Climate
Grade IX
Glossary
1.
Climate: Climate is the average weather conditions of a large duration of a sizeable area of the earth surface.
2.
Season: The predominance of an element of weather such as temperature, rainfall, cloudiness over a period of few months.
3.
Weather: Weather is the conditions of the atmosphere at any point of time over a smaller area.
4.
Monsoon winds: the complete reversal of the seasonal winds causing variations in the seasons. The reversal here means changes in the
direction of the wind.
5.
Climatic divide: The predominant land feature which divides the climates of the regions on its both sides.
Example: The Himalayas Mountain Wall acts as a climatic divide between India and Central Asia.
6.
Tropical Climate: The climate found in the tropical zone extending between the Tropic of Cancer and Tropic of Capricorn.
7.
Trade Winds: These are the planetary winds blowing constantly from the sub- tropical high pressure zones towards the Equatorial Low
Pressure Zones. Their direction is from North-east to the South-west in the Northern hemisphere and from South-east to North-west in the
South Hemisphere.
8.
Sub-tropical high pressure belt: The high pressure zones are found near 30 degrees North and the South latitudes in both the hemisphere
9.
(i) Inter-Tropical convergence zone: ITCZ is a broad trough of the low pressure found near the equator. Here North-east and the Southeast trade winds converge.
(ii) Monsoon trough: The inter tropical convergence zone when moved northwards in the summer and is established north in 25 degrees
north.
10.
Jet streams: The streams of intensely speedy winds flowing from west to east in the upper layers of the troposphere (12000 m).
11.
Cyclones: They are the speedy elliptical wind arrangement having the low pressure at their centre and the winds moving towards the centre
from outside.
12.
Burst or the break of the monsoon: Burst or the Break of the monsoon is the sudden setting in of the rainfall, the rainfall without the
warning. This occurs when the Monsoon branches and the jet stream comes into the contact with the each other all of the sudden.
13.
Western disturbances: they are the moisture laden cyclones originating over the Mediterranean Sea which reaches India through iran,
Afghanistan, and Pakistan and cause winter rains in the North-western parts of India.
14.
Loo: Loo are strong, gusty, hot and dry winds blowing during the day over north and north-western India during the summers.
15.
Cold Wave: The extreme cold weather conditions in winter over the northern plains when the temperature falls below 5 degrees celcius is
known as cold wave.
16.
Mango showers: The pre-monsoon showers occurring on the coastal regions of Kerala and Karnataka which help in the early ripening of the
mango fruit.
17.
Kalbaisakhi (Norwesters): The localized thunderstorms associated with the violent winds, torrential downpour and often accompanied by
the hails during the summer months in West Bengal.
18.
Period of transition: the intervening period between two seasons.
19.
Equable climate: the climate in which there is not much variation in the temperatures and the amount of rainfall.
20.
Precipitation: The moisture shed by the moisture laden winds on the surface of the earth which includes rainfall, snowfall, hailstorms, sleet
etc.
21.
Maritime clouds: The clouds which come into existence due to the condensation over the ocean or the sea and affect the coastal areas.
22.
October Heat: Conditions of the high temperature, humidity and the lack of air movement lead to the oppressive weather conditions in first
half of October.
23.
Coriolis Force: It is an apparent force associated with the earth’s rotation and is responsible for reflecting the wind towards the right in the
northern hemisphere and towards the left in the southern hemisphere. It is also known as the Ferrel’s law.
24.
El Nino: It is the periodic development of the warm ocean currents along the Peruvian coast as the temporary displacement of the cold
Peruvian current, every two to five years.
25.
ENSO (El Nino Southern Oscillation): The El Nino feature connected with the Southern Oscillation.
26.
Tornado: A violent hurricane frequent in the tropical countries.
27.
Vagaries of the monsoons: the unpredicted nature of the monsoons.
28.
Topography: A detailed account of the different features of a tract of country.
29.
Monsoons: The seasonal winds which blow from sea to land in summer and land to the sea in the winters.
30.
Range of Temperature: The difference between the maximum and the minimum recorded temperature of a particular place within a
particular period of time.
Question Bank:
1.
What does the monsoon imply?
2.
Name the elements of weather and climate.
3.
Name the place with the heaviest rainfall in India.
Or
Which place in India records the highest rainfall in the world?
4.
What are the rainiest months along the Tamil Nadu coast?
5.
When does the retreating S.W. Monsoon season begin in India?
6.
Which are the two characteristic features of the Tropical climate?
7.
Which part of India experiences the highest range of temperature in a day?
8.
Name the four months in which India receives the bulk of rainfall.
9.
What are the jet streams?
10.
What does the breaking of the monsoon mean?
11.
Name the states on the eastern coast that are frequently struck by the tropical cyclones.
12.
Name an area receiving rainfall from North-Eastern monsoon.
13.
Name the areas with less than 20cm of rainfall in Jammu and Kashmir.
14.
Name the season in which the Coromandel coast receives the rainfall.
15.
Mention two weather conditions which are associated with break or the burst of the monsoons.
16.
Name two states that are affected by the “Kal Baisakhis”.
17.
Why is there heavy rainfall in the north-eastern states? Give one reason.
18.
Western slopes of the Western Ghats receive the rainfall over 2500 millimeters. Write one reason for this.
19.
Which of the winds account for the rainfall in the Malabar coast and the Coromandel coast?
20.
Why do the North-east trade winds change their directions while blowing through the Ganga Valley?
21.
Give the reasons as to why parts of Rajasthan, Gujarat, and the leeward side of the western Ghats are drought prone
Or
Give the reasons why both western or Thar Desert and the interior of the Deccan Plateau are the regions of the low rainfall.
