It devastated Peru. According to the article written by Suplee (1996), residents of Chato Chico experienced heavy rainfall for weeks which also made the Piura River rise over those weeks. It was during Christmas time that the ocean was observed by fisherman to heat thus obtaining the name El Niño which actually means “the Christ Child”. After the heating up of the ocean, a large amount of precipitation will build up and will then pour on the coast of northwestern Peru.
On February 15, 1998, a massive amount of rain poured over Peru and the riverbanks of the Piura River gave off sweeping the residences in Chato Chico. Houses, livelihoods and everything else were washed away. The residents of Chato Chico were lucky for nearly all of them had survived the incident; the rest of the world was not. One of the more devastated places was Motse located 60 miles south of Chato Chico. The residents did not expect that the flood would reach them. But three days after, the flood receded and revealed that out of a population of 150, ten unfortunately died (Suplee, 1996).
In some places, there was no flooding but water pools would form. These water pools would be the best place for mosquitoes to reproduce which caused the increase in malaria cases. For areas along the Piura River, the cases reached a number of 30,000 out of 1.5 million residents (Suplee, 1996).
Predicting or claiming that the weather is normal poses high difficulty since the weather itself changes so often. But there exists a pattern in the climate along the equatorial pacific which was considered as a dependable pattern. In this climate pattern, the ocean in the western part of Australia and Indonesia, the seawater’s upper surface is heated by sunlight. This heating up of the water surface creates a low-pressure system at the surface. This low-pressure system is caused by the huge quantity of moist air which rises to a height of thousands of feet. As the air rises even more and subsequently cools, the air drops back as rain which further causes the monsoons in the affected areas. As the rain is discharged, the air becomes drier. This dry air cools even more and increases in density as it is taken by the winds present in the upper atmosphere. As it reaches the American west coast, the air travelling got even colder and denser creating a system of high pressure in the ocean’s water surface. As trade winds, the air travels back towards the location of Australia and Indonesia. Basically, this pattern happens when air at high altitudes travel from west to east and goes back to the west at low altitudes. This type of circulatory loop is commonly called as the Walker Circulation which was named from Sir Gilbert Walker who studied the said pattern (Suplee, 1996).
The El Niño Southern Oscillation or more commonly termed as ENSO. According to the article entitled El Niño, La Niña and Climate Impacts on Agriculture (2014), ENSO is defined as the phenomenon when the pressure of air in the equatorial Pacific changes or fluctuates. The article offers in depth discussion of the phases and was the basis for the discussion of the three phases. As the article stated, there exists three phases of ENSO. First is the warm phase which is more commonly known as El Niño, the cold phase is La Niña and the last phase is termed as neutral. The El Niño and La Niña are considered as the extremes of ENSO. Although extremes, these phases are not considered as direct opposites since each phase has its own magnitude and duration.
In the affected areas, namely Florida, Alabama and Georgia, El Niño has a big impact on agriculture. These impacts include the decrease in corn yields in comparison to other averages in the past years. The yields of vegetables namely tomatoes, bell peppers and corn are also significantly lower. This lower yield of tomato and bell peppers may be accounted from the bacterial and fungal diseases that appear during the El Niño phase. Also, as mentioned in the article El Niño, La Niña: The Southern Oscillation (ENSO) (2014), the equatorial current weakens as the trade winds also weaken. This results to the restriction of nutrients and deep water to rise to the surface. Furthermore, this causes some organisms, such as zooplankton, phytoplankton and fishes, to move away. Thus, decreasing the catch of the fishermen in the affected areas.
The other extreme phase of ENSO is La Niña. Since the other phase was named as Christ Child, La Niña is translated as Little Girl in Spanish. La Niña is roughly described by Bell (2013) as the lowering of temperature or cooling of the equatorial Pacific. In contrast with El Niño, temperatures of the equatorial Pacific is 4-6oF above the normal temperature. This lower temperature of the water in the eastern Pacific brings or changes the location of rising air, low pressures and thunderstorms towards the western Pacific. The cold water is also a good medium for the increase in nutrients essential for fish and plankton. Thus, improving fishing and food for feeding animals in the eastern Pacific. Also, subtropical jet stream is shifted to the northern US by the change in pressure which makes Florida sunnier while Georgia and Alabama on the track of storms. If El Niño would not last a year, La Niña in contrast would last at least a year and at most three years.
Since the temperature of La Niña is much lower than that of El Niño, yields of irrigated corns become higher. Also the intensity of fungal and bacterial diseases that affect tomatoes generally decreases but because of the cold weather, vegetables are expected to wilt or the possibility of wilting is higher than usual.
While the El Niño and La Niña are the extreme cases or phases or ENSO, when none of them is present, the neutral phase happens.
Through the years, prediction of these phases has intensified. One of the techniques used is through statistical data. These data were gathered throughout the century. But this statistical data were not enough since the weather is considered variable such that the accuracy of the prediction of the phases is low. Because of this, the technique of computer modeling existed. But then again, computer modeling needs data from a certain amount of time in this case data collected for the past hundreds of years to come up with an accurate computer modeling of the phases. So these techniques are used hand in hand in order to come up with a more accurate prediction (Suplee, 1996). More accurate predictions will then lead to a higher number of lives saved.
References:
Bell, G. (17 January 2013). Flavors of Climate Variability: El Niño, La Niña, Recurring Jet Stream patterns, Multi-Decadal Variability. Retrieved from http://www.cocorahs.org/FlavorsOfClimateVariability-Bell.pdf
El Niño, La Niña and Climate Impacts on Agriculture: Southeastern US. Retrieved from http://agroclimate.org/climate/ENSO-Impacts-southeast.pdf
El Niño, La Niña: The Southern Oscillation (ENSO). Retrieved from http://www.utdallas.edu/~pujana/latin/PDFS/Lecture 16- El Nino.pdf
Suplee, C. El Niño/La Niña: Nature’s Vicious Cycle. Retrieved from http://www.nationalgeographic.com/elnino/mainpage.htm
