Important Questions for Chapter 4 Climate Class 9 Geography
Important Questions1
Kal Baisakhi is associated with which state?
Answer
Bengal
VSAQ
2
Which is the coldest place in India?
Answer
Drass.
VSAQ
3
Why the peninsular part of India experiences peak summers earlier than northern India?
Answer
Due to northward movement of the sun, the global heat belt shifts northward.
VSAQ
4
Why Bengal, Orissa and Andhra Pradesh coasts are frequented by cyclones?
Answer
Low pressure conditions in northwest India lead to the creation of depression over Andaman sea.
VSAQ
5
Which place in India records the highest rainfall in the world?
Answer
Mawsynram.
VSAQ
6
Which part of India experiences the highest range of temperature in a day?
Answer
Thar Desert in Rajasthan.
VSAQ
7
What are Jet Streams?
Answer
Jet Streams are the fast blowing westerly winds found in a narrow zone at high altitudes above 12,000 m in the troposphere.
VSAQ
8
In winter the western cyclonic disturbances originate from which sea?
Answer
Mediterranean Sea.
VSAQ
9
Which is a component of upper air circulation?
Answer
Jet Streams.
VSAQ
10
What type of climate does Rajasthan desert have?
Answer
Continental climate.
VSAQ
11
From which pressure belts do the northeasterly trade winds originate?
Answer
Subtropical high pressure belt of the Northern Hemisphere.
VSAQ
12
Name two states where Mango showers occur?
Answer
Karnataka and Kerala.
VSAQ
1
Where is Mawsynram located? Why does Mawsynram receive the highest amount of rainfall?
Answer
Mawsynram is located in the southern ranges of the Khasi Hills at a height of 1,500 m above the sea level.
This place receives the highest amount of rainfall because it is enclosed by hills on three sides. The relief features give this place a tunnel-shaped location. The Bay of Bengal monsoon is trapped in these hills. The winds try to get out of it, but are forced to pour down there.
SAQ
2
What influence has the Himalayas on India’s climate?
Answer
• Himalayas act as natural barriers to the extremely cold winds from Central Asia and enables North India to have more or less uniform and comfortable temperatures.
• They act as a barrier to the south west monsoon in summer and precipitates heavy rain on the country.
• Most of the Indian rivers are fed by glaciers located in the Himalayas.
SAQ
3
Differentiate between climate and weather.
Answer
• Climate: It refers to the sum total of the weather conditions and variations over a large area for a long period of time.
• Weather: It refers to the state of atmosphere over an area at any point of time. The elements of weather and climate are the same.
SAQ
4
What are ‘Jet Streams’? How is Jet Stream related with Western Cyclonic Disturbances?
Answer
Jet Streams are a narrow belt of high altitude westerly winds in the troposphere. Their speed varies from about 110 km/h in summer to about 184 km/h in winter. Little amount of winter rains over the plains and snowfall in the mountains are an impact of western cyclonic disturbances from the Mediterranean Sea.
SAQ
5
Why does India have a monsoon type of climate?
Answer
• Climate of India is strongly governed by the monsoon winds. Monsoon winds are confined to tropical lands between 20° North and 20° South.
• In the India subcontinent, the Himalaya's guide the flow of the monsoon winds bunging the whole of subcontinent under the influence of this winds.
• These winds account for 75% to 90% of annual rainfall from tune to September.
SAQ
6
What are the factors affecting the climate of India?
Answer
Factors affecting the climate of India:
• Latitude: The temperature decreases from the Equator towards the poles. Places located on lower latitudes are hotter than the places located on higher latitudes. Solar energy is present at a higher rate more in lower latitudes.
• Altitude: At higher altitudes, the atmosphere becomes less dense and temperature decreases. Hills are cooler during summers, e.g., climate of Shimla climate is cooler than that of Delhi.
• Distance from the sea: Sea has a moderating influence on the climate. As the distance from the ocean or sea increases, its moderating influence decreases and extreme weather conditions are experienced, i.e., very hot in summer and very cold in winter.
SAQ
7
How does the latitude affect India's climate?
Answer
• The Tropic of Cancer passes almost from the middle of the country.
• Almost half of the country, lying south of the Tropic of Cancer, belongs to the tropical area.
• All the remaining area in the north of the Tropic lies in the sub-tropical area. Thus, India's climate has characteristics of tropical as well as sub-tropical type of climate.
