Education English | Explanation Text : The El Niño Phenomenon |
What Is El Niño?
El Niño is a warm water current which moves off the west coast of Chile and Peru. The current is believed to be closely associated with irregular variations in the global weather system and it occurs approximately every 7–11 years. The wider consequences of El Niño can be catastrophic. The current is associated with short–term changes in worldwide climate patterns, and may cause drought in place such as Australia and violent tropical cyclones in the Pacific Ocean. Some scientists fear that global warming may be making El Niño occur more frequently.
How Does El Niño Occur?
The combined influence of land, sea and air on weather conditions can create a global climate rhythm. In the Pacific Ocean, for example (A), trade winds normally blow from east to west (1) along the Equator, "dragging" sun–warmed surface waters into a pool of North Australia and there by the thermocline–the boundary between warm surface waters and the cooler layers beneath (2). High cumulus clouds form above these warm waters, bringing rain in the summer wet season (3). Cooler, nutrient-rich waters rise to surface off Southern America (4), supporting extensive shoals of anchovies on which a vast fishing industry has developed. The weather over this cold water region is dry.
Every 3–5 years a change occurs in the ocean-atmosphere interaction. The climatic pattern is reserved (B)–an event known as El Niño. The trade winds ease, or even reverse direction (5), during El Niño and the warm surface waters which have "pulled up" in the West Pacific flow back to warm the waters off South America by 2–3°C (6). This depresses the east thermocline (7) and dramatically affects the climate. In an El Niño year, drought and bush fires occur over Australia, while flood affect Bolivia and Peru. The warm waters off South America suppress upwelling of the cold nutrient rich waters, bringing disaster to the fishing industry.
Taken from Philip’s Science and Technology, Encyclopedia 1998
To Get More “Explanation Text” please Click Here
El Niño is a warm water current which moves off the west coast of Chile and Peru. The current is believed to be closely associated with irregular variations in the global weather system and it occurs approximately every 7–11 years. The wider consequences of El Niño can be catastrophic. The current is associated with short–term changes in worldwide climate patterns, and may cause drought in place such as Australia and violent tropical cyclones in the Pacific Ocean. Some scientists fear that global warming may be making El Niño occur more frequently.
How Does El Niño Occur?
The combined influence of land, sea and air on weather conditions can create a global climate rhythm. In the Pacific Ocean, for example (A), trade winds normally blow from east to west (1) along the Equator, "dragging" sun–warmed surface waters into a pool of North Australia and there by the thermocline–the boundary between warm surface waters and the cooler layers beneath (2). High cumulus clouds form above these warm waters, bringing rain in the summer wet season (3). Cooler, nutrient-rich waters rise to surface off Southern America (4), supporting extensive shoals of anchovies on which a vast fishing industry has developed. The weather over this cold water region is dry.
Every 3–5 years a change occurs in the ocean-atmosphere interaction. The climatic pattern is reserved (B)–an event known as El Niño. The trade winds ease, or even reverse direction (5), during El Niño and the warm surface waters which have "pulled up" in the West Pacific flow back to warm the waters off South America by 2–3°C (6). This depresses the east thermocline (7) and dramatically affects the climate. In an El Niño year, drought and bush fires occur over Australia, while flood affect Bolivia and Peru. The warm waters off South America suppress upwelling of the cold nutrient rich waters, bringing disaster to the fishing industry.
Taken from Philip’s Science and Technology, Encyclopedia 1998
To Get More “Explanation Text” please Click Here
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