Geog~Ch.6 Atmospheric Conditions Flashcards
(94 cards)
1
Q
What gases does the atmosphere consist of?
A
78% nitrogen
21% oxygen
0.9% argon
0.03% carbon dioxide
2
Q
Function of the atmosphere?
A
Holds heat from the sun while also blocking the earth from much of the sun’s incoming ultraviolet radiation
3
Q
What is the lowest layer if the atmosphere?
A
The troposphere
4
Q
What happens at the troposphere?
A
Weather conditions change constantly within this layer
5
Q
Insolation
A
Incoming Solar Radiation
6
Q
Two factors that affects the amount of insolation absorbed by the earth’s surface are:
A
- Angle of the sun’s rays
2. The content of the atmosphere
7
Q
3 factors influencing the angle at which sun rays strike the earth
A
1 the location
- Time of day
- Season
8
Q
Why is the temperature at its highest at the equator?
A
Because the suns rays are most direct at the equator
9
Q
What tropics do the sun move between?
A
Tropics of Cancer
Tropics of Capricorn
10
Q
The content of the atmosphere is affected by ____ and ____
A
- Reflection
• clouds and surface of the earth reflect energy back into space.
• Albedo - light reflect heat, dark absorb heat - Absorption
11
Q
Two energy transfers are:
A
Global winds
Ocean currents
12
Q
Wind is :
A
Air moving from a high pressure area to a low pressure area.
13
Q
High pressure is the result of
A
Descending air i.e cold air falling due to heaviness
14
Q
Low pressure is the result of
A
Rising air i.e warm air rises due to lightness
15
Q
Warm winds blow from the ______.
A
Equator
16
Q
Cool winds blow from the ______
A
High latitudes
17
Q
Latitude ?
A
Gives the location of a place on earth north or south of the equator.its the angular distance from the equator
18
Q
The global wind pattern is also known as :
A
The general circulation
19
Q
Explain how the global winds system works:
A
- Equator ➡️ warm air rises = zone of low pressure
- 30’ north or south ➡️ the warm air cools= heavier= sinks = area of high pressure
- some of this air blows back towards the equator (trade winds)
- 60’ north and south ➡️ some warm air meets cold polar air = form polar fronts = low pressure
- 90’ at the poles ➡️ cold air = zone of high pressure
- process continues over and over creating convection currents that keeps the atmosphere in constant motion.
20
Q
Name the 3 wind belts
A
• Tropical Easterlies
0-30' trade winds
• Prevailing Westerlies
30-60' westerlies
• Polar Easterlies
60-90' polar
21
Q
What is the Coriolis effect?
A
when the global winds are deflected due to the earth’s rotation.
22
Q
Zones that separate the 3 major wind belts
A
- the doldrums (equator)
- the horse latitudes ( still dry 30’)
- the polar fronts (60’)
23
Q
Factors influencing the ocean currents:
A
- rotation of the earth
- influence of the winds
- difference in temperatures in oceans
24
Q
Warm currents flow from :
A
From areas of low latitude to high
25
Cold currents flow from areas of
High to low latitude
26
Examples of warm currents:
* the gulf stream
| * North Atlantic drift
27
Examples of cold currents:
* labrador current
| * greenland current
28
Advantages of ocean currents:
* ice free coasts
* warmer winds
* good fishing grounds
29
Disadvantages of the ocean currents:
* creation of ice bergs
* colder winds
* hard sailing conditions
30
What is the atmosphere?
The atmosphere is a thin layer of gases surrounding the earth.(referred to as the air)
31
What is an air mass?
A large body of air with similar temperature,pressure and moisture levels throughout.
32
Maritime air is generally:
Moist and rain
33
Continental air is generally:
Dry
34
What is a front?
Boundaries between two air masses
35
List 4 air masses:
* Maritime polar
* Maritime tropical
* continental polar
* Continental tropical
36
Continental polar (cP)
North-east Europe
Dry cold
Frosty nights
37
Maritime polar (mP)
North Atlantic
Cold wet air
Showers
38
Continental tropical (cT)
Sahara desert
| Dry sunny
39
Maritime tropical (mT)
Azores
Thunderstorms in summer
Heavy rainfall in winter
40
Arctic (A)
North pole
| Cold
41
Whats a cold front?
A cold front forms when a cold air mass moves into a warm air mass.
42
Explain how a cold front works:
Cold air is heavy so it pushes underneath warm air = forces warm air up to cool and condense ➡️ clouds
The air behind is colder&drier than the air ahead of it
43
Whats a warm front?
A warm front forms when a warm air mass moves into a cold air mass.
44
Explain how a warm front works
```
Warm air (less dense) slides over colder air. ➡️ rain
Air behind a warm front = warm moist = high pressure =clear sky
```
45
High pressure systems are also called:
Anticyclones
46
What causes an anticyclone?
High pressure is a result of cold air descending on the earth's surface.
