Thursday, November 11, 2010

CLIMATE - GEAGRAPHY NOTES

CLIMATE
Climate refers to the sum total of weather conditions and variations over a large area for a long period of time.
It is the sum total of weather conditions for larger area.
Eg: for a country:
WEATHER:
It refers to state of atmosphere over an area at any point of time.
It is the total of weather conditions for limited area.
Eg: for a city
The elements of weather and climate are temperature, atmospheric pressure, wind, humidity and precipitation.

INDIAN CLIMATE
The climate of India is monsoon type.
•Monsoon is derived from ‘mausim’which means season and it refers to the seasonal reversal in the wind direction during a year.
•In Asia, this type of climate is found mainly in south and south-east.

DIFFERENCES IN INDIAN CLIMATE
In summer the temperature of Rajasthan is about 50’C but in Jammu & Kashmir it’s 20’c.
In winter at J&K the temperature is -45’C but in Thiruvanantapuram its 22’C.
While precipitation is in the form of snowfall in upper parts of Himalyas, it rains over the rest of country.
Most parts receive rainfall from June to July but some like Tamil Nadu receive it even in the season of October and November.

CLIMATIC CONTROLS
The major controls of climate are:
1.Latitude : Due to curvature the amount of solar energy received varies according to it.
2.Altitude: As we go higher there is a decrease in temperature of 16’
3.Pressure and Wind system: As per latitude and altitude temperature and rainfall also influences the climate.
4.Distance from sea: The sea exerts moderating influence on climate, regions near sea experiences moderate climate.
5.Ocean Currents: It leads continentality which means very hot during summers and very cold during winters.




FACTORS AFFECTING INDIAN CLIMATE
1.Latitude:
Tropic of cancer almost divides the country in two equal parts running from Rann of Kuchh to Mizoram.
The region lying in the south of tropic of cancer is tropical whereas the region in north is in sub tropical.
Therefore India receives both tropical as well as sub-tropical climate.

2.Altitude:
India has mountains in north with average height of 6000m and coast line of about 30m.
The Himalyas act as a barrier to enter winds in India from Centeral Asia.
That’s why it experiences mild winters as compare to Centeral Asia.

3.PRESSURE and WINDS
It is further devided in three parts.
•Pressure and surface winds
•Upper air circulation
•Western disturbances
Pressure and surface winds: India lies in the region of north-easterly winds which originate from northern hemispher and blow towards south but
deflected to right due to corollis force.These winds carry small silts that’s why don’t affect India’s rain.

4.Upper air circulation: Winds travel from a low pressure area to high pressure area. Air moves from indian ocean to south-east direction crossing equator and turns right towards indian subcountinent giving rain to it. The upper air circulation over warm oceans is called jet stream.

5.Western disturbances: During the time of winters in India cyclone formation takes place in ‘mediterranean sea’whose winds are very powerful that after crossing Pakistan, Afghanistan they finally reach jammu and kashmir leads to rainfall in winters there.

The unifying influence of the monsoon on the Indian subcontinent is quite perceptible.
The seasonal alteration of the wind systems and the associated weather conditions provide a rhythmic cycle of seasons.
 Even the uncertainties of rain and uneven distribution are very much typical of the monsoon.
The Indian landscape, its animal and plant life, the people, including their festivities, revolve around this phenomenon.
Year after year, people of India from north to south and from east to west, eagerly await the arrival of the monsoon.
These monsoon winds bind the whole country by providing water to set the agricultural activities in motion. The river valleys which carry this water also unite as a single river valley unit.

Early in the season, the windward side of the Western Ghats receives very heavy rainfall, more than 250cm.
The Deccan Plateau and parts of Madhya Pradesh also receive some amount of rain in spite of lying in the rain shadow area.
The maximum rainfall of this season is received in the north-eastern part of the country.
Rainfall in the Ganga valley decreases from the east to the west. Rajasthan and parts of Gujarat get scanty rainfall.
The breaks in the monsoon are related to the movement of the monsoon tough.
The trough and its axis keep on moving northward or southward. When the axis of the monsoon trough lies over the plains and widespread rain occur in the Himalayan Rivers.
Mawsynram in the southern ranges of the Khasi Hills receives the highest average rainfall in the world.
Ques. Why is monsoon known for its “uncertainties”?
While it causes heavy floods in one part, it may be responsible for droughts in the other.
It is often irregular in its arrival and its retreat. Hence, it sometimes disturbs the farming schedule of millions of farmers all over the country.


