La Nina as a Weather Phenomenon - Research Paper Example

This paper was prepared for the _________ taught by ____________. Meteorology: La Niña La Niña is a weather phenomenon, counterpart of the El Niño. It is part of the broader concept called El Niño-Southern Oscillation Climate Pattern. In common terms, El Niño can be described as the warm weather counterpart and La Niña can be characterized as a cool weather phenomenon. Introduction El Niño Southern Oscillation (ENSO) is a cycle. The warm phase, as mentioned above, is called the El Niño Phenomenon and the cool phase is the La Niña phenomenon. Their names come from Spanish, meaning boy and girl, respectively. To understand La Niña and El Niño, one must first discuss the El Niño Southern Oscillation (ENSO). ENSO is a periodic climate pattern that occurs across the Pacific Ocean, primarily on the tropical band. The southern oscillation refers to the differences on the tropical part of the Eastern Pacific Ocean. The cooling down of the southern oscillation (or oceanic phase) is termed La Niña and the warming up is called El Niño. Southern Oscillation also refers to air surface pressure on the tropical part of the Western Pacific Ocean. These two variations occur by pairs: El Niño, or the warm oceanic phase, is accompanied by high air surface pressure in the Western Pacific and the La Niña, or the cold oceanic phase, is accompanied by low air surface pressure, also in the Western Pacific. These differences and oscillations can cause extreme weather conditions such as floods and droughts. This occurs in different parts of the world. The countries that are mostly agricultural, like most Third World countries along the Pacific Ocean that depend of crops for food and fishing, are the ones that are mostly affected. However, the popular term of ENSO is just El Niño, or Little Boy in Spanish. This is because the people in South America observed that the phenomenon occurs around Christmas, and the Little Boy refers to Jesus Christ. La Niña is called so because it is opposite the meaning of El Niño. La Niña means Little Girl in Spanish. Sometimes, it is called the “anti-El Niño.” The La Niña phenomenon is usually preceded by El Niño. During La Niña, the sea surface temperature in the tropical part of the Eastern Pacific Ocean would be lower than the normal value by 3 to 5 degrees Celsius (as opposed to El Niño having high surface temperatures, in which the temperature of the waters increases by 0.5 degrees Celsius). If the temperature drop occurs for five months straight, that can be called La Niña. The El Niño phenomenon occurs longer from nine months to two years! La Niña is not as famous as El Niño – El Niño has some quite extensive effects on the weather, especially on Chile, Peru, New Zealand and Australia. Tropical cyclones occur more often when El Niño phenomenon is on. Causes The causes of the ENSO are still unknown, as it is being studied about. Most theories center on the fact that it is indeed a typical meteorological event, but the extreme conditions the we are experiencing right now are not because of the ENSO alone, but rather an effect of the global warming AND the ENSO phenomenon. Effects There are many effects of the La Niña and El Niño phenomenon, particularly on the weather conditions (e.g., hurricanes and tropical cyclones), the health of people, and even history. For La Niña, wetter countries happen. Africa becomes much wetter during La Niña. In Asia, tropical cyclones occur more, especially to the countries near the Western Pacific Ocean. The cyclones even make landfall on China (which is a rare occurrence). The significant drop of the temperature on the surface of the water can actually cause heavy flooding and rains. For example, last March 2008, Malaysia, Indonesia and the Philippines had experienced heavy flooding and heavy rains, leading to loss of crops, triggering economic problems for these countries. This effect also happens in North America, especially in the Northern Pacific Region. Some southern states also experience that (as the temperature shift from the Pacific actually affects the Atlantic Ocean as well), but not as heavily as the floods and rains in the Pacific Northwest. Disease occurrence is also related with the extreme weather conditions, especially on the incidence of epidemic diseases. Most of these are diseases transmitted by mosquitoes. For example, when the El Niño phenomenon is on, the incidence of malaria, dengue and Rift Valley fever in tropical countries escalate. This is especially true in tropical countries such as Venezuela, Colombia and India. In Australia, a different kind of encephalitis called Murray Valley encephalitis is associated with La Niña as the incidence escalates when there are heavy rains and flooding. Rift Valley fever is also documented in Somalia and Kenya, which, like Australia, are also subtropical countries. Civil conflicts are also connected to the ENSO phenomenon. According to the scientists at Columbia University, 21% of all the civil conflicts since 1950 are triggered by the ENSO in one way or another. The risk for civil conflicts would be double (from 3% to 6%) during the El Niño and La Niña years. History, politics and culture are affected, thus, by ENSO phenomenon. It has been said that ENSO conditions occurred as early as 10,000 years ago, during the early Holocene period. ENSO phenomena have regularly occurred in an interval of every three to seven years. It has been said that the El Niño phenomenon has been a reason for the demise of the Native Americans in Peruvian pre-Columbian Incas such as the Moche. Other incidences of the El Niño phenomenon related to historical events are during the period of the French Revolution. Scientists theorize that there was a strong El Niño effect during 1789 to 1793, causing a poor yield of crops in Europe. This helped touch off the French Revolution. From 1876 to 1877, one of the biggest famines of the world was actually the effect of the El Niño. This famine actually killed at least 13 million people in China. In 1893, a scientist named Charles Todd observed that droughts in Australia and India have the tendency to occur at the same time. In 1904, Norman Lockyer observed the same thing. However, the term was unnamed then. The term “El Niño” was coined on 1892 as Captain Camilo Carillo mentioned it to the Peruvian Geological Society as he was exploring the area. His sailors, apparently, called the warm northern current El Niño. They named it after the Christmas Child as it was noticeable during the Christmas time, as mentioned earlier. This was extremely important to the sailors then (and now) because this observation has big implications on their fishing industries as well as the guano industry. However, it was during 1982 to 1983 that the El Niño phenomenon sparked the highest interest. This was one of the most intense and the most recent El Niños in history. The 1990–1994 El Niño was unique because it occurred in very rapid succession. In 1998, the El Niño caused 16% of the world’s reef systems to die. This warmed the Earth’s air by 1.5 degrees Celsius, which is astronomically high compared to the usual 0.25 degrees Celsius associated with El Niño events. Since then, coral bleaching became common during El Niño. ENSO, Global Warming and Conclusion Much fuss has been made about ENSO and global warming in that they are related in (supposedly) one way or another. As no one can actually say what can prevent ENSO from happening as it is a natural and regular occurrence, and global warming is happening, what can we blame for the extreme weather conditions, flooding and super strong typhoons? It has been observed that lately, El Niño is reversely proportional to La Niña, in which case, if the number of El Niño occurrences increase, then there would be less occurrences of La Niña. The real question, though, is if this variation is a result of global warming. There are theories that state that if there are more El Niño occurrences in the initial stages of global warming, then it would pan out as the lower levels of water get warm as well (not just the temperature of the water surface). More research and more time would be needed for this to be answered. In the meantime, the knowledge is that El Niño, La Niña and the global warming greatly affect our lives, even though we do not know it. We can help ourselves by constantly being prepared and being vigilant, as we brace ourselves for stronger ENSO cycles. Read More