CLIMATE- class 9

Chapter Climate Reference Notes. Summary of the full chapter with picture references. Especially for class 9.

1. Climate -Dakshita Sinha IX-Orchids Geography

2. What is Climate Climate refers to the sum total of weather conditions and variations over a large area for a long period of time. . The climate record also includes extreme values such as record high temperatures or record amounts of rainfall. It is the long term weather of that area which remains at least 30 Years

3. What is Weather Weather is the state atmosphere at any point in time and space, it changes every moment. Example: Cloudy, dry, windy, wet weather .

4. Elements of Weather and climate Temperature , atmospheric pressure, wind, humidity, and precipitation.

5. Temperature :- Temperature is a measure of how hot or cold something is; specifically, a measure of the average kinetic energy of the particles in an object, which is a type of energy associated with motion.

6. Atmospheric Pressure That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer.

7. Wind Wind is the flow of gases on a large scale.

8. Humidity A quantity representing the amount of water vapour in the atmosphere or in a gas. Precipitation   Falling products of condensation in the atmosphere, as rain, snow, or hail. the amount of rain, snow, hail, etc., that has fallen at a given place within a given period, usually expressed in inches or centimetres of water.

9. Monsoon 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. The world is divided into a number of climatic Regions. The climate of India is described as the ‘monsoon’ type. This type of climate is found in South and Southeast Asia. Two Important elements- Temperature & Precipitation, often vary from place to place and Season to season .

10. Climatic Control Six major Control of Climate of any place- Latitude, altitude, pressure and wind system, distance from the sea, ocean currents and relief features.

11. Factors Affecting India’s Climate Latitude : Indian is situated roughly between 8 o  N and  37 o  N latitudes. India is divided into almost two equal parts by the tropic of cancer.  Altitude  or height above sea level - Locations at a higher altitude have colder temperatures .  This means that coastal locations tend to be cooler in summer and warmer in winter than places inland at the same latitude and altitude . The pressure and wind  conditions over India are unique. During winter, there is a high-pressure area 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 north-western India.

12. The Indian Monsoon The Climate of India is strongly influenced by monsoon winds. The sailors who came to India in historic times were on of the first to have noticed the phenomenon of the monsoon. They benefited from the reversal of the wind system as they came by sailing ships at the mercy of winds. The Arabs, who had also come to India as traders named this season reversal of the wind system ‘monsoon’.

13. The Onset Of The Monsoon And Withdrawal Withdrawal or the retreat of the monsoon is a more gradual process. The withdrawal of the monsoon begins in north-western states of India by early September. By mid-October, it withdraws completely from the northern half of the peninsula. The withdrawal from the southern half of the peninsula is fairly rapid.

14. The Seasons

15. The Cold Weather season (Winter) It extends from December to February. Vertical sun rays shift towards southern hemisphere. North India experiences intense cold where as this season is not well defined in south India. Occasional tropical cyclone visit eastern coast in this season.

16. The Hot Weather Season (Summer) It extends from March to May. Vertical sun rays shift towards northern hemisphere. The Temperature gradually rises from south to north. Highest Temperature experiences in Karnataka in March, M.P. in April and Rajasthan in May.

17. Advancing Monsoon (The Rainy Season) It extends June to September. Intense heating in north west India creates low pressure region. Low pressure attract the wind from the surrounding Region. After having rains for a few days sometime monsoon fails to occur for one or more weeks is known as break in the monsoon.

18. Distribution Of Rainfall The western coast and north-eastern India receive rainfall of over about 400 cm. It is less than 60 cm in western Rajasthan and adjoining parts of Gujarat, Haryana and Punjab. Rainfall is equally low in the interiors of the Deccan plateau and east of the Sahyadris.

19. The Himalayas protect the subcontinent from extremely cold winds from central Asia. This enables northern India to have uniformly higher temperatures when compared to other areas on the same latitudes. Similarly, the peninsular plateau, under the influence of the sea form three sides, has moderate temperatures. 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.