Climate Flashcards

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1
Q

Name the type of climate India has

A

Tropical monsoon type of climate

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2
Q

Why does India have the climate it does?

A

India lies in the tropical belt and its climate is influenced by monsoon winds which are largely confined to the Tropics i.e., between 20° N to 20° S

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3
Q

What is the range of the Tropics?

A

20° N to 20° S

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4
Q

Give the main characteristics of tropical monsoon climate

A

Relatively high temperatures and dry winters

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5
Q

Name two features that prevent high temperatures and dry winters, characteristic of tropical monsoon climate

A

The Himalayas in the north, the Indian Ocean in the south

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6
Q

How do the Himalayas provide India with distinctive characteristic features?

A

They protect northern India from the cold winds of Central Asia and Siberia and give it a continental climate, the characteristics of which are the prevalence of land winds, dryness of air, and large diurnal range of temperature

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7
Q

What are the characteristics of continental climate?

A

Prevalence of land winds, dryness of air, and large diurnal range of temperature

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8
Q

How does the Indian Ocean provide India with distinctive climatic conditions?

A

Gives India a hot monsoon climate more typical of the tropical than of the temperate zone

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9
Q

Name the states which have a similar monsoon type despite having different climatic conditions

A

The climatic conditions of Bihar and UP in the north differ from that of Kerala and Tamil Nadu in the south, yet all of these States have a similar monsoon type of climate

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10
Q

What are regional diversities?

A

Variations in climate that occur in different regions of the country despite it having a broad unity of the monsoon type of climate

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11
Q

How are regional variations expressed?

A

Expressed in the pattern of winds, temperature, and rainfall, the rhythm of seasons, and the degree of wetness or dryness. These regional diversities are known as the sub-type of monsoon climate

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12
Q

In what forms do variations occur in precipitation?

A

In the type of precipitation, in its amount and seasonal distribution

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13
Q

How much rainfall do Cherrapunji and Mawsynram get in a year?

A

about 1100 cm

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14
Q

What is the rainfall in a single day in Tura in Meghalaya equal to?

A

10 years of rainfall at Jaisalmer in Rajasthan

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15
Q

What does climate refer to?

A

Climate refers to a generalized and composite picture of the average weather conditions spread over a long period, for a given large area

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16
Q

Name the factors which influence the climate of India

A
  1. The Himalayas
  2. Varied Relief
  3. The Monsoon Winds
  4. Latitude
  5. Altitude
  6. Influence of the Surrounding Seas
  7. Western Disturbances
  8. Jet Streams
  9. Distance from the Sea
  10. El-Nino Effect
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17
Q

State the function of the Himalayas for India

A
  1. The Himalayas prevent the cold Siberian winds from entering the Indian region and India from becoming a cold desert
  2. They force the moisture laden South West Monsoon winds to shed rainfall in India or else India would be a dry region
  3. They provide glaciers, perennial rivers, which are used to generate power. They provide employment as they have timber, wildlife, tourist attractions.
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18
Q

How does relief play an important role in the climatic conditions of Western Ghats?

A

The Western Ghats get heavy rainfall on the western side because they stand in the way of the South West Monsoon winds which come from the Arabian Sea

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19
Q

How does relief play an important role in the climatic conditions of Deccan Plateau?

A

The Deccan Plateau gets less rainfall as it lies in the rain shadow region of the Western Ghats

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20
Q

How does relief play an important role in the climatic conditions of Rajasthan?

A

In Rajasthan, the Aravalli Range is parallel to the direction of the SW Monsoon winds, so it is unable to stop the moisture laden winds. It is also lower in height. This makes Rajasthan a dry area.

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21
Q

Why do the southern hills of Assam get heavy rainfall and the northern hills do not?

A

The southern hills force the moisture laden winds to shed their moisture before they proceed northwards

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22
Q

Which factor has a universal effect in bringing summer rains over the whole of South Asia?

A

The monsoons winds

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23
Q

Where do the south westerly winds move during summer (in India)?

A

During summers, the winds move quickly into Peninsular India towards the low pressure system of north-west India from the Arabian Sea and Bay of Bengal

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24
Q

Why does Tibet remain dry?

A

The moisture carried by the south westerly winds from the Arabian Sea and Bay of Bengal brings rain to the entire Indian subcontinent, leaving Tibet dry in the rain shadow region of the Himalayas

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25
Q

When does the SW monsoon start retreating from Punjab and UP?

