Go through these RBSE Class 11 Indian Geography Notes Chapter 6 Climate of India contain important concepts so that students can score better marks in the exam.
Rajasthan Board RBSE Class 11 Indian Geography Notes Chapter 6 Climate of India
→ The composite or generally prevailing weather conditions of a region, such as temperature, air pressure, humidity, precipitation, sunshine, cloudiness and winds throughout the year is called as climate.
→ Due to a large extension, India is a country of different climates.
→ Indian climate is monsoon type as it has unity in climatic diversities due to the monsoon effect.
Effecting Factors of Climate
- In the factors affecting the climate of India, the height from sea level, distance from sea, distance from equator, location of mountains, direction of mountains, direction of winds, high level air transmission etc. are included.
- In addition to these factors, the amount of cloudiness, vegetation cover and oceanic currents are considered as secondary factors affecting the climate.
- With the increase in height, the temperature falls down, i.e. temperature falls down 1°C with an increase in height of 165 m and it is called the Normal Lapse rate.
- With the increase in the distance from sea, the temperature also keeps on increasing.
- Slanting sun rays increases along the increase in distance from the equator.
- The location and situation of the mountains is responsible for excessive rain as well as drought.
- The direction of winds and the direction of mountains blocking the winds are also helpful in determining the climate.
- The relief and the wind circulation are also major controlling factors of Indian climate.
- The climatic conditions in India have been classified as North-Eastern or Winter Monsoon period and South-Western or Summer Monsoon period.
- The seasons of winter and summer are included in the North-Eastern Monsoon period. The autumn and rainy seasons are included in the South-Western Monsoon period.
- In India, winter season prevails from the month of December to February. The main climatic conditions in this season are clear sky, slow winds and lack of humidity.
- Winter season shows higher air pressure in Northern India and low air pressure in the Indian oceanic region in southern India.
- In this season, winds blow in the north-western direction towards the plains of Ganga. After crossing the northern Plains, these winds begin to blow in north -eastern direction. These winds are also known as North-Eastern Monsoons.
- This system of winds develops in winter season, so it is also known as Winter Monsoons. The rain that takes place due to cyclones is called the Mavath.
- This season prevails from March to mid June. The hot and dry winds that blow in the summer are called Loo.
- During this season, temperature in plains is found to be high, while in the coastal areas, it is low.
- During this season, the air pressure is low in the plains and it is high in the coastal areas.
- Less rainfall that occurs in this season in South India is known as Mango showers, or it is known as Cherry Blossoms in coffee producing regions.
- Rainy season prevails from mid-June to September. Most of the rainfall takes place in this season.
- The winds that blow in this season are called the South-Western Monsoons. These winds blow from the sea towards the land so they are full of humidity.
- The rain that falls in this season is classified as Arabian Sea Monsoon and Bay of Bengal Monsoon.
- The excessive rainfall occurring on the western slopes of the Western Ghats is called the burst of monsoon.
- The place named Mawsynram which is the branch of Bay of Bengal receives the highest rainfall in the world.
- It prevails between mid-September to December. This is also called the Monsoon Reversal Period.
- In this season, the temperature decreases with the sun moving towards the south.
- The returning monsoon causes rainfall in Tamil Nadu and in eastern coastal areas.
Distribution of Rainfall in India
- Unequal distribution of rainfall is found in India. There is 1300 cm rainfall in Mawsynram, while on the other hand, there is only 5 cm rainfall in Jaisalmer of Rajasthan.
- On the basis of rainfall, India is classified into the regions with excessive rainfall, moderate rainfall, low rainfall and inadequate rainfall.
Characteristics of Indian Rain
- Indian rain is irregular, uncertain, unevenly distributed. It takes place for more or less time and shows variation with the perspective of pattern of rainfall.
- The rainfall in India shows irregularity of monsoon.
Climate of India Notes Important Terms
→ Climate: The composite or generally prevailing weather conditions of a region, such as temperature, air pressure, humidity, precipitation, sunshine, cloudiness and winds throughout the year or a long time period.
→ Monsoon: A wind system that influences large climatic regions and reverses direction seasonally.