Or
Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought prone. Why?
22.
Explain with reasons, the weather conditions created by the Western disturbances in the Northern India in winter as distinct from the
Northern-Eastern Trade winds
Or
What are western disturbances? Name the two areas receiving the rains from them.
23.
What is rain shadow?
24.
Why are south-west monsoons less rainy in Tamil Nadu or Madras?
Or
Madras is comparatively dry when it is raining heavily on the Malabar coast in July. Why?
Or
Why do south-west monsoons give less rain in Tamil Nadu? Give two reasons.
25.
The Tamil Nadu coast receives winter rainfall. Give reason.
Or
The Eastern Coast of India (or Coromandel Coast) of Southern India receives more rain during the winter?
Or
Give reasons as to why does Tamil Nadu coast receives winter rainfall?
26.
The Punjab and Haryana also receive rain in winter. Why?
Or
Give two reasons why North-West India receives rain in winters.
27.
Name and give the direction of winds that cause snow and the rainfall in the northern parts of India during the winter season.
28.
Why does Mawsynram receive the highest rainfall in the world?
Or
Mawsynram receives the highest rainfall when Rajasthan is dry during the monsoons. Why?
29.
Why does Poona receive less rainfall than Bombay?
30.
Give one example each of :
(a) An equable climate
(b) Extreme type of climate
(c) The rainfall maxima during the south-west and the retreating monsoon
(d) Rainfall due to both western disturbances and monsoons in India.
Or
What is the extreme climate? Name two places of the extreme climate in India.
31.
What is the annual range of temperature? Explain it by giving the examples.
32.
Why has Trivandrum equable climate?
33.
Write two characteristics of Arabian Sea branch of the south-west monsoons.
34.
Write two differences between the loo and the cold wave.
35.
Which parts of India get (a) Heavy rainfall (b) Moderate rainfall (c) Low rainfall (d) Scanty rainfall
Or
Discuss the distribution of precipitation in the country and the consequences of its uneven distribution.
Or
Name two regions from India which receive over 200 cms of the annual rainfall.
36.
Why is the distribution of the rainfall in India uneven? Give four reasons.
37.
Why does the rainfall decrease from east to west in the Northern India?
Or
The rainfall decreases as we go up the Ganga Valley but increases as we go up the Indus Valley. Why?
Or
“Amount of rainfall decreases as we go westward from west Bengal to Punjab”. Mention two reasons.
38.
Rainfall decreases from east to west in the Northern Plain while it increases in the Peninsular India. Give two reasons for this pattern in each
area.
39.
Why does Delhi receive more rain than Jodhpur?
Or
“Delhi is rainier than Jodhpur”. Mention two reasons.
40.
Give reasons as to why the bulk of rainfall is concentrated over a few months.
41.
The delta region of the eastern coast is frequently struck by the cyclones. Give reasons.
Or
The deltas of Godavari, the Krishna, and the Kaveri are frequently struck by the cyclones. Give reasons.
42.
Define the monsoons. What do you understand by the break in the monsoon?
Or
Give the characteristics and the effects of the monsoon rainfall in India.
Or
Define the term Monsoon. Give four characteristics of the monsoon climate of India with the reference to the vagaries.
Or
What are the two characteristics features of the monsoon climate?
Or
What are the two problems being faced by our country due to the unequal distribution of the rainfall?
Or
“Monsoons in India are known for their uncertainties and the vagaries.” Explain this statement with four examples.
43.
What causes the reversal of the N.E. Monsoon winds? What influence does this have on the South-East Coast of India?
Or
Give reasons as to why seasonal reversal of the wind direction takes place over the Indian subcontinent.
44.
Distinguish between the weather and climate.
45.
Distinguish between: Equable and Extreme climate.
46.
Distinguish between the rainfall and precipitation.
47.
Distinguish between the windward and the leeward side.
48.
Why do the south-westerly winds cause the rainfall in India?
Or
How is the south-west monsoon different from the north-eastern monsoon? Write any four differences
49.
Distinguish between North-east monsoon and the retreating monsoons.
Or
What are retreating monsoons?
50.
What are the jet streams and how do they affect the climate of India?
51.
Valley of Kullu is more popular with the tourists. Why?
52.
What are the controls affecting the climate of India?
Or
Describe the location and the relief is important factors determining the climate of India.
Or
How does the relief affect the climate of India? Explain it with three specific examples from the different parts of India.
Or
How do the location and the extent of India affect its climate? Explain it with four examples.
Or
What type of climate would India have had, if the Arabian Sea, the Bay of Bengal and the Himalays had not been there? Explain it with
reference to the temperature and precipitation.
53.
Describe the regional variations in the climatic conditions of India with the help of the suitable examples.
Or
Give few examples of the apparent climatic contrasts in India to cover the following points:
(a) Range of temperature
(b) Direction of the rain- bearing winds
(c) Forms of precipitation
(d) Amount of rainfall
(e) Rainfall regime i.e. seasonal distribution
54.
Discuss the factors controlling the Indian weather conditions.
55.
Discuss the mechanism of the monsoons.
Or
Which phenomena are responsible for the rise of the south-west monsoon?
Or
Why does India have the monsoon type of climate?
56.
What are the monsoons? How are they caused? Describe briefly the summer monsoons and the winter monsoons.
Or
Why does not the Thar desert get rainfall even during the SW Monsoon period?
Or
“India would have been an arid land or desert if there had been no phenomena of monsoons”. Explain it by giving four points.
57.