A

By the end of September

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26
Q

When does the SW monsoon start retreating from Central India?

A

By October

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27
Q

When does the SW monsoon start retreating from South India?

A

By the end of November

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28
Q

Where does the retreating SW monsoon bring rain?

A

In the eastern coastal region

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29
Q

Which winds blow in the winter? From where to where?

A

During winter, dry offshore NE monsoon winds blow from high pressure to low pressure region which is centred at the head of Bay of Bengal

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30
Q

Where do yeh NE monsoon winds originate?

A

Mongolia and North West China

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31
Q

What is the nature of the NE monsoon winds? Give reason

A

They are cold and dry as they blow over a vast landmass

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32
Q

Why does Tamil Nadu get rain in the winters?

A

The NE monsoon winds join the Trade Winds to pass over the Bay of Bengal. They pick moisture from the BOB to bring rain to Tamil Nadu in winters.

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33
Q

Which imaginary line divided India?

A

The Tropic of Cancer

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34
Q

Where does the northern portion of India lie?

A

In the temperate zone

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35
Q

Where does the southern portion of India lie?

A

In the tropical zone

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36
Q

What is the effect of a sub-tropical or warm temperate climate on the northern zone?

A

A cold winter season and a hot summer season

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37
Q

Why is the northern zone cooler than the southern?

A

The northern zone does not have the mid-day sun almost vertically overhead during any part of the year, but the southern zone has the midday sun almost vertically overhead at least twice every year

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38
Q

Why are the mountains cooler than the plains?

A

There is a decrease in 1 C for every 166 m rise in height, because temperature decreases as you move to higher altitudes

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39
Q

Why does Ooty have a much lower temperature than Kochi?

A

Because of its higher altitude

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40
Q

By which three water bodies is India flanked?

A

The Indian Ocean, the Bay of Bengal, the Arabian Sea

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41
Q

What is the impact of the water bodies surrounding India?

A

They act as the major source of moisture to the summer monsoons and bring heavy rainfall to the whole area. It is because of the nearness of the sea that these areas have a moderate climate.

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42
Q

What are the weather conditions during winter in the subcontinent generally influenced by?

A

The distribution pattern of pressure in Central and West Asia

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43
Q

In the winter, why is there rain in the Northern Plains and snow in J&K?

A

In the winter season, due to the shifting of the pressure belts, the westerlies blow from 20 N to 50 N latitude and North India comes under the influence of the winds and cyclones rising from the Mediterranean Sea. These cyclones bring rain to the Northern Plains and snow in J&K

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44
Q

What are jet streams?

A

They are cold fast blowing winds that develop in the upper layers of the atmosphere

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45
Q

How do the jet streams influence the climate of India?

A

The westerly jet stream prevails over the North Indian Plains during the winter months, while the easterly jet stream steers the tropical depression over India. These depressions play a significant role in the distribution pattern of monsoon rainfall in the subcontinent. The highest rainfall occurs along the track of these depressions

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46
Q

What type of climate do coastal areas have?

A

Equable or maritime climate

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47
Q

What type of climate do areas in the interior of India have?

A

Extreme or continental climate

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48
Q

What is responsible for moderate climate in coastal areas?

A

The effect of land breeze and sea breeze cause by differential rate of heating and cooling of land and sea

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49
Q

To what is the moderating effect of the sea limited?

A

The coastal areas

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50
Q

Which feature prevents the winds from carrying their moderating effects inwards in the Peninsula?

A

The Western Ghats

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51
Q

What is El-Nino?

A

It is a warm ocean current which sometimes appears off the coast of Peru in South America during the month of December

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52
Q

What is the effect of El-Nino on the Indian Ocean?

A

It increases the surface temperature of the sea and affects the movements of the monsoon winds in the Indian Ocean and causes weak drought like situation in the Indian subcontinent

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53
Q

Why do monsoon winds develop?

A

Because of differential heating as well as cooling of land and sea

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54
Q

Give another name for monsoon winds

A

Periodic or seasonal winds

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55
Q

Name the wind systems that the monsoon winds are divided into

A

The Summer Monsoon, and the Winter Monsoon

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56
Q

What is the Summer Monsoon?

