Climate class9 geography 2nd upload with more effective and attractive

2. WEATHER
• It is the condition of the atmosphere over a
small area for a given period of time.
• It keeps changing every few hours of the day.
• For example: high temperature and high
humidity make the weather sultry and
uncomfortable.

3. Weather

4. CLIMATE
• It refers to the average weather conditions
over a large area and for a longer period of
time.
• It remains constant for a longer duration, may
be 3 months or 6 months or a year.

5. Four Seasons

6. MONSOON
• derived from the Arabic word ‘mausim’ means
season.
• It refers to the seasonal reversal in the wind
direction during a year.
• India climate called the monsoon climate.

7. • Two important elements of Indian climate are:
Temperature and precipitation
1.Temperature:- The degree of hotness or coldness of the
air is called as temperature.
2. Precipitation:- Air has weight and it exerts weight as
pressure on the surface of the Earth.
This weight of the air is called atmospheric pressure.
• Precipitation is in the form of
snowfall in Himalaya
rain over the rest of the country

8. Rajathan 550C
temperature in June
Tawang 190C in June
J&K -450C in
December night
Tiruvanantapuram &
Chennai 200C in
December night
Meghalaya
400cm rain
Jaisalmer in
Rajasthan receives
less than 10cm
rainfall

9. Six major controls of the climate
1. Latitude
2. Altitude
3. Pressure and wind system
4. Distance from the sea
5. Ocean currents
6. Relief features

10. Latitude
WARM
COLD
HOT

11. Altitude
• Higher the altitude, the lower is the
temperature.
• As one goes up, the density of the air
becomes less and less.
• Higher elevation- thinner air, therefore less air
to hold heat makes it colder.
• Lower pressure at higher altitudes causes the
temperature to be colder on the top of the
mountain.eg: Shimla is cooler than chandigarh

12. As one goes up, the density of the air becomes less
and less.

13. Pressure and wind system
• The variations in air temperature control the
pressure and wind system of a place.
• Warm air rises, creating low pressure areas,
while cold air sinks, creating high pressure
areas.
• As a result, winds blow outward from a high
pressure location towards lower pressures.

14. Pressure and WIND

15. Pressure and wind system
• The variations in air
temperature control the
pressure and wind system
of a place.
• Warm air rises, creating low
pressure areas, while cold
air sinks, creating high
pressure areas.
• As a result, winds blow
outward from a high
pressure location towards
lower pressures.

16. Distance from the sea
• The sea temperature changes slower than
land temperature.
• The sea keeps the coastal area warmer in
winter and cooler in summer.
• As the distance from the sea increases the
weather conditions become extreme.
• Places away from the sea have very hot
summers and very cold winters.
• This condition is known as continentality.

17. Ocean Currents
• Ocean currents along
with onshore winds
affect the climate of the
coastal areas.
• Warm currents, such as
the North Atlantic Drift
keeps the coast warm.
• Cold current, such as
Canaries Current keep
the area cold.

18. Movement of Ocean Current

19. Relief Features

20. Factor Affecting India’s Climate
• Latitude
• Altitude
• Pressure and wind

21. Latitude

22. Altitude

23. Pressure and Winds
• Pressure and surface winds
• Upper air circulation
• Western cyclonic disturbances and tropical
cyclones

24. Coriolis force
India –lies in the region of
north easterly wind
originated from the
subtropical high
pressure belt of NH.
Due to Coriolis force-
high pressure moves
towards equatorial low
pressure area.
• As these winds
originate and blow over
land bring little or no
rain.
• Due to this reason India
should have been arid
land but not so…..