During October-November, the monsoon trough or the low pressure trough over the northern plains becomes weaker. This is gradually replaced by a high-pressure system.
The south-east monsoon winds weaken and start withdrawing gradually. By the beginning of the October, the monsoon withdraws from the Northern Plains.
The months of October-November form a period of transition from hot rainy season to dry winter conditions. The retreat of the monsoon is marked by clear skies and rise in temperature.
While day temperatures are high, nights are cool and pleasant.

Owing to the conditions of high temperature and humidity, the weather becomes rather oppressive during the day. This is known as “OCTOBER HEAT”.
The low-pressure conditions, over north-western India, get transferred to the Bay of Bengal by early November.
This shift is associated with the occurrence of cyclonic depressions, which originates over the Andaman Sea.
These cyclones generally cross the eastern coasts of India cause heavy and widesprad rain.
These tropical cyclones are often very destructive.
The thickly populated deltas of the Godavari, the Krishna and the Kaveri are frequently struck by cyclones, which cause great damage to life and property.
THE SEASONS
The monsoon type of climate is characterised by a distinct seasonal pattern.
The weather conditions greatly change from one season to the other. The coastal
areas do not experience much variation in temperature though there is variation
in rainfall pattern. Four main seasons can be identified in India- the cold weather
season, hot weather season, the advancing monsoon and the retreating monsoon
with some regional variations.

THE COLD WEATHER SEASON (WINTER)
1. The cold weather season begins from mid- November in northern India and stays
till February.
2. December and January are the coldest months in the northern part of India.
3. The temperature decreases from south to the north.
4. Days are warm and nights are cold.
5. Frost is common in the north and the higher slopes of Himalayas experience
snowfall.
6. The northeast trade winds blow from land to sea and hence, for most part of the
country, it is a dry season.
7. Some amount of rainfall occurs on the Tamil Nadu coast from these winds as,
here they blow from sea to land.
8. The weather is normally marked by clear sky, low temperatures and low humidity
and feeble variable winds.
9. A characteristic feature of the cold weather season over the northern plains is a
the inflow of cyclonic disturbances from the west and the northwest.
10.They cause the much- needed winter rains over the plains and snowfall in the
mountains.
11.Total amount of winter rainfall locally known as ‘mahawat’ is small; they are of . immense importance for the cultivation of ‘rabi’ crops.
12. The peninsular region does not have well- defined cold season.

THE HOT WEATHER SEASON (SUMMER)

1. From March to May, it is hot weather season in India.
2. The influence of shifting of the heat belt can be seen clearly from temperature
recordings taken during March- May at different latitudes.
3. In peninsular India, temperature remain lower due to the moderating influence of the
oceans.
4.The summer months experience rising temperature and falling air pressure in the
northern part of the country.
5. Towards the end of May, an elongated low pressure area develops in the region
extending from the Thar Desert in the northwest to Patna and Chotanagpur plateau
and southeast.
6. The striking feature of the hot weather season is the ‘loo’. These are strong, gusty, hot, dry winds blowing during the day over the north and northwestern India.
7. Dust storms are very common during the month of May in northern India. These
storms bring temporary relief as they lower the temperature and may bring light rain
and cool breeze.
8. In West Bengal, these storms are known as ‘Kaal Baisakhi’.
9. Towards the close of the summer season, pre- monsoon showers are common
especially, in Kerala and Karnataka.
DISTRIBUTION OF RAINFALL
There are three types of rainfall :-
-Low rainfall (Less than 50 cm.)
- Average rainfall (Between 50 to 250 cm.)
- High rainfall (More than 250 cm.)

