudes, cooler air flows into the cyclone, increasing pressure, and the supply of moisture is cut off.
87
What causes updrafts at A?
Updrafts at A are caused by convection.
88
What direction do winds rotate in the Southern Hemisphere?
In the Southern Hemisphere, winds rotate in a clockwise direction.
89
What is the active quadrant of a cyclone?
The active quadrant is the strongest area where winds rotating around the storm center coincide with the winds moving the cyclone system from east to west.
90
What are the impacts of torrential rain?
Torrential rain can lead to flood risk.
91
What damage can strong winds cause?
Strong winds can cause damage and shatter windows.
92
What are storm surges?
Storm surges are unusually high water levels at the coast caused by approaching tropical cyclones.
93
What are some infrastructural damages caused by storms?
Infrastructural damage includes washed away roads and bridges, and damaged homes.
94
What health risks arise from damaged water pipes?
Damaged water pipes can lead to a lack of fresh water and outbreaks of disease.
95
What are the economic impacts of storms?
Economic impacts include financial strain on families, unemployment, and costly repairs.
96
How do strong winds relate to storm surges?
Strong winds can lead to storm surges, resulting in rapid sea level rises.
97
What environmental issues can arise from flooding?
Flooding can cause mudslides, landslides, and destruction of ecosystems and biodiversity.
98
What threats to food security can storms pose?
Flooding and rising sea levels can destroy agriculture and livestock.
99
What pollution issues can arise from storm damage?
Lack of clean water and damaged sewerage pipes can lead to pollution.
100
What are some strategies to minimize storm impacts?
Strategies include monitoring development, advanced weather predictions, early warnings, upgrading technology, and good medical care.
101
What should be done to prepare for flooding?
To prepare for flooding, evaluate low-lying areas, keep livestock in barns, and stay indoors.
102
What is the importance of good emergency services during storms?
Good emergency services should be well-equipped and well-prepared to respond effectively.
103
What are the characteristics of sub-tropical anticyclones?
Anticyclonic wind curl, subsidence, and divergence at lower levels of the atmosphere. The center of systems is a region of calm, while borders have more intense winds.
104
What are the three main factors that influence South Africa's weather?
Kalahari High Pressure (HP), South Atlantic HP, and South Indian HP.
105
What is the effect of the cold Benguela Current?
It flows over the Atlantic Ocean next to the west coast, bringing cold air with low moisture content.
106
What is the impact of the warm Agulhas Current?
It brings warm air that has high moisture content.
107
What are the conditions necessary for the development of anticyclones?
Descending air from tropical and mid-latitude cells at 30° N and S of the equator.
108
What is the circulation pattern of sub-tropical anticyclones?
Anticlockwise circulation with air diverging at the center.
109
What atmospheric conditions are associated with descending air in anticyclones?
Stable atmospheric conditions, clear skies, and intensified high-pressure systems.
110
What is the effect of adiabatic warming in anticyclones?
It leads to semi-arid conditions in South Africa as the air sinks.
111
When are anticyclones more prominent in South Africa?
During winter, due to the northward migration of the Tropical Convergence Zone (TCZ).
112
What are the impacts on the Namibian coast?
Semi-permanent and semi-stationary weather patterns influenced by seasonal changes linked to the seasonal shift of the ITCZ.
## Footnote
South Atlantic High Pressure System (HP TAC) causes clear stable weather.
113
What is the air movement around the South Atlantic HP?
Air moves anticlockwise around the system, bringing cool, dry air to the western and southern coasts.
## Footnote
This can deflect mid-latitude cyclones away from the coast in summer.
114
What are the summer temperature conditions above the central plateau?
Temperatures are warmer, and an inversion forms above the plateau, allowing moist air from the Indian Ocean to flow into the interior, resulting in summer rainfall.
115
What are the winter temperature conditions above the central plateau?
Temperatures are lower, and cool, dense air sinks onto the interior, compressing and heating adiabatically, creating an inversion below the escarpment.
116
What is the role of the Kalahari HP?
It rests on the escarpment, preventing warm air from the Indian Ocean from reaching the interior.
117
What are the characteristics of the South Indian HP?
It is semi-permanent and semi-stationary, with anticlockwise air movement that brings moist winds close to South Africa, blowing over warm ocean waters.
118
What weather conditions are associated with summer in South Africa?
Warm, moist onshore winds from the northwest lead to precipitation in eastern South Africa.
119
What weather conditions are associated with winter in South Africa?
Cold fronts occur, with the Anticyclone (AC) in a northerly position affecting the country, leading to frontal rain in the SW Cape and cool, dry conditions in the interior.
120
What happens when the AC is in a southerly position during winter?
It prevents cold fronts from affecting the country, leading to warm air rising and forming thermal low pressure systems, resulting in convective thunderstorms.
121
What are the effects of warm, moist air moving over the escarpment?
It leads to clouds and rain, characterized by high temperatures and humidity, along with moisture fronts and line thunderstorms.