How many seasons are recognized in India? Give their names.
Or
Give an account of the hot weather season in India.
Or
Give an account of the weather conditions and the characteristics of the cold season.
58.
Write a short note on the precipitation in India.
59.
Why most of the world’s deserts are located in the western margins of the continents in the subtropics?
60.
Explain the following terms:
(a) Coriolis Force
(b) Jet streams
61.
Describe the different types of the houses that are built in Rajasthan, in the Terai region, Goa, and
Mangalore and in Assam. What are the reasons for these differences?
62.
Describe the major controls of the climate of any place.
63.
Write a short note on the western cyclonic disturbances.
64.
Describe the main facts that are important to understand the mechanism of the Indian monsoon.
65.
Write a note on the onset of the monsoon.
66.
Write a short note on the withdrawal of the monsoon.
67.
Explain the features of the hot weather season (summer).
68.
Describe the main features of the Advancing Monsoon or the Rainy season or the south-west monsoon.
69.
What are the causes for the good rainfall and longer dry spells during the rainy season or the advancing monsoon?
70.
Write a short note on the retreating monsoon or the transition season.
71.
What is the highest temperature that reaches in Thar desert in Summer?
72.
To what extent do the temperatures come down in the winter at Drass?
73.
What is the maximum difference between the day and the night temperature found in Kerala and the Andaman and Nicobar island groups?
74.
State the six climate controls.
75.
Which jet streams are most constant?
76.
State the total annual rainfall received in Meghalaya.
77.
Mention major factors affecting the climate of our country.
78.
Which physiographic division acts as an influential climate divide between India and Central sea?
79.
Why is the tropical climate found in Northern India?
80.
Give two characteristics of the tropical climate.
81.
Which planetary winds blow from the subtropical high pressure zone to the Equatorial low pressure zone?
82.
Write the main cause of the formation of the Monsoon winds in India.
83.
What is the literal meaning of the Monsoon?
84.
Which is the influence area of the monsoon?
85.
Name the four months of rainy season in almost all over the country.
86.
Name the four seasons of India with their months.
87.
Give the names of the winter months in India.
88.
Where is the high pressure found during winter?
89.
Which winds blow in India during winter?
90.
What are the main characteristics of the trade winds?
91.
Where do the Western disturbances get originated?
92.
Name and give the direction of the winds that cause snow and the rainfall in the northern parts of India during the winter season.
93.
Which monsoon winds cause rains generally on the Tamil Nadu coast?
94.
Where is the maximum temperature in March?
95.
Which is the low pressure area in summer?
96.
What is the duration of the rainy season in the north-western parts of India?
97.
How much rainfall in the percentage occurs during the rainy season?
98.
Into which branches does the Peninsular India divide the Monsoon winds?
99.
Which mountain or hill range acts as a barrier in the path of the Arabian Sea Branch?
100
Which region receives the maximum amount of rainfall by the Arabian Sea branch of the South-west monsoon?
101.
What is the direction of the south-west monsoon in West Bengal?
102.
Which two branches in the Bay of Bengal branch split into?
103.
What is the nature of rainfall received from the Western branch?
104.
What type of rainfall does the north-east branch cause?
105.
Where does the heaviest rainfall of the World occur?
106.
What are the basic features of the monsoon?
107.
In which months does the Monsoon retreat?
108.
When does the monsoon leave the northern plains?
109.
Where does the low pressure area during November?
110.
Mention the two heaviest rainfall areas of the country.
111.
Which three regions receive less amounts of rainfall in India?
112.
Which regions of India experience snowfall regularly?
113.
What is relief rainfall?
114.
Why the Himalayas are called a climatic divide?
115.
Why is Kashmir Valley often called the Paradise on Earth?
116.
Enumerate the factors that influence the climate of the subcontinent of India.
117.
When is the Monsoon expected to break in Kerala and reach the plains of Punjab?
118.
What is meant by October Heat? Where is it experienced?
119.
What is the period of the transition?
120.
Write a short note on the conditions of Retreating monsoon.
121.
Inspite of abundant rainfall, India is a water thirsty land. Why is it so?
122.
Why does rainfall on the Western Ghats decrease from south to north?
123.
Why does Jodhpur enjoy desert climate? Give two reasons
124.
Enumerate regions of heavy rainfall.
125.
How is South-west Monsoon formed?
126.
Why the eastern sides of the Western Ghats are called a typical rain shadow area?
127.
Why does Chennai receive more rainfall during the winter?
128.
Which areas have more than 50cm and less than 5cm of rainfall in July? Why is it so?
129.
How have the easterlies assumed the name, Trade?
130.
Why does Shillong receive more rainfall than Calcutta? Give two reasons.
131.
What is the annual range of temperature? Explain it by giving one example.
132.
What is the extreme climate? Name two places of extreme climate in India.
133.
“Chennai gets more rainfall in winter than in summer”? Give two reasons.
134.
Write the three features of the monsoon rains in India.
135.
Write the main characteristics of the retreating monsoon.
136.
List the three main factors that determine the climate of India.
137.
State three dominant characteristics of the Indian monsoon.
138.
Name the two months in which cold weather season is experienced in most parts of India. Write one characteristics of this season.
139.
Give an account of the climatic conditions of India during summer season.
140.
How many seasons are recognized in India? Do they vary in their length from to south to north? If so, why?
141.
What are the elements of weather and climate?
142.
Explain the climate of India.
143.
Describe the seasonal variations in temperature.
144.
Explain the variations in precipitation received in India.
145.
What are jet streams?
146.
What is Indian monsoon?
147.
