Researchers have long known that there is an asymmetry in the El Niño-Southern Oscillation (ENSO), the confluence of wind and water currents that creates warm El Niño events and cooler La Niña events. Large-scale climate models tend to underrepresent this asymmetry for reasons that are still not fully understood. Better modeling of the mechanisms that make El Niño events warmer could both provide insight into Earth's climate system and improve future ENSO predictions.