Monitoring and early warnings related to the El Niño phenomenon

Hartmut Grassl
World Climate Research Programme, c/o WMO, Case Postale 2300, 1211 Geneva 2, Switzerland.
Tel. : +41-22-730 8246, Fax: +41-22-734 0357,
E-mail: grassl_h@gateway.wmo.ch

The El Niño phenomenon is a result of ocean/atmosphere interaction in the tropical Pacific resulting in irregular but strong positive temperature anomalies in the eastern tropical Pacific normally lasting for about a year and causing anomalous weather in large parts of the tropics and also mid-latitudes. With the advent of a near real-time observing system in and above the tropical Pacific and coupled ocean/atmosphere models (the TOGA project of the World Climate Research Programme (WCRP)) former empirical seasonal outlooks could be turned into skillful predictions of seasonal climate anomalies both for strong warm (El Niño) and cold events (La Niña). The breakthrough to physically-based climate variability predictions opens many new applications: water resource management over months, changed agricultural practices for the next season, adapted transport of oil for the next winter, forecasting of yields, etc. The presentation will give examples of successful applications and also outline the research strategy within WCRP to improve the understanding and thus predictions.