The document discusses differences in climate between northern and southern Africa, which are divided by the equator. The northern part includes the Sahara desert, while the southern part includes grasslands. Climate varies in different regions due to geography, with tropical climates near the equator and colder climates farther north and south. Additional factors like altitude, prevailing winds, and distance from the sea also impact regional climates. The document then covers various climate types, weather phenomena, factors influencing climate, and seasonal changes caused by the earth's axial tilt.

1. Weather, Climate and
Pressure

3. Africa map
What is the difference between the
Northern part of Africa and the
Southern part ?
What are the geographical features of the
Northern part?
What are the geographical features of
Southern part ?
So what does the Difference show ????

4. The reason ….
Geographically Africa is divided into two
Hemispheres, Northern hemisphere
and Southern hemisphere as the
Equator passes through the continent.
Thus Sahara is in the North and
Grasslands lie in the South. This
diversity is brought about by the
Geography. The climate of a region is
influenced by the Geography.

5. Thus geographically which are the
different regions ?
What climate do we find in deserts,
mountains, frozen lands , plateaus ,
plains, coastal lands ??????
Why is there difference in climate in
these regions ??????????

6. Differences in Climate !!!

7. Climate ??
Climate is the weather of a place averaged over
a length of Time. (approx 30 yrs)
That’s why climate varies from place to place,
creating a variety of Enviroments.
Climate changes with time.
Climate changes with Human activity – Like
burning of Coal, Natural gas, fossil fuels.

8. Climatologists – Scientists who study
Climate
They also study the changes in climate.
This area of study is very important to
us ????????
Can you tell WHYYYYYYYY !!!!!!!

9. Global Distribution of Climate
Tropical : Places located on the Equator
These also have equatorial climate.
These Places are Hot all around the
year and rains everyday. (avg temp is
27 degree C)

10. Tropical Grassland :
These places are also known as
Savannah. It is Hot all around the year,
has wet and a dry season. (Avg Temp
is 25 degree C)

11. Desert Climate :
These places are very hot around the
year. Rainfall is unrealiable. (Avg Temp
is 30 degree C, It may rise upto 50
degree C and falls below 0 degrees at
night)

12. Mediterranean Type of Climate :
These places are hot in summer and mild
in winter. It rains mainly in winter. (Avg
temp is 25 degree C in summer and 13
degree C in winter )

13. Continental Interior :
These places are hot in Summer and cold
in Winter. It rains mainly in summer.
(Avg temp in summer is 20 degree C
and in Winter is -15 degree C)

14. Temperature Maritime :
It is warm in Summer and mild in winter.
It rains around the year. (Avg Temp in
Summer is 16 degree C and in Winter
is 7 degree C)

15. Tundra Type :
These places have Short and Cool
summers and Long and Cold Winters.
(Avg Temp in summer is 3 degree C
and in Winter is -28 degree C)

16. Match the Columns
a. Very hot and dry all year 1 Tropical
b. Hot all year and rains everyday 2 Tropical grassland
c. Cool in summer and very cold in winter. 3 Desert
d. Hot all year with a wet and dry season 4 Mediterranean
e. Hot in summer and mild in winter 5 Continental interior
f. Hot in summer and cold in winter 6 Temperature
Maritime
g. Warm in summer and mild in winter 7 Tundra

17. Factors Affecting Climate
Latitude :
Solar energy is concentrated at the Equator.
This explains why Tropical climates are
always hot.
Towards the North and South Poles solar
energy is spread out and is filtered by its
longer, oblique- angled journey. (slanting
rays). This explains why it gets colder
towards the North and South Poles.

18. Altitude :
Altitude is the Height above sea level
The solar energy (heat) is absorbed by
gases in the atmosphere. The
atmosphere becomes thinner as
altitude increases. This means that
temperature falls by 6.5 degree C for
every 1000m
High land causes rainfall

19. Prevailing Winds :
Polar winds bring cold weather
Tropical winds bring warm weather
Sea winds bring precipitation (rainfall )
Land winds bring dry weather

20. Distance from the sea :
The sea has a moderating influence over the climate
In summer it takes a long time to heat up – cooling the
surrounding area.
In winter the sea takes a long time to cool – warming
the surrounding area.
Warm ocean currents flow from tropical areas warming
the surrounding areas
Cool ocean currents flow from the poles. They lower
the temperature and bring Fog.

