Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New forecasting method: Predicting extreme floods in the Andes mountains

14.10.2014

Predicting floods following extreme rainfall in the central Andes is enabled by a new method. Climate change has made these events more frequent and more severe in recent decades.

Now complex networks analysis of satellite weather data makes it possible to produce a robust warning system for the first time, as a study to be published in the journal Nature Communications shows.

This might allow for improved disaster preparedness. As the complex systems technique builds upon a mathematical comparison that can be utilised for any time series data, the approach could be applied to extreme events in all sorts of complex systems.

“Current weather forecast models cannot capture the intensity of the most extreme rainfall events, yet these events are of course the most dangerous , and can have severe impacts for the local population, for example major floods or even landslides,” says lead author Niklas Boers of the Potsdam Institute for Climate Impact Research (PIK). “Using complex networks analysis, we now found a way to predict such events in the South American Andes.”

When the monsoon hits South America from December to February, it brings moist warm air masses from the tropical Atlantic. Travelling westwards, these winds are blocked by the steep Andes mountains, several thousand metres high, and turn southwards.

Under specific air pressure conditions, the warm air masses, loaded with moisture, meet cold and dry winds approaching from the south. This leads to abundant rainfall at high elevations, resulting in floods in the densely populated foothills of the Bolivian and Argentinian Andes. “Surprisingly, and in contrast to widespread understanding so far, these events propagate against the southward wind direction,” says Boers.

‘Big Data’ analysis of observational time series from satellites

The international team of scientists performed a ‘Big Data’ analysis of close to 50,000 high-resolution weather data time series dating from the 15 years since high quality satellite data became available, generated by NASA together with the Japan Aerospace Exploration Agency.

“We found that these huge rainfall clusters start off in the area around Buenos Aires, but then wander northwestward towards the Andes, where after two days they cause extreme rainfall events”, says Boers. The new method makes it possible to correctly predict 90 percent of extreme rainfall events in the Central Andes occurring during conditions of the El Niño weather phenomenon when floods are generally more frequent, and 60 percent of those occurring under any other conditions.

“While the findings were hard to derive, local institutions can now apply them quite easily by using readily available data, which helps a lot,” says co-author José A. Marengo of the National Institute for Space Research in Sao Paulo, Brazil. “Major rainfall events can result in floods which for instance in early 2007 alone produced estimated costs of more than 400 million US dollars. It is now up to the affected countries to adapt their disaster preparation planning.”

Method can be applied to the climate, but also to financial markets

“Comparing weather data sounds simple enough, but it actually took the new mathematical tool that we developed to detect the intricate connections that lead to the extremes,” says co-author Jürgen Kurths, co-chair of PIK’s research domain Transdisciplinary Concepts and Methods. “The data was there, but nobody joined the dots like this before. The method provides a general framework that could now be applied to forecast extreme changes in time series of other complex systems,” says Kurths. “In fact, this could be financial markets, brain activity, or even earthquakes.”

Article: Boers, N., Bookhagen, B., Barbosa, H.M.J., Kurths, J., Marengo, J.A. (2014): Prediction of extreme floods in the eastern central Andes based on a complex networks approach. Nature Communications (online) [DOI: 10.1038/ncomms6199]

Weblink to the article once it is published: http://www.nature.com/naturecommunications

For further information please contact:
PIK press office
Phone: +49 331 288 25 07
E-Mail: press@pik-potsdam.de
Twitter: @PIK_Climate

Weitere Informationen:

http://www.nature.com/naturecommunications - Weblink to the article once it is published

Jonas Viering | PIK Potsdam
Further information:
http://www.pik-potsdam.de

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>