4.9 El Nino and La Nina

el ninc and la nina are phenomena associated with changing ocean surface temperatures in what ocean?

pacific ocean

phenomena like _____ and _____ can cause global changes to rainfall, wind, and ocean circulation patterns

el nino, la nina

t or f: el nino and la nina are not influenced by geological and geographic factors and can't affect different locations in different ways

f (they are majorly influenced by those types of factors)

what is a large scale water circulation that moves clockwise in the northern hemisphere and counter clockwise in the southern

gyre

what is the upward movement of ocean water?

upwelling

upwelling:

-mixes the water, bringing _____ and _____ water from the bottom of the ocean to the surface

-it supports large populations of phytoplankton, zooplankton, fish, and fish eating seabirds

cool, nutrient rich

what are 2 ways in which upwellings can occur?

far from shore or along the steep western coasts of some continents

where does upwelling occur when surface current move apart and draw water up from deeper layers?

far from shore

where does upwelling occur when winds are blowing along the coasts which pushes surface water away from land and draw water up?

along the steep western coasts of some continents

el nino happens during every few _____ in the pacific ocean

years

what happens during an el nino?

-normal shore upwellings are affected by changes in weather patterns

-prevailing tropical trade winds (east or west) _____ or reverse direction

-_____ pacific moves warmer water towards _____

-suppress the normal upwellings of _____, nutrient rich water

weaken, western, south america, cold

effects of el nino:

-reduces primary _____

-causes decline in _____ populations

-can alter the weather of at least two thirds of the globe especially in lands along the pacific and indian oceans

productivity, populations

_____ cools some coastal surface waters and brings back upwellings

la nina

la nina:

-more _____ hurricanes

-colder winters in canada and northeastern us

-_____ and _____ winters in the southeastern and southerwestern us, more wildfires

-wetter winters in the pacific northwest

-torrential rains in southeast asia

atlantic, warmer, drier