El Nino and La Nina :: essays research papers

What are El Nino and La Nina? El Nino and La Nina are unusual weather patterns that form in the period of 10 months. El Nino and La Nina both impact climates all around the world, each different in countries and regions. Normal weather patterns are when low atmospheric pressure is over northern Australia and Indonesia, and when high atmospheric pressure is over the Pacific Ocean. Winds move east to west over the Pacific. The east flows of the trade winds carries the warm surface waters to the west, and bring rainstorms to Indonesia and northern Australia. To the coast of Ecuador and Peru, warm surface water is pulled west, and the cold water beneath pulls up to replace it. This is called an upwelling. An El Nino happens in intervals of 3-7 years. The formation of this is related to the Pacific Southern Oscillation which is also the cycling of the Pacific Ocean circulation. The Pacific Southern Oscillation (the change of atmospheric pressures) happens when the easterly trade winds collapse, weaken, or even reverse. As this happens, the upwelling stops. The slight weakening of the winds cause a small change in sea surface temperatures, and the wind and pressure changes increase. The warm water of the western Pacific Ocean flow eastward and sea surface temperatures increase on the western coast of South America. When this occurs, the wet weather conditions (originally in the western Pacific) move east, and dry conditions (normally in the east) appear in the west. During El Nià ±o?s in the Pacific Northwest, the amount of precipitation greatly decreases, the winter temperatures get milder, and winter has below-average precipitation. Some economical and environmental impacts are that erosion is increasing due to severe storm surges, concerns that property built on low-lying areas or on top of unstable bluffs possibly be flooded or threatened by landslides due to regional climate changes, and various salmon species potentially endangered. In California, during El Nino?s they get extreme precipitation and snowfalls. Economical and environmental impacts are heavy precipitation, damage from debris flows or mudslides, and floods from the rain. El Nino seasons in Peru bring so much rainfall that there is now a lake made from the rain, compared to the desert it once was. Several economical and environmental impacts from El Nino include massive floods or mudslides, and since Peru lives in a cold-water zone, it carries many fish that are caught and so ld commercially, but during El Nino, a layer of warm water covers the nutrient-rich east coast waters, abruptly stopping the upwelling and the nutrients fail to come up.