GEOLOGY

Detailed explanation-1: -It also reduces the upwelling of cooler, nutrient-rich waters from the deep-shutting down or reversing ocean currents along the equator and along the west coast of South and Central America. The circulation of the air above the tropical Pacific Ocean responds to this tremendous redistribution of ocean heat.

Detailed explanation-2: -During an El Niño event, sea surface temperatures over the central and eastern Pacific become warmer than normal.

Detailed explanation-3: -During normal conditions, upwelling brings water from the depths to the surface; this water is cold and nutrient rich. During El Niño, upwelling weakens or stops altogether. Without the nutrients from the deep, there are fewer phytoplankton off the coast.

Detailed explanation-4: -During El Niño, the surface winds across the entire tropical Pacific are weaker than usual. Ocean temperatures in the central and eastern tropical Pacific Ocean are warmer than average, and rainfall is below average over Indonesia and above average over the central or eastern Pacific.

Detailed explanation-5: -During El Niño, a weather phenomenon that typically occurs every three to seven years, the Pacific Ocean’s climate changes dramatically. The transition zone between warm surface water and cold deep water deepens. Trade winds are also weak during El Niño. The combination of weak winds and deeper water limits upwelling.