Imagine a ribbon wrapped around Antarctica. Along this ribbon, as on a circular track, runs a wave: now warm water, now cold. It completes one lap in eight years. Sometimes the wave stalls so that one ocean warms while another cools. Previously, this frozen frame was mistaken for a separate phenomenon and called a dipole.

The new method works like a smart ear. It listens to all ocean oscillations at once and sorts them into categories, without requiring noise to be removed in advance. This made it possible to hear not only the main wave with two crests, but also quiet secondary waves that arise when the annual cycle superimposes on the four-year rhythm.

The wave with three crests has no such connection. It lives its own life, governed by local winds. Now that all the ocean's voices are heard, scientists can make predictions: how ice and water temperature will change in the coming seasons. The eight-year cycle continues, but now we know its music.