Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Data-driven tools cast geographical patterns of rainfall extremes in new light

20.12.2011
Using statistical analysis methods to examine rainfall extremes in India, a team of researchers has made a discovery that resolves an ongoing debate in published findings and offers new insights.

The study, initiated by Auroop Ganguly and colleagues at Oak Ridge National Laboratory, reports no evidence for uniformly increasing trends in rainfall extremes averaged over the entire Indian region. It does, however, find a steady and significant increase in the spatial variability of rainfall extremes over the region.

These findings, published in Nature Climate Change, are contrary to results of some earlier work on this subject. The new study uses statistical methods designed explicitly for modeling extreme values and associated uncertainties.

"Our research suggests that one needs to be aware of the different characterizations of extremes and that these characterizations require both interpretability and statistical rigor," said Ganguly, now a faculty member at Northeastern University in Boston.

In addition, it makes sense to look at local and regional drivers such as urbanization and deforestation in addition to global scale issues. Although this study focused on rainfall variability in India, the same methodology can be applied to any region of the world, Ganguly said.

Ganguly and co-authors Subimal Ghosh (Indian Institute of Technology Bombay, Debasish Das (Temple University) and Shih-Chieh Kao (ORNL) used their statistical methodologies to analyze data from 1,803 stations from 1951 to 2003. This information was provided in 1-by-1-degree spatial grids by the India Meteorological Department.

The research team noted that statistical observations offer complementary insights compared to the current generation of physics-based computational models. This is especially the case if the goal is to understand climate and rainfall variability at local to regional scales.

Understanding climate model-simulated trends of precipitation extremes and developing metrics relevant for water resources decisions were the focus of a paper published earlier this year in the Journal of Geophysical Research. In that paper, Ganguly and co-author Kao showed that while models provide relatively credible predictive insights of precipitation extremes at aggregate spatial scales, the uncertainty begins to increase significantly at localized spatial scales - especially over the tropical regions.

"Even as higher resolution models are attempting to get to the stage where spatially explicit insights can be generated, the kind of insights generated from observations in this study can be used as methods for model diagnostics and can help address science gaps," Kao said.

Ganguly noted that the Nature Climate Change paper, titled "Lack of uniform trends but increasing spatial variability in observed Indian rainfall extremes," is the result of a team effort with researchers from diverse disciplines. Ghosh, the first author, is a hydro-climate scientist and civil engineer; Das is a graduate student in computer science and data mining; Kao is a statistical who specializes in water availability and flood frequency analysis; and Ganguly, a civil engineer, specializes in climate extremes and water sustainability as well as data sciences for complex systems.

This research concept was initiated when all the authors were working with Ganguly at ORNL and was funded by the Laboratory Directed Research and Development program. The National Science Foundation's Expeditions in Computing program and the Department of Science and Technology of India also provided funding.

UT-Battelle manages ORNL for the Department of Energy's Office of Science.

Ron Walli | EurekAlert!
Further information:
http://www.ornl.gov

More articles from Earth Sciences:

nachricht Atmospheric pressure impacts greenhouse gas emissions from leaky oil and gas wells
21.10.2019 | University of British Columbia

nachricht Strong storms generating earthquake-like seismic activity
16.10.2019 | Florida State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

Fraunhofer LBF and BAM develop faster procedure for flame-retardant plastics

21.10.2019 | Materials Sciences

For EVs with higher range: Take greater advantage of the potential offered by lightweight construction materials

21.10.2019 | Materials Sciences

Benefit and risk: Meta-analysis draws a heterogeneous picture of drug-coated balloon angioplasty

21.10.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>