With temperatures on the rise in the Pacific Ocean, it is helpful to know what El Niño is. The El Niño weather pattern last had an impact here in the winter of 2009, when considerable snowfall and sub-zero temperatures were unprecedented. With El Niño occurring every two to seven years, we are long overdue to see the severe weather this system can cause.
El Niño means ‘boy child’, or ‘Christ child’ in Spanish, due to the fact that this weather phenomenon occurs around the Christmas season. The name originates from the 1600s, when fishermen off the coast of Peru noticed unusual warming of surface waters in the Pacific Ocean in December. Since these vital observations, improved ability to observe and track weather patterns has taught us more about what is essentially a relationship between the atmosphere and the ocean.
El Niño is the warm phase of the Southern Oscillation (ENSO), referring to the cycle of warm and cold temperatures in the Pacific Ocean, as measured by Sea Surface Temperature. Trade winds off the coast of South America weaken (and at times reverse), allowing warm water to flow east, which in turn displaces cooler water usually found in the eastern Pacific Ocean. This, combined with variations in air pressure, disrupts local and global weather patterns. Events such as sudden dumps of rain to usually dry areas, and extended periods of dry weather where it would normally be wet, are typical. La Niña, sister of El Niño, is the cool phase of the Southern Oscillation, and the opposite of her brother in every way. Between them, they can create weather phenomena that are unusual and extreme.
Every El Niño event is unique, but it is generally thought that for the UK the effect can be seen as increased rainfall in warmer months, followed by increased snowfall in the colder months. Other effects for us include a rise in prices of coffee, sugar, cocoa and rice, as affected foreign crops suffer. Perhaps the most frightening prospect is the possibility of creating a long, bitterly cold, snowy winter for the British Isles, one that we are poorly equipped to deal with. Some believe that the recent Storm Frank, which devasted the UK with flooding following a record-breaking warm December, was linked to El Niño and that this is a precursor to very cold conditions for early 2016.