Explain El Nino.
148.
What are the four seasons of India?
149.
Distinguish between Western Cyclonic disturbances and Tropical cyclones.
150.
Discuss the withdrawal of monsoon.
151.
Give an account of the summer season of India.
152.
Discuss the features of the Retreating monsoon.
153.
Explain the distribution of rainfall in India. Also discuss variability of the rainfall in India.
Multiple Choice Questions:
1.
2.
3.
Which is the definition of weather?
(a) Sum total of the
(b) State of the
weather
atmosphere
conditions and the
over an area at
variations over a
any point of
large area for a
time
long period of
time
Monsoon type of climate is found mainly in:
(a) South Asia
(b) South east Asia
(c)
State of the
atmosphere over a
large area for a
longer period of time
(d)
None of the above
(c)
West Asia
(d)
South West Asia
(d)
5 degree Celsius
On a winter night what is the temperature at Drass in Jammu and Kashmir?
(a) 1degree Celsius
(b) -5 degree
(c) -45 degree Celsius
Celsius
4.
In which place the day temperature may rise upto 50 degree Celsius and drop down to near 15 degree Celsius the same night?
(a) Peninsular region (b) Andaman and
(c) Himalayan Region
(d) Thar Desert
Nicobar Islands
5.
In which of the areas there is hardly any difference in the day and the night temperature?
(a) Andaman and the (b) Kerala
(c) Jammu
(d) Chennai
Nicobar Islands
6.
Which of the statements are true about the rainfall in most parts of the country?
(a) Most parts of the
(b) Most parts of
(c) Most parts of the
country receive
the country
country receive the
the rainfall from
receive the
rainfall from January
October to
rainfall from
to March
November
June to
September
7.
In which months Tamil Nadu receives rainfall?
(a) October and
(b) December and
November
January
(d)
Most parts of the country receive the rainfall from
April to June
(c)
May and June
(d)
July and August
Where the houses thick walls and the flat roof?
(a) Punjab
(b) Haryana
(c)
Tamil Nadu
(d)
Rajasthan
9.
In which area are the houses built on the stilts?
(a) Meghalaya
(b) Assam
(c)
Tamil Nadu
(d)
Kerala
10.
Which of the following is the correct definition for the burst of the monsoon?
(a) The normal
(b) Normal rainfall
(c) Normal rainfall
rainfall increases
stops suddenly
continues for weeks
(d)
None of the above
8.
suddenly and
continues
constantly for the
several days
and again starts
together
11.
Where does the Arabian Sea branch of the monsoon reach approximately on the 10 th of June?
(a) Karnataka
(b) Madhya
(c) Delhi
(d) Mumbai
Pradesh
12.
Which is the period of the cold weather season or the winter in the northern India?
(a) Mid-November –
(b) September(c) January- March
(d)
February
November
13.
Which one is the characteristic feature of the cold weather season over the northern plains?
(a) Cyclonic
(b) Cyclonic
(c) Cyclonic
(d) Cyclonic disturbances from the west and north-west
disturbances from
disturbances
disturbances from
the east
from north
the south
14.
Which is the period of the hot weather season or summer?
(a) January to March (b) March to May
(c) February to March
(d)
October-December
May to July
15.
Which mountains prevent the cold winds from the Central Asia from entering the sub-continent?
(a) Vindhya
(b) Hindukush
(c) Himalayas
(d) Shivaliks
16.
Which of the following are the two branches of the monsoon?
(a) The Arabian Sea
(b) The Bay of
(c) The Western branch
branch
Bengal branch
17.
Where do the two branches of the monsoon merge with each other?
(a) North western
(b) Mumbai
(c) Madhya Pradesh
parts of the
Ganga Plains
18.
What is “ Kaal Baisakhi” called in West Bengal?
(a) Thunder storm in
(b) Thunder storm
winter
in summer
season
19.
Which one is the tentative date for the arrival of the monsoon in Delhi?
(a) 28th June
(b) 29th June
(c) 30th June
20.
When does the Bay of Bengal branch of monsoon reach Assam?
(a) First week of May (b) First week of
(c) Second week of June
June
Which one is the effect of the dust storm during the summer?
(a) Brings the
(b) Brings the dust
(c) Brings the dust and
temporary relief
and spoil the air
raises the
as they lower the
temperature
temperature and
bring the light rain
and the cool
breeze
21.
(c)
Thunder storm in
autumn season
(d)
The Eastern branch
(d)
Karnataka
(d)
Thunder storm in rainy season
(d)
1st July
(d)
Second week of May
(d)
Brings the dust and the hot breeze
22.
Why is there no noticeable change in the temperature pattern during the winters in the peninsular region?
(a) Due to the high
(b) Due to the
(c) Due the lower
(d) Due to the Deccan plateau
mountains
moderating
mountains
influence of the
sea
23.
Which is the wettest place on earth?
(a) Mawsynram
(b) Guwahati
(c)
Cherrapunji
(d)
Shillong
24.
Which of the following are the features of the loo in the north and the north western India?
(a) Strong winds
(b) Gusty winds
(c) Hot winds
(d) Cold winds
25.
Why are Tiruvanantapuram and Shillong rainier in June than in July?
(a) Due to the inflow
(b) Due to the
(c) Due to the western
of the South-west
north-east
cyclonic disturbances
monsoon in India
monsoon
26.
27.
Why Tiruvanantapuram does have the equable climate?
(a) It is near to the
(b) It is near to the
(c)
Tropic of cancer
sea
Why Jodhpur does have a hot desert type of climate?