SAQ
8
Describe the western cyclonic disturbance and its impact on climate.
Answer
• Western cyclonic disturbances are a weather phenomena of the winters.
• They are brought in by the westerly flow from the Mediterranean region.
• They usually influence the weather of the North and North-western regions of India.
SAQ
9
Highlight any three characteristics of cold weather season in India.
Answer
• The temperature decreases from South to North. The days are warm and nights are cold.
• Frost is common in the North and the higher slopes of the Himalayas experience snowfall.
• North-east trade winds blow all over the country. They blow from land to sea. For most part of the country it is a dry season. Some amount of rainfall occurs on the coast of Tamil Nadu from these winds, as in this region they blow from sea to land.
SAQ
10
What is meant by the term ‘Monsoon’? Mention main characteristics of the monsoon.
Answer
The word monsoon is derived from the Arabic word ‘mausim’, which literally means ‘season’. Monsoon refers to the seasonal reversal in the wind direction during a year.
Characteristics of Indian monsoon:
• They are not steady winds but pulsating in nature. They vary from year to year.
• They have tendency of breaks in rainfall. It has wet and dry spells. They take place only for a few days at a time.
• The monsoons are known for their uncertainties. They are often irregular in their arrival and retreat.
SAQ
11
What is the coriolis force? Describe its effect briefly on the world climate.
Answer
Coriolis force is an apparent force caused by the Earth's rotation. It is responsible for deflecting winds towards the right in the northern hemisphere and
towards the left in the southern hemisphere. Under the effect of coriolis force, the trade winds moving from sub-tropical high pressure belts to equational low pressure belts become north-east trade winds in the northern hemisphere and south-east trade winds in the southern hemisphere. Thus, they bring heavy rainfall to the east coast and the west coast remains dry.
SAQ
12
What is Inter Tropic Convergence Zone (ITCZ)? Explain.
Answer
• It is a trough normally positioned about 5 degree North of the Equator.
• This zone lies more or less parallel to the Equator.
• Moves North or South with apparent movement of the sun.
• It is a broad trough of low pressure in equatorial latitudes.
SAQ
13
Define monsoon. Differentiate between ‘Burst of Monsoon’ and ‘Break of the Monsoon’.
Answer
Monsoon refers to the seasonal reversal in the wind direction during a year.
Burst of the Monsoon: Rainfall increases suddenly and continues constantly for several days.
Break of the Monsoon: Monsoon rains take place for a few days only. And it is characterised by rainless intervals.
SAQ
14
What are Tropical cyclones?
Answer
• They occur during the monsoon, as well as in October and November.
• These disturbances affect the eastern coastal regions of India.
• They originate over the Andaman sea and are often very destructive.
SAQ
15
State any three factors which help us to understand the mechanism of monsoon.
Answer
The factors which help us to understand the mechanism of monsoon are:
• The differential heating and cooling of land and water.
• The shift in the position of Inter Tropical Convergence Zone [ITCZ].
• The presence of the high pressure – East of Madagascar.
• The Tibetan Plateau gets intensely heated during summer.
SAQ
16
What are Western Disturbances? How do they affect the climate of India?
Answer
Western Disturbances are the temperate cyclones which originate over the Mediterranean Sea and Western Asia, and move into India, along with the westerly flow of jet streams.
• They disturb the calm and quite weather of North and North-western India by causing cyclonic rains over the plains and snowfall in the mountains.
• Winter rainfall caused by them locally known as 'Mahawat’ is of immense importance for the cultivation of Rabi crops.
SAQ
17
Describe the climatic conditions of India during Retreating Monsoon.
Answer
Climatic conditions during Retreating Monsoons:
• This is the transition period during the months of October and November.
• The season changes from hot and rainy to dry winter conditions. The retreat of the monsoon is marked by clear skies and rise in temperature. Day temperatures are high and nights are cool and pleasant.
• Low pressure conditions get transferred to the Bay of Bengal by early November.
SAQ
1
Explain how the pressure and wind conditions over India are unique.
Answer
• During winter, a high pressure area develops north of the Himalayas.
• Cold dry winds blow from this region to the low pressure areas over the oceans to the south.
• In summer, a low pressure area develops over interior Asia as well as over northwestern India.
• This causes a complete reversal of the direction of winds during summer.
• Air moves from the high pressure area over the southern Indian ocean in a south-westerly direction, crosses the equator and turns right towards the low pressure area over the Indian sub-continent.
