CLASS IX CLIMATE NOTES AND STUDY MATERIAL

Written By Avinash Sharan

28th May 2020

CLASS IX CLIMATE NOTES AND STUDY MATERIALS

CLIMATE CHAPTER NOTES

        CLIMATE CHAPTER NOTES

Class IX climate notes and study materials are definitely going to be helpful to you. Climate is one of the most difficult chapters of Geography. It’s a big chapter with many new concepts of Geography. You can understand this chapter only when the pressure belts and wind system is clear https://shapingminds.in/pressure-belts-and-wind-system/ . In this article, you will understand the difference between weather and climate. Also you will know about the arrival and departure of monsoons in India. You have already read about the Latitudes and Longitudes in chapter 1 https://shapingminds.in/अक्षांश-latitude…तर-longitude-रेख/ ‎  India- size and location which is also important to understand about the climate of India.

CLASS IX CLIMATE NOTES AND STUDY MATERIALS: IMPORTANT TERMS 

Weather: Weather is the state of the atmosphere for a short period of time. e.g. today morning the weather was very pleasant. In the afternoon, it was extremely hot. At night the weather was very humid.

Climate: Climate is the state of the atmosphere for a long period of time. e.g. near the poles the climate is extremely cold. Deserts have hot and dry climate. Near the sea the climate is very humid.

Monsoon : Seasonal reversal of wind direction due to change in season

Loo: Hot, dry and dusty winds which blows in the northern plains in summer.

jet Streams: High velocity winds which blows in the upper layer of the atmosphere.

Burst of Monsoon: Sudden change in weather conditions from hot and dry to wet and humid due to the arrival of monsoon.

Cloud burst: Extreme amount of rainfall in a short period of time and in a smaller area.

Break in monsoon: The gaps between the rainy season when it does not rain for 3-4 days.

CLASS IX CLIMATE CLASS NOTES AND STUDY MATERIALS

DIFFERENCE BETWEEN WEATHER AND CLIMATE:

  1. Weather is for a short period of time but climate is for a long period of time.
  2. It covers a smaller area where as climate covers a larger area.
  3. can change very frequently, on the other hand climate takes time to change.
  4. difficult to predict exactly but climate can be predicted easily.
  5. weather is the day to day state of the atmosphere where as climate is the average of weather over 30 years.

MAJOR ELEMENTS OF WEATHER AND CLIMATE:

a) Temperature

b) Wind

c) Humidity

d) Atmospheric pressure

e) Precipitation (rainfall)

SIX MAJOR CLIMATIC CONTROLS:

i) Latitude i.e. distance from the equator.

ii) Altitude i.e. height of a place from sea level.

iii) Distance from the sea i.e. how far a place is located from the sea.

iv) Pressure and wind system

v) Physical features  https://shapingminds.in/physical-divisio…f-india-class-ix/ i.e. mountains, plateaus, plains, desert etc.

vi) Ocean currents ( warm and cold )

FACTORS AFFECTING INDIA’S CLIMATE:

i) LATITUDE: 

Tropic of cancer divides India into two equal parts.

Places below the tropic of cancer lies in the Tropical region where as places above the tropics lie in Temperate region.

ii) ALTITUDE:

i) Height also affects the climate of a place.

ii) Himalayas play an important role in stopping monsoon winds which brings rain.

iii) Himalayas also stop cold Siberian winds from entering India during winter.

iii) PRESSURE AND WINDS:

i) Difference in pressure over land and sea also affect the climate.

ii) during summer, low pressure develops over the land.

iii) During winter, high pressure develops over the land.

iv) Difference in temperature and pressure causes movement of wind.

iv) UPPER AIR CIRCULATION:

I) Hot wind rises up as they are light.

ii) After rising high they blow at a high speed.

iii) When they cool down, they descend (come down) and affects the climate.

iv) These hot winds which blows in the upper layer of the atmosphere are called https://www.nationalgeographic.com/environment/weather/reference/jet-stream/ Jet streams.

v) WESTERN CYCLONIC DISTURBANCES:

i) These winds come from the Mediterranean sea during winter.

ii) They are brought by the westerly Jet streams.

iii) These winds bring heavy rain or snowfall in Northern India.

CLASS IX CLIMATE CLASS NOTES AND STUDY MATERIALS

MONSOON:

CHILDREN ENJOYING MONSOON CLIMATE

CHILDREN ENJOYING MONSOON CLIMATE

Seasonal reversal of wind direction due to change in season is called Monsoon.

