CLIMATE OF INDIA
EL NINO AND SOUTHERN OSCILLATIONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Dry / Cold air that rises
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Moist / Cold air that rises
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Dry / Warm air that rises
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Moist / Warm air that rises
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Detailed explanation-1: -Areas where the air is warmed often have lower pressure because the warm air rises. These areas are called low pressure systems.
Detailed explanation-2: -In a depression (low pressure), air is rising and blows in an anticlockwise direction around the low (in the northern hemisphere). As it rises and cools, water vapour condenses to form clouds and perhaps precipitation.
Detailed explanation-3: -This, combined with the rising of the hot air, results in a low-pressure area called a thermal low. Monsoon circulations are caused by thermal lows which form over large areas of land and their strength is driven by how land heats more quickly than the surrounding nearby ocean.
Detailed explanation-4: -A low pressure system develops when relatively warm and moist air rises from the surface of the Earth. Air near the centre of a low pressure system is unstable. As the warm humid air spirals upwards, it cools and clouds form. These may be thick enough to give rain or snow.