Lemitar, NM, United States
Lemitar, NM, United States

Time filter

Source Type

News Article | May 9, 2017
Site: www.rdmag.com

Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning -- the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs. Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms. The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations. Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space -- all without any advance warning. Compared to typical CMEs, which erupt from the sun as fast as 1800 miles per second, stealth CMEs move at a rambling gait -- between 250 to 435 miles per second. That's roughly the speed of the more common solar wind, the constant stream of charged particles that flows from the sun. At that speed, stealth CMEs aren't typically powerful enough to drive major space weather events, but because of their internal magnetic structure they can still cause minor to moderate disturbances to Earth's magnetic field. To uncover the origins of stealth CMEs, the scientists developed a model of the sun's magnetic fields, simulating their strength and movement in the sun's atmosphere. Central to the model was the sun's differential rotation, meaning different points on the sun rotate at different speeds. Unlike Earth, which rotates as a solid body, the sun rotates faster at the equator than it does at its poles. The model showed differential rotation causes the sun's magnetic fields to stretch and spread at different rates. The scientists demonstrated this constant process generates enough energy to form stealth CMEs over the course of roughly two weeks. The sun's rotation increasingly stresses magnetic field lines over time, eventually warping them into a strained coil of energy. When enough tension builds, the coil expands and pinches off into a massive bubble of twisted magnetic fields -- and without warning -- the stealth CME quietly leaves the sun. Such computer models can help researchers better understand how the sun affects near-Earth space, and potentially improve our ability to predict space weather, as is done for the nation by the U.S. National Oceanic and Atmospheric Administration. A paper published in the Journal of Geophysical Research on Nov. 5, 2016, summarizes this work.


News Article | May 8, 2017
Site: phys.org

Watch the evolution of a stealth CME in this simulation. Differential rotation creates a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space. The image of the sun is from NASA's STEREO. Colored lines depict magnetic field lines, and the different colors indicate in which layers of the sun's atmosphere they originate. The white lines become stressed and form a coil, eventually erupting from the sun. Credit: NASA's Goddard Space Flight Center/ARMS/Joy Ng, producer Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning—the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs. Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms. The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations. Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space—all without any advance warning. Compared to typical CMEs, which erupt from the sun as fast as 1800 miles per second, stealth CMEs move at a rambling gait—between 250 to 435 miles per second. That's roughly the speed of the more common solar wind, the constant stream of charged particles that flows from the sun. At that speed, stealth CMEs aren't typically powerful enough to drive major space weather events, but because of their internal magnetic structure they can still cause minor to moderate disturbances to Earth's magnetic field. To uncover the origins of stealth CMEs, the scientists developed a model of the sun's magnetic fields, simulating their strength and movement in the sun's atmosphere. Central to the model was the sun's differential rotation, meaning different points on the sun rotate at different speeds. Unlike Earth, which rotates as a solid body, the sun rotates faster at the equator than it does at its poles. The model showed differential rotation causes the sun's magnetic fields to stretch and spread at different rates. The scientists demonstrated this constant process generates enough energy to form stealth CMEs over the course of roughly two weeks. The sun's rotation increasingly stresses magnetic field lines over time, eventually warping them into a strained coil of energy. When enough tension builds, the coil expands and pinches off into a massive bubble of twisted magnetic fields—and without warning—the stealth CME quietly leaves the sun. Such computer models can help researchers better understand how the sun affects near-Earth space, and potentially improve our ability to predict space weather, as is done for the nation by the U.S. National Oceanic and Atmospheric Administration. A paper published in the Journal of Geophysical Research on Nov. 5, 2016, summarizes this work. Explore further: Sun's eruptions might all have same trigger More information: B. J. Lynch et al. A model for stealth coronal mass ejections, Journal of Geophysical Research: Space Physics (2016). DOI: 10.1002/2016JA023432


