Every year, extreme climatic problems occur around the globe, with droughts in some places and floods in others. Variations in climate and weather can significantly impact our daily lives in subtle ways. We are irrevocably linked to our ecosystem in events resulting from extremely cold winters, crop failure from draught, or emergency conditions such as flooding, heat waves, or forest fires. Some of these widely dispersed climatic extremes might have a common origin in the occasional warming of sea surface water in the central and eastern Equatorial Pacific Ocean. Currents of Change, explains in simple terms what El Niño is, its far-reaching impacts on all of us and how those impacts might be forecast. El Niño refers to the anomalous increase in sea surface temperatures from the coasts of Peru and Ecuador to the Equatorial Central Pacific. This is nothing but an abnormal state of the ocean-atmosphere system in the Tropical Pacific with important consequences for weather around the globe. Global climate anomalies tending to be opposite to those of El Niño is referred to as La Niña and is characterised by usually cold ocean temperatures in the equatorial Pacific, as compared to El Niño, which is characterised by unusually warm ocean temperatures in the Equatorial Pacific.
El Niño was originally recognised by fisherman of the coast of South America as the appearance of unusually warm water in the Pacific Ocean, occurring in the beginning of the year. El Niño means The Little Boy or Christ child in Spanish. This name was used for the tendency of the phenomenon to arrive around Christmas. La Niña means The Little Girl. La Niña is sometimes called as El Viejo, anti-El Niño, or simply “a cold event” or “a cold episode”. El Niño is often called a “warm event”. There has been a confusing range of uses for the terms El Niño, La Niña and El Niño/ Southern Oscillation (ENSO) by both, the scientific community and the general public.
Each El Niño contains seeds of its own destruction, that is for every Niño there is a Niña. The subsurface ocean waves explain more than the origin and propagation of El Niños. They also explain how El Niños end. The wave first hit the South American coast, some reflect back and when the reflected wave reaches Asia, they rebound again. The cool temperature dilutes the warmer liquid at the surface, causing a temperature drop in the eastern Pacific, and the decrease is nothing but La Niña.
El Niño has direct implications on the USA Economy as well as that of Asian countries. Weather and climate sensitive industries are directly impacted by weather (such as agriculture, construction, energy distribution, and outdoor recreation) accounting for nearly 10 percent of GDP. El Niño impacts important business variables like sales, revenues, and employment in a wide range of climate-sensitive industries and sectors. Overall, total U.S. economic impacts of the 1997-1998 El Niño were estimated to be on the order of $25 billion. In the same period Asian countries experienced tremendous food shortage. These economic impacts lead to both gains and losses among regions and within industries. For example, department store sales were up by five to 15 percent during the abnormally warm winter in the Midwest, but sales of snow equipment like snowmobiles were down by nearly 35 percent. Skiing was up in the West but down in the Midwest. In the highly weather sensitive energy sector, households and businesses saved $2- 7 billion in heating costs, while energy production and distribution businesses suffered from reduced sales. In fact, on balance, the effect of the 1997-98 El Niño in the U.S. could well have been an economic benefit, with gains and losses across regions and industries. While economic impacts tend to cancel each other out at the national level, El Niño does cause real economic losses such as storm damage or crop losses, which are not offset by gains elsewhere. These are losses that can be prevented or reduced by a better forecast or mitigation.
Reference: National Oceanic and Atmospheric Administration Magazine.
By Dr. Ganesh Bora, Florida
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