Predicting the duration of a Central Pacific El Niño event has long frustrated climate scientists and forecasters. Now, a new study reveals that Central Pacific El Niños follow two fundamentally different life cycles—and the difference is determined months before they peak.
The research group, led by Prof. Xin Wang from the South China Sea Institute of Oceanology, Chinese Academy of Sciences, China, shows that strong Central Pacific El Niño events essentially self-destruct by triggering negative feedbacks from the distant Indian and Atlantic Oceans. Weaker events, however, survive by forming a lasting partnership with a regional North Pacific climate pattern. Their findings were recently published in Atmospheric and Oceanic Science Letters .
"We found that strong Central Pacific El Niños destroy themselves through long-distance oceanic connections," says Prof. Wang, corresponding author of the study. "These powerful events send atmospheric signals across the globe, but the response from other oceans comes back like a boomerang to extinguish them."
In contrast, weaker events lack the strength to trigger these remote connections. Instead, they excite the North Pacific Meridional Mode—a seesaw pattern that creates a self-sustaining feedback loop within the Pacific itself. This local partnership allows the El Niño to persist through the following summer.
A surprisingly simple prediction method
Most importantly, the research team developed a two-factor empirical model that can predict which pathway a Central Pacific El Niño will follow with over 80% accuracy. The empirical model uses only the developing summer intensity in the central Pacific and subtropical northeastern Pacific sea surface temperatures during peak winter.
"The two factors are completely independent, which makes our prediction framework unusually robust," explains Dr. Chen, first author of the study. "We can now forecast months in advance whether a Central Pacific El Niño will persist into the following year."
Why this matters for seasonal planning
This discovery has immediate practical value. El Niño patterns influence droughts, floods, agricultural yields, and extreme weather worldwide. Knowing whether an event will persist allows farmers, water managers, and disaster preparedness agencies to make better decisions.
The framework could be integrated into current forecast systems to improve seasonal-to-interannual climate predictions. This is particularly important as climate change is projected to increase the frequency of Central Pacific El Niño events in the coming decades.
The study also resolves a long-standing paradox in climate science: why some seemingly strong El Niños vanish rapidly while weaker ones stubbornly persist. The answer lies not in peak winter strength, as previously thought, but in conditions established during the early developing summer.