News Article | May 11, 2017
Site: news.yahoo.com

The sun regularly shoots material out into the void of space, and the largest of these blasts are known as coronal mass ejections, or CMEs. A team of scientists led by the Space Sciences Laboratory at University of California, Berkeley has developed a model that simulates the evolution of stealth CMEs, which explode into space with no warming. CMEs are usually telegraphed in advance. The warning varies; sometimes there's a bright flash of a flare, other times a burst of heat or a flurry of solar energetic particles. A standard CME also moves fast, with a speed of 1,800 miles per second leaving the sun. NASA describes stealth CMEs as having a "rambling gait" in comparison, flying at 250 to 435 miles per second, roughly the same speed as the constant stream of charged particles that flows from the sun known as solar wind. Using the space agency's Solar Terrestrial Relations Observatory (STEREO) and Solar and Heliospheric Observatory (SOHO), the scientists made a model of the sun's magnetic fields. They discovered that the sun's rotation is crucial to the mystery of stealth CMEs. A star like the sun is not a solid body of mass like Earth or Mars. It rotates unevenly, faster at the equator than the poles. That differential in rotation makes the sun's magnetic fields stretch and spread at varying rates. This pulling and stretching creates enough energy to produce a stealth CME in about two weeks, the scientists discovered. The rotation stresses the magnetic fields until they are warped into a strained coil of energy. "When enough tension builds," NASA says, "the coil expands and pinches off into a massive bubble of twisted magnetic fields - and without warning - the stealth CME quietly leaves the sun." A stealth CME can moderately disturb the Earth's magnetic fields, but it's unlikely that we'll ever be directly affected by one. But understanding the weather of the sun -beyond "always hot"- can help us predict space weather elsewhere, which will come in handy as we look past the Moon and start traveling deeper into the solar system. You Might Also Like


News Article | May 12, 2017
Site: www.latimes.com

This summer, darkness will fall across the face of America. Stars will become visible in the daytime sky. In about 100 days, a total solar eclipse will sweep across the continental United States for the first time since 1918. Astronomers are calling it the Great American Eclipse. For the amateur sky-watcher, a total eclipse presents a rare opportunity to witness a cosmic hiccup in our day-night cycle. For solar astronomers, however, the eclipse offers something else: three minutes (give or take) to collect as much data as possible about the sun’s usually hidden outer atmosphere. Researchers have been anticipating the event for years. A solar eclipse is coming in August. Here’s what it will look like where you are » Some will take measurements from the sky; others have engaged vast networks of citizen scientists to track the eclipse as its shadow moves across the ground. Ultimately, they hope their findings will tell them more about the sun’s magnetic field, the temperature of its outer atmosphere and how energy moves through the star and out into space. Doing science during a total eclipse may be exciting, but it can also put you on edge. No matter how carefully you plan, nature may conspire against you with something as trivial as a cloud momentarily passing through the wrong patch of sky. “I’ve had those experiences and it’s heartbreaking,” said Shadia Habbal, who studies the solar wind at the University of Hawaii’s Institute for Astronomy. If you remember donning those paper eclipse glasses to watch as the moon appears to take a bite out of the sun, you may think you have seen a total eclipse. But you haven’t. What you witnessed was a partial eclipse, a phenomenon as different from a total eclipse as day is from night. Literally. The sun is so bright that even when 99% of it is covered by the moon, the remaining 1% is still bright enough to make the sky blue, said Jay Pasachoff, an astronomer at Williams College in Massachusetts who has seen 33 total eclipses and 32 partial eclipses. During a total solar eclipse, the moon completely obscures the face of the sun, causing the daytime sky to darken by a factor of 1 million. This moment of totality lasts only a few minutes. Those who have seen it say it’s unlike anything they’ve ever experienced. “It’s a really unique feeling, standing in the shadow of the moon,” said Matt Penn, an astronomer at the National Solar Observatory in Tucson who has witnessed two total eclipses. “Crickets start to chirp. Birds start to roost. Chickens do weird things. And it’s all in reaction to the strange light.” A total solar eclipse occurs somewhere on Earth about once every 18 months, and it can happen absolutely anywhere. That means most eclipse-chasers have to travel far from home to see one for themselves. On Aug. 21, however, what’s known as the path of totality will cut a 60-mile-wide arc across the United States, beginning in Oregon at 10:15 a.m. local time and ending in South Carolina about an hour and a half later. Experts estimate that 11 million people won’t have to travel at all to observe the total eclipse, and an estimated 76 million more will be within a 200-mile drive of it. Because of this unusual accessibility, it will probably be the most-viewed eclipse of all time. Scientists expect it will be the most-studied eclipse of all time as well. Most researchers plan to study the sun’s outer atmosphere, or corona. This is a vast region of superheated gas held in place by the sun’s magnetic field. Under normal circumstances, we can’t see the corona from the ground because it is overwhelmed by the brightness of the photosphere, the sun’s main disk. But with the photosphere blocked, the corona will become the main event in the sky — a pale, spiky halo of streamers that appears to radiate from the blacked-out solar surface. Composite images and measurements made during other eclipses reveal that the corona is composed of a complex swirl of gases much hotter than what you’d find on the surface of the sun. The surface is a toasty 6,000 degrees Kelvin (more than 10,000 degrees Fahrenheit), but the temperature of the corona averages 1 million degrees Kelvin (1.8 million degrees Fahrenheit). “The fundamental question we are asking is, what is causing the atmosphere to heat up like that?” Habbal said. “This is one of the scientific mysteries regarding the sun that remains unanswered.” But not for lack of trying. Habbal has led 14 eclipse expeditions since 1995, traveling as far as the Arctic. This year, she and her colleagues will make the most of the Great American Eclipse by viewing it from five distinct sites from Oregon to Nebraska. Each group will wield custom-made cameras with long focal lenses that can capture images of the corona in the spectrum of visible light. The teams will also take spectra measurements to see which elements are in the corona and how hot they are. Any answers Habbal comes up with would shed light on the processes that shape not only the solar atmosphere, but the atmosphere of other stars that are similar to the sun, she said. On the other side of the country, researchers from the Harvard-Smithsonian Center for Astrophysics are planning to study the corona from a plane flying at 49,000 feet. The group, led by solar physicist Ed DeLuca, is building an instrument that will allow them to examine the solar atmosphere in infrared wavelengths. Their ultimate goal is to better understand the magnetic fields in this outer region of the sun — in part because this is where coronal mass ejections originate. “Measuring these magnetic fields is really useful for understanding how energy is stored in the corona and when we expect it to be released,” DeLuca said. “Once we understand that, we can make better space weather predictions.” A coronal mass ejection sends millions of tons of the sun’s material hurtling through space. If a well-aimed one hits Earth, it can mess with the planet’s magnetosphere and inflict damage on satellites, astronauts and even the power grid. Water in Earth’s atmosphere can interfere with infrared measurements, but the higher up in the atmosphere you go, the less water you’ll find. At an altitude of nearly 50,000 feet, the researchers say, their instruments will be able to measure 100 times more infrared light coming from the corona than if they were at sea level. DeLuca is hoping the weather won’t be a problem. The flight is happening over Tennessee, where thunderstorms have been known to go quite high, but they usually don’t develop until later in the afternoon. “The flight’s at noon, so we should be OK,” he said. This isn’t just any plane. The modified Gulfstream V jet is owned by the National Science Foundation and has been turned into a flying laboratory. On the day of the eclipse, the researchers will have to make sure the light from the solar atmosphere comes through a 6-by-9-inch window on the right side of the plane. Then it will hit a telescope that feeds a spectrograph enclosed in a cryogenic vacuum chamber positioned on the floor of the cabin. The plane will fly along with the shadow of the moon, giving the scientists an additional minute of observing time. That may not sound impressive, but every minute counts when you have less than five minutes to collect data. Pasachoff, who is recognized among eclipse chasers as the person who has seen more eclipses than anyone else on the planet, started planning his Great American Eclipse observations more than four years ago. After traveling to Ternate in Indonesia, Svalbard in the Norwegian Arctic archipelago and Gabon in West Africa to observe these cosmic events, he said it’s going to be quite a change to see an eclipse here in the U.S. His team of a dozen astronomers will be stationed near Salem, Ore., a site they selected because the region has an excellent chance of clear skies in August. (Knock on wood.) Pasachoff and his collaborators plan to use two spectrometers and several telescopes with high-resolution imaging capabilities to measure the different gases in the solar atmosphere, study the dynamics of the corona, determine how hot it is, and compare its overall shape to scientists’ predictions. There are other observing plans afoot as well. Penn, of the National Solar Observatory, is leading an ambitious effort to watch how the corona changes over the full 90 minutes that the eclipse will be visible somewhere in the U.S. He calls it the Citizen CATE Experiment (short for Continental America Telescopic Eclipse). On the big day, 70 volunteers will use specially designed telescopes to film the corona for the roughly two minutes of totality in their area. Those images will be stitched together into a movie. Penn said his team’s primary focus will be to measure the velocity of the solar wind, the outflow of particles coming from the sun. “These particles are accelerated at high speeds, but we don’t know how that acceleration works,” he said. Another group from UC Berkeley’s Space Sciences Laboratory has partnered with Google to collect images from more than 1,000 citizen scientists. By combining them into a “megamovie,” they hope to see how the corona changes over time. Amid all this activity, the scientists are budgeting a little time to marvel at the rare intersection of our daily lives and the mechanics of our solar system. “It’s a cosmic event we are witnessing and a reminder of how puny we are,” Penn said. Lead photo: A total solar eclipse as viewed from Svalbard, Norway, on March 20, 2015. It is optimized for a higher contrast than visual range to bring out overlapping coronal streamers. (Ron Dantowitz and Jay Pasachoff) Do you love science? I do! Follow me @DeborahNetburn and "like" Los Angeles Times Science & Health on Facebook. A solar eclipse is coming in August. Here’s what it will look like where you are The human nose has been underrated for 150 years, but science is setting the record straight Dinosaur named for 'Ghostbusters' creature found in Montana 75 million years after its death