During summer season, direct rays of the sun falls on Tropic of cancer.

Due to this, the Northern and Central India gets intensely heated.

when it gets heated, the air becomes hot and rises upwards.

When the hot air rises up, it creates a low pressure area.

we already know that the Trade winds blow from Tropic of cancer to equator but,

as the low pressure is created over the land, these trade winds reverses it’s direction.

It starts blowing from the equator to Tropic of cancer for sometime which is called Monsoon therefore.

Monsoon is the Seasonal reversal of wind direction due to the change in season.

TWO TYPES OF MONSOON WINDS:

  1. WINTER MONSOON

a) Winter monsoons arrive in October.

b) The air is cold and dry because it blows from land to sea.

c) The summer monsoon winds return after colliding with Himalayas.

d) They are also known as the North East monsoon.

e) As it travels from Bay of Bengal, it brings rain in the Eastern coastal regions.

2. SUMMER MONSOON

a) Summer monsoons arrive in May.

b) It brings huge moisture as it blows from Ocean to land.

c) It enters India from Kerala and reaches up to Himalayas in Punjab.

d) They are also known as South West monsoon.

e) It has two branches i) Arabian sea branch and ii) Bay of Bengal branch.

INDIAN CLIMATE: MECHANISM OF MONSOON IN  (HOW AND WHY MONSOON ARRIVES IN INDIA)

i) Differential heating and cooling of land and water:

During summer season the land of India gets heated continuously.

The air present over the land also gets heated and rises up.

Rising air creates a low pressure region over the land.

At this time, air over the oceans are comparatively cold.

Cold air creates high pressure.

We know that wind blows from high pressure to low pressure.

Therefore air over the Oceans get attracted towards the Northern Plains which has low pressure.

ii) Shift of the position of Inter Tropical Convergence Zone (ITCZ):

i) The sun rays directly fall on equator.

II) This makes equator a low pressure region.

iii) winds from both, Tropic of Cancer and Capricorn blow towards equator.

iv) That low pressure area where winds try to converge, is known as Inter Tropical Convergence Zone.

Now,

In the month of June, the direct rays of sun falls on Tropic of Cancer instead of Equator due to the tilt of earth.

Therefore, much lower pressure region is created near 20° N (Ganga plains)

As the low pressure region shifts from equator to Tropics, similarly ITCZ also shifts from equator to Tropics.(20°N)

iii) High pressure area to the east of Madagascar islands:

I) During summer, low pressure is created over land and high pressure over oceans.

ii) Madagascar islands lies to the south east of Africa at around 20° S.

III) At that time there is winter season in the southern hemisphere.

iv) hot winds which rises from northern plains sinks at Madagascar.

v) This increases the intensity of winds which brings enough rainfall.

iv) Heating of the Tibetan Plateau:

The Tibetan plateau gets intensely heated during summer.

The winds rises vertically high creating a low pressure region which attracts monsoon.

v) Jet streams:

westerly jet stream to the north of Himalayas and

Tropical easterly  jet stream over the Indian peninsula,

together has the impact on Indian monsoon https://www.jagranjosh.com/general-knowledge/how-does-el-nino-and-la-nina-impact-on-indian-weather-1511874379-1  .

INTER TROPICAL CONVERGENCE ZONE (ITCZ) AND IT’S SIGNIFICANCE:

ITCZ is a broad belt of low pressure. It lies between 5° N & S of Equator.

It moves to 20° North during summer and 20°S during winter.

SIGNIFICANCE OF ITCZ

i) it’s a zone of convergence of N.E. and S.E. Trade winds.

ii) this zone is the wettest zone.

iii) it does not have a dry season.

iv) here, it’s constantly hot and humid.

CHARACTERISTICS OF INDIAN MONSOON:

i) It accounts for 90% of the total rainfall.

ii) Rainfall is neither continuous nor regular.

iii) It may be strong or weak.

iv) Rainfall is unevenly distributed.

v) Monsoons in India are erratic.

ARRIVAL AND WITHDRAWAL OF MONSOON AFFECTS CLIMATE:

Monsoon in India arrives from early June to September. It shed it’s moisture for almost 100 days. Arrival of monsoon and sudden increase in rain for several days is known as the “Burst” of monsoon.

