El Niño/Southern Oscillation - ENSO
El Niño is the common name used in media referring to the East Pacific sea-surface temperature variations affecting the global climate. El Niņo is only part of a warm/cold cycle that takes place in the Pacific; there is also a pressure oscillation tied to the Pacific temperature variations known as the Southern oscillation because it is observed in the Southern Hemisphere. ENSO is responsible for climate variations throught the world. Use the links below to learn more about El Niņo-Southern Oscillation.
Image from An Introduction to the Dynamics of El Nino & the Southern Oscillation
By Allan J. Clarke