El Nino Phenomenon

El Nino has been a reoccurring phenomenon for centuries. What exactly is El Nino? “The term El Nino refers to a massive warming off the coastal waters of Peru and Equador that frequently extends more than 90 degrees of longitude. It is related to the Southern Oscillation, the atmospheric component of this phenomenon… ” (Gottschalk, 1998). Because El Nino and Southern Oscillation are often coupled, the term ENSO is used. (Garrison, 1999) This event usually last up to a year but can last up to three years. El Nino occurs every several years.

The areas that are most affected by this event are all ocean areas at tradewind latitudes in both hemispheres. (Garrison, 1999) El Nino has been linked to flood and droughts all over the world. El Nino causes significant changes in biology and weather when it occurs. During an El Nino cycle there are many biological changes. During an El Nino thermocline is low and therefore there is less photosynthetic activity following in a decrease in the primary life forms.

The warmer waters that are brought by El Nino hold less oxygen demanding the fish to go somewhere else. Cook 1998) “Although upwelling may occur during an ENSO event, the source of upwelled water is nutrient-depleted water in the thickened surface layer approaching from the west”(Garrison, 1999). This does not help the fisherman to make money or eat during an ENSO event. This biological decrease also hurts the economy because the fishermen in the areas affected are not catching the right amount of fish to make money. Biological change is due to the climate and during El Nino. The surface winds that move the ocean currents are a major controller in weather.

During El Nino when the easterlies weaken and retract eastward during the early stages, the upwelling slows and the ocean warms along with the moist air above the ocean. The change in the ocean temperatures causes a major rain section over the western Pacific to move eastward. In this way small changes in the ocean and wind currents continue to magnify each other until a full-blown El Nino occurs. ” The increased evaporation intensifies coastal storms, and rainfall inland may be much higher than normal”(Garrison, 1999).

The impacts of El Nino upon climate in temperature show up most during wintertime. Most El Nino winters are not that cold over western Canada and parts over the United States, and wet over the Southern United States and from Texas to Florida. (Whipple, 1998) According to Helvarg (1998), El Nino occurs at irregular intervals ranging from two years to a decade, and no two events are ever exactly alike. The 1982-83 El Nino was a surprise because it was not proceeded by a period of stronger easterlies on the Equator. It also occurred late in the calendar year.

The economic impact was large. The Equador and Peru fishing industries suffered heavily. Up to a hundred inches of rain fell in Equador and Peru. The new vegetation swarmed grasshoppers, which increased the toad and bird population. Further west they found abnormal wind patterns and this shifted typhoons and sent them to Hawaii and Tahiti, which was unaccustomed to severe weather. The total amount of damage was $8 billion. “This years El Nino [1997-1998] has been the strongest ever recorded” (Helvarg, 1998). This El Nino drought had more of an impact than its rains.

El Nino also infuriated tornado and storm activity in the Southeast. ” In Alabama 34 people were killed and some 5,000 acres of trees knocked down in April when deadly tornadoes struck” (Helvarg, 1998). This record braking tornado event was spawned by the collision of warm, moist air that lingered over the warm Pacific and a polar front that had dropped from the north. (Garrison, 1999) In parts of Northwest U. S. there where massive clear-cut logging operations have to take place on mountain slopes, El Nino”s rains and big surfs contributed to what has become a pattern of landslide and flooding.

In the Hawaiian Islands El Nino weakened the tradewinds that normally bring rain, resulting in a three month long winter drought. This damaged crops and sparked wildfires that depleted hundreds of acres of endangered native species. (Helvarg, 1998) Conditions from this year El Nino did not return to normal until late spring of 1998. (Garrison, 1998) “Estimates of worldwide 1997-1998 damage exceeded $25 billion”(Garrison, 1999) According to Garrison(1999), the contrasting colder events that occur are known as La Nina. As conditions to the east cool off, the ocean to the west warm rapidly.

The renewed thrust of the trade winds piles this water upon itself, depressing the upper curve of the thermocline too more than 100 meters deep. According to Whipple (1998), weather from El Nino and La Nina are not symmetrical. Scientists have only recently recognized La Nina events. Since World War II there have been only one La Nina for every three El Ninos. Delivered along with El Nino”s wrath has been increased emphasis on the need to understand this often destructive weather phenomenon” (Gottschalk, 1998). If we understand El Nino we can better prepare and find better equipment to predict it.

Buoys were arranged in the ocean to understand and predict ocean currents better. These buoys were placed between New Guinea and the Galapagos Islands. Each buoy measures surface wind, air temperature, humidity, sea surface temperature and subsurface temperature down to 500 meters. The data is then transferred to weather centers all over the world. The data is then analyzed and used for climate forecasting. Scientists are also trying to predict El Nino by National and Oceanic Administration weather satellites. From these satellites they have been able to track shifting patterns of sea surface temperatures.

NASA satellite images also help us to see the shifting patterns of storms over the equator. NASA”s EOS provides ocean sea-surface vector winds. This will be launched in the year 2000. This is called SeaWinds microwave radar. “Adding to the El Nino data pile will be MODIS with its sea-surface temperature and ocean color sensors, Jason 1 for sea-surface height, and TRmm for tropical rainfall. On the ground, the EOS Data and information System (EOSDIS) ground will focus on processing, analyzing, and disseminating information gathered by this orbiting army of satellites” (Gottschallk, 1998).

Over the years, several NASA missions have studied the effects associated with El Nino. Earliest efforts at mapping sea surface temperatures and cloud cover were done using two different satellites in 1978. Since then there have been many improvements made. The number of channels was increased from 4 to 5. These channels allow the instruments to view in parts of the electromagnetic visible and infrared spectrum. This increases the amount of readily available information on El Nino. All these things above help to better predict El Nino and to allow the countries the will be affected to prepare for it.

This is important for the developing countries because the economy is very sensitive to climate change. Rice and cotton are two primary crops of Peru and are highly sensitive to rainfall (Encyclopedia). Therefore, if the farmers were told that El Nino were coming they would know whether to plant more rice or cotton in a year. Tropical countries have the most to gain from predictions but non-tropical countries require a more accurate prediction of El Nino. Countries such as Japan and United States will benefit in the strategic planning in areas such as agriculture, the management of water resources and the reserves of grain and fuel oil.

Scientists and governments are working together to design and build a global system for predicting El Nino and other irregular climates. Governments should make climate predictions available daily like they make weather forecasts available to the public today. The ability to prepare how climate will change leads to better management of agriculture, water supplies, fisheries and other resources. By doing all these things people are going to become better adept to all irregular rhythms of climate.