1. Parts of western coast and northern India receive over about 400 cm of rainfall
annually.
2. It is less than 60cm in western Rajasthan and adjoining parts of Gujarat, Haryana and
Punjab.
3. Rainfall is equally low in the interior of Deccan plateau, and east of the Sahyadris.
4. The rest of the country receives moderate rainfall. Snowfall is restricted to the Himalayan region.

Because of the nature of monsoons, the annual rainfall is highly variable from year to year. Variability is high in the regions of low rainfall such as parts of Rajasthan, Gujarat and leeward (rain shadow area) side of the Western Ghats. While the areas of high rainfall are responsible to be affected by the floods and the areas of low rainfall are drought- prone.

SOME IMPORTANT TERMS

1. Frost- A state in freezing, frozen dew.
2. Loo- Strong, gusty, hot, dry winds blowing during the day over the north and
northwestern India.
3. Mango showers- Pre-monsoon showers in Kerala and Karnataka help in ripening of
mangoes earlier, known as monsoon showers.
4. Trough- large vacuum in between of the Himalayas and the peninsular plateau, the
plains.
5. Leeward- Rain shadow area.
Apara Sanwaria







102 comments:

  1. mam,
    I could not find the answer for triangular slave trade.Please could you tell me the respective page number.
    Chapter-1
    History

    ReplyDelete
    Replies
    1. DEAR,
      THE TRADE WAS BETWEEN AMERICA , EUROPE , AND AFRICA.
      THEREFORE APROX. FORMING THE TRIANGLE ON THE MAP.

      Delete
    2. Ayush i thik Rahul bro had explained enough according to class 9.....we ll get fulll marks after giving this answer in exams....

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    3. a slave trade b/w america ,Europe and africa

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    4. It's a triangular trade between these countries

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    5. The reluctance of Europeans to work in distant land met with the shortage of labour and this led to the Triangular Slave trade between Europe, Africa and The Americans

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    6. For further explanation you can add the below points:-
      French merchants sailed from ports of Nantes to the African coast where they bought slaves.
      Te slaves were then shackled and tightly packed into boxes and took to the Caribbean and then sold to the Plantations.

      Delete
    7. If you are providing something to the student then you first explain the topics in brief way so the student should get understand very easily and they should not get problem in any topic and by your notes the student should understand the topic very easily and by reading your notes the student should not use book or any side book to understand the topics . You should see that your notes should contain diagram to explain the student so that the student could easily learn and should not forgive ever. If you like my opinion then I request you to send me a sample book for class 9 and class 10 because every side book only question and answer but not notes and by providing notes to children by internet and books you will become popular and you will earn a lots of money. You should read my whole paragraph it will help you and change your life.

      Delete
  2. hello mam...
    mam can you pls tell me that the sub topics of the project cricket is the same with the sub topics you had posted on jan 2011?

    ReplyDelete
  3. Mam...
    Pls u tell me ''Why is it said that 'Monsoon wind is known for its uncertainties' ? Explain any three reasons.''

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    Replies
    1. it is said like that because we cannot determin what will happen next.
      the alteration of wet and dry spells vary in intensity, frequency and duration. while it causes heavy floods in one part,it may be responsible for droughts in other part. it is often irregular in its arrival and retreat.

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    2. and excuse me i m not mam, i m a student !!!!.....

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    3. Wow!That's cool !! 😂😂

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  4. this really helped me alot. thank you so much :)

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    Replies
    1. This comment has been removed by the author.

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  5. thankyou these notes are very short and easy to understand

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  6. This comment has been removed by the author.

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  7. This comment has been removed by the author.

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  8. Why the different location of a country is responsible for its own climate?

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  9. hello mam i am a new student and i want some typical questions for geography of chapter-4 climate of class-9

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  10. thanks a lot it helped me alllllllot

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  11. mam , i could not understand the wind system in india . plzzzz can u explain it.

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  12. wind travel fom high pressure to low pressure

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  13. OH ITS COOL IT HELPED ME A LOT TO SECURE FULL MARKS IN GEOGRAPHY """"""""THANKS""""""""A""""LOT!!!!!!!""""""""

