Why does the rainfall decrease from the west in northern india

4. CLIMATE NCERT QUESTIONS (i) What are the elements affecting the climate of India? The elements affecting the climate are temperature, atmospheric pressure, wind, humidity and precipitation. (ii) Why does India have a monsoon type of climate? India is defined as a climatic region with monsoon climate. It is strongly governed by thmonsoon winds. (iii) Which part of India experiences the highest diurnal range of temperature and why? The Thar Desert has a wide difference between day and night temperatures. There is no sea around to moderate the range of variation of temperatures during day and night. (iv)Which winds account for rainfall along the Malabar Coast? Malabar Coast gets rains from depressions and cyclones. (v) What are jet streams and how do they affect the climate of India? Jet streams are high velocity westerly winds blowing through a narrow zone in the upper troposphere. The westerly flows are responsible for the western disturbances experienced in the north and north-western parts of the country. The easterly jet streams cause tropical depressions during the monsoon as well as October-November months. (vi) Why is the monsoon considered a unifying bond? Monsoons are uncertain but all the same they act as a unifying force on the climatic unity of India. July and August are wet almost all over the country. In spite of their vagaries, the monsoons have a very important place in the cultural life of the people. There is so much poetry and music that centres round t...

The bulk of rainfall in India is received during the four months of the rainy season i.e. June, July, August and September. This is the period of South-West Monsoons blowing from sea to land. These sea to land Winds are the rain giver, as these moisture-laden winds are on-shore winds. The tropical cyclones add to the amount of rainfall. Easterly tropical jet stream, too, helps in the monsoonal rain during this period.

Rainfall decreases from east to west in Northern India because: i. When the Bay of Bengal Branch of south west monsoon is obstructed by the Nepal and eastern Himalayas, maximum amount of rainfall is received in West Bengal, Bihar etc. ii. When these winds advance towards west they go on shedding moisture. iii. In Kolkata the amount of rainfall is 105 cms.

The rainfall decreases from east to the west in Northern India because monsoon rises from both the Arabian Sea and the Bay of Bengal, which causes heavy rainfall in the Brahmaputra valley and the Assam hills. As soon as they move toward Himalayas they take western turn and move up the Ganga valley, but due its westward approach it become drier and drier resulting in lesser rainfall North West India. The shrinking moisture levels results in decrease in rainfall from east to the west.