News Article | May 8, 2017
Site: news.yahoo.com

Solar storms are unlike storms on Earth in that they’re far more difficult to predict. They aren’t particularly dependent on the systems we rely on here on Earth to tell us what to expect from the weather. And not only are they difficult to predict, there are several types of solar storms to track and study as well, some more difficult than others. Scientists at the University of California, Berkeley, have found a way to simulate these unpredictable solar storms, called coronal mass ejections, CMEs or stealth CMEs, that can cause slight disruptions to the Earth’s magnetic field. CME stands for coronal mass ejection and essentially happens when the sun shoots solar material into space. The corona is the outer atmosphere of the sun, structured mostly by strong magnetic fields. Sometimes the atmosphere releases bursts of gas that propel into space, coming in contact with anything in its way. This means the possible billions of tons of matter CMEs expel can end up disrupting Earth. Sometimes these CMEs come with a bit of a warning like a flare or a burst of heat, NASA said. But sometimes they come with no warning at all. These are called stealth CMEs. What researchers and scientists at Berkeley were able to do was develop a model that can help simulate the pattern of such CMEs so they could have a better understanding of “near-Earth space” and these solar weather events as a whole. The simulations may even help researchers predict space weather in the future. These predictions were led by the Space Sciences Laboratory at Berkeley, thanks to partial funding from NASA as well as access to research completed on NASA missions STEREO and SOHO, a release from NASA said. What they found is the rotation of the sun is differential, meaning different parts of it rotate at different times, and that causes the magnetic fields to stretch and change shape at different speeds. This causes the magnetic field lines to change and stress over time, and turn into a coil of energy. When that coil gains enough energy, it pinches off and leaves the sun with no warning, the research indicated. Normal CMEs come off the sun at 1,800 miles per second while stealth CMEs travel 250-435 miles per second, NASA said. The stealth CMEs travel at such a slow speed, they rarely make it out far enough into space to cause major weather events, but they are powerful enough to cause slight disruptions in Earth’s magnetic field. The research was published in the Journal of Geophysical Research, however, the full article is not available to the public for free.