    ReplyDelete
  14. i like it...................
    cooooool..............

    ReplyDelete
  15. This comment has been removed by the author.

    ReplyDelete
  16. Can you please upload the same type of notes for Poverty As A Challenge........

    ReplyDelete
  17. helped me a lot in my exam time

    ReplyDelete
  18. This comment has been removed by the author.

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  19. This comment has been removed by the author.

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  20. Very good notes. Hrpped me a lot. Could u explain me ehy it is said to be unifying bong

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  21. Very good notes. Hrpped me a lot. Could u explain me ehy it is said to be unifying bong

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  22. gud notes,helped me a lot.......

    ReplyDelete
  23. why many of the comments are removed by the author...
    i'm asking dis cozz we should also know how others felt bout d site...........

    ReplyDelete
  24. why many of the comments are removed by the author...
    i'm asking dis cozz we should also know how others felt bout d site...........

    ReplyDelete
  25. why have u deleted the comment...????

    ReplyDelete
  26. why have u deleted the comment...????

    ReplyDelete
  27. gud notes,helped me a lot.......

    ReplyDelete
  28. Hi suryanarayanan Kumar!! Your notes are accurate and useful.. Thay are nice and well presented.. Plz upload the notes of rest of the chapter.. It will be great...Thanks!! I also agree with ram that comments should not be removed.. Others point of view must be showed and respected..let us also know what they think of this site.. :-D ☺☺

    ReplyDelete
  29. Hi suryanarayanan Kumar!! Your notes are accurate and useful.. Thay are nice and well presented.. Plz upload the notes of rest of the chapter.. It will be great...Thanks!! I also agree with ram that comments should not be removed.. Others point of view must be showed and respected..let us also know what they think of this site.. :-D ☺☺

    ReplyDelete
  30. I would like to make a correction about the Indian rainfall differences.... part.....according to the textbook it is June to September but you mentioned June to july

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  31. hmm you should not remove the comments ..
    it helped a lot but there should be a seprate portion or point for rain as a unifying bond .. thnx

    ReplyDelete
  32. Please give me some tips to prepare for my social studies exam as only 2 says are left
    Please reply plz i want ur help
    Anyone can comment

    ReplyDelete
  33. There is no information about Advancing and Reatreating Monsoon.

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  35. go for exell up that is better one...
    they have the best notes

    ReplyDelete
  36. What are the two important elements of monsoon

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  38. This comment has been removed by the author.

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  39. thank you its better than my teacher's notes

    ReplyDelete
  40. Thank you ma'am,it was really helpful

    ReplyDelete
  41. This is amazing! Thanks a lot.

    ReplyDelete
  42. helped a lot for exams THANK YOU!!!!!!!!!!!!!!!!!!

    ReplyDelete
  43. Mam it was really helpful! ! But can u tell "why india has a variation in temperature and precipitation?"
    Plz

    ReplyDelete
  44. Wat about advancing and retreating monsoon??

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  45. Can you tell more about jet stream?

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  46. Can you tell more about jet stream?

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  47. This notes is short and easy to understand and very helpful for students like us

    ReplyDelete
  48. What about "The Indian Monsoon" and "The onset of the monsoon and withdrawal"? Can you make one....plzz

    ReplyDelete
  49. The spelling of "geography" is wrong in the title
    You have written "geagraphy"

    ReplyDelete
  50. Superb work . Thank u it was helpful for exam

    ReplyDelete
  51. Really Appreciate your article, information is awesome. Will you please help me to find out the School in Sirsi Road, Jaipur.

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  52. Very helpful in understanding the concept clearly.

    ReplyDelete
  53. Please tell me short note on transition
    Seasin

    ReplyDelete
  54. It's nice
    BUT PLS GIVE THE NOTES IN SKETCHES FORM

    ReplyDelete
  55. Thankss it's really interesting !!!!

    ReplyDelete
  56. Shining Star International School has just open their new school in Mussafah, Abu Dhabi, Affiliated with Abu Dhabi CBSE and works under Indian Curriculum Abu Dhabi

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  57. What do you mean by burst in monsoon?

    ReplyDelete