• These winds are known as south-west monsoon winds.
• These winds blow over the warm oceans, gather moisture and bring widespread rainfall over the mainland of India.
LAQ
2
Explain why the distribution of rainfall in India is uneven?
Answer
• Monsoon rains are limited only to few months of a year.
• The topography of India leads to more rainfall in some regions while less in others.
• Cyclones help rain scattering at places, while other places remain without rain.
• Whole of India does not receive rain by monsoon winds. Eastern Coast of India gets rain only from North-east monsoons during the month of December-January.
LAQ
3
What are the six major controls of the climate of the world?
Answer
• Latitude: Due to the round shape of the Earth, the amount of solar energy received varies according to latitude. As a result, air temperature decreases from the equator towards the poles.
• Altitude: As one moves up to the higher altitudes, the atmosphere becomes less dense and temperature decreases.
• Pressure and winds: Pressure and wind system of an area depend on the latitude and altitude of the place.
• Distance from the sea: If the region is close to the sea, it makes the temperature moderate but if it is away from the sea, it experiences extreme weather conditions.
• Ocean currents: Ocean currents along with the onshore winds affect the climate of a coastal area. Any coastal area with warm or cold currents flowing past it, will become warm or cold if the winds are onshore.
• Relief: High mountains act as barriers for cold and hot winds. They may also cause precipitation if they lie in the path of rain-bearing winds. The leeward side of mountains remains dry.
LAQ
4
Define burst of monsoons. Give an account of the climatic conditions of the cold weather season in India.
Answer
Burst of Monsoons: When monsoons arrive in India, the normal rainfall increases suddenly and continues constantly for several days. This is called ‘burst ofmonsoons:
• Cold weather season – November to February
• The temperature decreases from South to North.
• Days are warm and nights are cold.
• North-east trade winds prevail over the country.
• The weather is marked by clear sky, low temperature, low humidity and feeble variable winds.
• Low pressure system of Mediterranean Sea moves into India and causes rainfall over the plains and snowfall in the mountains.
LAQ
5
Describe any five characteristic features of the hot weather season in India.
Answer
• Between March to May.
• Low pressure develops extending from Thar Desert, in the North-west to Patna and Chotanagpur Plateau in the East and South-east.
• Temperature ranges between 38 degree Celsius to 45 degree Celsius in the North.
• Pre- monsoon showers are common; are know as Kaal Baisakhi, Mango Showers.
• Loo, a hot, dry, dusty and strong wind blows over the North and North-west India, dust storms.
LAQ
6
Why does the rainfall decrease from east to west in Northern India?
Answer
The bulk of rainfall in India comes from the southwest monsoons.
• The Arabian Sea branch of south-west monsoon approaches from the western side of the peninsula and moves in a southwesterly direction and reaches the Northern Plains by first week of July.
• The Bay of Bengal branch of southwest monsoon brings heavy rainfall to the northeastern states. It arrives in Assam in the first week of June. The lofty mountains of the Purvanchals causes the monsoon winds to deflect towards the west over the Ganga Plains.
• They cause heavy rainfall on the eastern parts of the Northern Plains as the moisture content of the onshore winds are high. As the winds move westwards their moisture content decreases and hence, the rainfall decreases.
• The Arabian Sea branch of monsoons approach the Northern Plains from the west. But the highlands, the Aravalis, in the western part of the country, lie parallel to the direction of the onshore winds. Hence, very less or no rainfall is experienced in the western limits of the plains.
• They provide more rainfall on the central and eastern parts of the plains when the rain bearing winds strike the Himalayas.
• Both the branches merge over the northwestern part of the Ganga Plains. Delhi receives its showers from either of the branches.
LAQ
7
Distinguish between southwest monsoon and northeast monsoon.
Answer
• The southwest monsoons blow in a southwesterly direction to the mainland of India from June to September. While, the northwest monsoons blow in a northeasterly direction across India from mid-November to February.
• The southwest monsoons are seasonal winds influenced by differential heating of land and water. The southeasterly trade winds are attracted by low pressure over northern India. They are deflected to southwest after crossing the equator due to the Coriolis force while the northeast monsoons are the northeasterly trade winds.
• The southwest monsoons are onshore winds as they blow from the Indian Ocean as Arabian Sea and Bay of Bengal branches to land areas. Hence, they are moisture laden winds and bring heavy rainfall. While the northeast monsoons are offshore winds as theyblow from land to sea.
LAQ