Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate model predicts dramatic changes over next 100 years

18.10.2005


The most comprehensive climate model to date of the continental United States predicts more extreme temperatures throughout the country and more extreme precipitation along the Gulf Coast, in the Pacific Northwest and east of the Mississippi.


These graphics illustrate some of the changes in climate predicted for the 21st century by Purdue University’s Noah Diffenbaugh and his team of scientists using a computer simulation they recently completed. The simulation indicates that the entire continental United States will experience more intense heat waves, most dramatically in the desert Southwest (top figure). It also indicates that several areas, notably the Gulf Coast, will experience more storms that bring heavy precipitation (bottom figure). The computer model, which incorporates many climatic factors in unprecedented detail, suggests that these changes will be significant enough to disrupt our national economy and infrastructure. (Purdue graphic/Diffenbaugh Lab)



The climate model, run on supercomputers at Purdue University, takes into account a large number of factors that have been incompletely incorporated in past studies, such as the effects of snow reflecting solar energy back into space and of high mountain ranges blocking weather fronts from traveling across them, said Noah S. Diffenbaugh, the team’s lead scientist. Diffenbaugh said a better understanding of these factors – coupled with a more powerful computer system on which to run the analysis – allowed the team to generate a far more coherent image of what weather we can expect to encounter in the continental United States for the next century. Those expectations, he said, paint a very different climate picture for most parts of the country.

"This is the most detailed projection of climate change that we have for the U.S.," said Diffenbaugh, an assistant professor of earth and atmospheric sciences in Purdue’s College of Science and a member of the Purdue Climate Change Research Center. "And the changes our model predicts are large enough to substantially disrupt our economy and infrastructure."


The research team also includes Diffenbaugh’s Purdue colleague Robert J. Trapp, as well as Jeremy S. Pal and Filippo Giorgi of the Abdus Salam International Centre for Theoretical Physics in Trieste, Italy. Their paper appears in today’s (Monday, Oct. 17) online edition of the journal Proceedings of the National Academy of Sciences.

Climate models are sophisticated computer codes that attempt to incorporate as many details about the complex workings of our environment as possible. Hundreds of dynamic processes, such as ocean currents, cloud formations, vegetation cover and – of particular import – the increase in atmospheric greenhouse gases, are programmed into the computers, which then attempt to discern the net effects on square-shaped plots of land that represent small pieces of the Earth’s surface. The smaller these squares are, the better the resolution the model can provide.

"Just as a digital camera that creates images with more pixels can result in a better photograph, we want to make those squares as small as possible," Diffenbaugh said. "We’d also like to incorporate as much of the climate system as we can so the analysis will be realistic."

Despite the number-crunching power of the linked computers used for these simulations, a model must factor in so many changing variables that a full analysis can require months of nonstop computational effort. Diffenbaugh’s team required five months to run their model on a cluster of Sun computers at the Rosen Center for Advanced Computing on Purdue’s campus.

"The results were worth it, though, because this model allows us to project changes in climate with unprecedented resolution," Diffenbaugh said.

Until now, the fastest computers have been used to resolve squares 50 kilometers to a side, which can return a reasonably accurate but rather grainy "photograph" of climate change.

"We can now analyze areas that are only 25 kilometers to a side, which, for example, allows us to discern more clearly where California’s central valley stops and the Sierra Nevada mountain range begins."

With their improvements over previous models, the team has been able to make several observations about the change in climate over the next century, particularly for the late century when greenhouse gas accumulation could have greater effect than, say, a decade from now.

"These projections are not necessarily about specific weather events," Diffenbaugh said. "But they do give us a good idea about what kind of weather to expect over the long run in a particular part of the country."

Some of these expectations include:

• The desert Southwest will experience more heat waves of greater intensity, combined with less summer precipitation. Water is already at a premium in the four-corners states and southern Nevada and, as years pass, even less water will be available for the region’s burgeoning populations, with extreme hot events increasing in frequency by as much as 500 percent.

• The Gulf Coast will be hotter and will receive its precipitation in greater volumes over shorter time periods. "The region actually will get more rainfall than it does now, but it will not be steady," Diffenbaugh said. "We project more dry spells punctuated by heavier rainfalls. We need to perform further analyses to understand how much of this is related to tropical cyclone activity."

• In the northeastern United States – roughly the region east of Illinois and north of Kentucky – summers will be longer and hotter. "Imagine the weather during the hottest two weeks of the year," Diffenbaugh said. "The area could experience temperatures in that range lasting for periods of up to two months by century’s end."

•Similarly, the continental United States will experience an overall warming trend: Temperatures now experienced during the coldest two weeks of the year will be a past memory, and winter’s length will diminish as well, according to the model.

The model, Diffenbaugh said, assumes that greenhouse gases will attain a concentration more than twice their current levels, but he said he is confident that the model’s performance gives as accurate a picture of the future as we can hope for at the moment.

"We checked our model’s performance by analyzing the period from 1961 to 1985 for which, of course, we do not need a prediction," Diffenbaugh said. "The model performed admirably, which tells us we’ve got a good understanding of how to represent the physical world in terms of computer code. It’s certainly not perfect, but we’ll need a computer at least 100 times as powerful as the cluster we used to really improve the accuracy. We would like to have access to such computing power in the future."

Diffenbaugh emphasized that, while the model was in no way designed to return an alarmist image of our climate’s future, the picture it painted should be considered.

"The more detail we look at with these models, the more dramatic the climate’s response is," he said. "Critics have complained that climate models lack sufficient spatial detail to be trusted. In terms of looking at the whole contiguous United States, we’ve quadrupled the spatial detail and, as a result, it appears that climate change is going to be even more dramatic than we previously thought. Of course, we can never be completely certain of the future, but it’s clear that as we consider more and more detail, the picture of future climate change becomes more and more severe."

Commenting on the study, Stanford University’s Stephen H. Schneider said the results confirm scientists’ suspicions about the future of climate change.

"This study is the latest and most detailed simulation of climatic change in the United States," said Schneider, who is Stanford’s Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies. "Critics have asserted that the coarse resolution of previous studies made their sometimes dire predictions suspect, but this new result with a very high resolution grid over the United States shows potential climatic impacts at least as significant as previous results with lower resolution model. As the authors wisely note, such potential impacts certainly should not be glibly dismissed."

This research was funded in part by a grant from the National Science Foundation.

The Rosen Center for Advanced Computing is a research computing center named in memory of Saul Rosen, who served as director of Purdue’s Computing Center from 1968-87 and who helped to establish Purdue as a pioneering academic institution in high-performance computing. The Rosen Center is a part of Information Technology at Purdue, which is responsible for planning and coordinating the central computing and telecommunications systems on the West Lafayette campus.

Writer: Chad Boutin, (765) 494-2081, cboutin@purdue.edu

Source: Noah S. Diffenbaugh, (765) 494-0754, diffenbaugh@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Chad Boutin | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>