Arrival of Monsoon or Advancing monsoon:

i) it begins by early June.

ii) Low pressure is created over the Northern plains.

iii) this attracts winds from southern hemisphere.

iv) as a result, windward side of W.Ghats receives heavy rain.

v) it has a tendency to have breaks.

Retreating monsoon or Returning of monsoon:

i) it falls between October-November.

ii) a period of transition (change) from rainy to dry winter.

iii) marked by clear skies and rise in temperature.

iv) day temperatures are high and humid but nights are cool and pleasant.

v) In the 2nd half of October, the mercury begins to fall rapidly.

WHAT DO YOU MEAN BY OCTOBER HEAT ?

i) In the month of October, monsoon starts returning and temperature falls.

ii) It is a period of transition (change) from hot rainy season to dry winter season.

iii) Though the monsoon is returning but the land is still moist.

iv) when the sun rises, evaporation takes place which makes the weather hot and humid.

v) This is commonly known as October Heat.

DISTRIBUTION OF RAINFALL:

I) more than 400 cm of rainfall takes place in western coastal plains and N.E India.

ii) less than 60 cm of rainfall takes place in Rajasthan, Gujarat, Haryana and Punjab.

iii) very low rainfall is received in the interiors of Deccan plateau.

iv) snowfall takes place only in the Himalayan region ( jammu & Himachal)

v) annual rainfall varies from year to year.

HOW MONSOON ACTS AS A UNIFYING BOND ?

I) By providing a rhythmic cycle of seasons.

ii) it fills all the water bodies like lakes, ponds, rivers etc.

iii) people of whole country eagerly wait for monsoons.

iv) recharges the underground water level.

v) Agricultural season (KHARIF) starts with the monsoons.

CLASS IX CLIMATE NOTES AND STUDY MATERIALS

MULTIPLE CHOICE QUESTIONS FROM CLIMATE:

1 Who among the following studies the monsoon winds scientifically ?

a) Arabs

b) Britishers

c) Portuguese

d) Chinese.

2. Which place in India experiences wide differences between day and night temperatures.

a) Plains

b) Plateaus

c) Deserts

d) Hilly regions

3. Which force is responsible for deflecting winds towards right in the Northern Hemisphere.

a) Atmospheric pressure

b) Coriolis force

c) Gravitational force.

d) Magnetic force.

4. Who among the following coined the term “Jet Stream”?

a) Herodotus

b) Galileo

c) H. Seilkopf

d) Sir Gilbert Walker.

5. What is the name given to localized thunder storms in the state of West Bengal?

a) Baisakhi

b) Kaal Baisakhi

c) Amphan

d) Eastern disturbance.

6. Where will you find very little difference between day and night temperatures?

a) Jodhpur

b) Bhopal

c) Bangalore

d) Chennai

7. The amount of ________ present in air atmosphere is called humidity.

a) dust

b) smog

c) water vapour

d) oxygen

8. The eastern part of Aravali hills receive rain due to

a) Arabian sea branch

b) Bay of Bengal branch

c) Jet streams

d) retreating monsoon

9. What is the full form of ITCZ ?

a) Interstate Tropical Convergence Zone.

b) International Tropical Convergence Zone.

c) Inter Tropical Congruent Zone.

d) Inter Tropical Convergence Zone.

10. The seasonal reversal of wind direction during a year is called ____________

a) Monsoon

b) Jet streams

c) anti cyclones

d) Loo

CLASS IX CLIMATE CLASS NOTES AND STUDY MATERIALS

GEOGRAPHY- CLASS IX  – CHAPTER 4 – CLIMATE   NCERT SOLUTIONS 

Q1.  What are the controls affecting the climate of India? 

Ans) Six major controls affecting the climate of India are:

i) Latitude i.e. distance from the equator.

ii) Altitude i.e. height of a place from sea level.

iii) Distance from the sea i.e. how far a place is located from the sea.

iv) Pressure and wind system

v) Physical features and

vi) Ocean currents

Q 2. Why does India have a monsoon type of climate ?

Ans) India has monsoon type of climate because:

i) Indian climate is strongly governed by monsoon winds.

ii) Monsoons are confined to 20° N and S.

iii) These winds account for 90% of annual rainfall.

Q 3. Which winds account for rainfall along the Malabar coast ?

Ans) South West monsoon winds.

Q 4. What are jet streams? How do they affect the climate of India ?

