Introduction
There’s something odd that happens on the coasts of the Pacific Ocean that occurs every three to five years in December and January. This not strange among fishermen in South America, because for centuries, they suffered the brunt of this weather phenomenon, where their catch virtually dwindles as fish can be caught when El Niño sets in. Yes, the South American fishermen were the first to nickname this scorching phenomenon as El Niño or the “The Child” in Spanish. They named it as such in honor of the birth of Jesus, thus the Christ child. As time went on, the effects of El Niño have not been exclusively felt on the coasts of the Pacific Ocean alone, but it has become a worldwide concern. With the advent of computers, satellites, and data gathering techniques, scientists have concluded that the El Niño phenomenon has partly to blame for drastic climate change experienced globally (Evans, 2006).
El Niño Southern Oscillation
Also called as El Niño Southern Oscillation (ENSO) cycle, the National Oceanic and Atmospheric Administration (NOAA) identified this phenomenon as “an oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe” (NOAA Website, n.d.). Saying that ENSO is an oscillation means that the atmosphere and ocean influence each other in a very continuous, cyclical way (Wallace and Vogel, 1994). The atmospheric changes help produce the changes observed in the ocean, and these changes, in turn, act to influence and ultimately change the atmosphere above, which, in turn, bring about further changes in the ocean, and so on. Within the ocean in a macro sense, the ENSO phenomenon manifests itself as a slow sloshing of water in the huge bathtub we call the Pacific Basin. The warm water sloshes to the east and then a year or more later, back to the west. The sloshing is manifested by a series of very large-scale internal waves called Kelvin and Rossby waves.
In the atmosphere, a similar transfer of air takes place that results in a flip-flop in pressure patterns and winds. Although the oscillation is most evident and consistent in the Tropical Pacific, research has shown that global weather patterns are also reliably influenced; and that the effects, like the modes of the oscillation in the Pacific, are opposite from one mode to the other. The two modes have been given the names El Niño (The Boy) and La Niña (The Girl). Although La Niña, El Niño’s lesser-known sibling, gets much less media attention, it may have more negative effects than El Niño on the climate, at least in the United States. La Niña brings more frequent destructive hurricanes, severe thunderstorms and tornadoes, and costly winter cold waves (D’aleo & Grube, 2002, p. 2).
El Niño episodes have been also described as “lower-than-normal air pressure over the eastern tropical Pacific and higher-than-normal air pressure over Indonesia and northern Australia”. This weather condition forms into a pressure pattern that reflects the negative phase of the southern oscillation “and is associated with weaker-than-normal low-level equatorial easterly winds over the central and eastern Pacific”. This is followed by conditions that the oceanic upwelling becomes weaker than normal and the sea surface temperature becomes warmer than normal in the central and eastern Pacific. Due to the upsurge of sea surface temperatures, the atmosphere favors the development of atmospheric convection and rainfall that is experienced temperatures exceeds 28°C (82°F) (Gadgill et al., 1984).
Increased rainfall
As a result of the oscillation of the ocean-atmosphere system, disruptive consequences are experienced like “increased rainfall across the southern tier of the US and in Peru, which has caused destructive flooding, and drought in the West Pacific, sometimes associated with devastating brush fires in Australia”. The NOAA considered that observing the conditions in the tropical Pacific are very important for the prediction of short term (a few months to 1 year) climate variations” that characterize the El Niño phenomenon (NOAA Website, n.d.).
It was from 1997 to 1998 that everyone in the world was alerted to the worst El Niño phenomenon ever. UNESCO reported that the El Niño “caused hotter, drier weather in some parts of the world, was followed by mass bleaching, severely damaging some 16% of the world’s coral reefs”, especially in East Africa (UNESCO Press Release, 2002). Also, a previous El Nino of 1991-1995 brought extreme drought to Queensland, in northeastern Australia, drying out farmland and costing the state economy approximately $1 billion (Australian) a year. The drought, for example, dropped rainfall levels to all-time lows in Toowoomba, one of the state’s prime cereal-growing regions (Tibbets, 1996).
As severe droughts were happening in Asia and Africa, the El Nino weather patterns drew torrential storms in California and Florida. Record rainfall occurred in parts of California and Florida during the El Niño of 1997–1998. In California, strong storms brought hurricane-force winds, thirty-foot waves, and flooding rains. Thirty-five California counties were declared federal disaster areas. It severely damaged the beaches of the Gulf Coast of the Florida peninsula. It was reported that “cyclonic storm patterns influenced by El Nino moved across the Gulf of Mexico from the southwest, approaching the coast of Florida from the southwest, a direction that differs from that of the usual winter frontal passage direction. The El Nino effects along the Florida Gulf Coast are in the form of subtropical, low-pressure systems including mild temperatures, frequent storms with sustained winds, high wave energy, and record amounts of rainfall” (Hepner and Davis, Summer 2004).
Conclusion
Although there is a long history of knowledge that characterizes how El Nino behaves, recent studies have proven that the El Nino phenomenon suddenly changed. Experts have blamed the onset of global warming as the culprit why this weather phenomenon has gone awry. By rapidly increasing the atmospheric concentration of greenhouse gases, people themselves have changed Earth’s climate. In the case of the worsening of global warming and the appearance of the worst El Niños, our role should now is to focus on minimizing the potential problems by decreasing the atmospheric concentration of greenhouse gases that is a by-product of human industrial and agricultural activities.
References
D’aleo, Joseph S., and Grube, Pamela G. The Oryx Resource Guide to El Niño and La Niña. Westport, CT: Oryx Press, 2002.
Evans, Kim Masters (Ed.). The enhanced greenhouse effect and climate change. The Environment: A Revolution in Attitudes. Detroit: Thomson Gale, 2006.
Gadgill, S., Joseph. P. V., and Noshi, N. V. Ocean-atmosphere coupling over the monsoon regions. Nature. 312 (1984): 141-143.
Hepner, Tiffany L., and Davis, Richard A. Jr. Effect of El Nino (1997-98) on beaches of the Peninsular Gulf Coast of Florida. Journal of Coastal Research 20.3 (2004): 776-794.
National Oceanic and Atmospheric Administration (NOAA). What is El Niño? NOAA. 2007. Web.
Tibbetts, John. Farming and fishing in the wake of El Nino. BioScience 46.8 (1996): 566-570.
United Nations Educational, Scientific, and Cultural Organization (UNESCO). World’s coral reefs are recovering but for how much longer? UNESCO Press Release 2002-103, 2002. UNESCO. 2007. Web.
Wallace, John M. and Vogel, Shawma. El Niño and Climate Prediction, Reports to the Nation on our Changing Planet, Boulder, CO: UCAR, 1994.