47
High pressure: air moves from an area of _____ pressure to an area of ____ pressure.
High ↪️ low (causes winds)
48
Characteristics of a high pressure system
* clockwise winds
* no fronts
* warm air descends
* slow
* isobars are well spaces = calm winds
* forms over land
49
Weather with high pressure system
* clear cloudless sky
* calm dry
* summer hot
* winter cold nights due to clear skies
50
Lows pressure systems are also called:
Cyclones
51
What causes a low pressure system ?
Lows develop as a result of warm air rising
52
In a low pressure system air moves from an area of ___ pressure to an area of ___ pressure
High ↪️ iow (as winds blow into a low,air descends up = clouds & precipitation
53
Characteristics of a low pressure system
* anticlockwise
* air rises temperature falls
* isobars close together = strong wind
* cloud
* cyclonic rainfall
* warm tropical air meets polar air over the Atlantic
54
Weather with low pressure
* cloudy skies
* windy wet
* unpredictable
55
What is a depression?
A depression is an area of low pressure
| That develops when a warm front meets a faster moving cold front.
56
Explain how a depression works:
Warm air=area of low pressure
Cold air swirls in an anticlockwise direction = warm air surrounded by colder air
= 2 fronts develop, warm front in front of cold
Faster colder air catches up with the colder air ahead= warm sector pushed up ➡️ occlusion
57
What's weather?
Weather is the day to day state of the atmosphere over any place on the earth's surface
58
What is a weather forecast?
Global patterns of weather
59
Name the 7 different elements of weather
* temperature
* humidity
* atmospheric pressure
* precipitation
* wind speed and direction
* sunshine
* cloud amounts
60
Whats a meteorologist
A person who studies and forecasts (predicts) weather
61
Whats meteorology?
The study of weather
62
Isobars?
Lines on a weather map which connect places of equal atmospheric pressure.
63
Isotherms?
Lines on a weather map which connect places of equal temperature
64
Isohyets?
Lines on a weather map which join places with equal rainfall
65
Isohels?
Lines on a weather map showing equal sunshine
66
Whats temperature?
Measures how hot or cold the air is
67
What is a thermometer?
Used to measure temperature
•mercury or alcohol
• +temperature ➡️ liquid rises up
• -temperature ➡️ liquid falls
68
What measures the highest temperature for the day?
```
Maximum thermometer (mercury)
The index stays at the highest point it reached a day
```
69
What measures the lowest temperature for the day?
```
Minimum thermometer (alcohol)
Index stays at lowest point
```
70
Mean temperature?
Average
| Day = maximum+minimum➗2
71
Temperature range?
Highest - lowest = range
72
What is humidity?
The amount of water vapour and moisture in air.
73
When air has absorbed as much moisture as it can , its ______
Saturated
74
Relative humidity?
Amount of water vapour in air compared to the amount it would contain if saturated. (Hygrometer)
75
Hygrometer:
Mix of wet and dry thermometers
76
What instrument is used to measure humidity
Hygrometer
77
What instrument is used to measure wind force (speed)
Anemometer
78
Instrument for measuring sunshine?
Campbell stokes meter
79
Instrument for atmospheric pressure?
Barometer
80
Instrument for speed direction?
Wind vane
81
Instrument for precipitation?
Rain gauge
82
Unit of measurements for atmospheric pressure
Millibars
83
3 types of barometers?
Mercury
Aneroid
Barograph
84
Explain how one type of barometer works
Barograph: connects a barometer to an inked pen resting on a drum which rotates
85
Explain a wind vane
Has a horizontal arm with arrow at 1 end and a bigger tail on other.
Wind blows tail around arrow points at de direction the winds cominh
86
Explain how a campbell stokes sunshine recorder works
Made up o a solid glass sphere that focuses the suns rays onto a sensitive strip of paper slotted into the semi circular frame behind the ball.
Suns rays ♨️ the paper and as the sun moves during the day, the scorch marks moves along too
87
What is a stevenson screen?
Its a meteorological screen that shields and stores weather instruments.
88
Describe how a stevenson screen looks
White (reflects sunlight) Louvered (slanted) panels ➡️ keep out the direct rays of sun and rain but allows air to circulate freely into the box ➡️ box raised on stilts 1.4m off ground ( no effect from the ground temperature
89
Use of weather in everyday life
```
Fishing
Airplanes
Sports
Tourists
Farmers
```
90
Name 3 main types of clouds
* stratus
* cumulus
* cirrus
91
Stratus clouds:
Like a blanket ↔️ stretches out across sky & blocks sun
| Overcast day or steady rain
92
Cumulus clouds:
Like puff of cotton
| Heavy showers
93
Cirrus clouds :
Wispy & high up & scattered
| Fair weather
94
List 3 rainfall types
Convectional rainfall
Cyclonic / frontal rainfall
Relief rainfall
