Paper Example on El Nino Southern Oscillation

Introduction

El Nino is a term used to refer to the large-scale ocean-ecosystem weather interaction linked to a periodic warming in sea floor temperatures throughout the central as well as east-central Equatorial Pacific. It can also be defined as a climate cycle that usually occurs in the Pacific Ocean, which impacts on the patterns of weather. This cycle starts when the warm water in the western tropical of the Pacific Ocean moves eastward lengthwise the equator to the South Americas coast. This warm water usually pools towards the Philippines as well as near Indonesia. When an El Nino occurs, the warm surface waters of the Pacific usually sits on the South Americas northwestern offshore. (Wang, Shanshan, 753)

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All El Ninos are usually not the same also the ocean as well as the atmosphere follows patterns that vary from one El Nino to the other. Occurrence of the El Nino varies, but usually occur after every three to five years or as frequently as two years also every seven years rarely. According to experts, El Ninos occurs more often than the La Nina and when each event occurs, it last for nine to twelve months. Their formation begins for spring, between December and January they reach peak strength and eventually decay by may of the following year. Their strength differs significantly between cycles. (Wang, Chunzai, 85)

Theories on Warming of the Ocean

The Anthropogenic Global Warming Theory

This theory explains that as a result of the greenhouse gases emitted by human activities such gases, including methane, carbon dioxide as well as nitrous oxide, there is increased disastrous global temperatures. These are so because energy travels from the sun, it cuts through space and hits the earth directly and when the heat reflects, these greenhouse gases that are usually in the atmosphere absorbs the heat resulting to the atmosphere being warmer than normally it should be hence global warming. These global warming results for less snow as well as ice cover, after the ice and the snow melts, the water in the open and ground increases, which is less reflective that ice and snow hence absorbing more solar heat. (Shepherd, Theodore, 703) This causes increased warmth of the ocean waters.

The Ocean Current Theory

This theory propounds that ocean water is usually transferred continuously as of the surface mixed layer to the interior deep-sea through the ventilation process. According to experts, the ocean usually ventilates itself after the everyone thousand to two thousand years over a polar region where deep-sea subsidence of the cold salt water as well as a recompensing upwelling of less salty warmer water in the tropics. The ocean circulation is known as the Meridional Overturning Circulation. When the Thermohaline Circulation becomes weaker, the earth experiences less cooling, less net evaporation as well as less upwelling of the deep-sea cold water. Here energy amasses on the upper mixed layer of the ocean and therefore after a decade or two the general worldwide ocean starts warming. (Singh, Jagdev, Devendra Kumar, and Juan, 111)

Southern Oscillation is the comprehensible interannual fluctuation of the atmospheric pressure that occurs at the tropical indo-Pacific region. It is the atmospheric constituent of a single largescale attached interaction. The southern oscillation is usually an atmospheric incident which is usually strongly related to the observation and prediction of El Nino by the fact that any changes to the surface air pressure is usually as a result of movements of air mass in the atmosphere. The flagging of the east-to-west trade winds during a point of the southern oscillation usually allow warm waters on the western margin to move back to the east. This occurs by increasing the flow of the Equatorial Counter Current. The temperatures of the surface water as well as the sea level decreases in the west and in the east, it increases hence producing an event known as the El Nino.

The combination of El Nino and Southern Oscillation (ENSO) is therefore defined as an irregular episodic variation in sea surface temperatures as well as winds over the tropical eastern Pacific Ocean, thereby causing an effect on the climate or weather of the tropics also the subtropics. The southern oscillation is the atmospheric constituent that accompanies joined with the temperature variation while El Nino is convoyed by a high air surface compression in the tropical western pacific.

The world has been experiencing El Nino since long ago and experienced the strongest and the most shocking episode in the 20th Century in the year 1982-1983 until the 1997-1998 El Nino. The 1982-83' El Nino was held responsible for the killing of over 2000 people as well as more than $13 billion property damage as well as livelihood worldwide. During that period, the South American coast thermocline fell to around 500 feet. Along the coastal village of Paita in Peru, on 22rd September the temperatures of the sea-surface rose by 7 degrees F in just 24 hours. Below is a table indicating the loses and areas affected by the El Nino.

The Southern Oscillation Index (OSI) is an index used in the measurement of the difference in the pressure of the surface air between the Darwin and the Tahiti. (Wang, Shanshan, 90) The negative values of this index usually correspond to the conditions of El Nino on one hand while on the other hand the positive values coincide with the La Nina episodes. Other indices used in the prediction of El Nino includes the Nino 3.4 (N3.4) that is used in the representation of the average equatorial SST all through the Pacific towards the American Coast from about the date line. Another indices includes the Trans-Nino index (TNI) this is given by the variance amongst the normalized SST irregularities averaged in the Nino-1+2 as well as the Nino-4 regions.

