- Number 431 |
- January 26, 2015
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‘Iron Sun’ is not a rock band, but a key to how stars transmit energy
Working at temperatures matching the interior of the sun, researchers at the Z machine at DOE's Sandia National Laboratories have been able to determine experimentally, for the first time in history, iron’s role in inhibiting energy transmission from the center of the sun to near the edge of its radiative band — the section of the solar interior between the sun’s core and outer convection zone.
Because that role is much greater than formerly surmised, the new, experimentally derived amount of iron’s opacity — essentially, its capacity for hindering the transport of radiative energy originating in nuclear fusion reactions deep in the sun’s interior — helps close a theoretical gap in the Standard Solar Model, widely used by astrophysicists as a foundation to model the behavior of stars. -
Ames scientists use genetic markers to discover the rhizosphere
It’s a science lesson so fundamental that we teach it to small children, planting bean seeds in Styrofoam cups: plants take nutrients from the soil to grow.
It is surprising, then, that the complex interchange between the microorganisms in soils and the cellular activities of plants’ root systems, what scientists call the rhizosphere, remains one of science’s great mysteries.
“We want to know how plants and microbes in the soil talk to each other,” said Marit Nilsen-Hamilton, an Ames Laboratory scientist and professor in the Roy J Carver Department of Biochemistry, Biophysics and Molecular Biology at Iowa State University. “We know they’re communicating with each other, but how? Multicellular communities are vastly more complex than we currently understand. How do we go about finding out?” -
Model explores location of future U.S. population growth
Researchers at DOE’s Oak Ridge National Laboratory have developed a population distribution model that provides unprecedented county-level predictions of where people will live in the U.S. in the coming decades.
Initially developed to assist in the siting of new energy infrastructure, the team’s model has a broad range of implications from urban planning to climate change adaptation. The study is published in the journal Proceedings of the National Academy of Sciences.
“We do a census every 10 years because those data help us do long-term socioeconomic planning,” said Budhendra Bhaduri, who leads ORNL’s Geographic Information Science and Technology group. “Population projection numbers are important, but many pressing societal needs also require an understanding of where people are going to be. This has always been a challenge; we’ve never had a good method to make future projections spatially explicit.” -
On the right track for tropical clouds
Think of a tropical storm about the size of Alaska. Large and lumbering, the Madden-Julian Oscillation (MJO) affects weather patterns in every corner of the world. Unlike its well-known cousin El Niño, the MJO is both variable and unpredictable, earning the title of the largest and least understood element in the tropical atmosphere. However, scientists at DOE's Pacific Northwest National Laboratory and collaborators at the Indian Institute of Technology recently discovered what forces cause the MJO to begin and keep moving. Understanding the MJO could allow accurate weather forecasts beyond 10 days, enabling better prediction of severe storms.
The team began with data collected during the ARM MJO Investigation Experiment (AMIE)/Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaigns. The campaigns took place in the winter of 2011 over the Indian Ocean. With this data, they ran high-resolution regional model simulations.