A

In summer, the land gets heated more than the sea. Hence, a centre of low pressure develops on land. Over the adjoining sea, the air is comparatively cool, and a high pressure develops there. This causes the winds to blow from sea to lands. It is the Summer Monsoon.

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57
Q

When are the plains of the Indian subcontinent heated by the vertical rays of the Sun?

A

May, June, July

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58
Q

What is the SW summer monsoon?

A

Winds blow from the Indian Ocean northward and north-westward into Asia. As they blow from the sea to land, they bring heavy rainfall in some parts of India. The summer monsoon winds blow south-west, so they are known as SW summer monsoon

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59
Q

What is NE winter monsoon?

A

During winter season, a high pressure develops over a big landmass stretching from Central Asia up to north-west Indian plains. At the same time, a low pressure zone develops in the Indian Ocean. As the winds blow from land to sea, they bring cold dry weather and no rain.

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60
Q

What is the winter monsoon called? Why?

A

The winter monsoon winds blow north-east, so the monsoon is known as the NE winter monsoon

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61
Q

Which parts in India get rain from winter monsoons?

A

The Southern Coromandel Coast (Tamil Nadu and southern tip of Andhra Pradesh)

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62
Q

Why do the coastal areas not have very distinct seasons?

A

Due to the influence of the sea, they do not experience much variation in temperature though there occurs variation in the pattern of rainfall

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63
Q

Name the four principal seasons on the basis of monsoon variations

A
  1. The Hot and Dry Summer
  2. The Hot and Wet or Rainy Season or the South West Monsoon
  3. The Retreating South West Monsoon
  4. The Cold and Dry Winter Season or North-East Monsoon
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64
Q

What is the duration of the Hot and Dry Summer?

A

March to May

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65
Q

What is the duration of the Hot and Wet Season?

A

June to September

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66
Q

What is the duration of the Retreating South West Monsoon?

A

October to November

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67
Q

What is the duration of the Cold and Dry Winter Season?

A

December to February

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68
Q

Where do the vertical rays of the sun fall in the Hot Dry Summer? (21 March)

A

Directly over the Tropic of Cancer

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69
Q

Why does the length of the day increase in March-May?

A

Due to the apparent northward movement of the path of the sun’s vertical rays

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70
Q

What does the increasing length of the day in the hot dry summer result in?

A

In the increase in solar radiation which moves northward over the tropical areas of South Asia and the temperature starts rising

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71
Q

What is the temperature range in most parts of India in the Hot Dry Summer?

A

30 C and 32 C

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72
Q

What is the common temperature on the north-western part of India in the Hot Dry Summer?

A

Around 48 C

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73
Q

What keeps the temperature lower in South India in the Hot Dry Summer?

A

The moderating influence of the oceans together with the Peninsular situation of south India

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74
Q

What is the temperature range in South India in the Hot Dry Summer?

A

26 C and 32 C

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75
Q

Why are plateaus and hills relatively cool in the Hot Dry Summer?

A

Because of the elevation

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76
Q

What is large in the interior part lying on the west of the subcontinent in the HDS?

A

Diurnal Variation

77
Q

What causes a low pressure between Thar Desert and Chota Nagpur Plateau in the Hot Dry Summer?

A

The warm area shifts from the Deccan to northwest India. The high temperature in the subcontinent causes a low pressure.

78
Q

Where does a comparatively high pressure develop in the Hot Dry Summer?

A

By the end of May, a comparatively high pressure region develops near Cape Compton extending towards the Arabian Sea

79
Q

Where is the centre of the inland low pressure system in the Hot Dry Summer in June?

A

Over the Indus lowlands and Baluchistan

80
Q

What leads to thunderstorm with strong dusty winds in the HDS?

A

The low pressure over the Northern Plains draws winds from the surrounding areas and gives rise to thunderstorms with strong dusty winds. These winds cause a shower of rain mostly in Punjab, Haryana and UP

81
Q

Where do the thunderstorms with strong dusty winds mainly occur in the HDS?

A

Punjab, Haryana and UP

82
Q

What is loo?

A

Strong and dusty winds which blow during the day over northern and north-western India in the HDS

83
Q

What is the temperature range of loo?

A

Between 45 and 50 C

84
Q

Which medical condition occurs in north and north western India in the HDS? Why?