Satellite sensors are the new technology adapted for the measurement of thermal increase of heating water on the eastern parts of the basin that rises the sea level in these regions. These sensors are used to measure these changes in sea level hence varying sea levels are good indicators of an occurrence or presence of El Nino. (Barnard and Patrick, 807)

Impacts of El Nino

El Nino can affect product prices as well as the economies of diverse countries throughout the world. Its capable of affecting the supply of the rainfall dependent agricultural products by reducing the agricultural yields, affect services goings-on as well as construction activities, it may cause social unrest in the poor countries product dependent who primarily depend on brought in food for their survival. El Nino is also capable of creating generalized inflation as well as food-prices in the country. Generally, El Nino always has economic impacts whenever it occurs. It also has environmental impacts in that whenever it occurs it may bring about dry and drought conditions, flooding, may lead to the occurrence of hurricanes, typhoons as well as very cold weather conditions. Below are some of the impacts of El Nino.

Effects on Sea Birds as Well as Aquatic Species

Normally, the ocean water usually carries nutrients that lie beneath the ocean to the top in order for the fish living on upper waters may feed on the planktons which grow or develop as a result of these nutrients. The seaweeds on the other hand also rely on waters that are rich in nutrients for their growth and survival. When an El Nino occurs, it lessens the uplifting of these nutrients and the cold waters from beneath the ocean. These leads to either migration or the death of fish during this period because of inadequate food. When fish migrate, those other aquatic creatures such as the sea birds also are affected. On the coasts of California, the aquatic populations such as the sea lions, fish, sea birds as well as seals are usually affected and most of them recorded dead during the El Nino period.

Dry and Drought Situations

El Nino always creates great changes in the weather conditions despite its varying presentations to different occasions. In some occurrences, it may result to drought as well as extreme dry spells. California is mainly affected by such conditions which to some extend becomes extremely disastrous leading to increased bush fires and very poor crop yields. These conditions occur mainly when the winds that usually bring rain to these regions becomes weaker. In 1876, it is believed that there was a deadly worldwide famine that resulted from El Nino and contributed to the death of millions of people and animals.

Impact on Commercial/Local Fishing and Flooding

El Nino conditions always goes for many months consecutively with temperatures of the ocean evening out, this results to heavy rainfall in the oceans that brings heavy floods that lasts for long and more periods. These floods are usually experienced far outside the shores of the ocean in the main land which destroys properties as well as leaving people homeless for many months. Fishing for both locally and commercial purposes is also affected negatively. In Peru, Ecuador and the South America regions are mostly affected during the El Nino period when it comes to fishing for commercial and local use.

Occurrence of Typhoons, Very Cold Weather as Well as Hurricanes

Occurrences of serious typhoons, very cold weather and hurricanes are at times tied to the warm pacific air in different parts of the world. In south America, tropical cyclones which in other words are referred to as the hurricanes as well as the thunderstorms are mostly associated with the changes in the global wind cycle circulation due to atmospheric heat displaced eastwards. Whenever hurricanes are fewer, during autumn and winter, very cold and wetter weather is usually witnessed. Evidences from meteorological departments indicates that the very cold weathers in Europe are usually because of the El Nino. In Japan and South Korea for example, its believed that the intense typhoons are usually caused by the warm pacific wind currents.

Other Impacts Both Economic and Environmental

El Nino may mean a lot to the people of California due to the worst droughts experienced there since it brings waters to the people in the region

El Nino consequence is found to be intense on the Pacific and Asia regions by the fact that it results to dry and hot summers in the southeast Australia regions; it rises the severity and frequency of forest fires; it lessens wheat exports in the regions and as a result drives up the global prices of wheat. According to meteorological departments, El Nino mostly coincides with a period of high and increasing temperatures as well as weak monsoon in India that affects India's agricultural sector leading to increased prices of domestic food, this results to high inflation expectations in the country. (Singh, Jagdev, Devendra Kumar, and Juan 101)

In Indonesia, the mining equipment mainly relies on hydropower and with low river currents as well as deficient rains there is less nickel that is used in the strengthening of steel. This affects the world market share for nickel because Indonesia is the World's top exporter of nickel. In California, El Nino brings about wet climatic conditions hence benefitting crops such as avocados, limes and almonds which are highly produced in this region. It reduces fires in the western parts and brings to the Northeast warmer winters, it increases rains in the south, reduces tornadic action in the Midwest as well as decreasing the hurricanes number that usually hits the east coast in the United States. ( Singh, Jagdev, Devendra Kumar, and Juan, 112)

Poultry farming is affected in most of the tropical Asia mainly bec...