(a) Because it is a
(b) Because it is a
(c)
undulating sandy
mountainous
plain covered with
region
the sand dunes
(d)
None of the above
It is a mountainous
region
(d)
It is a plain
Because it has no
rainfall during the
year
(d)
Because it is near to the sea.
28.
Besides the landform and the drainage, which is the third basic element of the natural environment?
(a) Temperature
(b) Wind
(c) Rainfall
(d) Climate
29.
Why do we wear the woollen clothes in the winters?
(a) To ward off the
(b) To ward off the
(c)
cold
heat
To remain calm
(d)
To remain drenched
30.
The sum total of the weather conditions and the variations over a large area for a long period of time is called:
(a) Weather
(b) Climate
(c) Hot weather
(d) Cold weather
31.
The state of the atmosphere over an area at any point of time is known as:
(a) Weather
(b) Climate
(c) Heat
32.
33.
34.
(d)
Why do the coastal areas experience less contrast in the temperature conditions?
(a) Due to the
(b) Due to the
(c) Due to the heat
(d)
moderating effect
landmass
conditions
of the sea
Which of the following climatic controls is the most important?
(a) Latitude
(b) Altitude
(c) Pressure and the
wind system
An apparent force caused by the earth’s rotation is called:
(a) Coriolis force
(b) Centrifugal
(c) Centripetal force
force
Cold
Due to none of the above three
(d)
Continentality
(d)
Jet streams
(d)
ITCZ
35.
A broad trough of low pressure in the equatorial latitudes is known as:
(a) Coriolis force
(b) Jet streams
(c) Centripetal force
36.
The state of the normal rainfall increasing suddenly and continuing constantly for the several days is named as:
(a) Break
(b) Burst
(c) Mango shower
(d) Kaal baisakhi
37.
What is mango shower?
(a) Pre monsoon
rainfall in
Karnataka and
Kerala
1.
(b)
Rainfall in June
to September
(c)
Rainfall in the winter
days
(d)
Rainfall caused by the western disturbances
Some Important Questions
Define monsoons. What do you understand by the break in the monsoon?
Monsoon is the seasonal winds which reverse their directions with the change in the seasons:
(a) From land to the sea during the winters.
(b) From sea to land during the summers.
Break in the monsoon means the sudden start of the monsoon or the onset of the monsoons.
2.
Why the monsoon is considered the unifying bond?
The monsoon is considered the unifying bond due to the following reasons:
The monsoons exercise an all embracing and unifying influence in the weather conditions of India. The seasonal reversal in the wind system
and the weather conditions, influx of the maritime air during the summer and the inflow of the western depressions during the winter constitute
the Monsoon regime. Really the Monsoon type of the climate prevails as much over the dry sands of the Thar as on the flooded paddy fields
of West Bengal and Kerala. The variations are the only regional facts of a composite meteorological reality. The Himalayas have imparted a
tropical touch of the climate even in the regions lying beyond the Tropic of Cancer where the climate should have been the temperature type.
3.
Why does the rainfall decrease from east to west in the Northern India?
The rainfall decreases from east to west in Northern India due to the following reasons:
(a) When the Bay of Bengal branch of the south west monsoon is obstructed by the Nepal and the Eastern Himalayas, maximum
amount of rainfall is received in West Bengal, Bihar etc.
(b) When these winds advance towards the west they go on shedding the moisture.
(c) In Kolkata the amount of rainfall is 105 cms.
(d) In Delhi, it is only 59 cms.
(e) Further it goes on decreasing and in Ambala it is less than 40 cm.
4.
Why the seasonal reversal of the winds does takes place over the Indian subcontinent?
The reasons are:
(a) During the summers ITCZ (Inter Tropical Convergence Zone) or the low pressure area develops over the north- west India and
Pakistan due the intense heating of the subcontinent.
 Monsoon winds (South-west monsoon winds) aim at the ITCZ and begin to blow from south-west but in the Bay of
Bengal, they begin to blow from the south-east to the north-west due to the Himalayan range in the north of the
subcontinent.
 They are the moisture laden and cause the rainfall throughout India.
 South-west monsoon winds from the Arabian Sea blow to the north-west India in the north-east direction.
 These winds cause the rainfall in Punjab, Haryana and J&K.
(b) During the winter the High Pressure area develops over the North-west India and Pakistan. The ITCZ or the low pressure area
begins to shift towards the Bay of Bengal.
 The winds begin to blow from the north-west to the east, south-east as the retreating monsoon.

When they reach Bay of Bengal they get the moisture and cause rains on the Coromandel Coast and the Orissa coast
as retreating monsoon
 In the December and January these winds come under the influence of the north-east trades and cause winter rains on
the Coromandel Coast. Their direction is from north-east to the south-west in the winters.
5.
Why is the bulk of the rainfall in India concentrated over a few months?
The reasons are:
1. Low pressure area remains only for a few months in the North- west India and Pakistan.
2. South-west monsoon begins to blow aiming this area.
3. They cause rainfall all over India.
4. After a few months the low- pressure area begins to shift towards east and the south-east.
5. With this shift of the low-pressure area (ITCZ) rains begin to withdraw.
6. It rains only for June to September in India.
6.
Why does the Tamil Nadu coast receive winter rains?
(a) Tamil Nadu coast lies on the eastern coast of the Peninsula. During the summer, the Arabian Sea Branch of the South-west
Monsoon ascends the Western Ghats and causes maximum rainfall on its western side. On the other hand, the Tamil Nadu coast
remains dry due to its location off the way of the South-west Monsoon as moving towards east they go on shedding their moisture.