A

Heat strokes occur due to loo, and scarcity of water

85
Q

Where do tornado like dust storms take place in the HDS?

A

In Punjab and Haryana and UP

86
Q

What is Kalbaisakhi?

A

These are local winds that occur as thunderstorms accompanied with strong winds and heavy rainfall in the HDS in Assam and West Bengal

87
Q

What does Kalbaisakhi mean?

A

The calamity of the month of Baisakh

88
Q

What is Kalbaisakhi known as in Assam?

A

Bardoli Chheerha

89
Q

Where do the Kalbaisakhi winds originate?

A

Over the Chota Nagpur Plateau and are carried eastward by westerly winds

90
Q

Where do the Kalbaisakhi winds bring rainfall?

A

Assam, West Bengal, Odisha

91
Q

Which crops are Kalbaisakhi winds beneficial for?

A

This rainfall, if less, is good for growing jute and rice in West Bengal and tea in Assam

92
Q

When do the Kalbaisakhi winds cause thunderstorms?

A

April/May

93
Q

What are mango showers?

A

Thunderstorms cause rainfall along the Kerala and Karnataka coasts. The little rainfall even that they bring is important for mango, tea and coffee plants. Such rains are called mango showers as they help in the early ripening of the mango crop.

94
Q

What are mango showers called in Karnataka?

A

Cherry blossoms

95
Q

Which season is the season of general rainfall?

A

The SW monsoon season

96
Q

What causes the formation of an intense low pressure in the north-western part of the Indian subcontinent during April and May?

A

The large landmass to the north of the Indian Ocean gets intensely heated during April and Mayor. This causes the formation of an intense low pressure in the north-western part of the Indian subcontinent.

97
Q

Where do the South East Trade Winds prevail?

A

In the southern hemisphere

98
Q

What attracts the South East Trade Winds to the Indian Subcontinent?

A

The high pressure in the ocean to the south of India (Indian Ocean)

99
Q

Why are the SE Trade Winds deflected?

A

After being attracted by the high pressure in the Indian Ocean in the SW monsoon season and crossing the equator, these winds are deflected towards the right because of the Coriolis force and reach the west coast as South West Monsoon

100
Q

What do the SW monsoon winds bring to India in SW monsoon season?

A

Heavy rainfall accompanied by violent thunder and lightning

101
Q

What climatic event takes place in the first week of June?

A

Burst of the Monsoon - Sudden violent onset of rainfall in the first week of June

102
Q

What is the Break of the Monsoon?

A

When the South-West Monsoon fails to bring rainfall for two or more weeks and there is a dry period in the rainy season

103
Q

Which is the first State to receive the monsoons showers and also the last to see its withdrawal?

A

Kerala

104
Q

Why does the SW Monsoon divided into two branches?

A

As a result of the tapering topography of peninsular India

105
Q

Name the two branches of the SW monsoon

A

The Arabian Sea branch

The Bay of Bengal branch

106
Q

Why is there relief only as long as it rains in the HDS?

A

Because the relative humidity is quite high during July-August

107
Q

By how much does the temp in Mumbai drop after a week’s rain?

A

By 10 C

108
Q

What is the temperature in May vs in July in Nagpur after it has rained?

A

In Nagpur, a maximum of 45 C in May is seen which drops to 31 C in July

109
Q

How many branches does the Arabian Sea branch spilt into?

A

3

110
Q

Where do the three branches of the Arabian Sea branch go?

A
  1. One branch is obstructed by the Western Ghats
  2. The second strikes the coast north of Mumbai, cause rainfall in Central India, then enter the Ganga Plain and meet the Bay of Bengal Branch
  3. The third strikes the Saurashtra Peninsula and the Kutch, then passes over western Rajasthan and along the Aravalis, and joins the Bengal Branch in Punjab and Haryana
111
Q

Where does the first branch of the Aravalli branch bring rainfall?

A

To the windward side of the Sahyadri and the Western Coastal Plains

112
Q

Why do the winds of A-1 cause little rainfall east of the Western Ghats?

A

After causing heavy rains in the western side of the Western Ghats, these winds descend, get heated up and thereby, the humidity in the winds is reduced. Consequently, they cause little rainfall in the rain shadow area of the WG

113
Q

Where do the A-2 winds cause rainfall in the HDS?

