El Niño and La Niña

Florida’s climate is strongly influenced by the temperatures of the Atlantic and Pacific oceans (Henry 1998). When the temperature of the Atlantic near the equator is higher than normal, less rain falls on Florida. This is a result of changing wind patterns that bring less moisture over Florida from the Gulf of Mexico.

El NiñoName given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the tropical Pacific trade winds weaken and the usual upwelling of cold, nutrient rich deep ocean water off the coast of Ecuador and Peru is reduced. The El Niño normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time period is an unseasonably warm ocean current that generally occurs every 3 to 7 years and lasts an average of about a year to 15 months. El Niño and La Niña are phenomena that occur in the Pacific Ocean off the coast of Peru.

Peruvian fishermen first identified the event and named it El Niño after the Christ Child because it appeared off their coast around Christmas. Scientists do not fully understand this phenomenon. It begins when Pacific trade winds become weak and the top layer of the eastern Pacific gets warmer and warmer. The mass of clouds created by the warm water is carried eastward by the subtropical jet streamA high-speed, meandering wind current, generally moving from a westerly direction at speeds often exceeding 400 kilometers (250 miles) per hour at altitudes of 15 to 25 kilometers (10 to 15 miles). .

La Niña (also sometimes called El Viejo) is the opposite of El NiñoName given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the tropical Pacific trade winds weaken and the usual upwelling of cold, nutrient rich deep ocean water off the coast of Ecuador and Peru is reduced. The El Niño normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time period . La Niña occurs when stronger than normal trade winds stir up cooler water from the ocean depths.

El NiñoName given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the tropical Pacific trade winds weaken and the usual upwelling of cold, nutrient rich deep ocean water off the coast of Ecuador and Peru is reduced. The El Niño normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time period years bring greater than normal amounts of rainfall to Florida in the winter than La Niña, or neutral years, as well as more intense and frequent storms from the Gulf of Mexico. La Niña years bring less winter rainfall. Hurricanes, which originate in the Atlantic, are less frequent during El Niño years than during La Niña or neutral years. By monitoring the Pacific Ocean west of Peru, scientists can now forecast El Niño and La Niña events

This knowledge is critical to agriculture, forestry and emergency management. Winter vegetables and fruits are a big industry in Florida. Growers now know whether they are likely to face a wet or a dry growing season. Strawberry growers, for example, have learned to plant drought-tolerant varieties during La Niña years (Florida Consortium 1999). Dry La Niña winters may mean greater risk of forest fires in the normally dry spring. During El NiñoName given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the tropical Pacific trade winds weaken and the usual upwelling of cold, nutrient rich deep ocean water off the coast of Ecuador and Peru is reduced. The El Niño normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time period years, although winters are wetter than normal, vegetation tend to be drier than normal in many parts of the state. These conditions may result in fires in early summer, as occurred in June 1998. Knowledge of La Niña helps emergency managers plan in advance for a hurricane season that will probably be more active than normal.