Innovative approach automatically resizes, resumes, and recovers video to ensure nonstop recording from a classroom PC; allows faculty and students to capture learning anytime, anywhere, despite common user errors and environmental challenges RESTON, VA--(Marketwired - May 16, 2017) - Echo360 announced, today, the launch of new capabilities for their popular lecture capture software to provide faculty and students with the most reliable video capture solution on the market for classroom PCs. The new features are rooted in an advanced, algorithmic approach which anticipates, identifies, and corrects issues that often arise with lecture capture by automatically handling common problems such as shifting inputs and resolutions to ensure that the capture continues and is successful, regardless of the devices used. "As faculty experiment with an array of pedagogical approaches -- from online to flipped, small group or hybrid models -- we see increased application for lecture capture and lecture streaming," said Perry Samson, professor of Climate and Space Sciences and Engineering at the University of Michigan at Ann Arbor and head of teaching innovation at Echo360. "A multitude of capture contexts and devices, however, requires solutions that can ensure reliability despite inevitable interruptions, user errors, and challenges in the implementation environment." As a growing number of institutions rely on general-purpose computers to record lectures and small group interaction, Echo360's new capture algorithms build on its existing cloud-based scheduling and administrative monitoring capabilities to make software capture more reliable, mitigating the risks that can happen with video to ensure a seamless and easy to use way to record learning in real time. Even in the face of technical interruptions, the software continues to capture the teaching content and learning moments. Additional features of the company's new lecture capture software include: "The purpose of technology in the classroom is to make teaching and learning more efficient, effective, and engaging for students today," said Bradley Fordham, CTO of Echo360. "Since we know capture problems occur in real-life instructional environments such as system reboots, instructors forgetting to end a capture, or faculty switching from a camera to a smartboard on the fly, we want to protect the instructional moments algorithmically. The new features are designed to counteract inevitable challenges and issues, and adapt in real-time to create a more seamless and reliable way to capture teaching and learning." The features are now available. For more information, visit http://bit.ly/2qmbNNE. About Echo360: Echo360 believes that improved outcomes start with great moments in the classroom. Developed by educators, Echo360 helps instructors capture and extend those moments to improve student engagement before, during and after class. Through our video and engagement platform, students have 24/7 access to classroom discussion, presentation materials, and the lecture itself. We generate data that helps instructors and institutions identify problems early and act. Today, Echo360 technologies are used by over 3M students in 11,000 classrooms at 750 institutions across 30 countries. Echo360 is backed by Revolution Growth led by Steve Case, Ted Leonsis and Donn Davis.