21. True or False
Solar energy is concentrated at the North and
South Pole.
The atmosphere is thinner at the top of the
mountain.
High land receives more rainfall.
Winds blowing form the sea bring dry weather
The sea winds bring rainfall.
Cool ocean currents cause Fog.
Tropical winds bring warm weather.

22. What does this Picture show ?

23. This is Weather Forecast
Why do we need Weather forecasts ????
To decide what to wear when we plan for trips,
to avoid / avert dangers
Weather is the state of atmosphere at
some place and time.
How is weather information collected ?
Find out ??????

24. The Facts..
Earth is not the Only Planet with a variety
of weather conditions.
For Eg : Titan, a natural satellite of
Saturn also has Atmosphere.
Weather also affects the agriculture,
transportation, industry and delays
flights.
Do you know HOW ?????

25. Winter snows and Fogs delays
transportation and Flights.
Weather affects agriculture as in todays
days we don’t know how the weather
will be like ?????????/
Why are we so unsure of weather?????
Has weather affected Human Life ?

26. What causes Weather ???
Weather takes place in Atmosphere, the
layer that surrounds the Earth. Air is a
mixture of gases and suspended
particles (dust).
Nitrogen is available in large number
78 %
Oxygen is 20 %
Other gases constitute 1 %

27. Pie Diagram

28. The other gases also play a vital role in
Earth’s Atmosphere
Eg Water Vapour is an invisible gas but
without this gas there would be no
clouds , no rain, no snow, not even
plants and animals.
Ultimately What would it Affect ???????

29. Parts of Atmosphere !!!

31. Most of the weather occurs in the lowest
part of the Atmosphere. (Troposphere )
How is the atmosphere held around the
Earth ?
The force of gravity pulls the gases of
the atmosphere towards the Earth and
prevents them from escaping into
space.

32. Types of Weather
Temperature :
describes how hot or cold is the air.
Precipitation :
describes any type of water falling from the
atmosphere, includes rain, snow, hail.
Air Pressure :
describes the weight of air. Warm air rises
causing low air pressure. Cool air sinks
causing high air pressure.

33. Wind :
The movement of air from one place to another.
Wind blows from high pressure to low
pressure areas.
Humidity :
Actual amount of water vapor in the
atmosphere.
Clouds :
Tiny water droplets in the atmosphere.

34. Questions
What is weather ?
What is wind ?
What is humidity ?
Find out the instruments to measure :
Temperature
Precipitation
Air pressure
Wind
Humidity

35. What is this
instrument called

36. Why do we have seasons ?
The Four seasons – Spring , Summer,
Autumn and Winter are caused by the
tilt of the Earth’s Axis. As the Earth
moves around its axis, different parts
are tilted towards the Sun for a few
months at a time. The part leaning
towards the Sun has Summer, while the
part leaning away from the Sun has
Winter.

37. Find out the hottest and Coldest place on
Earth ?
How many countries have two seasons ?
What kind of climate does Antartica have
Why ?

38. Greenhouse effect

39. What is greenhouse Effect
The Greenhouse effect is caused by cars,
factories and power stations, releasing
gases like carbon dioxide into the
atmosphere. Like a house these gases
trap the heat and gradually make the
climate warmer.

40. Reflection
Is today’s climate changing?
Is it different from the climate which
existed 5 years ago ?
Prepare a Questionnaire to ask a person
from the weather department ?
Also prepare what could be the possible
reasons?

41. Sea breeze
Have you noticed that people go to
seaside on hot sunny days – to enjoy
the cool sea climate. These breezes are
caused due to the difference in
temperature between land and sea. The
land and the sea heat up at different
levels.

42. Sea breeze
Sea breezes are light winds that travels
from sea to land.
During the day the land warms up quickly.
Comparatively the sea warms up more
slowly. In summer the difference in
temperature between the sea and land is
quite big. This helps the winds to move. The
warm air over the land rises and the cool air
of the sea replaces it.

44. Land breeze
At night the land cools down faster
than the sea. The air above the sea
is warmer than the land and it rises
creating a low pressure area. Thus
the breeze form the land moves to
the sea.

46. Related topics
Is there a hole in the Ozone layer ? How
did it come about ?
Can we stop some of the climatic
changes ? Or is it too late ? If yes , then
How ?
How will the future be affected by Man’s
activities ? Is there a bright and healthy
Future ???????????????????

47. References :
• Wind and Air Pressure – Allan Rogers
and Angella Streluk , Heinemann , 2002,
Oxford
• 100 questions and answers on World’s
Climate and Weather - Dick File et all
Navneet, 1995, Mumbai