![]() ![]() La Niña ("The Girl" in Spanish) is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. However, over time the term has evolved and now refers to the warm and negative phase of the El Niño–Southern Oscillation (ENSO). Originally, the term El Niño applied to an annual weak warm ocean current that ran southwards along the coast of Peru and Ecuador at about Christmas time. Although pre-Columbian societies were certainly aware of the phenomenon, the indigenous names for it have been lost to history. : 23 Terminology Īn early recorded mention of the term "El Niño" ("The Boy" in Spanish) to refer to climate occurred in 1892, when Captain Camilo Carrillo told the geographical society congress in Lima that Peruvian sailors named the warm south-flowing current "El Niño" because it was most noticeable around Christmas. The other two main ones are Pacific Decadal Variability (or oscillation) and Atlantic Multi-decadal Variability (or oscillation). In climate change science, ENSO is known as one of the internal climate variability phenomena. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. The extremes of this climate pattern's oscillations cause extreme weather (such as floods and droughts) in many regions of the world. Mechanisms that cause the oscillation remain under study. An especially strong Walker circulation causes La Niña, resulting in cooler ocean temperatures due to increased upwelling. Weakening or reversal of the Walker circulation (which includes the trade winds) decreases or eliminates the upwelling of cold deep sea water, thus creating El Niño by causing the ocean surface to reach above average temperatures. The Walker circulation is caused by the pressure gradient force that results from a high-pressure area over the eastern Pacific Ocean, and a low-pressure system over Indonesia. The two phases relate to the Walker circulation, which was discovered by Gilbert Walker during the early twentieth century. The two periods last several months each and typically occur every few years with varying intensity per period. ![]() ![]() The Southern Oscillation is the accompanying atmospheric component, coupled with the sea temperature change: El Niño is accompanied by high air surface pressure in the tropical western Pacific and La Niña with low air surface pressure there. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. This component is an oscillation in surface air pressure between the tropical eastern and the western Pacific Ocean waters.Įl Niño–Southern Oscillation ( ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The Southern Oscillation is the atmospheric component of El Niño. Southern Oscillation Index timeseries from 1876 to 2023. ( Learn how and when to remove this template message) ( December 2023) ( Learn how and when to remove this template message) Please help improve the article by providing more context for the reader. This article provides insufficient context for those unfamiliar with the subject.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |