El Nino
...rm clouds. As a result, this strip of ocean stays free of clouds during normal years and rain in the equatorial belt is largely confined to the extreme western Pacific near Indonesia. But when the easterlies weaken and retreat eastward during early stages of an El Nino event, the upwelling slows and the ocean warms. The moist air above the ocean also warms. It becomes light enough to form deep clouds which produce heavy rain along the Equador. The change in ocean temperatures causes a major rain zone over the western Pacific to shift eastward. Related adjustments in the atmosphere cause barometers to drop over the central and eastern Pacific and rise over Indonesia and Australia. This results in a further weakening and eastward retreat of the easterlies. In this way small changes in the ocean and wind currents continue to amplify each other until a full blown El Nino event occurs. Dense tropical rain clouds alter the air flow 5 to 10 miles above sea level (ex. Rocks distort the flow of a stream). These clouds create waves in the airflow that in turn determine the positions of monsoons, the storms tracks and belts of strong winds above the earth that separate warm and cold regions of the earth’s surface.(referred to as jet streams). The impacts of El Nino upon climate in temperature show up most clearly during wintertime. Most El Nino winters are mild over western Canada and parts over the United States, and wet over the southern United States from Texas to Florida. El Nino affects temperature climates in all other seasons as well. But even during wintertime El Nino is only one of a number of factors that influence temperature climates. El Nino years are not always marked by "tropical" El Nino conditions the way they are in the tropics. Scientists noticed that a monsoon season with low index conditions are often marked by droughts in Australia, India, Indonesia and parts of Asia. Although scientists did not realize the magnitude of what they were discovering they knew they had discovered only a small portion of this phenomenon. It would require a knowledge of wind patters above ground level (which were not recorded at that time) to continue to gain knowledge. In the following decades researchers added new pieces to the emerging picture of Southern Oscillation. The march of the seasons is quite predictable. In contrast El Nino recurs at irregular intervals ranging from two years to a decade, and no two events are ever exactly alike. For example the 1982-83 El Nino caught scientists by surprise because unlike previous El Niños it was not preceded by a period of stronger easterlies on the equator. To further confuse scientists this event also set in unusually late in the calendar year. In order to guard against the possibility of being surprised by another El Nino scientists continue to document as many past events as possible by piecing together bits of evidence from many different sources such as sea surface temperatures, daily observations of atmospheric pressure and rainfall and regarded as the strongest this centuries by many "experts". I t was not predicted and not even recognized by scientists during its early stages. The economic impacts were large. The Equador and Peru fishing industries suffered heavily when there anchovy harvest failed and their sardines unexpectedly moved south into Chilean waters. Up to 100 inches of rain fell in Equador and northern Peru. This transformed the coastal desert into a grassland dotted with lakes. The new vegetation attracted swarms of grasshoppers which fueled explosions in the toad and bird populations. The new lakes also created a temporary habitat for fish that had migrated up stream from the sea and had become trapped. Many of them were harvested by local residents as the lakes dried up. In some of the flooded coastal estuaries, shrimp production records were set, but so did the number of mosquito-borne malaria cases. Further to the west abnormal wind patterns shifted typhoons off their usual tracks and sent them to the islands of Hawaii and Tahiti, which are unaccustomed to such severe weather. They also caused the monsoon rains to fall over the central Pacific instead of the western side which caused droughts and forest fires throughout Indonesia and Australia. Many winter storms battered southern California and caused flooding throughout the southern United States. Overall the loss to the world economy as a result to climate changes resulted in $8 billion. For research purposes an array of buoys were deployed in order to understand and predict ocean currents better. There are nearly 70 buoys moored with steel cable spanning between the Galapagos islands and New Guinea. They are approximately 900 miles apart in the east-west direction and about 150 miles apart in the north-south direction. Each buoy measures surface wind, air temperature, humidity, sea surface temperature and subsurface temperatures down to 500 meters. Some buoys also measure ocean currents, rainfall and solar radiation. The data is transmitted to operational weather centers all over the world where the data in analyzed and used for climate forecasting. Wind and ocean current data from buoys have also been used by nations to locate overdue or missing vessels in the western Pacific. Scientists are also trying to predict El Nino by taking advantage of observations from the National and Oceanic Administration weather satellites, scientists have been able to! track shifting patterns of sea surface temperatures. The pool of warm waters that normally resides in the western waters of the Pacific has been seen to drift eastward toward the western coast of South America. NASA satellite images also help us to see the shifting patterns of storms over the equator that are a consequence of the shifting locations of the warm water pool. Towering cumulus clouds, reaching high into the atmosphere with multiple regions of strong up and down vertical motions, form and move eastward along across the Pacific as they are generated by the warm surface waters. This movement of the powerfully active convective regions alters the surface winds, and weakens the normally prevailing east to west trade winds. Scientists believe that one way to lessen the impact of El Nino is to be able to predict it and give a warning. Over the years, several NASA missions have studied the effects associated with EL Nino. Initial efforts at mapping sea surface temperatures and cloud cover were conducted using two different satellites in 1978. These satellites greatly increased the amount of readily available information. Since that time there have been many improvements made. The number of channels was increased from four to five. These channels allow the instruments to view in different parts of the electromagnetic visible and infrared spectrum. In the near future, small NASA missions known, known as Earth Probes, are planned to address specific Earth science...