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  • richardmitnick 3:40 pm on April 10, 2017 Permalink | Reply
    Tags: , , , NJIT, ,   

    From NJIT: Putting Students Closer to Explosive Solar Events 

    NJIT Bloc

    New Jersey Institute of Technology

    1

    April 6, 2017

    NJIT has a long-established reputation as a leader in researching phenomena originating on the star closest to Earth — the Sun. NJIT’s optical telescope at Big Bear Solar Observatory and radio telescope array at Owens Valley, both in California, have greatly expanded our understanding of solar events that periodically impact our home planet, events such as solar flares and coronal mass ejections (CMEs) that can disrupt terrestrial communications and power infrastructure in addition to other effects.

    NJIT Big Bear Solar Observatory, located on the north side of Big Bear Lake in the San Bernardino Mountains of southwestern San Bernardino County, California, approximately 120 kilometers east of downtown Los Angeles

    Ten antennas of NJIT’s 13-antenna Expanded Owens Valley Solar Array (EOVSA)

    Under the auspices of the university’s Center for Solar-Terrestrial Research (CSTR), NJIT investigators are collaborating with colleagues in the U.S. and other countries to gain even more critical knowledge of solar physics. It’s knowledge essential not only for better basic understanding of the Sun but also to improve prediction of the solar explosions that threaten our technologies and to devise better countermeasures.

    What’s more, NJIT researchers are committed to fully engaging students in the search for this knowledge — researchers like Assistant Professor of Physics Bin Chen, who joined the NJIT faculty in 2016. Chen was recently awarded a five-year CAREER grant totaling more than $700,000 by the National Science Foundation (NSF). The NSF’s Faculty Early Career Development (CAREER) program offers the foundation’s most prestigious awards in support of younger faculty who, in building their academic careers, have demonstrated outstanding potential as both educators and researchers.

    Chen completed his Ph.D. at the University of Virginia in 2013 with a focus on solar radio astronomy. His Ph.D. advisor introduced him to fellow solar astronomer, and now NJIT colleague, Distinguished Professor of Physics Dale Gary. Through his acquaintance with Gary, and the opportunity to collaborate on a research project using observational data from NJIT’s Owens Valley Solar Array, Chen learned about the university’s leading-edge efforts in solar radio physics. But before he joined NJIT after receiving his doctorate, Chen added to his research experience through a postdoctoral fellowship under NASA’s Living With a Star program and as an astrophysicist at the Harvard Smithsonian Center for Astrophysics, where he worked on space missions dedicated primarily to solar science.

    Shocking Insights

    Although not yet fellow faculty members at NJIT, Chen and Gary did collaborate with researchers from the National Radio Astronomy Observatory, the University of California, the University of Applied Sciences and Arts Northwestern Switzerland and the University of Minnesota on an article for the journal Science published in 2015, Particle Acceleration by a Solar Flare Termination Shock. The article presented radio imaging data that provides new insights into how a phenomenon known as termination shock associated with solar flares, the most powerful explosions in the solar system, helps to accelerate energetic electrons in the flares to relativistic speeds — propelling these particles into space at nearly the speed of light.

    Chen is now continuing this investigation at NJIT. “There is a lot we don’t know about the ‘inside’ of these solar explosions and how they release so much energy so quickly and so catastrophically,” he says. “For example, how is the energy stored and suddenly released, often in a matter of seconds?

    “The relativistic particle acceleration that we are also studying as part of this research is a process taking place across the universe and is a phenomenon associated with, for example, the massive star explosions known as supernovae. The Sun is a good place to research this phenomenon because its nearness in astronomical terms allows us to acquire a volume of high-resolution data impossible to obtain from observing vastly more distant stars.”

    For his research, Chen is drawing on streams of radio data from a number of sources. In addition to NJIT’s radio observatory at Owens Valley, these include the Karl G. Jansky Very Large Array in New Mexico operated by the National Radio Astronomy Observatory and the Atacama Large Millimeter/Submillimeter Array in Chile.

    NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Recent upgrades at Owens Valley put it at the forefront of this research as a “new-generation” radio telescope. Another very important advantage afforded by Owens Valley, as Chen emphasizes, is that it is a facility dedicated full-time to solar research.

