it is atmosphere geography work

1. THE ATMOSPHERE

2. DEFINITION
The layer of gases that surrounds the
earth.
COMPOSITION OF THE ATMOSPHERE
• Solids: dust particles and salt crystals
• Liquid: Water in the form of clouds
• Gases: Nitrogen (78%) – plant growth
Oxygen (21%) – respiration
Argon (1%)

3. STRUCTURE OF THE ATMOSPHERE:

4. LAYER 1 - TROPOSPHERE
• Layer closest to the earth.
• 8 – 16 km thick. 8km (poles) and 16km
(equator)
• Contain al the gases which are essential for
life.
• Contains all weather conditions.
• Temperatures DECREASE

6. LAYER 2 - STRATOSPHERE
• Contains the layer of Ozone (O3).
• Ozone absorb all the ultraviolet rays
(UV) from the sun.
• Temperature INCREASE due to the
absorption of UV-rays.

7. Reasons why planes fly here:
• Little to no turbulence is found in the
stratosphere
• Stratosphere is very dry and few clouds are
formed in this layer.
• All cloud cover is in the lower layer
• Stable conditions in the stratosphere

8. LAYER 3 - MESOSPHERE
• Layer is very cold
• Prevents dust and rocks from space
from entering the lower layers of the
atmosphere.
• Temperature DECREASE - Air is thin
and fewer molecules can absorb
incoming radiation from the sun.

9. LAYER 4 - THERMOSPHERE
• Layer furthest from the earth.
• Layer absorb the sun’s harmful X-rays
and ultraviolet rays.
• Temperature INCREASE

10. IMPORTANCE OF ATMOSPHERE
• Protects us from harmful ultraviolet rays
of the sun.
• Contain gases that are essential for life.
• Water vapour (clouds) gives us rain and
moisture.
• Weather takes place in the atmosphere.

11. THE OZONE LAYER

12. DEFINITION
- Ozone is a gas that is made up of three
molecules of oxygen.
- The ozone layer protects the earth as it
absorbs ultraviolet radiation.

13. CAUSE OF OZONE DEPLETION:
• CFC’s inside aerosol sprays,
refrigerators, air conditioners release
this gas into the atmosphere.
• Ozone layer becomes thinner and
cause holes in the ozone layer.

15. MONTREAL PROTOCOL(1987):
• Gathering of different countries to discuss
sustainable ways to reduce ozone depletion.
• Target was as follow:
- Developed countries must reduce the use
of CFC’s by 1995.
- Developing countries must replace all the
CFC products by 2010.

16. EFFECTS OF OZONE DEPLETION:
EFFECT ON PEOPLE:
• Skin cancer
• Sun burn
• Eye cataracts in people and animals
• Weaken the body’s immune system so
the body can’t fight diseases.

17. EFFECT ON PLANTS AND MARINE
LIFE:
• Disrupt photosynthesis
• Kills phytoplankton in the sea and
disrupts marine eco systems;
• Crop yields get less – cotton, soya beans,
rice, beans and peas.

18. REDUCING OF OZONE DEPLETION:
• Stop the use of CFC’s.
• Use environmental friendly aerosol sprays.
• Regulate CFC’s in factory waste.
• Plant more trees.
• Increase solar power.
• Make use of public transport on regular basis.

19. HEATING OF THE ATMOSPHERE

21. PROCESSES OF HEATING:
RADIATION:
Emission of heat and energy in the form of
waves.

22. CONDUCTION:
The transfer of heat by contact.
CONVECTION:
The transfer of heat by vertical movement.

23. INSOLATION VS TERRESTRIAL
RADIATION
INSOLATION:
• Radiation that comes from the sun in the form
of waves.
• It usually happens during the day when
radiant heat is transferred.
• In the form of long and short wave.
• Primarily heats the Earth’s surface.

24. TERRESTRIAL RADIATION:
• Radiation (heat) that comes from the earth
and its atmosphere.
• Mostly happen at night.
• Consist of long waves.
• Water vapour and Carbon Dioxide are
concentrated close to earth where as more
absorption takes place and the air is warmer.

26. FACTORS THAT AFFECT
TEMPERATURE

27. LATITUDE:

28. • Areas at A:
Long waves with large area that are
heated causing the heat to be less
concentrated and thus not that warm.
• Areas at B:
Short waves with small area that are
heated causing the heat to be more
concentrated and thus to be very
warm/hot.

