Breakthrough in El Nino forecasting

Jul 01, 2013
Credit: NASA

Irregular warming of the Eastern Pacific Ocean, dubbed El Niño by Peruvian fishermen, can generate devastating impacts. Being the most important phenomenon of contemporary natural climate variability, it may trigger floods in Latin America, droughts in Australia, and harvest failures in India.

In order to extend forecasting from six months to one year or even more, scientists have now proposed a novel approach based on advanced connectivity analysis applied to the . The scheme builds on high-quality data of and clearly outperforms existing methods. The study will be published this week in the Proceedings of the National Academy of Sciences.

"Enhancing the preparedness of people in the affected regions by providing more early-warning time is key to avoiding some of the worst effects of El Niño," says Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research and co-author of the study by Josef Ludescher et al (Justus-Liebig Universität Giessen). The new approach employs network analysis which is a cutting-edge methodology at the crossroads of physics and mathematics. Data from more than 200 measurement points in the Pacific, available from the 1950s on, were crucial for studying the interactions between distant sites that cooperate in bringing about the warming.

Extending the forecasting time but also enhancing the reliability

According to Schellnhuber a new algorithm was developed and tested which does not only extend the forecasting time but also enhances the reliability. In fact, the novel method correctly predicted the absence of an El Niño-event in the last year. This was made in 2011 already, whereas conventional approaches kept on predicting a significant warming far into 2012.

El Niño is part of a more general oscillation of the Pacific ocean-atmosphere system called ENSO, which also embraces anomalous cold episodes dubbed La Niña which can inflict severe damages as well. The present study focuses on the warming events only. However, an El Niño-year is followed by a La Niña-year, as a rough rule.

Climate change: a factor for ENSO changes?

"It is still unclear to which extent global warming caused by humankind's emissions of greenhouse gases will influence the ENSO pattern," says Schellnhuber. "Yet the latter is often counted among the so-called tipping elements in the Earth system, meaning that at some level of climate change it might experience a relatively abrupt transformation." Certain data from the Earth's past suggest that higher mean global temperatures could increase the amplitude of the oscillation, so correct forecasting would become even more important.

Explore further: New detector sniffs out origins of methane

More information: Ludescher, J., Gozolchiani, A., Bogachev, M.I., Bunde, A., Havlin, S., Schellnhuber, H.J. (2013): Improved El Niño forecasting by cooperativity detection. Proceedings of the National Academy of Sciences (early online edition) DOI:10.1073/pnas.1309353110

Related Stories

La Nina caused global sea level drop

Oct 29, 2012

The 2011 La Niña was so strong that it caused global mean sea level to drop by 5 millimeters (0.2 inches), a new study shows. Since the early 1990s, sea level has been rising by about 3 millimeters (0.1 inches) per year, ...

New rhythm for El Nino discovered

May 26, 2013

El Niño wreaks havoc across the globe, shifting weather patterns that spawn droughts in some regions and floods in others. The impacts of this tropical Pacific climate phenomenon are well known and documented.

Recommended for you

New detector sniffs out origins of methane

14 hours ago

Methane is a potent greenhouse gas, second only to carbon dioxide in its capacity to trap heat in Earth's atmosphere for a long time. The gas can originate from lakes and swamps, natural-gas pipelines, deep-sea ...

The tides they are a changin'

19 hours ago

Scientists from the University of Southampton have found that ocean tides have changed significantly over the last century at many coastal locations around the world.

Lightning plus volcanic ash make glass

Mar 03, 2015

In their open-access paper for Geology, Kimberly Genareau and colleagues propose, for the first time, a mechanism for the generation of glass spherules in geologic deposits through the occurrence of volcan ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.