News Article | April 17, 2017
Site: www.eurekalert.org

Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results from NASA's MAVEN spacecraft. The metal ions can reveal previously invisible activity in the mysterious electrically charged upper atmosphere (ionosphere) of Mars. "MAVEN has made the first direct detection of the permanent presence of metal ions in the ionosphere of a planet other than Earth," said Joseph Grebowsky of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Because metallic ions have long lifetimes and are transported far from their region of origin by neutral winds and electric fields, they can be used to infer motion in the ionosphere, similar to the way we use a lofted leaf to reveal which way the wind is blowing." Grebowsky is lead author of a paper on this research appearing April 10 in Geophysical Research Letters. MAVEN (Mars Atmosphere and Volatile Evolution Mission) is exploring the Martian upper atmosphere to understand how the planet lost most of its air, transforming from a world that could have supported life billions of years ago into a cold desert planet today. Understanding ionospheric activity is shedding light on how the Martian atmosphere is being lost to space, according to the team. The metal comes from a constant rain of tiny meteoroids onto the Red Planet. When a high-speed meteoroid hits the Martian atmosphere, it vaporizes. Metal atoms in the vapor trail get some of their electrons torn away by other charged atoms and molecules in the ionosphere, transforming the metal atoms into electrically charged ions. MAVEN has detected iron, magnesium, and sodium ions in the upper atmosphere of Mars over the last two years using its Neutral Gas and Ion Mass Spectrometer instrument, giving the team confidence that the metal ions are a permanent feature. "We detected metal ions associated with the close passage of Comet Siding Spring in 2014, but that was a unique event and it didn't tell us about the long-term presence of the ions," said Grebowsky. The interplanetary dust that causes the meteor showers is common throughout our solar system, so it's likely that all solar system planets and moons with substantial atmospheres have metal ions, according to the team. Sounding rockets, radar and satellite measurements have detected metal ion layers high in the atmosphere above Earth. There's also been indirect evidence for metal ions above other planets in our solar system. When spacecraft are exploring these worlds from orbit, sometimes their radio signals pass through the planet's atmosphere on the way to Earth, and sometimes portions of the signal have been blocked. This has been interpreted as interference from electrons in the ionosphere, some of which are thought to be associated with metal ions. However, long-term direct detection of the metal ions by MAVEN is the first conclusive evidence that these ions exist on another planet and that they are a permanent feature there. The team found that the metal ions behaved differently on Mars than on Earth. Earth is surrounded by a global magnetic field generated in its interior, and this magnetic field together with ionospheric winds forces the metal ions into layers. However, Mars has only local magnetic fields fossilized in certain regions of its crust, and the team only saw the layers near these areas. "Elsewhere, the metal ion distributions are totally unlike those observed at Earth," said Grebowsky. The research has other applications as well. For example it is unclear if the metal ions can affect the formation or behavior of high-altitude clouds. Also, detailed understanding of the meteoritic ions in the totally different Earth and Mars environments will be useful for better predicting consequences of interplanetary dust impacts in other yet-unexplored solar system atmospheres. "Observing metal ions on another planet gives us something to compare and contrast with Earth to understand the ionosphere and atmospheric chemistry better," said Grebowsky. The research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA Goddard manages the MAVEN project and provided two science instruments for the mission. The University of California at Berkeley's Space Sciences Laboratory also provided four science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. NASA's Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.


