Rossby waves are a type of long, planetary-scale wave that travels through the atmosphere and oceans. They are named after the Norwegian-American meteorologist Carl-Gustaf Rossby, who first described them in 1939.

Rossby waves are caused by the rotation of the Earth and the resulting Coriolis force. The Coriolis force deflects objects moving in the atmosphere and oceans to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection creates a wave-like motion that can propagate over long distances.

Rossby waves are typically hundreds to thousands of kilometers in length and have periods of several days to weeks. They can travel at speeds of up to 100 kilometers per hour.

Rossby waves play an important role in our weather and climate. They can affect the movement of storm systems, the formation of clouds, and the distribution of precipitation. Rossby waves can also influence the ocean currents and sea levels.

For example, the El Niño-Southern Oscillation (ENSO) is a climate phenomenon that is caused by changes in the strength and direction of the trade winds in the Pacific Ocean. These changes in the trade winds cause changes in the ocean currents and sea levels, which can in turn affect the weather patterns around the world.

Rossby waves are a complex phenomenon, but they are an important part of our planet's weather and climate system. By understanding Rossby waves, we can better understand how our planet works and how it is changing.