(b) During the winter, the north-east dry monsoon winds blow over the Bay of Bengal. As they pass over the Bay of Bengal they pick up
the moisture and bring rain to the Tamil Nadu coast as now they are under the effect of the on shore winds, full of moisture. That is
why, Tamil Nadu coast receive rainfall more in the winters than in the summers.
7.
Why the delta region of the eastern coast is frequently struck by cyclones?
The reasons are:
 Rainy season does not receive rainfall regularly
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8.
When there is dry season tropical cyclones develop around the Andaman Sea.
Intense cyclones come in the influence of the Easterly Jet streams. They are boosted into India. They first strike on the delta
regions on the east coast and cause the heavy rainfall.
Some of the cyclones also develop during the season of the Retreating monsoon. They are very intense and cause havoc on the
Orissa, Andhra, and Tamil Nadu coasts, during October and November.
Why are the parts of Rajasthan, Gujarat, and the leeward side of the Western Ghats are drought prone?
The reasons are:
(a) Rajasthan and Gujarat generally fall parallel to the Arabian Branch of the South-West monsoon. They do not cause rainfall in this
region as Aravalli hills fall parallel to these monsoon winds and do not cut as a barrier.
(b) The windward side of the Western Ghats receives the heaviest rainfall due to the instant ascent of the south west monsoon winds
on the slopes of the Western Ghats and shed maximum moisture there.
When they cross the windward slopes and come on the leeward side they become dry and cause very little rainfall. Hence these areas
remain rainless or receive very scanty rainfall.
9.
Describe the regional variations in the climatic conditions of India with the help of the suitable examples.
Regional variations in the climatic conditions of India:
(a) Temperatures
 During the summer Rajasthan Desert experiences temperatures as high as 50 degree Celsius on a day while Pahalgaon
in Jammu and Kashmir is as 20 degrees Celsius.
 On a winter night Drass in J&K experiences temperatures as low as -45 degrees Celsius while the temperature on the
same night is 20 degrees Celsius in Tiruvanantapuram.
 Temperatures in Kerala and in Andaman and Nicobar islands remain uniform throughout the year.
(b) Precipitation
 In Himalayas precipitation generally occurs in the form of snow while in the rest of the country precipitation occurs in the
form of the rainfall.
 Precipitation is very heavy in Meghalaya. It is more than 400cms of the annually. On the other hand, it is less than 10cm
in Rajasthan Desert and Ladakh region.
 Tamil Nadu coast receives rainfall during the seasons of the retreating and the winter while rest of the country receives
the rainfall during the season of the South-west monsoon.
10.
Give the characteristics and the effects of the monsoon rainfall in India.
The characteristics are:
 Monsoon winds are not trades as trade winds are steady and permanent winds.
 They are not steady winds but are pulsating in nature.
 They are affected by different atmospheric conditions encountered by it. On its way over the warm tropical seas.
 The duration of the monsoon varies from 100 to 120 days from early June to mid-September.
 Around the time of its arrival, the normal rainfall increases suddenly and continues regularly for the several days.
 This is called the burst of the monsoon.
 They are distinguished from the pre-monsoon showers because of their increase in the rainfall amount and regularly.
 The monsoon arrives at the southern tip of the Indian Peninsula generally by the first week of June. From here it divides itself into
two- the Arabian Sea branch and the Bay of Bengal branch
 The Arabian sea branch reaches Mumbai about ten days later on 10 June.
 This is fairly the rapid advance.

The Bay of Bengal branch also advances rapidly and arrives in Assam in the first week of June.
 On reaching the eastern Himalayas it is deflected towards the west over the Ganga plains.
 By the mid-June the Ararbian Sea branch of the monsoon arrives Saurashtra- Kuchchh region and the central part of the country.

The Arabian Sea and the Bay of Bengal branches of the monsoon merge over the north-western part of the Ganga Plains.
 Delhi mostly receives the monsoon showers from the Bay of Bengal branch by the end of June.
 By the first week of July, Uttaranchal western Uttar Pradesh, Punjab, Haryana and eastern Rajasthan experiences monsoon rains.
 June 29 is the scheduled date of the monsoon arrival in Delhi.
 By the mid-July the monsoon reaches Himachal Pradesh and the rest of the country.
 Monsoon onsets in the islands very early. They receive the first monsoon showers, progressively from south to north; form the first
week of April to the first week of May.
Effects of the Monsoons:
 As it is often irregular in its arrival and its retreat, it sometimes disturbs the farming schedule of the millions of the farmers all over
the country.
 Sometimes the heavy rainfall brings in their wake, devastating floods causing damage to the life and property in the plains.
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11.
13.
Because of its uncertainties, if the dry spell is longer and there is no rain in an area, it may lead to the drought in that area.
South-west monsoon does not cause rains regularly. Their amount also varies from year to year.
After heavy rainfall there is a decrease in its quantity. Sometimes large durations of the rainy season go without rains.
Cyclones at the head of the Bay of Bengal control the effectiveness of the monsoon winds. From June to September the number
of the cyclones is about 8. Intense cyclones give strength to the Monsoon winds and help in causing heavy rainfall, their less
intensity causes dry spells.
 Monsoon trough of the low pressure situated over the North Plains also affects the distribution of the rainfall. The axis of the
trough close to the Himalayas causes the heavy rains in the mountains and floods in the plains resulting in a great loss to man
and material.
 Occurrence of heavy rains and dry spells leads to uncertain and uneven distribution of rainfall. Thus floods and the dry spells are
twin phenomena in the country.
