The research, led by LLNL atmospheric scientist Govindasamy Bala, appears in the April 1 edition of the Journal of Climate.
The researchers used the Community Climate System Model (CCSM), which is sponsored by the National Science Foundation and Department of Energy. CCSM is a global ocean-atmosphere modeling framework designed to simulate the climate of the Earth. It is a comprehensive general circulation model that consists of complex submodels for the atmosphere, ocean, ice and land. In the earlier versions, spectral methods were available to solve the transport of water vapor, temperature and momentum in the atmosphere.
In the LLNL simulation, the researchers assessed the performance of a new dynamical method for atmospheric transport that was developed at NASA by Ricky Rood (a co-author of the study at the University of Michigan) and Shian-Jiann Lin of the National Oceanic and Atmospheric Administration. The new method is called finite volume transport.
The Livermore team found substantial improvements in the simulated global surface winds and sea surface temperatures. Team members also noted large improvements in the simulation of tropical variability in the Pacific, distribution of Arctic sea ice thickness and the ocean circulation in the Antarctic Circumpolar Current.
“We found that this coupled model is a state-of-the-art climate model with simulation capabilities in the class of those used for assessments for the Intergovernmental Panel on Climate Change (IPCC),” Bala said.
The simulation was performed on the LLNL supercomputer Thunder, using about 500 processors or slightly more than 10 percent of Thunder’s capacity. The 400-year-long simulation, performed over a period of three months, was part of an LLNL Grand Challenge Computing project. This simulation, at about 100-kilometer resolution for the atmosphere, is the highest resolution multi-century CCSM simulation to date.
Under the same Grand Challenge Computing project, the researchers earlier performed a 1,000-year-long simulation corresponding to the climate of pre-industrial times that enabled the scientists to estimate the “climate noise” in frost days, snow depth and stream flow in the Western United States. The collaborative study between LLNL and the Scripps Institution of Oceanography, which appeared in a Science article earlier this year, pinpointed the cause of that regional diminishing water flow to humans.
The present study is a collaborative effort between LLNL, the University of Michigan, Scripps Institution of Oceanography and NCAR. Other LLNL researchers include Art Mirin, Julie McClean, Dave Bader, Peter Gleckler and Krishna Achuta Rao (who is now at the Indian Institute of Technology Delhi).
Source: Lawrence Livermore National Laboratory
Related stories:
Recovery efforts not enough for critically endangered Asian vulture
Captive breeding colonies of a critically endangered vulture, whose numbers in the wild have dwindled from tens of millions to a few thousand, are too small to protect the species from extinction, a University of Michigan analysis shows.
Petascale climate modeling heats up
The development of powerful supercomputers capable of analyzing decades of data in the blink of an eye mark a technological milestone capable of bringing comprehensive changes to science, medicine, engineering, and business worldwide. Researchers at the University of Miami's Rosenstiel School of Marine and Atmospheric Science, collaborating with NCAR (National Center for Atmospheric Research), COLA (Center for Ocean-Land-Atmospheric Studies) and the University of California at Berkeley are utilizing a $1.4M award from the National Science Foundation (NSF) to generate new "petascale" computer models depicting detailed climate dynamics, and building the foundation for the next generation of complex climate models.
Numerical simulations of nutrient transport changes in Honghu Lake Basin
Nutrients transported from catchments are one of the most important sources for lake eutrophication. The Honghu Lake Basin, located at the middle reaches of the Yangtze River, was chosen as the study area, the numerical simulations were used to assess the relative roles of natural, climate-induced changes versus human-related activities in changes of the nutrient transportation. The simulation results showed that the effect from human activities increased rapidly, and had become a dominant factor.
Getting to the root of the matter
Like most things that exist underground, plant roots are out-of-sight and easily forgotten, but while flowers, leaves, and other aboveground plant parts are more familiar, plant roots are equally deserving of our appreciation. Beneath every towering tree, tasty crop, and dazzling ornamental lies a root system that makes it all possible. Roots provide anchor and support for plants, extract water and nutrients from soil, and reduce soil erosion. Roots also play an important role in soil carbon cycling and the global carbon balance.
Drier, warmer springs in US Southwest stem from human-caused changes in winds
Human-driven changes in the westerly winds are bringing hotter and drier springs to the American Southwest, according to new research from The University of Arizona in Tucson.
Scientists demonstrate the sharpest measurement of ice crystals in clouds
Scientists have created an instrument designed to help determine the shapes and sizes of tiny ice crystals typical of those found in high-altitude clouds, down to the micron level (comparable to the tiniest cells in the human body), according to a new study in
Optics Letters, a journal published by the Optical Society. The data produced using this instrument likely will help improve computer models used to predict climate change.
Space science simulation at UNH now better, faster, cheaper
Cashing in on the underlying technology that seamlessly renders graphics for state-of-the-art video games, space scientists at the University of New Hampshire have bundled together 40 PlayStation3 consoles to affordably simulate one of the "grand challenges" of modern computational science - the interaction between Earth's magnetic field or "magnetosphere" and the solar wind. Climate change is another supercomputing grand challenge.
Jaguar upgrade brings ORNL closer to petascale computing
Upgrades to Oak Ridge National Laboratory’s Jaguar supercomputer have more than doubled its performance, increasing the system’s ability to deliver far-reaching advances in climate studies, energy research, and a wide range of sciences.
