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Mitigating Future Climate ChangeSimulations show that cuts in greenhouse gas emissions would save arctic ice, reduce sea level rise. The threat of global warming can still be greatly diminished if nations cut emissions of heat-trapping greenhouse gases by 70 percent this century, according to a study led by scientists at the National Center for Atmospheric Research (NCAR). While global temperatures would rise, the most dangerous potential aspects of climate change, including massive losses of Arctic sea ice and permafrost and significant sea level rise, could be partially avoided. To simulate a century of climate conditions, the researchers used more than 2000 processors of NERSC's Franklin, a Cray XT4 system, as well as computers at the Oak Ridge and Argonne Leadership Computing Facilities and at NCAR. Over the past two years, the NCAR team received a total allocation of 50 million processor hours on NERSC computers for a variety of climate studies.
The results of the research have been published in the journal Geophysical Research Letters with NCAR scientist Warren Washington as the lead author. Read the full story here The figure above shows the results of simulations suggesting that the extent that average air temperatures at Earth's surface could warm by 2080-2099 compared to 1980-1999, if (top) greenhouse gases emissions continue to climb at current rates, or if (bottom) emissions are by 70 percent. In the latter case, temperatures rise by less than 2°C (3.6°F) across nearly all populated areas. However, unchecked emissions could lead to warming of 3°C (5.4°F ) or more across parts of Europe, Asia, North America, and Australia. (Image: Geophysical Research Letters, adapted by LBNL.) |
Mismatched Alloys, A Good Match for Thermoelectrics
Researchers in the Berkeley Lab's Materials Sciences Division used NERSC'S
Franklin supercomputer to demonstrate that the introduction of oxygen atoms
into the semiconductor zinc selenide will produce a "highly mismatched alloy"
for which thermoelectric performance is substantially enhanced with no loss of electrical conductivity.
Thermoelectrics are a promising technology for "green" energy production.
Franklin Helps Find First Superbright Supernova
Extraordinarily bright, and long-lasting supernova SN 2007bi is the first unambiguous example of a "pair-instability" star,
the kind that is believed to have first populated the Universe.
This discovery was made using Franklin to generate numerous synthetic spectra for comparison with the observed spectrum.
Multi-Billion Macroparticle Simulation for Free Electron Lasers
A recent study used Franklin to look at beam dynamics in electron linacs
for design of the next-generation x-ray free electron lasers (FELs).
The parallel macroparticle
simulation code includes three-dimensional space-charge effects, short-range structure
wakefields, coherent synchrotron radiation (CSR) wakefields, and treatment of radio-frequency (rf )
accelerating cavities using maps obtained from axial field profiles.
A study of microbunching instability, which causes
severe electron beam fragmentation and is a
critical issue for future FELs, used in excess of 1 billion macroparticles.
The study showed that a
reasonable beam quality can be achieved at the end of the
linac.
NERSC Contributes to Award-Winning EMGeo Mapping Software for Finding Hidden Oil and Gas Reserves
The objective: Apply new, highly rigorous, massively parallel, 3-D imaging techniques to
create geophysical maps of hydrocarbon reservoirs in unprecedented levels of detail.
Implications: New detection abilities and exploration savings by revealing
where hydrocarbon deposits reside, even when covered by ocean over a mile deep
and several more miles of rock below the ocean. Can also be used for locating potential sites for CO2 sequestration.
Result: Software developed by LBNL scientists Gregory Newman and Michael Commer using NERSC's
Franklin system scales easily to 10s of thousands of cores and was
honored with a 2009 R&D 100 Award. The software has already provided insight into complex
geology of Campos Basin, a petroleum rich area near Brazil.
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