What does El Niño refer to in terms of oceanic conditions?

El Niño refers specifically to a periodic warming of the central and eastern Pacific Ocean, which is a significant climatological phenomenon that affects global weather patterns. This warming occurs in the sea surface temperatures and typically takes place every few years, characterized by a rise in ocean temperatures due to a weakening of the trade winds.

During El Niño events, typical weather patterns can be altered significantly, leading to various effects such as increased rainfall in some regions and droughts in others. The warming impacts not only marine ecosystems but can also substantially influence atmospheric conditions. Therefore, recognizing El Niño as the warming of the central and eastern Pacific Ocean is crucial for understanding its wide-ranging climate effects worldwide.