A Kelvin wave is a type of wave that travels along the boundary of a fluid, such as an ocean or atmosphere. It is characterized by its ability to maintain its shape while moving, often influenced by the Earth's rotation. These waves are important in understanding ocean currents and weather patterns. Kelvin waves can be generated by various phenomena, including changes in wind patterns or temperature. They play a significant role in the dynamics of the ocean and can affect climate events like El Niño and La Niña, which have global implications for weather and ecosystems.