News Article | March 30, 2017
Site: www.scientificcomputing.com

The San Diego Supercomputer Center (SDSC) at the University of California San Diego and the  Simons Foundation’s Flatiron Institute in New York have reached an agreement under which the majority of SDSC’s data-intensive Gordon supercomputer will be used by Simons for ongoing research following completion of the system’s tenure as a National Science Foundation (NSF) resource on March 31. Under the agreement, SDSC will provide high-performance computing (HPC) resources and services on Gordon for the Flatiron Institute to conduct computationally-based research in astrophysics, biology, condensed matter physics, materials science, and other domains. The two-year agreement, with an option to renew for a third year, takes effect April 1, 2017. Under the agreement, the Flatiron Institute will have annual access to at least 90 percent of Gordon’s system capacity. SDSC will retain the rest for use by other organizations including UC San Diego's Center for Astrophysics & Space Sciences (CASS), as well as SDSC’s OpenTopography project and various projects within the Center for Applied Internet Data Analysis (CAIDA), which is based at SDSC. “We are delighted that the Simons Foundation has given Gordon a new lease on life after five years of service as a highly sought after XSEDE resource,” said SDSC Director Michael Norman, who also served as the principal investigator for Gordon. “We welcome the Foundation as a new partner and consider this to be a solid testimony regarding Gordon’s data-intensive capabilities and its myriad contributions to advancing scientific discovery.” “We are excited to have a big boost to the processing capacity for our researchers and to work with the strong team from San Diego,” said Ian Fisk, co-director of the Scientific Computing Core (SCC), which is part of the Flatiron Institute. David Spergel, director of the Flatiron Institute’s Center for Computational Astrophysics (CCA) said, “CCA researchers will use Gordon both for simulating the evolution and growth of galaxies, as well as for the analysis of large astronomical data sets.  Gordon offers us a powerful platform for attacking these challenging computational problems.” The POLARBEAR project and successor project called The Simons Array, led by UC Berkeley and funded first by the Simons Foundation and then in 2015 by the NSF under a five-year, $5 million grant, will continue to use Gordon as a key resource. “POLARBEAR and The Simons Array, which will deploy the most powerful CMB (Cosmic Microwave Background) radiation telescope and detector system ever made, are two NSF supported astronomical telescopes that observe CMB, in essence the leftover ‘heat’ from the Big Bang in the form of microwave radiation,” said Brian Keating, a professor of physics at UC San Diego’s Center for Astrophysics & Space Sciences and a co-PI for the POLARBEAR/Simons Array project. “The POLARBEAR experiment alone collects nearly one gigabyte of data every day that must be analyzed in real time,” added Keating. “This is an intensive process that requires dozens of sophisticated tests to assure the quality of the data. Only by leveraging resources such as Gordon are we be able to continue our legacy of success.” Gordon also will be used in conjunction with the Simons Observatory, a 5-year $40 million project awarded by the Foundation in May 2016 to a consortium of universities led by UC San Diego, UC Berkeley, Princeton University, and the University of Pennsylvania. In the Simons Observatory, new telescopes will join the existing POLARBEAR/Simons Array and Atacama Cosmology Telescopes to produce an order of magnitude more data than the current POLARBEAR experiment. An all-hands meeting for the new project will take place at SDSC this summer. A video describing the project can be viewed by clicking the image below. The result of a five-year, $20 million NSF grant awarded in late 2009, Gordon entered production in early 2012 as one of the 50 fastest supercom­puters in the world, and the first one to use massive amounts of flash-based memory. That made it many times faster than conventional HPC systems, while having enough bandwidth to help researchers sift through tremendous amounts of data. Gordon also has been a key resource within NSF’s XSEDE (Extreme Science and Engineering Discovery Environment) project. The system will officially end its NSF duties on March 31 following two extensions from the agency. By the end of February 2017, Gordon had supported research and education by more than 2,000 command-line users and over 7,000 gateway users, primarily through resource allocations from XSEDE.  One of Gordon’s most data-intensive tasks was to rapidly process raw data from almost one billion particle collisions as part of a project to help define the future research agenda for the Large Hadron Collider (LHC). Gordon provided auxiliary computing capacity by processing massive data sets generated by one of the LHC’s two large general-purpose particle detectors used to find the elusive Higgs particle. The around-the-clock data processing run on Gordon was completed in about four weeks’ time, making the data available for analysis several months ahead of schedule.


News Article | May 8, 2017
Site: www.eurekalert.org

Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning -- the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs. Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms. The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations. Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space -- all without any advance warning. Compared to typical CMEs, which erupt from the sun as fast as 1800 miles per second, stealth CMEs move at a rambling gait -- between 250 to 435 miles per second. That's roughly the speed of the more common solar wind, the constant stream of charged particles that flows from the sun. At that speed, stealth CMEs aren't typically powerful enough to drive major space weather events, but because of their internal magnetic structure they can still cause minor to moderate disturbances to Earth's magnetic field. To uncover the origins of stealth CMEs, the scientists developed a model of the sun's magnetic fields, simulating their strength and movement in the sun's atmosphere. Central to the model was the sun's differential rotation, meaning different points on the sun rotate at different speeds. Unlike Earth, which rotates as a solid body, the sun rotates faster at the equator than it does at its poles. The model showed differential rotation causes the sun's magnetic fields to stretch and spread at different rates. The scientists demonstrated this constant process generates enough energy to form stealth CMEs over the course of roughly two weeks. The sun's rotation increasingly stresses magnetic field lines over time, eventually warping them into a strained coil of energy. When enough tension builds, the coil expands and pinches off into a massive bubble of twisted magnetic fields -- and without warning -- the stealth CME quietly leaves the sun. Such computer models can help researchers better understand how the sun affects near-Earth space, and potentially improve our ability to predict space weather, as is done for the nation by the U.S. National Oceanic and Atmospheric Administration. A paper published in the Journal of Geophysical Research on Nov. 5, 2016, summarizes this work.


