Find answers to questions about these atmospheric patterns, which play a key role in year-to-year weather and climate variation around the world.

There's major disagreement among scientists on exactly what might be causing a tendency toward colder winters over the last few years in places like the central and eastern United States, Europe, and Russia.

If today’s tools for multiyear climate forecasting had been available in the 1990s, they would have revealed that a slowdown in global warming was likely on the way, according to new research.

For millions of people, El Niño or La Niña indicates whether they’re likely to face unusually warm, cold, wet, or dry conditions over the coming winter. A new modeling study pins down the process that apparently determines why La Niña events often last twice as long as typical El Niño events—a result with major implications for seasonal predictions.

Known from their frequent film and TV appearances, the large, charismatic birds are in danger. By 2100, according to a new study, their numbers will have fallen by around 19% and will continue to decline, qualifying the species for endangered status.