What is the primary effect of the El Niño climate cycle?

The primary effect of the El Niño climate cycle is the warming of tropical Pacific waters. This phenomenon occurs when the trade winds weaken, leading to a buildup of warm water in the central and eastern Pacific Ocean. The increased sea surface temperatures in these regions disrupt typical weather patterns not just locally but also globally. This can result in various climatic impacts, such as altered rainfall patterns, increased storm activity, and changes in marine ecosystems.

In contrast to options that describe cooling effects, precipitation changes in polar regions, or stabilization of ocean temperatures, El Niño specifically refers to the significant rise in temperatures in the tropical Pacific, which has far-reaching consequences on weather and climate systems across different parts of the world. Understanding this warming process is crucial for predicting the associated weather anomalies that can arise during an El Niño event.