ITS FOR CLASS 9 GEOGRAPHY

2. INTRODUCTION
Monsoon is traditionally defined as a seasonal reversing wind accompanied
by corresponding changes in precipitation. It is also described as seasonal
changes in atmospheric circulation and precipitation associated with the
asymmetric heating of land and sea. Usually, the term monsoon is used to
refer to the rainy phase of a seasonally changing pattern, although technically
there is also a dry phase. The English word monsoon came from Arabic word
mawsim and Hindi word "mausam”.
The climate of India is described as ‘monsoon’ type. In Asia, this type of
climate is found mainly in the south and the south-east. Despite an overall
unity in the general pattern, there are
perceptible reasonal variations in
climatic conditions within the country.

3. FACTORS AFFECTING MONSOON
•LATITUDE
•ALTITUDE
•PRESSURE AND WINDS- i)Pressure and surface winds
ii)Upper air circulation
iii)Western cyclonic disturbances and tropical
cyclones

4. LATITUDE:- Latitude is an angle (defined below) which ranges from
0° at the Equator to 90° (North or South) at the poles. Lines of constant
latitude, or parallels, run east-west as circles parallel to the equator.
Latitude is used together with longitude to specify the precise location
of features on the surface of the Earth.
ALTITUDE:- The distance measured perpendicularly from a figure's
vertex to the opposite side of the vertex. The perpendicular height of a
triangle is known as its altitude. The angular distance of a heavenly
body above our Earth's horizon.
PRESSURE AND WINDS:-
• Pressure is the amount of force exerted per unit of surface area. It
always decreases vertically with height and is exerted equally in all
directions.
• Wind is the perceptible natural movement of the air, especially in the
form of a current of air blowing from a particular direction.

5. THE INDIAN MONSOON
The climate of India is strongly influenced by monsoon winds. The Arabs,
who had also come to India as traders named this seasonal reversal of the
wind system ’monsoon'. The monsoon advances in the early June creating
a low-pressure condition over the Northern Plains while during October –
November, with the apparent movement of the sun towards the south
retreats the monsoon which is marked
by clear skies and rise in temperature.
It is accompanied by some seasonal
winds such as Loo, Mango showers,
Kaal-baisakhi.

6. THE MONSOON SEASONS OF INDIA
The monsoon type of climate is characterized by a distinct seasonal pattern. They are-
The Cold Weather season(Winter) and The Hot Weather season(Summer).
The Cold Weather Season begins from mid-November in northern India and stays till
February. December and January are the coldest months in the northern part of India.
Days remain warm and nights become cold. Although the total amount of winter
rainfall is locally known as ‘mahawat’ is small, they are of immense importance for the
cultivation of rabi crops.
Due to the apparent northward movement of the sun, the global heat belt shifts
northward. As such, from March-May, it is hot weather season in India. The
temperature remains 38°C-45°C. During this season strong, gusty dry winds blow blows
during the day over the north and north-western India.

7. Following the summer and winter seasons,
the rainy season brings ‘advancing monsoon’.
THE ADVANCING MONSOON (THE RAINY
SEASON)
By the early June, the low-pressure condition
over the Northern Plains attracts the trade
winds of the southern hemisphere. Early in
the season, the windward side of the Western
Ghats receives very heavy rainfall, more than
250 cm. now the phenomenon associated
with monsoon is its tendency to have ‘breaks’
in rainfall. Thus, it has wet and dry spells. It
is often irregular in its arrival and its retreat.
Hence, it sometimes disturbs the farming
schedule of millions of farmers all over the
country. With the season’s arrival, the normal
rainfall increases suddenly and continues
constantly for several days. This is known as
the burst of monsoon.

8. THE RETREATING MONSOON
(THE TRANSITION SEASON)
During October-November, with the
apparent movement of the sun towards the
south, the monsoon trough or the low-
pressure trough over the Northern Plains
becomes weaker. This is gradually replaced
by high-pressure system. The months of
October to November forms a period of
transition from hot rainy season to dry
winter conditions. The retreat of the
monsoon is marked by clear skies and rise in
temperature. While day temperatures are
high, nights are cool and pleasant. Owing to
the conditions of high temperature and
humidity, the weather becomes rather
oppressive during the day. This is commonly
known as October heat. The low-pressure
conditions over north-western India, gets
transferred to the Bay of Bengal by early
November due to which the state with its
neighboring states are often struck by
cyclones.

9. DISTRIBUTION OF
RAINFALL
The distribution of rainfall in India is
uneven. While Rajasthan receives less
than 60 cm of rainfall, Mawsynram
being the wettest place on the earth
receives around 1200 cm of annual
rainfall. To the western part of India,
monsoon is to the lowest point due to
which the eastern part of India is
flooded during the monsoon season.
Variations of rainfall even affect the
lifestyles of people in the particular
regions highly.

10. Acknowledgement
The success and final outcome of this project required a lot of
guidance and assistance from many people and we extremely
fortunate to have got this all along the completion of our project
work. Whatever we have done is only due to such guidance and
assistance and we would not forget to thank them.
We would not forget to remember our respective subject teacher-
Mr. Imran Hussain for his encouragement and more over for his
timely support and guidance till the completion of our project
work.
We are also thankful to and fortunate enough to get constant
encouragement, support and guidance from all co-group mates
which helped us in successfully completing our project work.

11. CONCLUSION
Monsoon has always been an unifying bond for India. The seasonal
alternation of the wind systems and the associated weather condition
provide a rhythmic cycle of seasons. The uncertainties of rain and
uneven distribution are very much typical of the monsoons. The
Indian landscape, its animal and plant life, its entre agricultural
calendar and the life of the people including their festivities revolve
around this phenomenon. The river valleys which carry this water also
unites as a single river valley unit

12. This presentation has been completed by:-
R.NO. STUDENTS NAME
01 Abhishek Das
08 Chironjit Chakraborty
09 Deepak Pandit
21 Khushboo Somani
27 Mehnaz Naseem
29 Muquaddisa Sabreen
32 Preksha Gattani
39 Shreya Ghosh
40 Sunil Pandit