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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normal conditions
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La Nina
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El Nino
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none of above
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Detailed explanation-1: -With a deeper thermocline and decreased westward transport of water, the sea surface temperature increases to greater than normal in the Eastern Pacific. This is the warm phase of ENSO, called El Niño.
Detailed explanation-2: -As an El Niño episode evolves, significant changes occur in both the subsurface temperatures and in the depth of the oceanic thermocline (The thermocline separates the warm upper ocean from the cold deep ocean waters.).
Detailed explanation-3: -In studying the tropical Pacific Ocean, the depth of 20C water ("the 20C isotherm") is often used as a proxy for the depth of the thermocline. Along the equator, the 20C isotherm is typically located at about 50m depth in the eastern pacific, sloping downwards to about 150 m in the western Pacific.
Detailed explanation-4: -The slope of the thermocline shallowing changes markedly during ENSO. As El Niño piles up warm water in the eastern Pacific, the thermocline deepens in that location whereas the La Niña part of the cycle corresponds to a very shallow thermocline in the eastern Pacific.