by Austin Yeung 2015-06-13
El Niño, ‘the Christ Child’, was first named by fishermen in Peru during Christmas when they noticed unusual warm currents affecting the Pacific coastline of South America. It is an anomaly – a prolonged warming of the central and east-central Pacific Ocean sea surface temperatures (SST).
El Niños often happen in intervals between two to seven years, and last nine months to two years. When this El Niño warming happens for only a brief 7-9 months, it is classified as an El Niño “condition,” whereas when the El Niño period lasts longer, it is known as an “episode.”
Coral reefs, rainforests of the oceans, are susceptible to coral bleaching as a result of high water temperatures. Bleaching occurs when coral tissues expel algae, known as zooxanthellae, that reside in the coral, and die. The entire coral reef then turns white as if it were bleached. That’s why coral scientists pay attention to such ocean warming events as El Niño.
Currently, NOAA just declared that the most recent El Niño commenced in March 2015. The latest forecast showed a 90% chance of the El Niño continuing in the fall and an 85% chance into winter of 2015/16. Many anticipated a stronger El Niño since the 1998 El Niño occurrence. With an increase of 4°C in SST, the 1998 happening of the El Niño undersizes the current El Niño, which saw a greater than 1.9°C SST. Although this is not a weak El Niño appearance, it is not a strong one either.