What phenomenon involves changes in the ocean and atmosphere over the Pacific Ocean?

The phenomenon that involves significant changes in the ocean and atmosphere over the Pacific Ocean is known as El Niño. This climate pattern is characterized by the warming of surface waters in the central and eastern Pacific Ocean, which can lead to widespread impacts on weather patterns globally. During an El Niño event, the altered ocean temperatures can disrupt typical weather systems, resulting in changes such as increased rainfall in some areas and droughts in others.

This phenomenon is part of a larger climate oscillation known as the El Niño-Southern Oscillation (ENSO), which also includes the opposite phenomenon, La Niña, characterized by cooler ocean temperatures. Understanding El Niño is crucial for predicting weather patterns and preparing for potential impacts, especially in regions that depend on seasonal weather conditions.