 Success or failure of the agriculture crops depend on the amount of the rainfall. Thus the Indian Agriculture still remains a gamble
to monsoon though we have tapped irrigation potential to a great extent.
 Uncertain and the uneven distribution of the rainfall and the alteration of the floods and the dry spells are the essence of the
vagaries of the South-west monsoon
 Rural as well as the urban folk of the population of the population has to bear the brunt of the monsoon equally.
Why the houses in Rajasthan have thick walls and the flat roofs?
Thick walls:
 During the winter extreme cold is experienced during night.
(i)
Thick walls do not allow cold to enter the houses.
(ii)
Hence houses inside remain warm.
 During the summer extreme heat is experienced during the days.
(i)
Thick walls do not allow heat to enter inside the houses.
(ii)
They absorb heat and inside is cool.
Flat roof:
 There is sand everywhere on the ground.
 Flat roofs are used to dry the crops and bring out grains.
 Dry fodder is kept on the flat roofs of the houses.
 Flat roofs are used for sleeping during summer nights.
 Flats are ideal for keeping the houses cool during summer and the warm winter.
 Due to scanty rainfall there is no risk of breaking the flat roofs in the heavy rains.
Why is it that the houses in the Tarai regions and in Goa and the Mangalore have sloping roofs?
The reasons are:
 Rainfall occurs heavily in these regions.
 To avoid the risk of the flooding the roof, sloping roofs are made.
 It allows rain water flow speeding. Non- accumulation water allows sloping roofs being safe during raining season.
14.
Why the houses in Assam are built on the stilts?
 Due to the heavy rainfall atmost throughtout the year the ground is always wet.
 Stilts also allow free flow of water and the houses are not flooded.
 Several poisonous reptiles live on the ground.
 To avoid the wetness and danger from poisonous reptiles the houses are built on the stilts.
15.
Why most of the world’s deserts are located in the western margins of the continents in the subtropics?
The world’s deserts are located in the western margins of the continents in the subtropics like Alakama, Colorado, Sahara, Saudi Arabia and
the Western and the Central Asia.
 They fall in the path of the trade winds.
 They move from east to west.
 When they reach western margins of the continents they are almost devoid of moisture and cause little rainfall.
 Cold currents pass along these coasts. They do not let the evaporation take place. Air does not contain moisture. Thus they remain
devoid of the rainfall.
16.
Why does Chennai receive more rainfall during the winters?
The coast of Tamil Nadu or Chennai coasts have more than 5cm of rainfall in the winters. It is because the North-east monsoon winds
passing over the Bay of Bengal get moisture and when they reach the Tamil Nadu coasts they cause rainfall here.
17.
Why does Shillong receive more rainfall than Calcutta?
Shillong is situated on the Meghalaya Plateau which receives the highest rainfall in the country.
Shillong is situated on the lofty mountains, funnel shaped. Here condensation is intense causing heavy rainfall. Kolkata is located on the
Ganga-Brahmaputra Delta. There is no mountain range obstructing the South west monsoon. Hence, it receives less rainfall.
18.
Write two differences between Loo and the Cold wave.
Loo
(i)
Loo is the local hot winds which blow during the
summer afternoons in the north-west and the Ganga
valley regions.
(ii)
Sometimes they are accompanied with dust storms
and the light drizzle which bring temperatures down in
the afternoon.
(i)
(ii)
Coldwave
Cold wave is that condition of weather during winter
when very icy cold winds blow in the north-west and
the Ganga valley regions of India.
This brings the temperature below 5 degree celcius
and keeps the weather clear, cold and windy.
19.
Chennai gets more rainfall in the winter than in the summer. Give two reasons
(i)
Chennai lies on the eastern coast of the Peninsula. During summer, Arabian sea branch of the South-west monsoon ascends
the western ghats and causes the maximum rainfall on its western sides. On the other hand, the Tamil Nadu coast on which
Chennai is located remains dry due to its located remains dry due to its location off the south-west Monsoon as moving
towards east they go on shedding their moisture.
(ii)
During winter the north-east dry monsoon winds blow over the Bay of Bengal. As they pass over the Bay of Bengal they pick
up the moisture and bring the rain to the Tamil Nadu coast as now they are under the effect of the on-shore winds, full of
moisture. Chennai is situated on the east coast. That is why, Chennai receives rainfall more in winter than in summer.
20.
Write the three main features of the monsoon rains in India.
(i)
Monsoon rains in India mainly occur during the four months- June, July, August and September
(ii)
It goes on decreasing from the east to the west ( rains from the Bay of Bengal branch) and from the west to the east, southwest to the north-east (rains occurring from the Arabian Sea branch)
(iii)
Most of the monsoon rains occur during the season of the advancing monsoon around 85 percent of the total annual rainfall.
21.
Write the main characteristics of the retreating monsoon.
(i)
October and November are the months of the retreating monsoon.
(ii)
During this season low monsoon trough becomes weak and is replaced by the high pressure. Thus, monsoon begins to
retreat. By the beginning of the October it retreats completely from the northern plains.
(iii)
This period is the period of the transition from the hot rainy season to the cold winter season. It is marked by the clear sky,
moist ground and the high temperatures giving birth to the October heat.
(iv)
Low pressure trough shifts to Bay of Bengal. They give rise to the cyclonic depressions which cause havoc on the eastern
coast – especially the coast of Orissa, Andhra Pradesh, and Tamil Nadu.
How many seasons are recognized in India? Do they vary in their length from South to North? If so, why?
The meteorologists have recognized four seasons in India. They are as follows:
(i)
The cold season
(ii)
The hot season
(iii)
The season of the south-west monsoon
(iv)
The season of the retreating monsoon
This seasonal pattern is not well marked in all the parts of the country. They vary in their period from South to North.
