Henk A. Dijkstra

In 2010, the Pacific Ocean was brewing a strong El Niño, but all forecasting models collectively overestimated it. They looked at water temperatures and missed the key point: the ocean had already begun to reorganize, not loudly but quietly, linking distant points in pairs.

A wave travels westward, reflects off the coast, and returns six months later to alter temperatures along the eastern Pacific. This journey of Rossby and Kelvin waves Mori-Zwanzig formalism turns into an equation with memory. Previously, climatologists added delays to El Niño models by intuition, relying on physical insight.

The ocean remembers its past. Heat given to the water off the coast of Norway does not vanish without a trace: it embarks on a long journey across the Atlantic, only to return decades later and alter the temperature at those same shores once again.

In the Atlantic, a giant invisible conveyor operates: warm surface waters flow north, cool, sink, and return south. This circulation, AMOC, carries heat, making Europe noticeably milder than Canada at the same latitudes. But the conveyor isn't eternal: if diluted by fresh water from melting Greenland ice, the engine stalls.