What are El Nino and La Nina? - National Ocean Service

El Niño means Little Boy, or Christ Child in Spanish. South American fishermen first noticed periods of unusually warm water in the Pacific ... Home Facts WhatareElNiñoandLaNiña? WhatareElNiñoandLaNiña? ElNiñoandLaNiñaareclimatepatternsinthePacificOceanthatcanaffectweather worldwide. ToviewthisvideopleaseenableJavaScript,andconsiderupgradingtoawebbrowserthat supportsHTML5video Warmerorcolderthanaverageoceantemperaturesinonepartoftheworldcaninfluence weatheraroundtheglobe.WatchthisOceanTodayvideoto seehowthisworks. DuringnormalconditionsinthePacificocean,tradewindsblowwestalong theequator,takingwarmwaterfromSouthAmericatowardsAsia.Toreplacethatwarmwater,cold waterrisesfromthedepths—aprocesscalledupwelling. ElNiñoandLaNiñaaretwoopposingclimatepatternsthatbreakthesenormalconditions. ScientistscallthesephenomenatheElNiño-SouthernOscillation(ENSO)cycle.ElNiñoandLa Niñacanbothhaveglobal impactsonweather,wildfires, ecosystems, andeconomies. EpisodesofElNiñoandLaNiñatypicallylastnineto12months,butcansometimeslastfor years.ElNiñoandLaNiñaeventsoccureverytwotosevenyears,onaverage,buttheydon’t occuronaregularschedule.Generally,ElNiñooccursmorefrequentlythanLaNiña. ElNiño DuringElNiño,tradewindsweaken.Warmwaterispushedbackeast,towardthewestcoastofthe Americas. ElNiñomeansLittleBoy,orChristChildinSpanish.SouthAmericanfishermenfirstnoticed periodsofunusuallywarmwaterinthePacificOceaninthe1600s.Thefullnametheyusedwas ElNiñodeNavidad,becauseElNiñotypicallypeaksaroundDecember. ElNiñocanaffect ourweathersignificantly.ThewarmerwaterscausethePacificjetstreamtomovesouth ofitsneutralposition.Withthisshift,areasinthenorthernU.S.andCanadaaredryerand warmerthanusual.ButintheU.S.GulfCoastandSoutheast,theseperiodsarewetterthanusual andhaveincreasedflooding. ElNiñocausesthePacificjetstreamtomovesouthandspreadfurthereast.Duringwinter,thisleadstowetterconditionsthanusualintheSouthernU.S.andwarmeranddrierconditionsintheNorth. ElNiñoalsohasastrongeffectonmarinelifeoffthePacificcoast.Duringnormal conditions,upwellingbringswaterfromthedepthstothesurface;thiswateriscoldandnutrient rich.DuringElNiño,upwellingweakensorstopsaltogether.Withoutthenutrientsfromthedeep, therearefewer phytoplanktonoffthecoast.Thisaffectsfishthateatphytoplanktonand,inturn,affects everythingthateatsfish.Thewarmerwaterscanalsobringtropicalspecies,likeyellowtailand albacoretuna,intoareasthatarenormallytoocold. LaNiña LaNiñameansLittleGirlinSpanish.LaNiñaisalsosometimescalledElViejo,anti-ElNiño,or simply"acoldevent."LaNiñahastheoppositeeffectofElNiño.DuringLaNiña events,tradewindsareevenstrongerthanusual,pushingmorewarmwatertowardAsia.Offthe westcoastoftheAmericas,upwellingincreases,bringingcold,nutrient-richwatertothe surface. ThesecoldwatersinthePacificpushthejetstreamnorthward.Thistendstoleadtodroughtin thesouthernU.S.andheavyrainsandfloodinginthePacificNorthwestandCanada.DuringaLa Niñayear,wintertemperaturesarewarmerthannormalintheSouthandcoolerthannormalinthe North.LaNiñacanalsoleadtoamore severehurricaneseason. LaNiñacausesthejetstreamtomovenorthwardandtoweakenovertheeasternPacific.DuringLaNiñawinters,theSouthseeswarmeranddrierconditionsthanusual.TheNorthandCanadatendtobewetterandcolder. DuringLaNiña,watersoffthePacificcoastarecolderandcontainmorenutrientsthanusual. Thisenvironmentsupportsmoremarinelifeandattractsmorecold-waterspecies,likesquidand salmon,toplacesliketheCaliforniacoast. MoreInformation ObservingElNiño(OceanTodayvideo) ElNiñoandLaNiñaFAQs ElNiñoviaSatellite ENSOImpacts SearchOurfacts GetSocial Social Lastupdated: 06/04/21 Author:NOAA Howtocitethisarticle ContactUs