Network based systems

German scientists develop network application for climate forecasting

Prediction of high-impact climate phenomena can be dramatically improved by a new mathematical approach that analyzes connectivity and patterns between geographic locations, scientists say in a new publication.

This can potentially save thousands of lives and prevent billions of economic losses. Prediction times for events such as El Niño, monsoons, droughts or extreme precipitation could be significantly increased, up to a month or in some cases even a year in advance, depending on the type of event .

New forecasting approach

The new framework may thus become essential for improving adaptation to the global warming crisis, explains Josef Ludescher of the Potsdam Institute for Climate Impact Research (PIK), lead author of the ‘Perspective‘article published in the Proceedings of the United States National Academy of Sciences (PNAS).

“The new forecasting approach has, on several occasions in recent years, proved to be very effective in predicting different climatic phenomena much earlier than before. El Niño, for example, could be predicted up to a full year in advance, compared to around six months with standard prediction methods.

“The onset of the Indian summer monsoon in central India, vital for the economy of this region, was predicted more than a month in advance, much earlier than the forecast currently in use, thanks to the new approach . “

Network application model

Extreme events like floods, heat waves or droughts often happen with little or no warning time, making effective short-term adaptation difficult, if not impossible. The new forecasting framework fundamentally improves this, as Jürgen Kurths of PIK, a pioneer of the network application to forecasting climatic phenomena and co-author of the article, points out:

“Currently, for example, there is no reliable forecast of heavy rainfall in the eastern central Andes causing flooding and landslides with devastating effects on the people of this part of South America. Our network-based approach can predict these events up to two days in advance – it’s a crucial time for people to prepare, save lives, and limit damage.

A mathematical approach to help save lives

Traditional weather and climate predictions are based primarily on numerical models that mimic atmospheric and oceanic processes. These models, while generally very useful, cannot perfectly simulate all of the underlying processes – and phenomena such as the onset of the monsoon, floods or droughts can be predicted too late. This is where network-based forecasting comes in.

“Instead of looking at a large number of local interactions, which represent physical processes such as the exchange of heat or humidity, we are directly examining the connectivity between different geographic locations, which can span across continents or oceans, explains Ludescher.

“This connectivity is detected by measuring the similarity in the evolution of physical quantities such as air temperatures at these locations. For example, in the case of El Niño, strong connectivity in the tropical Pacific tends to develop in the calendar year preceding the onset of the event. “

Connection places

Kurths adds, “This is a fundamentally different approach to traditional numerical modeling used in weather and climate forecasting. It does not simulate the entire Earth system, but analyzes large-scale connectivity patterns in observational data.

“These models, that is, the connectivity between locations and how they change over time, can provide new information essential for forecasting – and, hopefully, make the respective regions safer,” says the co-author Maria Martin, also at PIK.

Hans-Joachim Schellnhuber, former director of the institute, concludes: “In this perspective, we have gathered several success stories which demonstrate the scientific power of the network approach for forecasting – and, therefore, to potentially save thousands of people. lives and avoid billions in economic costs.

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