→ Latitude: The angular distance of a place north or south of the equator of the earth or the equator of a celestial object, usually expressed in degree and minutes.
→ Range of Temperature: The annual range of temperature is the difference between the hottest and the coldest months. It may be daily, monthly or seasonal.
→ Insolation: Insolation is the solar radiation that reaches to the surface of the earth.
→ Snowline: An imaginary line on mountain that marks the height above which snow does not completely melt.
→ Temperate zone: The part of the surface of the earth lying between the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere and characterised by having a climate that is warm in the summer, cold in the winter and moderate in the spring and rainfall.
→ Tropical zone: The part of the earth’s surface lying between the Tropic of Cancer and the Tropic of Capricorn, characterised by a hot climate.
→ Rain Shadow Area: A dry area on the leeward side of a mountain area (away from the monsoon winds). The mountains block the passage of rain-producing weather systems and cast a shadow of dryness behind them.
→ Rain: The condensed moisture of the atmosphere falling visibly in separate drops.
→ Troposphere: The lowest layer of the atmosphere extending from the surface of the earth to an average height of about 12 km (the lower boundary of the stratosphere).
→ Vegetation: The plants community of an area or a region.
→ Sea current: Ocean current is a seasonal directed movement of sea water generated by forces acting upon this mean flow, such as breaking waves, wind, the coriolis effect, cabbeling, temperature and salinity differences, while tides are caused by the gravitational force of the sun and the moon.
→ Season: The seasons are the main periods into which a year can be divided and each of which have their respective typical weather conditions.
→ Freezing point: The temperature at which a liquid solidifies.
→ Atmospheric Pressure : The pressure exerted the weight of the atmosphere, which at sea level has a mean value of 113.25 mb.
→ Sub-Continent: A large distinguishable part of a continent, such as North America or the part of Asia containing India, Pakistan and Bangladesh.
→ Isobar: A line on a map connecting places having the same atmospheric pressure at a given time or on average over a given period.
→ Winter Monsoon: The seasonal wind of the Indian Ocean and Southern Asia, blowing from the north-east in winter.
→ Westerlies or west winds: The wind blowing from the west, high ground and prevailing westerlies give a lot of rainfall.
→ Cyclone: A storm or system of winds that rotates about a center of low atmospheric pressure, advances at a speed of 20 to 30 miles per hour, and often brings heavy rainfall.
→ Mavath: Rainfall in winter season is known as Mavath in India.
→ Bay: A broad inland of the sea where the land curves inwards.
→ Loo ( the hot-wind): Strong, dusty, hot and dry summer wind which blows over the western Indo-Gangetic plain region of North India and Pakistan.
→ Mango Showers: Rainfall occurring in South India before the Summer Monsoon.
→ Cherry Blossoms: Rainfall occurring in Karnataka during the summer period.
→ Agriculture: The science or practice of farming including cultivation of the soil for growing of crops and rearing of animals to provide food and other products.
→ Equator: An imaginary line drawn on the earth equidistant from the poises, dividing the earth into northern and southern hemispheres and constituting the parallel of 0° latitudes.
→ Trade winds: Winds blowing steadily towards the equator from the north-east in the northern hemisphere or from the south-east in the southern hemisphere especially at sea.
→ Burst of Monsoon: Heavy rainfall occurring suddenly and continuing constantly for several days.
→ Ferrel’s Law: Ferrels’ Law is related to changes in direction of winds. According to Ferrel’s Law, the winds turn to the right in the Northern Hemisphere and turn to the left in the Southern Hemisphere.
→ Valley: A low area of land between hills or mountains, typically with a river or stream flowing through it.
→ Autumn: Autumn is the season after summer when leaves fall from trees. It is the third season of the year coming after summer and before winter.
→ Returning Monsoon: Returning Monsoon season starts with the beginning of the withdrawal of Southern-Western Monsoon.
→ Desert: A desert is a landscape form or region that receives very little precipitation.
Windward side: The direction upwind from the point of reference, alternatively the direction from which the wind is coming.
→ Shower: A brief and usually light fall of rain, hail, sleet or snow.
→ Erosion: The process by which rocks or soil gradually degrades by wind, rain or sea.