Slashdot reader overheardinpdx shares a video from the SC17 supercomputing conference where Bruce Tulloch from BitScope "describes a low-cost Rasberry Pi cluster that Los Alamos National Lab is using to simulate large-scale supercomputers." Slashdot reader mspohr describes them as "five rack-mount Bitscope Cluster Modules, each with 150 Raspberry Pi boards with integrated network switches." With each of the 750 chips packing four cores, it offers a 3,000-core highly parallelizable platform that emulates an ARM-based supercomputer, allowing researchers to test development code without requiring a power-hungry machine at significant cost to the taxpayer. The full 750-node cluster, running 2-3 W per processor, runs at 1000W idle, 3000W at typical and 4000W at peak (with the switches) and is substantially cheaper, if also computationally a lot slower. After development using the Pi clusters, frameworks can then be ported to the larger scale supercomputers available at Los Alamos National Lab, such as Trinity and Crossroads.
BitScope's Tulloch points out the cluster is fully integrated with the network switching infrastructure at Los Alamos National Lab, and applauds the Raspberry Bi cluster as "affordable, scalable, highly parallel testbed for high-performance-computing system-software developers."

An anonymous reader quotes MIT Technology Review: A group of Australian marine scientists believe that altering clouds might offer one of the best hopes for saving the Great Barrier Reef. For the last six months, researchers at the Sydney Institute of Marine Science and the University of Sydney School of Geosciences have been meeting regularly to explore the possibility of making low-lying clouds off the northeastern coast of Australia more reflective in order to cool the waters surrounding the world's biggest coral reef system...

Last year, as El Nino events cranked up ocean temperatures, at least 20% of the reef died and more than 90% of it was damaged. The Australian researchers took a hard look at a number of potential ways to preserve the reefs. But at this point, making clouds more reflective looks like the most feasible way to protect an ecosystem that stretches across more than 130,000 square miles, says Daniel Harrison, a postdoctoral research associate with the Ocean Technology Group at the University of Sydney. Cloud brightening is the only thing we've identified that's scalable, sensible, and relatively environmentally benign," he says... Next month, he plans to start computer climate modeling to explore whether cloud brightening could make a big enough temperature difference to help.
They're collaborating with Silicon Valley's Marine Cloud Brightening Project, which has spent the last seven years "developing a nozzle that they believe can spray salt particles of just the right size and quantity to alter the clouds. They're attempting to raise several million dollars to build full-scale sprayers." The article describes them as "one of several research groups that have started to explore whether cloud brightening, generally discussed as a potential tool to alter the climate as a whole, could be applied in more targeted ways."