What phenomenon is associated with warmer-than-normal ocean surface temperatures in the Pacific?

The phenomenon associated with warmer-than-normal ocean surface temperatures in the Pacific is El Niño. During an El Niño event, the usual patterns of oceanic and atmospheric activity are disrupted. Typically, trade winds push warm water toward the western Pacific, whereas during El Niño, these winds weaken, leading to a rise in sea surface temperatures in the central and eastern Pacific. This warming has significant impacts on global weather patterns, causing changes in precipitation and temperature across various regions.

In contrast, La Niña is characterized by cooler-than-normal sea surface temperatures in the same area, showing that El Niño and La Niña are opposites in terms of temperature effects. The greenhouse effect and ozone layer depletion are broader climate phenomena or environmental issues that do not specifically relate to ocean surface temperatures in the Pacific.