29. ALTITUDE:
Places at a higher altitude are colder than places
at a lower altitude.
Environmental lapse rate: The rate at which
moving air cools down as the height increase.
Positive lapse rate: Decrease in temperature
with increase in height (0.65°C for every 100m).

30. • Negative lapse rate: Temperature increase
with height.

32. ALBEDO:
What is Albedo?
Measures the amount of light or heat that’s
reflected.

33. • Darker colours absorb more heat – areas with
dark soil and trees are warmer. Only 20% are
reflected back to the atmosphere.
• White or shiny surfaces like snow reflect high
amount of heat. 85 – 90% of heat is reflected
to the atmosphere.
• Water reflect 10% of the heat from the sun.

34. OCEAN CURRENTS:
• A movement of surface ocean water that
is caused by winds.
• Places next to warm oceans are warmer.
• Places next to cold oceans are colder.
• Air blow from ocean to land causing the
land temperature to be hot (moist) or
cold (dry).

36. TWO OCEAN CURRENTS THAT AFFECT
SOUTH AFRICA’S TEMPERATURE:
• Warm Mozambique current ( Eastern part of
SA/Durban) – ocean current is warm therefore
climate will be warm and moist. Warms the
land.
• Cold Benguela current ( Western part of SA/
Cape Town) – ocean current is cold with dry
air therefore less rain. Cools the land.

37. DISTANCE FROM THE SEA:
• A large mass water takes a lot of time to
heat up and cools down slowly. (Keep its
heat)
• A large landmass heats up quickly and
cools down quickly.
• RESULT: Sea is colder than the land in
the summer but warmer during the
winter.

38. MARITIME AND CONTINENTAL
CLIMATE:
MARITIME CLIMATE: CONTINENTAL CLIMATE:
Average temperatures due to
the effect of the ocean.
Extreme temperatures due to
places that are far from the
ocean.
Average temperatures Extreme temperatures
Small variation in seasonal
temp
Big variation in seasonal temp
Warm days cool nights Warm days cold nights
Low daily temp variation High daily temp variation
Warm summers and cool
winters
Warm summers and cold
winters

39. ASPECT:
• Definition: The direction in which
the slope is facing.
• North- facing slopes are warmer
because a smaller piece are heated.
Perpendicular sun rays are more
concentrated.

41. GREENHOUSE EFFECT:
Definition: Trapping of long wave radiation heat by
gases in the lower atmosphere.
Greenhouse gases:
• Carbon dioxide (CO2) – fires and burning of fossil
fuels.
• Methane (CH4) – cow faeces and rotten plants.
• Water vapour

42. HOW DOES A GREENHOUSE WORK?

43. • Glass structure with see through
roofs and walls.
• Absorb heat and prevent air from
cooling down.
• Used during the winter to grow crops
that is not frost resistant.

44. IMPACT OF GREENHOUSE EFFECT ON
PEOPLE AND THE ENVIRONMENT:
• Loss of habitats which leads to disruption in
ecosystem.
• Melting of ice cause the increase in the sea levels.
• Leads to more droughts and floods.
• Increase in transmitted disease like malaria.
• Decrease in crop yields leads to famine.
• More erosion.
• Increase in amount of acid rain.

45. SOLUTIONS TO REDUCE GREENHOUSE
EFFECT:
• Carbon tax should be paid on amount of
heat released with generating of
electricity;
• Increase amount of public transport;
• Decrease speed on roads;
• Decrease fertilisers for agricultural use;
• Decrease production of CFC’s.

46. GLOBAL WARMING:

47. DEFINITION:
The increase in the temperature on Earth.

48. CAUSE OF GLOBAL WARMING:
• Burn of more fossil fuels cause the
release of more carbon dioxide.
• Deforestation leads to less trees to
absorb carbon dioxide.
• Increase of methane due to rice
plantations.
• Use of fertilisers release nitrogen oxides.

50. CONSEQUENCE OF GLOBAL
WARMING:
• More rain and more droughts in some
areas.
• Some plant and animal species may
become distinct.
• Destruction of tropical forests.
• Less water resources.
• Less crops thus more hunger and
malnutrition.

51. • Melting of glaciers and ice caps.
• Increase in diseases like malaria and
cholera.
• Rise in sea-level.
• Increase in uncontrolled fires.

52. SOLUTIONS AND STRATEGIES:
• Rewards and incentives for reducing
carbon emissions.
• Carbon taxes: More release more paying
of tax.
• Use of environmental friendly sources :
Solar power, wind power, hydroelectricity
and biofuels.

