Transcript Climate - GeoInteractive

Factors which influence
climate
Today’s Aim 1. To learn the different factors that affect
climate.
Keywords
Latitude, Equator, Sea Breeze, Prevailing Wind,
North Atlantic Drift, Altitude.
Factors that affect CLIMATE
Brainstorm the factors which you
think effect climate in the back of
your book – discuss with people
around you.
Factors Affecting
Climate
1 - Latitude
1.
The further you travel away from the equator the
cooler it gets. Why is this?
2. This is because the Earth is curved. Look at the
picture above. The sun rays hitting the Earth at a
higher latitude are spread out over a greater area.
Over the Equator the rays are concentrated in to a
smaller area – this is why it is hot at the equator and
very cold at the poles.
3. However, the picture is more complicated than this as
other factors have a bearing on the climate in
different parts of the world.
Factors Affecting Climate
2 - Altitude
This is the effect of
height
on
temperature - the
higher you go, the
colder it gets. The
sun heats up the
earth’s surface and
then heat is radiated
back up into the
atmosphere.
Factors Affecting Climate
3 - Prevailing Winds
The movement of the earth’s winds starts
at the equator, where it is hottest.
There are certain set patterns of winds
called prevailing winds, which means that
direction winds travels most of the time.
Wind affects the climate where it has
travelled over the :
Maritime - ocean
Continental - overland
Other Factors Affecting Climate
• Distance from
the coast
• Ocean
Currents
• Shelter
• How built up a
place is.
Major Climatic Regions
Maritime
Tundra
Tropical
Mediterranean
Hot
Deserts
Tropical
Grasslands
Summary
• The Climate is the average weather over
many years.
• Many areas around the world have similar
climates
• Climates are affected by latitude, altitude, ,
distance from the sea, ocean currents and
prevailing winds.
Questions
(Copy out the question before answering it please
apart from Q4)
1. Why is it very cold in the Arctic?
2. Why are high mountains covered in snow
and ice?
3. Why are inland areas hotter than coastal
areas in the summer? Draw a diagram to
help explain your answer.
4. Try questions 4 and 5 in Geog 2, page 37
1 – Indian Monsoons
LOW
July
1 Sea is cooler than the land in the wet
season (summer). So air over the land
heats up and rises, creating low
pressure.
2 As it cools it moves towards the sea.
3 It then descends to the sea creating
high pressure.
HIGH
4 Wind moves from high to low
pressure and as it travels over sea it
picks up water so is able to rain,
creating the ‘monsoon (wet) season’.
What do you need to know today?
1. There are many different causes of
weather in the atmosphere.
2. Many different atmospheric processes
affect the world’s weather.
World Wind and Pressure Belts
1.
Colour high pressure
areas BLUE and low
pressure RED
2.
Add Hadley Cells,
latitude numbers and
wind direction arrows
How is a Hadley Cell Formed?
As air cools
it can no
longer rise
Cold air
sinks at the
Horse
Latitudes
Air rises and
cools in the
atmosphere
WIND moves between
high and low pressure
HIGH
Ground
heats air
LOW
Sun heats
equator
World Wind and Pressure Belts
1 – Indian Monsoons
HIGH
January
1 Land is cooler than the sea in the
dry season (winter). So air over the
sea heats up and rises, creating
low pressure.
2 As it cools it moves towards the
land.
3 It then descends to the ground
creating high pressure.
LOW
4 Wind moves from high to low
pressure and as it travels over land
it does not pick up water so is dry.
2 – Tropical Revolving Storms
HURRICANES
in the
Caribbean
TYPHOONS
in the North
West Pacific
CYCLONES in
the Indian
Ocean
2 – Tropical Revolving Storms
The Inter-Tropical Convergence Zone (ITCZ)
The ITCZ has:1.
2.
3.
4.
5.
air masses on either side of it which are similar
no clear fronts
no warm sector
hurricanes, typhoons and cyclones
the sea has to be 27°C or above
2 – Tropical Revolving Storms
The Process of Hurricane Formation
1. Water vapour evaporates from the sea very quickly as
the sea is extremely warm.
2. Air rises very rapidly.
3. Water vapour condenses as it rises.
4. Huge cumulo-nimbus clouds develop.
5. Torrential rain falls from the huge clouds.
6. Pressure gradient is steep causing very fast winds
which swirl around the centre.
7. Dry air at the top of the hurricane sinks into the calm
‘eye’ of the storm (the centre).
8. The winds and rain caused by hurricanes can kill many
people.
Summary of Climate
1. The global pattern is affected by:
Latitude; land and sea; relief & ocean currents
2. ITCZ- max heating and air is forced to
risedaily thunderstorms
3. Sub-tropical high pressure descending air  low
rainfall
4. Low pressure  depressions and anticyclones
from tropical air meeting cold polar air
5. Passage of air mass moist, dry, cold or warm.