The following reasons determine this:
(i)
The southern part of the country experiences the tropical weather conditions throughout the year because of its proximity to
the equator and the nearness to the sea. Seasons are not well marked in this part. South India experiences only two seasonsdry and wet.
(ii)
The northern part of India experiences well marked four seasons. They are recognized as summer and the winter seasons due
to the distance from the sea and the equator. The other two seasons include the season of the advancing south- west
monsoon and the season of the retreating monsoon.
22.
23.
Explain El Nino.
El Nino is the name given to the periodic development of a warm ocean current along the coast of Peru as a temporary replacement of the
cold Peruvian current. This current starts flowing during the winters. The presence of El Nino results in an increase in the sea-surface
temperatures and weakening of the trade winds in the region.
24.
Distinguish between the Western Cyclonic disturbances and Tropical Cyclones.
Western Cyclonic disturbances
Tropical Cyclones
Weather phenomenon of the winter months
Weather phenomenon of the monsoon and the retreating monsoon
months (October and November)
Brought from the Mediterranean region by the Westerly Jet Streams
They are the parts of the easterly flow.
into the north and the north-western parts of India.
They influence the weather of the north and the north-western parts
of India and cause the widespread winter rains here.
They do not cause any damage and are generally beneficial for the
rabi crops
25.
Distinguish between the South-west monsoon and the North-east monsoon.
South-west monsoon
North-east monsoon
The winds blowing from the south-west to the north east direction
The winds blowing in India from north-east to the south west direction
during the period from December to February constitute the north
during the months of June to September in India are called Southeast monsoon winds
west monsoon winds
During the period of these winds low pressure region has become
established in the northern plains of the country. Hence they move
from the south-west towards low pressure region.
They come from the tropical seas and the oceans. Hence they are
moisture laden and hot.
These winds cause 75 to 90 percent of the total annual rainfall during
the season of the south west monsoon.
The south west monsoon has two branches- the Arabian Sea branch
and the Bay of Bengal branch.
Rainy days, soothing winds and overcast sky are the characteristic
features of the South-west monsoon.
26.
They influence the coastal areas of India and cause storms and the
heavy rains there.
Sometimes they cause disasters on the coasts of Orissa and Andhra
Pradesh coasts.
Distinguish between Wind and the Jet Stream
Wind
Winds are moving air from high pressure to low pressure areas.
They move horizontally on the surface of the earth.
Their speed is upto 75km per hour
Winds are divided as dry winds, moist winds, cold winds and the hot
winds.
North- east monsoon winds blow from the high pressure region
towards the seas where the low pressure exists these days.
They blow from land. Hence they are cold and dry.
They absorb moisture passing over the Bay of Bengal and cause
rainfall on the Tamil Nadu coast during the winters.
They do not have branches, western disturbances also occur during
this season. But their occurrence is based on the different factors.
Most of the countries experiences clear sky, low temperature. Gentle
breeze and the rainless fine weather makes the season very healthy.
Jet Stream
Jet streams are the fast moving mass of air in the upper troposphere.
They move horizontally in the upper troposphere. Their speed
exceeds 200km per hour.
Jet streams are the western and the eastern jet streams.
They are responsible for the sudden outbreak of the monsoon in the
northern India.
27.
Distinguish between the South-west monsoon and the retreating monsoon.
South-west monsoon
Retreating monsoon.
The period from June to September is the season of the south west
The period from October to November is the period of the retreating
monsoon.
monsoon.
It is the season of the rain bearing winds advancing towards the
It is the period of the transition between rainy season and the north
east monsoon season.
whole of India
The monsoon winds blow from the sea to land. Hence they are the
These monsoon winds blow from land to sea. Hence they are dry.
They do not cause rains over most of the parts of the country except
moisture laden winds and cause wide spread rainfall all over India.
the east coastal India and Tamil Nadu coasts.
75 percent to 90 percent of the annual rainfall occurs during the
Less than 5 percent of the annual rainfall occurs during this period.
period of these Monsoon winds.
28.
Distinguish between the Equable and the extreme climate.
Equable Climate
Equable climate does not have high temperature during summer and
the low temperature during the winters.
The regions of the equable climate experiences very low diurnal and
annual ranges of the temperature.
Equable climate is found in the coastal regions. In India Kerala
coasts experience this type of climate
Because of this climate being found in the coastal regions, it is also
called the maritime climate.
Extreme Climate
The climate has high temperatures during summer and low
temperatures during the winter.
These regions have very high diurnal and the annual ranges of
temperature.
The interior parts of the countries and the continents experience
extreme climate.
Because of this climate being found in the interior of the continents, it
is termed as the continental climate.
29.
Distinguish between Rainfall and Precipitation
Rainfall
The moisture shed by the moisture laden air in the form of water
droplets on the surface of the earth is called rainfall.
Rainfall occurs mainly in the form of the water droplets, drizzle,
downpour, and heavy rainfall.
Rainfall is a form of precipitation.
Rainfall is generally occurs in the low latitude regions like the
monsoon lands and the equatorial regions.
Precipitation
The moisture shed by the moisture laden air on the surface of earth
in any form
Precipitation occurs in the form of rainfall, snowfall, sleet, hail-storm,
drizzle and the heavy down pour.
Precipitation is wider term having rainfall as one of its several forms.
Snowfall occurs in the high latitude regions and the high altitudes.
Rainfall in the low latitudes and the hail storms and the drizzle
sometimes accompany rainfall in these regions.