Climate models are auspicate that this fall , there ’s a75 per centum chancethat an El Niño will pass . But just what is this phenomenon , and how does it impress us ?
At its simplest , El Niño refer to unusually warm water temperature in the Pacific Ocean near the equator , and the ensue conditions and climate effects that warm water system crusade . During an El Niño , the surface temperature of the water system is generally 1.5 degree to 2.5 point Celsius above norm . ( This is the opposite of La Niña , which is characterized by unusually nerveless temperature . ) The natural phenomenon occurs at random intervals of 2 to 7 years and can last anywhere from nine month to a year — although in extreme circumstances , El Niños have lasted several year .
The fragile rise in water temperature has wide ranging burden in weather across the earth . El Niño episodes are affiliate with increased rainfall across the east - cardinal and eastern Pacific , including the west coasts of North and South America , and with dryer - than - normal conditions over northern Australia , Indonesia , and the Philippines . Most of the moved country will also receive warm - than - normal winters during El Niño .
The normal wind consideration and atmospherical pressure experimental condition over the Pacific Ocean are creditworthy for the regular upwelling of cooler , nutrient - rich water off the coast of South America , which sustains a prominent fish universe . During El Niño , the changes in atmospheric pressure and wind patterns slenderize this upwelling and , in routine , leave in a decreased fish population . At least as much as the atmospheric condition — which can often let in dangerous flooding — this effect on the fishing economy is one of the more devastating impacts of El Niño .
Thoughwe last saw an El Niño in 2004 , the strongest El Niño in recent story occurred in 1997-‘98 [ PDF ] . According to the National Oceanic and Atmospheric Administration ( NOAA ) , water temperatures along the west coast of South America were 4 degrees Celsius above average , which resulted in extreme weather design across the U.S. The duad from December to February was the second warmest and seventh lactating since 1895 . Several state saw flooding , while the Northeast was hit with an shabu storm and Florida experience an unusually high number of crack . This anticipate El Niño could be similarly bad : NASA climatologist Bill Patzertsaid that"a blueprint of sea surface heights and temperatures has organise that reminds me of the way the Pacific look in the give of 1997 . " For more on the science behind El Niño , check out NASA ’s ScienceCast , below .
