enso Flashcards
what is an el niño
during an el niño, the east to west trade winds weaken in the pacific, blowing warmer surface water back towards the east.
what a la niña
a la niña occurs when the east to west trade winds intensify and blow water further west.
how does el niño / la niña affect biological productivity
many organisms rely on nutrient rich deep water to sustain and create life. during upwelling, this nutrient rich deep water rises to the surface
in an el niño, there is decreased upwelling resulting in a decrease in bioproductivity
in a la niña, there is increased upwelling resulting in an increase in bioproductivity
how does el niño / la niña affect weather in the us
the enso mainly affects north american weather during the winter (its peak)
during an el niño, the warmer water moves the jet stream southwards over the southern us. this results in increased precipitation and flooding in the south (especially southwest) and dry conditions in the north.
during a la niña, the jet stream moves over the northern us. this results in increased precipitation in the north (especially pacific northwest) and dry drought conditions in the south.
what has been happening to the enso
el niño events have been getting more intense and frequent over time. the noaa uses the oceanic niño index to track the frequency and intensity of the enso.
how does el niño / la niña affect global weather
during el niño, warmer water is pushed eastward. this leads to drier conditions in asia and australia but wetter conditions in the us due to rising air over the warmer surface water. it also leads to an overall warmer global climate as there is less cold water upwelling and cooling the air.
during la niña, warmer water is pushed westward. this leads to wetter conditions in asia and australia due to rising air over the warmer surface water but drier conditions in the us. it also leads to an overall colder global climate as there is more cold water upwelling and cooling the air.
