There have been climatic changes over the years that have led to the development of research in the meteorological department. Certain climatic changes have led to the occurrence of one event or the other. All the parts of the world face climatic changes in one way or the other. However, some parts of the world become more affected than others due to differences in landscape and the overall environment (Miller 2007). In Australia, one of the reasons why there have been variations in climate is due to the existence of the Southern Oscillation. In some instances, the southern oscillation may also be referred to as El-Nino.
Before indulging much into the facts about the southern oscillation, it is good to know its meaning. This is a geographical terminology that was adopted by many scientists to explain the climatic changes that had occurred in Australia. The southern oscillation refers to the differing of the temperature of the Pacific Ocean. This occurrence was more prevalent in the eastern side of this ocean. The differences in temperature here mean the respective warming as well as cooling of the area mentioned. According to scientists, the warming of this surface was known as El-Nino while the cooling was known as La Nina.
Ideally, the occurrence of these events starts at the ocean. These changes then cause climatic changes in the landscape of the adjacent areas (Wittenberg 2010). The changes in temperature affect the amount of water that is collected in the oceans in the form of moisture. When more than usual moisture rises from the ocean due to extreme temperatures, this translates to more than usual rainfall in the adjacent areas. More so, extreme cooling of the ocean may cause more than usual drought in the adjacent landscape. When there is excessive cooling in the ocean, there will be little moisture that will be collected. This means that there will be little or no moisture that will fall in the adjacent landscape in the form of rainfall. This will then translate to prolonged drought in these areas.
In this study, it is also very important to understand the meaning of the term southern oscillation index. The southern oscillation index measures the changes in air pressure that cause differing temperatures in the eastern part of the Pacific Ocean. This terminology was very important in explaining the fluctuations that had taken place in the most affected areas of Australia. One of the most affected areas of Australia was Tahiti. The occurrences that took place in this place were matched with the ones that had taken place in the Darwin area of Australia. Between these two areas, there was an anomalous change in the air pressure. These changes were not normal since they happened in extreme ends, that is, too high and too low.
The southern oscillation index has been used to predict the climate of most parts of the world. However, this has not come so easy since abnormal occurrences have been taking place over the years. Research in the meteorological department has shown that most predictions rely on historical data (Collins 2010). It is however worth noting that these predictions have been very important in instituting measures to reduce the adverse effects of bad weather. For instance, in Australia, after the first El-Nino had occurred, the meteorological department sensitized people on the expected weather. If the expected weather was bad, the meteorological department advised people on the best course of action. This helped a lot to reduce the adverse effects of the bad weather that had followed.
While the eastern Pacific is characterized by changes in the temperatures, the western Pacific is characterized by changes in the air pressure. The southern oscillation usually takes place in two phases. El-Nino, the first phase is also known as the warm oceanic phase. The other phase, La Nina, is also known as the cold phase (Miller 2007). El-Nino is associated with high pressure of the air while La Nina is associated with low air pressure. These changes in air pressure experienced in both phases occur in the western Pacific.
Scientists have also come up with the possible signs of the El-Nino. El-Nino usually occurs at intervals of between three to seven years. On average, it may occur for a period of around five years. Some of the signs of El-Nino in Australia are:
Increase in the pressure of the surface over Australia.
Decline in the air pressure in the areas of Tahiti.
Decline in the air pressure in the eastern as well as the central parts of the Pacific Ocean.
The weakening of the trade winds that are experienced in the southern parts of the Pacific.
The rising of warm air near Peru, causing the nearby deserts to experience rain.
The movement of warm water from the western parts of the pacific. This water moves to the eastern parts of the pacific. As a result, the dry parts of the east pacific experience rainfall while the west Pacific become dry.
The walker circulation is an important geographical terminology that can be used to explain the occurrence of the southern oscillation. It was developed by a British scientist named Walker (McLurg 2011). The walker circulation refers to the movement of east trade winds from the east to the west. These winds bring moisture to the areas of Australia. This explains partly why these areas experience a lot of rainfall. The trade winds then move to the eastern direction. By this time, the winds have become dry. Therefore, the walker circulation creates fluctuation in the areas of Darwin and Tahiti. The fluctuations brought about by this circulation are called the southern oscillation.
It is important to take a case study of Tahiti and Darwin in order to analyze the occurrence of the southern oscillation in Australia. The southern oscillation index will be important to explain the changes in the climatic conditions that had been experienced in these two areas.
The above diagram shows fluctuations in the climatic conditions that had taken place in Tahiti and Darwin. Most of the changes that had occurred were anomalous, meaning that they were not normal. The negative part of the southern oscillation index shows that the air pressure in Tahiti is below normal. At the same time, Darwin is experiencing above normal air pressure. At some instances, there are prolonged periods of negative values of the southern oscillation index. This shows that there are abnormal waters that are warm in nature that are experienced in the eastern parts of the Pacific. Generally, as the years go by, the pattern becomes almost similar. This helps the meteorological department to form predictions about the expected future.
The Impact of the Southern Oscillation in Australia
The effects of the southern oscillation in Australia are not uniform. This is simply because this oscillation occurs in two phases which bring about different impacts in the country. For instance, La Nina is associated with excessive rainfall. On the other hand, El-Nino is associated with dry periods. The dry weather has led to drought in some parts of the country. However, wet weather has led to floods in some parts of the country. Australia has many people who engage in agriculture and businesses. There were many farmers who had engaged in farming when La Nina had occurred. When there was high rainfall in the farming areas, farming was largely affected. In the year 2000, this country experienced a lot of rainfall that brought about adverse effects.
Some of the crops that had been planted were destroyed, leading to losses to the farmers. This translated to loss to the government through lost revenue. Most of the parts of the country were flooded, making some places to be impassable. In addition to this, there were a lot of properties that were destroyed (Collins 2010). Vehicles were not left since the floods were so strong. People who lived in unstable houses were rendered homeless due to the adverse effects of the floods. As the floods persisted, people started to fall sick due to water borne diseases. Among these diseases were Pneumonia and Cholera.
The impact of the southern oscillation in Australia in 2000 made the government to work on measures to reduce the effects of any occurrence of such event in the future (McLurg 2011). This was done through the meteorological department, which was sensitized to carry out more research on the southern oscillation. As a result, the adverse effects of the southern oscillation in the country have reduced to a great extent.
Conclusion
It may be difficult to predict the occurrence of an unforeseen event. However, it is possible to detect La Nina. It is recommended that once it has been detected, the length of the La Nina should be forecasted. Once it has been forecasted, people can know what to expect and the correct measures can be put in place to reduce the adverse effects. Although Australia is still experiencing wet climatic conditions, there are measures that have been put in place to prevent adverse climatic effects. Finally, all countries should ensure that any detected anomalies in climatic conditions should be forecasted in terms of length and possible effects. This will reduce the damage of properties in case any contingency occurs.
References
Miller, D. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK: Cambridge University Press.
Collins, M. 2010. The impact of global warming on the tropical Pacific Ocean and El Niño. London. Palgrave Macmillan.
McClurg, L. 2011. El Niño and its relationship to changing background conditions in the tropical Pacific Ocean. London. Palgrave Macmillan.
Wittenberg, M 2010. The Impact of Global Warming on the Tropical Pacific and El Niño. New York. Mc-Grave Hill.