A

In Mumbai. Then, they move further along the Narmada and Tapi river valleys and cause fair amount of rainfall in Central India. The Chota Nagpur Plateau receives 15 cm of rainfall from this branch, after which it enters the Ganga plain and mixes with BB.

114
Q

How much rainfall do the Chota Nagpur Plateaus get from A-2?

A

15 cm

115
Q

Where does A-3 cause rainfall?

A

The Saurashtra Peninsula and the Kutch. Then, it passes over western Rajasthan and along the Aravalis causing scanty rainfall

116
Q

Where do the BOB branch and the Arabian Sea branch meet?

A

In Punjab and Haryana, and cause rainfall in the Western Himalayas

117
Q

Where do the BOB branch and Arabian Sea branch cause rainfall together?

A

In the Western Himalayas

118
Q

Name the three permanent winds

A

Trade winds, westerlies, polar winds

119
Q

Why do Coromandel Coast and Northern Circas barely get rainfall?

A

They are near the coast and lie on the same latitude; however, they lie on the Eastern Ghat’s leeward side, so no rainfall (hardly 40-50 cm)

120
Q

Where is the BOB branch directed?

A

Towards the coast of Myanmar, Indonesia, Malaysia and part of south-east Bangladesh

121
Q

Why does a large part of the BOB branch get deflected towards the Indian subcontinent?

A

Owing to the presence of the Arakan Yoma Hills along the coast of Myanmar

122
Q

From where does the BOB branch enter India?

A

They entire West Bengal and Bangladesh from south and south east instead of the south westerly direction because they get deflected toward the Indian subcontinent

123
Q

In which two branches does the BOB branch divide?

A

One along the Ganga plains, and the other along the Brahmaputra Valley

124
Q

Where do the BOB branches cause rainfall?

A

In the Ganga Plains, Brahmaputra Valley and Garo and Khasi Hills of Meghalaya.

125
Q

Which places receive the highest average annual rainfall in the world?

A

Cherrapunji and Mawsynram, located on the crest of the southern range of Khasi Hills

126
Q

What is the distribution of rainfall received from South-West Monsoons largely government by?

A

Relief or topography

127
Q

Why does Mahabaleshwar receive over 250 cm of rainfall whereas Pune receives less than 70 cm of rainfall in the SW monsoon season?

A

Mahabaleshwar is on the windward side of WG & Pune is on the leeward side of these Ghats

128
Q

Why is there heavy precipitation in north eastern states in the SW Monsoon season?

A

Due to the occurrence of hilly ranges in these states

129
Q

What is the trend in rainfall as one goes from east to west in the SW monsoon season?

A

There is a decrease in rainfall

130
Q

Why does the Tamil Nadu coast remain dry in the HDS?

A

The Tamil Nadu coast is parallel to the Bay of Bengal branch of the SE monsoon. Further, it lies in the rain shadow area of the Arabian sea branch of the SW monsoon

131
Q

When does the SW monsoon start retreating from northern India?

A

Early October

132
Q

Which months are known for the retreating monsoon?

A

October and November

133
Q

What is the reason for the retreat of the SW monsoon?

A

The Monsoon trough of low pressure over the Ganga Plains becomes weaker due to the apparent southward movement of the Sun. The low pressure trough is gradually replaced by high pressure, and so the monsoon retreats from high to low pressure.

134
Q

What is the retreat of the SW monsoon marked by?

A

Clear skies and drop in the night temperature. The land remains moist. The weather is oppressive due to high temperature and humidity.

135
Q

What is October Heat?

A

An oppressive weather marked by the combination of high temperature and humidity due to the retreat of the SW monsoon. It is a transition period between the hot rainy season and the cold dry season.

136
Q

Why does the day temperature rise in the month of October?

A

Due to clear skies

137
Q

Where are the low pressure conditions transferred to by early November?

A

To the centre of the Bay of Bengal

138
Q

What is the shift of low pressure area to Bay of Bengal marked by?

A

Cyclonic depressions which originate over the Andaman Sea

139
Q

Why are there heavy and widespread rains on the coast of TN and parts of Odisha?

A

Cyclonic depressions that originate over the Andaman Sea as a result of the low pressure belt shift manage to cross the eastern coasts of the southern peninsula resulting in heavy and widespread rains on the coast of Tamil Nadu and parts of Odisha. These cyclonic storms move from the north-east to the south-west.

