El Nino
El Nino
We live on an incredibly large planet. Even broader than the size of the planet are the amount of changes and relationships between humans, animals, environment, weather, and the affects of each. Many times with busy schedules and modern lifestyles we forget the interaction that goes on between any number of concepts or idea’s. We fail to realize that a specific weather occurrence in the Pacific Ocean can have an affect on every day life in the United States. El Nino is one of the largest scientific phenomenons that scientists have ever explored. The main concepts of El Nino are very simple and there are many variations, causes, affects, and relationships to study.
The main idea behind El Nino is that the wind changes direction across the Pacific Ocean. In a non El Nino year (normal), the trade winds blow from east to west across the ocean, from North and South America towards the tropical regions of the Pacific Ocean. In an El Nino year, the trade winds change direction and blow from Asia and the tropical Pacific towards North and South America (NOAA B, 2004). The changes in these winds, commonly called Southern Oscillation winds because the majority of activity happens in the southern parts of the Pacific, produce many other changes. In the final analysis, the winds are the root of this scheme. John Daly (2004) discussed how the winds produce major changes in the temperature of the ocean water. This is the second main concept of El Nino. In normal years, when the wind blows from east to west, the temperature at “Sea Surface” is about 8 degrees cooler in the west than in the east. During El Nino, the winds blow a certain amount of water towards the west, thus piling it up and making its depth approximately one half meter deeper. Because of the loss of water at either coast, the deeper ocean water rises to replace what is gone. The deeper/cooler water is the source of many incomes in North and South America; however, in an El Nino year, the warmer water sits on top of the ocean, which creates many tribulations relating to both income and weather. The last main point of El Nino is the weather that follows due to the changes in water temperature. Precipitation follows the warmer water, whichever direction it flows. During the normal wind patterns the rainfall in the southern Pacific islands is consistent and creates their tropical identity. When the wind shifts the other direction it creates droughts and heat waves in the western Pacific and often time’s floods, or blizzards, in the eastern Pacific (NOAA A, 2004).
The theory of El Nino was originally explored and documented in the 1560’s. Mayell (1997) discussed how fishermen from Peru wondered why in certain years the normally cold water would become warm and the flow would reverse in an opposite direction. The change in water temperature would kill the majority of the fish and thus cause major problems for fishermen and many others who relied on fish. The changes in the water temperature usually began near Christmas, therefore the fishermen called this phenomenon El Nino, which means The Christ Child in Spanish.
Scientists who studied El Nino stayed only on the South American coast until the early 1900’s. British scientist Sir Gilbert Walker was stationed in India to study weather patterns after a monsoon in 1899 devastated the country. As he studied the monsoon’s he noticed a connection between water temperature and rainfall. He also discovered that the barometer readings of eastern and western Pacific Ocean were almost always identically opposite. He noticed that