Ans) Jet streams are the high velocity winds which blows in the upper layer of the atmosphere (12000 m). They affect the climate of India by:

i) causing a low pressure region during summer season (monsoon)

ii) causing western disturbances during winter season.

iii) Helps in increasing the intensity of rainfall.

Q 4. Define monsoons. What do you mean by “break” in monsoons.

Ans)  Monsoons are the seasonal reversal of wind direction due to change in season.

Monsoons tend to have “breaks” in rainfall, which means there are wet and dry spells.

The rain less intervals during rainy season is known as “break” in monsoon.

Q 5. Why is the monsoon considered a unifying bond ?

Ans) Monsoon is considered as a unifying bond because:

I) it provides a rhythmic cycle of seasons.

ii) it fills all the water bodies like lakes, ponds, rivers etc.

iii) people of whole country eagerly wait for monsoons.

iv) it recharges the underground water level.

v) Agricultural season (KHARIF) starts with the monsoons.

Q 6. Why does the rainfall decrease from East to West in Northern India.

Ans) The rainfall decreases from East to West in Northern India because:

i) as the winds enter from the East, they carry moisture from the Bay of Bengal.

ii) when they move from East to West in India they lose moisture content as they are blowing over the land.

CLASS IX CLIMATE CLASS NOTES AND STUDY MATERIALS

2. Give reasons as to why:

  1. seasonal reversal of wind direction takes place over the Indian sub continent.

Ans) During summer interior of India gets intensely heated.

Air becomes hot and rises up creating a low pressure region.

Due to difference in temperature and pressure over land and oceans, winds reverse their direction.

2. The bulk of rainfall in India is concentrated over a few months.

Ans) Low pressure area over India is only formed during summer.

This attracts winds from the oceans and cause heavy rainfall for 2-3 months.

3. The Tamilnadu coast receives winter rainfall.

Ans) When the North-East monsoon returns in October-November, they pick moisture from the Bay of Bengal.

As Tamilnadu falls on the way of these winds, it causes heavy rainfall in December.

4. The delta region of the Eastern coast is frequently struck by cyclones.

Ans. Delta is a region where the river is very wide.

During summer, the Bay of Bengal branch easily enter in the delta regions.

This causes cyclonic rainfall in the Cavery, Godawari and Mahanadi .

5. Parts of Rajasthen, Gujarat and leeward side of Western ghats are drought prone.

Ans) All these regions fall on the leeward  (back) side  of mountains where the rainfall is less, hence drought prone.

CLASS IX CLIMATE CLASS NOTES AND STUDY MATERIALS

 LONG ANSWER TYPE QUESTIONS:

Q 1. Describe the regional variations in the climatic conditions of India with the help of suitable examples.

Ans) There are two important elements which cause these regional variations: they are temperature and rainfall.

i) During summer the temperature in Jodhpur may be around 50° C whereas it may be around 20°C  in Pahalgam (J&K)

II) During winter Dras in J & K  has -40°C on the other hand coastal regions may have around 30° C

III) Similarly, Cherrapunji receives the maximum rainfall in the world where as deserts are drought prone.

iv) coastal regions have moderate climate through out the year whereas interiors have continental.

Q 2. Discuss the mechanism of monsoons.

Ans) Following are the points which explains the mechanism of monsoons.

i) Differential heating and cooling of land and water

ii) Shift of the position of Inter Tropical Convergence Zone (ITCZ)

iii) High pressure area to the east of Madagascar islands

iv) Heating of the Tibetan Plateau

v) Jet streams

Q 3. Give an account of weather conditions and characteristics of cold weather season.

Ans)  i) In India, winter season begins from October to February.

ii) weather conditions greatly vary from season to season.

iii) interiors and Himalayan regions are extremely cold during this time.

iv) Deserts have warm days and extremely cold nights.

v) However, coastal regions do not have much variations.

Q 4. Give the characteristics and effects of the monsoon rainfall in India.

Ans) Characteristics of Indian monsoons are:

i) It accounts for 90% of the total rainfall.

ii) Rainfall is neither continuous nor regular.

iii) It may be strong or weak.

iv) Rainfall is unevenly distributed.

v) Monsoons in India are erratic.

Effects of Indian monsoon:

i) it gives relief to the people from scorching sun.

ii) it directly affect the income and livelihood of the people engaged in agriculture.

iii) Good monsoon ensures good production and boosts Indian economy.

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