The El Niño-Southern Oscillation (ENSO) is a climatic phenomenon that has captivated scientists, policymakers, and the public alike for its profound impact on the global climate system. ENSO is a complex interplay between the ocean and atmosphere in the equatorial Pacific, leading to periodic fluctuations between El Niño, La Niña, and neutral conditions. These fluctuations have significant implications for weather patterns, ecosystems, and human societies worldwide. At the heart of ENSO are the oceanic and atmospheric conditions in the tropical Pacific Ocean. The phenomenon typically operates on a cycle of three to seven years, although the intensity and duration of specific events can vary widely. El Niño, the warm phase of ENSO, occurs when sea surface temperatures (SST) in the central and eastern Pacific Ocean are significantly warmer than average. This warming alters atmospheric circulation patterns, leading to a range of climatic effects across the globe. Conversely, La Niña represents the cool phase of ENSO, characterized by colder-than-normal SSTs in the same regions.
During which phase of ENSO are sea surface temperatures in the central and eastern Pacific Ocean warmer than average?