A new study predicts that intense El Niño episodes might occur every 10 years instead of 20 years due to global warming.
According to the National Oceanic and Atmospheric Administration (NOAA), El Niño is characterized by higher than normal warm ocean temperatures in the Equatorial Pacific. The increased oceanic temperature affects the weather around the globe which usually results to increased rainfall across the U.S and Peru, drought in the West Pacific, and wildfires in Australia.
Researchers from the CSIRO Marine and Atmospheric Research led by climate scientist Wenju Cai found that extreme El Nino episodes characterized by waters warmer than 82 degrees Fahrenheit (28 degrees Celsius) starts to appear in the usually dry and cold season along the equatorial part of the Pacific Ocean. They believe that because this area of the Pacific is usually colder than the western part, a slight change in temperature of these waters might lead to devastating effects.
Cai told LiveScience.com, "Under global warming, the barrier to convection shifts.Therefore, it is easier to generate this massive atmospheric circulation associated with an extreme El Niño event."
To better analyze the effect of the future cycles of El Niño, Cai and his team tested 20 models of extreme episodes of El Niño. However, instead of analyzing sea temperatures, they focused instead on the amount of rainfall over the eastern Pacific region. The results revealed that El Nino might be expected to happen every 10 years instead of the usual 20 years. This frequency is expected to happen in the present year up to 100 years in the future.
Although this altered frequency might be good news to drought-prone areas in the Western part of the U.S., which will receive extra amounts of rain fall, an extreme episode of El Nino will have great implications on global weather.
During past El Niño, countries in the Western Pacific region like Indonesia and Australia has experienced droughts and wildfires. Similarly, heavy floods occurred in the eastern equatorial region of countries such as Peru and Ecuador. The most recent El Nino, which happened from 1997 to 1998, killed 23,000 people worldwide and cause a damage worth $35 billion in the U.S.
The study was published in the Jan.19 issue of Nature Climate Change.
