El Nino and La Nina
Introduced| English | Meaning |
|---|---|
| El Niño/el ˈniːnjəʊ/ | The warm phase of the El Niño-Southern Oscillation, involving unusually warm central or eastern equatorial Pacific surface waters and associated atmospheric changes. |
| La Niña/læ ˈniːnjə/ | The cool phase of the El Niño-Southern Oscillation, involving unusually cool central or eastern equatorial Pacific surface waters and associated atmospheric changes. |
| upwelling/ˈʌpwəlɪŋ/ | The rising of cold, nutrient-rich water from the deep ocean to the surface. |
The Pacific's mood swings
- Every few years, the Pacific Ocean shifts its temperature and winds.
- These swings change the weather far beyond the ocean.
- They can bring floods to one continent and drought to another.
- The two phases are called El Niño and La Niña.
Normal conditions and upwelling
- Normally, strong trade winds push warm surface water west across the Pacific.
- This lets cold, deep water rise near South America — called upwelling 上升流.
- The cold, nutrient-rich upwelling feeds huge fisheries off Peru.
- This is the usual, balanced state of the Pacific.
Normal conditions and El Niño across the equatorial Pacific
El Nino and La Nina are shifts in…
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El Nino and La Nina are natural shifts in Pacific Ocean temperatures and winds that alter weather worldwide.
El Niño: warm water shifts east
- In an El Niño 厄尔尼诺, the trade winds weaken or reverse.
- Warm water then spreads back east across the Pacific.
- The upwelling is cut off, so the fisheries collapse and coasts warm.
- Rainfall patterns shift worldwide — floods in some places, drought in others.
During El Nino, the trade winds weaken and warm water…
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In El Nino, weak trade winds let warm water spread east, changing rainfall around the globe.
Cold, nutrient-rich water rising to the surface off Peru is called ____.
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Upwelling brings cold, nutrient-rich water up, feeding rich fisheries — it weakens during El Nino.
La Niña: the opposite
- In a La Niña 拉尼娜, the trade winds grow stronger than normal.
- Even more warm water is pushed west, and cold upwelling intensifies.
- It is like an extra-strong version of normal conditions.
- La Niña, too, shifts weather around the globe, often opposite to El Niño.
El Nino or La Nina?
Sort each condition by whether it happens during El Nino or La Nina in the Pacific.
El Nino and La Nina can change weather far beyond the Pacific, around the world.
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These Pacific shifts ripple into droughts, floods, and storms across many continents.
Select all true statements about El Nino and La Nina.
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Their effects are global, not local to one bay. The other three are correct.
El Niño and La Niña are natural cycles, not the same as human-caused climate change. They come and go every few years. But they are important because their effects reach worldwide — a Pacific shift can cause a drought or a flood on the other side of the planet.
El Niño and the Peruvian fishery:
- Normally, cold upwelling off Peru feeds one of the world's richest fisheries.
- During an El Niño, warm water spreads in and shuts off the upwelling.
- Without the nutrients, the fish vanish and the fishery collapses — a Pacific shift felt directly by fishing communities.
El Niño and La Niña are natural shifts in Pacific Ocean temperatures and winds. In El Niño, weak trade winds let warm water spread east, cutting off cold upwelling and collapsing fisheries. La Niña strengthens the normal pattern. Both change weather worldwide, causing droughts and floods far from the Pacific.