Over view of the Lesson
The climate of India can be described as 'tropical monsoon type'. India is marked with a broad unity of monsoon type of climate. Many striking regional variations expressed in the pattern of temperature, rain fall, wind humidity and pressure belts. The large size of the country and its varied relief play a crucial role in determining the differences in climatic characteristics in different part of India. If we examine the regional variations, the highest recorded temperature of 50 °C was in June in the arid region of Rajasthan while the lowest, - 40 °C was recorded at Dras sector near Kargil during December. Between these two extreme different places have different temperatures. These differences are equally striking in rainfall distribution also. Mawsynram receives the highest average annual rain fall of 1141 cms and Jaisalmer in West Rajasthan receives the lowest average annual rain fall of 12 cms.
The coastal lands are characterised by low diurnal range of temperatures, cool sea breeze, moist and moderate climate with a high degree of uniformity. The interior parts of the country are known for their extreme weather conditions which can be described as continental type of climate. All the differences in the climate characteristics are determined by location of the place, its altitude, and distance from the sea or the mountain. These diversities are described as regional types that come under the over all spectrum moonsoon climate.
Main Points
* The state of Atmospheric conditions over an area at a particular time refers to weather.
* Climate refers to such conditions over a large area and follows a similar general pattern over many years.
* The elements of weather and climate are:
i) Temperature
ii) Atmospheric pressure
iii) Wind
iv) Humidity and
v) Precipitation
* The factors that affect climate are called 'climatic controls'. These are includes
(i) Latitude (ii) Land water relationship (iii) Relief (iv) Upper air circulation.
* Intensity of temperature depends on the latitudes.
* The solar radiation received on the surface of the Earth is called "insolation".
* The country is divided into two parts by the tropic of cancer approximately. The part of the south of the tropic of cancer lies in the "Tropical Zone". The part of the north of the tropic cancer lies in the Temperature Zone.
* A large part of Southern India, because of its long coast line, comes under the moderating influence of the sea.
* The ocean absorbs and loses heat more slowly than land. This affects climate in many ways. One of this is the formation of land and sea breezes.
* Hills and Mountains will have lower temperature than locations on the Plains.
* The German word "Trade Means Track" and stands for blowing steadily in the same directions and in a constant course.
* The Northern hemisphere subtropical, high pressure belt gives rise to permanent winds. They blow towards the equatorial low pressure belt by reflecting towards west and are called "Trade Winds".
* The temperature decreases as latitude increases. Hence, hills and mountains will have lower temperature than locations on the plain.
* The temperature in the Indian land mass considerably reduce from Mid - November and this cold season continuous till February.
* The Northern Plain experiences dry and hot winds called "Loo".
* October, November is a period of Transition from a hot raising conditions to dry winter conditions.
* The heating of land creates low pressure on the land mass of Indian sub-continent.
* Though a raise of 2°C in average temperature may appear to be small, it would result in a rise of one meter in sea levels by early next country.
* The faster melting of Himalayan glaciers would disturb the livelihood of fresh water, fisher folkes as their natural habitat of fish is affected.
* Darker areas such as heavily vegetated regions tend to be good absorbers, lighter areas such as snow and ice covered regions tend to be good reflectors.
* The climate of India also affected by the movement of upper currents known as "Jet Streams".
* The Moonsoon forms in the tropical area approximately between 20 °N and 20 ° S latitudes.
* The bulk of the rain fall in India is received from the South-West Monsoon.
* As the earth started to take shape from a fiery ball to a planet, many gases were released. These gases did not escape into outer space because of the earth gravitational pull, which still holds them back.
* The atmosphere traps a lot of solar energy that reaches earth by preventing it from totally escaping back into space. This is called global warming.
* The planet, our earth has been warming up rapidly due to human activity which is called
AGW (Anthropogenic Global Warming).
