With ref. to El Nino-Southern Oscillation
(ENSO), which of the following statements are Correct?
1.El Nino is a climate pattern that
describes the unusual warming of surface waters in the Central Equatorial
Pacific Ocean.
describes the unusual warming of surface waters in the Central Equatorial
Pacific Ocean.
2.It stops upwelling of cold, nutrient-rich
water to the Euphotic Zone, in the Eastern Equatorial Pacific Ocean.
water to the Euphotic Zone, in the Eastern Equatorial Pacific Ocean.
3.During ENSO, the westward blowing trade
winds weaken along the Central Pacific Ocean near the Equator.
winds weaken along the Central Pacific Ocean near the Equator.
Which of the above statement(s) is/are Correct?
Choose the alternative from below
A) 1 and 2 Only
B) 2 and 3 Only
C) 1 and 3 Only
D) 1, 2 and 3
| Ans: Option B Explanation: Statement 1 is incorrect. El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern equatorial Pacific Ocean. El Niño Modoki is characterized by changes in sea-surface temperatures in the central Pacific. |
| Statement 2 is correct. The thick layer of warm water accumulated due to unusual warming of surface waters does not allow normal upwelling to occur. Without an upwelling, the euphotic zone can no longer support its normally productive coastal ecosystem in eastern equatorial Pacific Ocean. |
| Statement 3 is correct. During an El Niño event, westward-blowing trade winds weaken along the Equator along the areas of central pacific ocean. These changes in air pressure and wind speed cause warm surface water to move eastward along the Equator, from the western Pacific to the coast of northern South America. |