IMAGE:  The left figure shows the P-T pseudosection calculated for the representative tonalitic sample (J13). The melt compositions simulated for three isobaric melting processes under high, medium and low pressure conditions... view more The ancient continental crust in the earth was mainly formed in the Archean, 2.5~4.0 billion years ago, and is chiefly composed of tonalite, trondhjemite and granodiorite (TTG rocks). These three kinds of rock preserve pivotal information of the formation and evolution of early continental crust. Study on the petrogenesis of TTG rocks can provide great contributions to elucidate the tectonic regimes of the early earth. A latest research, using quantitative phase modeling approach to document the partial melting process of tonalitic gneiss, presents an innovative viewpoint of petrogenesis of Archean trondhjemite in the Eastern Hebei, China. Research paper titled: "Petrogenetic simulation of the Archean trondhjemite from Eastern Hebei China", is published in Science China Earth Sciences. The corresponding author is Professor Wei Chunjing, School of Earth and Space Sciences, Peking University. A forward method for studying the petrogenesis of granitoids is to use high-temperature and high-pressure experiments by selecting different bulk-rock compositions as starting materials and to compare the melts compositions experimentally constrained with those of real rocks. Results from previous experimental studies suggest that the Archean TTG rocks were formed by partial melting of hydrous mafic rocks, and low melting degrees or melting under high pressure conditions tend to produce trondhjemitic melt. Field observations in many Precambrian terrains shows that trondhjemite commonly occurs as small veins, intrusions and/or as leucosomes within tonalitic gneiss, being in-situ melting origin. This suggests that that trondhjemitic melt can be generated by partial melting of tonalitic rocks. Thus, a systematic research is implemented to simulate the origin of trondhjemite. Taking trondhjemitic rocks from the Eastern Hebei as an example, the authors present phase modeling for a representative tonalitic sample using recent internally consistent thermodynamic data set, available activity models of minerals and melt and the THERMOCALC software. On the basis of the calculated P-T pseudosection, melt compositions were constrained under different P-T conditions, and compared with those of trondhjemitic rocks in the Eastern Hebei. The simulation results show that melts generated under 0.9~1.1GPa/800~850?C with melting degree of 5~10wt.% are comparable with trondhjemitic rocks from the Eastern Hebei in both major and trace element compositions. In addition, zircon U-Pb isotopic dating reveals that the formation age of trondhjemitic veins in the Eastern Hebei is consistent with the metamorphic age of the country tonalitic gneiss, further supporting the viewpoint that trondhjemitic rocks can be formed by the partial melting of tonalitic rocks. Using quantitative phase modeling approach, we simulate partial melting of tonalite and propose a new view that trondhjemite can be a melting product of tonalite rather than only produced by partial melting of mafic rocks under high pressure conditions. This will be significant for elucidating the Archean tectonic regime for the formation of TTG rocks. Moreover, this study provides a new and effective method for documenting of the genesis of granitoids. This research was funded by the key project of National Natural Science Foundation of China (No. 41430207) See the article: ZHANG ShiWei, WEI ChunJing, DUAN ZhanZhan, 2017. Petrogenetic simulation of the Archean trondhjemite from Eastern Hebei, China. Science China Earth Sciences http://engine.

Loading Space Sciences Inc collaborators
Loading Space Sciences Inc collaborators