140
Q

Where do the retreating monsoons cause rain?

A

Coastal areas of Tamil Nadu, Odisha and parts of Karnataka

141
Q

From where is the bulk of the rainfall of Coromandel Coast derived in the retreating monsoon season?

A

From depressions and cyclones

142
Q

Why do the interior parts of the Deccan remain dry during the retreating monsoon?

A

Because they lie in the rain shadow of the Eastern Ghats

143
Q

What leads to tropical cyclones in November and December?

A

There are tropical depressions (low pressure systems) originating in the Bay of Bengal caused by local variations of heat and moisture

144
Q

Where do the tropical cyclones originate in November and December?

A

In the neighbourhood of the Andaman Islands between 12 N and 17 N and travel west or northwest over the Bay of Bengal

145
Q

What is the result of tropical cyclones in November and December?

A

They cause great loss of life and property due to heavy rains on the eastern coastal region of India

146
Q

When do fine weather conditions prevail over the continent?

A

By the end of October or by the beginning of November

147
Q

What are the characteristics of the North East Monsoon Season

A

The skies are relatively clear with dry weather. Night temperatures are low, especially in northern India, but the days are pleasantly warm.

148
Q

What is the mean temperature in the northern plains in the NE monsoon season?

A

Below 20 C, and gets even lower in Punjab, Haryana, J&K and Himachal Pradesh

149
Q

Which is the coldest month in the winter season?

A

January

150
Q

What is the temperature gradient vertically across the country in the North East Monsoon season?

A

The temperatures decrease from south to north

151
Q

What is the mean maximum temperature for the month of January at Thiruvananthapuram?

A

31 C

152
Q

What is the mean maximum temperature for the month of January at Calicut?

A

26 C

153
Q

What is the mean maximum temperature for the month of January at Varanasi?

A

About 16 C

154
Q

What is the mean maximum temperature for the month of January at Jammu?

A

10 C

155
Q

What is the mean maximum temperature for the month of January at Chennai?

A

24 C

156
Q

What is the range of night temperature in the Gangetic Plains in the NE monsoon season?

A

2.5 C - 17.5 C

157
Q

Which is the coldest place in India?

A

Dras Valley in Kashmir near Kargil which has a minimum temperature of -45 C

158
Q

What is the minimum temperature recorded in India?

A

-45 C in Dras Valley in Kashmir

159
Q

State the reasons for the excessive cold in north India during the NE monsoon season

A
  1. In the month of February, the cold winds from the Caspian Sea and Turkmenistan being cold wave over the northwestern parts of India
  2. Punjab, Haryana and Rajasthan experience continental type of climates as they are located far away from the sea to experience its moderating influence
  3. The snowfall in the nearby Himalayan ranges creates cold wave situation
160
Q

What is the average temperature in Peninsular India in the NE monsoon season?

A

20 C to 25 C

161
Q

What is the mean maximum temperature for June and January at Thiruvananthapuram?

A

June - 29.5 C

January - 31 C

162
Q

What is the weather in the NE monsoon season characterised by? (pressure)

A

Feeble high pressure conditions over the north-western part of the plain

163
Q

Why are there feeble high pressure conditions over the north western part of the subcontinent in the NE monsoon season?

A

Because of the oblique rays of the sun which reach the subcontinent as the sun moves to the southern hemisphere

164
Q

Why does the Coromandel Coast receive some rainfall in the NE monsoon season?

A

During this season, the NE Trade Winds prevail over the country. These winds blow from land to sea and hence, for most parts of the country it is dry season. However, when these winds pass over Bay of Bengal they pick up some moisture and cause some amount of rainfall on the Coromandel Coast

165
Q

Why the NE Monsoon Winds called so?

A

As these winds blow from north east to south west, they are called NE monsoon winds

166
Q

What are the western disturbances?

A

The low pressure depressions from the west and the north-west that come in during the cold weather season

167
Q

Where do the western disturbances originate?

A

They originate in West Asia and the regions near the Mediterranean Sea

168
Q

Give the course of westerly disturbances

A

They originate in West Asia and regions near the Mediterranean Sea, they travel eastwards across Iran and Pakistan and reach India during the winter season

169
Q

How many depressions affect India in each of the winter months?

A

Four or five such depressions in each of the winter months. They bring the much needed winter rains over the plains and snowfall in the mountains

170
Q

When are the western disturbances inactive in India?