26. Reason why India not an arid land
despite Coriolis force of wind
High Pressure area over southern
indian ocean,in south east
direction,cross equator,turn rights
to the low pressure
Low Pressure
over interior
Asia
High Pressure over
Himalaya ( Cold dry wind
Low Pressure area over
ocean to the south

27. Jet Streams
Westerly Jetstream
blow whole year
except summer Tropical easterly jetstream, blows
during summer

28. Western cyclonic disturbances

29. The Indian Monsoon
• The Monsoon – seasonal reversal of wind
• Sailors:-
first notice the phenomenon
Benefited from the reversal of the wind
• Word monsoon derived from Arabic word
mausim.
• Experience in the tropical area roughly
between 20*N and 20*S

30. Mechanism of Indian Monsoon
• The differential heating and cooling of land
and water
• The shift of the position of Inter Tropical
Convergence Zone (ITCZ)
• The presence of the high –pressure area,east
of Madagascar
• The Tibetan plateau gets intensely heated
• Westerly Jet stream and Easterly Jet stream

31. The differential heating and cooling of
land and water
• Land absorbs the heat
very fast and also
releases the heat very
fast
• Water absorbs the heat
very slow and releases
the heat very slow

32. The shift of the position of Inter Tropical
Convergence Zone (ITCZ)
• It is a broad trough of low pressure
• The belt is formed due to convergence of
Northeast and Southeast trade winds.
• It’s normal position is a equatorial latitude but
it moves North or South with the apparent
movement of the sun.
• Important point: the wind move during ITCZ is
trade wind.

33. YouTube link of ITCZ
https://www.youtube.com/watch?v=ZQSzzh0gX
0Q

34. The presence of the high–pressure area,
east of Madagascar
The presence of high
pressure area, east of
Madagascar
approximately at 20*C
over the Indian Ocean.
The intensity and position
of this high pressure area
affects the Indian
Monsoon.
Madagascar

35. The Tibetan plateau gets intensely heated
• The Tibetan high level plateau gets intensely
heated during summers which results in
strong vertical currents and formation of high
pressure over the plateau at about 9km above
sea level.

36. During Summer Northern Hemisphere face
towards sun due to which Tibet Plateau
heated and the Indian Plateau become cool.
The low pressure of theTibet
Plateau
India
High
Pressure,
cool wind
Low Pressure
hot wind

37. Westerly Jet stream and Easterly Jet
stream
Westerly Jetstream
Easterly Jetstream

38. ENSO(El Nino, Southern Oscillations)
ENS0
El Nino
EN SO
Southern Oscillation
It is a warm ocean
Current that flows past
the Peruvian coast in
place of cold Peruvian
current every 2 to 5 years.
The periodic change in
pressure conditions

39. YouTube link of ENSO
https://www.youtube.com/watch?v=iVCviVp4rL
U

40. The Onset of the Monsoon and
Withdrawal
• Onset of monsoon: beginning of four month,
june to september monsoon
season over India.
• Duration of the monsoon: 100 to 120 days
• Burst of monsoon : When normal rainfall increases
suddenly and continues constantly for several days.

41. On Set of The Monsoon

42. The monsoon divides into two – Arabian
sea branch and the Bay of Bengal branch

43.  Arabian sea branch
reaches:
• 10th July - approx Mumbai
• Mid June – over
Saurashtra-Kuchchh and
Central part of India
 The Bay of Bengal
branch:
• 1st week of June-
Assam.
• End of the June-Delhi
• 1st week of July-
Punjab,Haryana,West
U.P, East Rajathan

44. Retreating of Monsoon
• Early-Sep : Begins in Nothwestern state of
India.
• Mid-Oct : complete withdraws from Northern
part of peninsular
• Early-Dec : withdraw from rest of the country

45. Island
• 1st week of April to
May: First monsoon
shower from South to
North.
• 1st week of Dec to 1st
week of Jan :
Withdrawal monsoon
from North to South

46. Four main season of India
1. The Cold Weather Season -Winter
2. The Hot Weather Season - Summer
3. Advancing Monsoon – The Rainy Season
4. Retreating Monsoon – The Transition Season

47. ASSIGNMENT
1. Define Weather and Climate
2. Explain the factors affecting the climate of a
place.
3. Mention the characteristics of monsoon
mechanism in India.
4. Discuss the factors controlling the Indian
climatic condition.

48. 5.Read the textbook carefully and fill in the
blanks in the right column
The Season Durations Temperature
Variation in
different places
Characteristic
features
Crops and any
other plants
grows during
the season
Winter
Summer
Rainy
Retreating
Monsoon

49. Write a short note on
Monsoon as Unifying Bond