53. • Planting trees and reserve forests.
• Recycling
• Educating people and make them aware
how to reduce their carbon footprint.

54. GLOBAL WARMING ON AFRICA:
• Less water causing shortage of water for
drinking and growing crops.
• Deserts will expand – less land for growing.
• Some areas more rain – destroy
infrastructure.
• Rising sea levels threaten areas along
coasts.
• Higher temperatures lead to spread of
diseases.

55. MOISTURE IN THE
ATMOSPHERE:

56. FORMS OF WATER IN THE
ATMOSPHERE:
• Solid – Ice – Hail and Snow
• Liquid – Water – Cloud, fog and rain.
• Gas – Water vapour

57. THE WATER CYCLE:
• Precipitation: Moisture which falls from the
atmosphere.
• Evaporation: Change of a liquid into water
vapour.
• Condensation: Change of water vapour into
ice.
• Transpiration: Process of plants giving off
moisture.

59. HUMIDITY
• Definition: The amount of water vapour in
the air.
• Warm air has more space for water vapour.
• Cold air is dense therefore less space for water
vapour.
Cold air
Warm air

60. • Dew: Drops of water that condense and cools
down when air is saturated.
• Frost: Small ice crystals that collect on
surfaces when air is below freezing point.

61. CLOUDS:

62. DEFINITION:
• Water droplets and ice crystals floating in
the atmosphere.
• Clouds form when air that contains water
vapour is cooled so that it reach dew
point.
• Water vapour then condenses into tiny
water droplets and ice crystals.

63. CLOUD NAMES AND WEATHER
CONDITIONS:
• Cirrus: High clouds
• Stratus: Layered appearance
• Cumulus: Look like cotton wool.
Clouds and weather conditions:
• Cumulonimbus: Thunderstorms
• Cirrus: Cold fronts
• Cirrostratus: Snowy clouds

65. TYPES OF PRECIPITATION:
• Rain: Precipitation that reaches the ground in
liquid form.

66. • Hail: A frozen form of precipitation that falls
as ice pellets.

67. • Snow: A frozen form of precipitation that falls
as tiny ice crystals in the form of snowflakes.

68. TYPES OF RAINFALL:
1. Relief rainfall/Orographic rainfall:
Warm moist air that rises over a
mountain. Cause thick clouds with drizzle
rain.

69. 2. Convectional rainfall:
Warm air that rises by convection causing
cumulonimbus clouds with heavy rain.

70. 3. Frontal rainfall:
Rainfall that forms when warm moist air
rise up a cold front. Associated with
nimbostratus clouds with light rainfall.

71. SYNOPTIC WEATHER MAPS:
Definition: Map that shows a range of weather
conditions for a particular area on a particular
day.

72. Isobars: Lines on synoptic map that join points
with equal pressure.
• Measured in hectopascals (hPa) with a barometer.
TWO TYPES OF PRESSURE CELLS:
HIGH PRESSURE: LOW PRESSURE:

73. HIGH PRESSURE CELL:
- Pressure increase towards the middle.
- Warm, stable and sunny conditions.
LOW PRESSURE CELL:
- Pressure decrease towards the middle.
- Rainy, unstable and cloudy conditions.

74. WEATHER ELEMENTS ON SYNOPTIC
MAPS:
Air temperature
Dew point temperature
Type of precipitation
Cloud cover
Wind direction
Wind speed

75. TYPES OF PRECIPITATION:

76. CLOUD COVER:

77. WIND SPEED:

78. TYPES OF FRONTS:
COLD FRONT: WARM FRONT:
Leads with warm air and brings
cold air behind.
Leads with cold air and brings
warm air behind.
In front: Warm air In front: Cold air
Behind: Cold air Behind: Warm air
Impact on weather: Bring cold
weather to South Africa.
Impact on weather: Little to no
effect on climate.

79. WINTER SYNOPTIC MAP:

80. FEATURE OF A WINTER MAP:
• The date on the map;
• High pressure cell over the interior of South
Africa;
• Other high pressure cells are closer to land
and more North;
• Low temperatures over the land;
• Cold fronts are present.

81. SUMMER SYNOPTIC MAP:

82. FEATURE OF A SUMMER MAP:
• The date on the map;
• Low pressure cell over the interior of South
Africa;
• High temperatures over the land;
• Occlusion of cold and warm front are present
(Tropical cyclone).