A

Between December and February

171
Q

What is winter rainfall important for?

A

Rabi crops

172
Q

Why do most parts of India not receive rainfall in the winter season?

A

The winter monsoons have little humidity and due to anti-cyclonic circulation on land, the possibility of rain from them decreases

173
Q

Name the areas that receive rainfall in the winter season

A
  1. Central parts of India and northern parts of Peninsula get occasional rainfall
  2. Some weak temperature cyclones from the Mediterranean Sea cause rainfall in Delhi, Haryana, Punjab and western UP
  3. The north eastern part of India also gets rainfall during the winter months. Arunachal Pradesh and Assam gets rains between 25 mm and 50 mm during winters
  4. In the months of October and November, the North East Monsoon while crossing over the Bay of Bengal, picks up moisture and brings torrential rainfall over Tamil Nadu coast and southern tip of Andhra Pradesh
174
Q

Name the factors which determine the distribution of rainfall

A
  1. The pressure conditions and the direction of the relief features
  2. The direction of the winds bearing moisture
  3. Cyclonic depression determined by the pressure gradient
175
Q

How many rainfall regions can India be divided into?

A

4

176
Q

Why is Chennai so hot?

A

It lies in the torrid zone (south of Tropic of Cancer) & gets vertical sunrays twice a year

177
Q

When do the sun rays fall directly on the Tropic of Cancer?

A

June 21 is marked as the Summer Solstice, when the sun falls directly on the Tropic of Cancer.

178
Q

When is Summer Solstice?

A

21 December

179
Q

Give another name for Western Ghats

A

Sahyadris - in Maharashtra and Karnataka

180
Q

Why do coastal areas hardly experience any seasonal change in the distribution pattern of temperature in the NE monsoon season?

A

Due to proximity to the Equator and the moderating influence of the Sea

181
Q

Differentiate between tropical and temperate cyclones

A
  1. Tropical cyclones are largely a summer phenomenon, whereas temperate cyclones are the most intense in the winter season.
  2. Tropical cyclones are generally smaller in size and their shape is more or less circular, whereas temperate cyclones are bigger in size and oval in shape
  3. Tropical cyclones develop over seas, whereas temperate cyclones develop over continents
  4. Tropical cyclones develop in the tropical region of the Bay of Bengal and influence Indian coastal climate, whereas temperate cyclones develop in the temperate region of the Mediterranean Sea
  5. Tropical Cyclones bring heavy rainfall with strong winds over the Coromandel Coast of India, whereas temperate ones bring light to moderate rainfall in the North Western part of India under the influence of westerly jet streams
182
Q

Name the 4 rainfall regions India is divided into

A
  1. Heavy Rainfall Region
  2. Moderate Rainfall Region
  3. Low Rainfall Region
  4. Scanty Rainfall Region
183
Q

How much rainfall does the Heavy Rainfall Region receive?

A

More than 200 cm of rainfall annually

184
Q

How much rainfall does the Moderate Rainfall Region receive?

A

Ranging from 100 cm to 200 cm a year

185
Q

How much rainfall does the Low Rainfall Region receive?

A

Varying from 50 cm to 100 cm

186
Q

How much rainfall does the Scanty Rainfall Region receive?

A

Less than 50 cm annually

187
Q

Give the main sources of rainfall for Punjab and Haryana

A
  1. Western disturbances
  2. SW monsoon winds - Arabian Sea Branch
  3. SW monsoon winds - BOB branch
188
Q

Give the main sources of rainfall for Tamil Nadu coast

A
  1. SW monsoon winds
  2. NE monsoon winds
  3. Retreating monsoon winds
189
Q

Give the main features of Indian rainfall

A
  1. There is rainfall over three months and the rest of the year is mostly dry. Seventy per cent of annual rainfall occurs in the rainy season.
  2. The rains are mainly of the relief type. The windward slopes of mountains get more rainfall than the leeward side.
  3. Only a small portion of the rainfall is received from sources other than monsoon, like cyclonic and convectional rainfall
  4. The quantity and the time of occurrence of rainfall cannot be predicted as the rainfall is erratic. It is because of this uncertainty that sometimes there are floods, and sometimes droughts.
  5. India has an agrarian economy dependent on rainfall. As such rainfall affects the economy of the country.