Final answer:
El Niño occurs when there is a warming of the ocean surface in the tropical Pacific Ocean, disrupting global weather patterns.
Step-by-step explanation:
El Niño occurs when there is a warming of the ocean surface in the central and eastern tropical Pacific Ocean. It typically begins around Christmas time and lasts for about one to two years. The warm ocean currents disrupt the normal patterns of weather and ocean currents, leading to changes in climate worldwide.
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