Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Giant see-saw of monsoon rains detected

26.09.2016

When the summer rains in China are weak, they are strong in Australia, and vice versa – scientists have discovered a previously unknown see-saw relationship between these two monsoon regions. This effect does not occur from one year to another, but on decadal and centennial time scales. To detect the pattern, the team developed a novel mathematical method to analyze traces of climatic events of the past 9000 years archived in ancient dripstones from caves.

The regional monsoon has huge effects on agriculture and hence on the livelihoods of half of the world’s population, including India and Indonesia. Understanding how seasonal periods of rainfall in the Northern and Southern Hemispheres of our planet are linked is important for assessing possible long-distance effects of climate change.

“We’ve been surprised by how clearly the ups and downs of precipitation in East Asia on the one hand and Australia on the other hand are opposed, it’s really a giant see-saw,” says Deniz Eroglu from the Potsdam Institute for Climate Impact Research (PIK) and University of São Paulo, lead author of the study to be published in Nature Communications. “We needed to cut through the data clutter to detect this pattern. While our method of sophisticated statistical time series data analysis might seem quite complicated, our findings have substantial real-world consequences.”

Data from caves in China and Australia – these countries are most affected

Australia, just like China, heavily depends on the monsoon summer rains. “Both countries have experienced drier and wetter periods in the past. For instance the Northwest of Australia’s tourism and agriculture industries are vulnerable to flooding and bush fires, so any change from the current precipitation pattern will have huge impacts for the people living here,” says co-author Thomas Stemler from the University of Western Australia.

“However, this is an issue way beyond the region – in fact, the East-Asian-Indonesian-Australian summer monsoon provides a heat source that drives global circulation of airstreams during what is the winter season in the US, Russia and Europe. It will be exciting to investigate how the see-saw we found may be affecting these far-away parts of the world.”

Since there are no direct records of monsoon dynamics over past millennia, the scientists need to work with indirect data evidence. “Dripstones in ancient caves are amazing witnesses of the Earth’s past. Since they’re growing just fractions of a millimeter per year, we can see changes in the chemical composition over time from one layer to another,” says co-author Norbert Marwan from PIK who himself explored various caves, for instance in India. For the new study, the team used data from Dongge Cave in Southern China and cave KNI-51 in Northwestern Australia.

“Though it might seem challenging to climb into the caves to access the dripstones,” says Marwan, “the real challenge is to decrypt the information they carry – analyzing thousands of isotope samples and attributing them to specific climatic conditions. For this, we need sophisticated statistics.” A key partner in this process has been the Institute for Geology, Mineralogy & Geophysics at Ruhr-Universität Bochum.

Mechanics of the heavens are a driver, but human-made warming can change the dynamics

“The monsoon see-saw is likely driven by factors humans cannot influence, including the tilt of our Earth’s axis and solar activity, so that’s celestial mechanics,” says co-author Jürgen Kurths, co-chair of PIK’s research domain Transdisciplinary Concepts and Methods.

“However, disturbing circulation and precipitation patterns is something we unfortunately can do and already are doing by emitting greenhouse gases and thereby warming our planet. Understanding the natural East-Asian-Australian monsoon variability will help us to better understand certain human-caused climate risks in the future.”

Article: Deniz Eroglu, Fiona H. McRobie, Ibrahim Ozken, Thomas Stemler, Karl-Heinz Wyrwoll, Sebastian F. M. Breitenbach, Norbert Marwan, Jürgen Kurths (2016): See-saw relationship of the Holocene East Asian-Australian summer monsoon. Nature Communications [10.1038/NCOMMS12929]

Weblink to the article once it is published: http://dx.doi.org/10.1038/NCOMMS12929

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

www.pik-potsdam.de

Mareike Schodder | Potsdam-Institut für Klimafolgenforschung

More articles from Earth Sciences:

nachricht The seismicity of Mars
25.02.2020 | ETH Zurich

nachricht Major wind-driven ocean currents are shifting toward the poles
25.02.2020 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Scientists 'film' a quantum measurement

26.02.2020 | Physics and Astronomy

Melting properties determine the biological functions of the cuticular hydrocarbon layer of ants

26.02.2020 | Interdisciplinary Research

Lights, camera, action... the super-fast world of droplet dynamics

26.02.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>