    Chen is one of the few researchers seeking new knowledge of the Sun by taking advantage of an observing technique called dynamic spectroscopy imaging. This technique allows capturing an image of the Sun every 50 milliseconds at more than a thousand frequencies, and at two different polarizations. This adds up to 40,000 images per second and terabytes of raw data in a day that can be converted into 3D images with resolution far greater than previously obtainable. “This gives us the potential to learn so much more about what is going on in the heart of solar explosions,” Chen says.

    Beyond greater understanding of the fundamental physics involved, Chen adds that his research is very much supportive of the goals of the U.S. National Space Weather Strategy and Action Plan, which reflects critical awareness of how space weather generated by solar phenomena impacts many aspects of terrestrial life and infrastructure. He says, “Solar flares and CMEs are the main drivers of space weather. Better understanding of these drivers is essential for better prediction of such events and the implementation of protective measures.”

    Bringing the Sun to Campus

    In Chen’s estimation, NJIT is uniquely experienced in building, operating and maintaining facilities dedicated to radio observation of the Sun. Potentially, for students, this presents exceptional opportunities to learn at the frontier of the many disciplines relevant to investigating the Sun in the radio spectrum — including hands-on familiarity with the equipment involved. While a limited number of students do have a chance to work at Owens Valley, as well as at Big Bear, distance and lack of appropriate accommodations prevent many more from participating in solar research on site. That’s why Chen also plans to apply a portion of his CAREER funding to creating a Solar Radio Laboratory on campus in Newark.

    “The idea behind the Solar Radio Laboratory is to have a facility on campus with the same state-of-the-art technology found at Owens Valley, just without the antennas,” Chen explains. “We’ll have all the electronics, the radio technology, the data-science capability for processing data streaming from California. This will give students the same hands-on opportunities for working and experimenting with the instrumentation that NJIT has at Owens Valley, instrumentation that is really unique in the United States. Another goal is to use this as a test bed for future improvements at Owens Valley, and to engage students in developing those improvements.”

    For Chen, a complementary educational goal is to also advance the Hale COLLAborative Graduate Education (COLLAGE) program in solar physics, which commemorates the name of the pioneering American solar astronomer George Ellery Hale. There are very few graduate programs in this field in the U.S. and the necessary faculty and physical resources are widely distributed across educational institutions as well as geography. To address this situation, Philip Goode, NJIT distinguished research professor of physics and former CSTR director, proposed that NJIT join with the University of Colorado-Boulder and several other institutions that had solar physics programs in what is now known as the COLLAGE program.

    “COLLAGE gives more students in different parts of the country access to the instruction and resources that allow them to complete master’s and Ph.D. degrees in solar physics,” Chen says. “I am already working with some 20 students, and that’s actually quite a large number for our field. But not only are we increasing opportunities to study solar physics at the graduate level, we’re learning more about coordinating resources among schools and teaching effectively online, which will benefit students who want to study many different complex subjects.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NJIT campus

    Welcome to the New Jersey Institute of Technology. We’re proud of our 130 years of history, but that’s only the beginning of our story – we’ve doubled the size of our campus in the last decade, pouring millions into major new research facilities to give our students the edge they need in today’s demanding high-tech marketplace.

    NJIT offers 125 undergraduate and graduate degree programs in six specialized schools instructed by expert faculty, 98 percent of whom hold the highest degree in their field.

    Our academic programs are fully accredited by the appropriate accrediting boards, commissions and associations such as Middle States, ABET, and NAAB.

     
  • richardmitnick 1:17 pm on March 31, 2017 Permalink | Reply
    Tags: Igniting a Solar Flare in the Corona with Lower-Atmosphere Kindling, NJIT   

    From NJIT: “Igniting a Solar Flare in the Corona with Lower-Atmosphere Kindling” 

    NJIT Bloc

    New Jersey Institute of Technology

    3.28.17
    Tracey Regan

    1

    Scientists from NJIT’s Center for Solar-Terrestrial Research are providing some of the first detailed views of the mechanisms that may trigger solar flares, colossal releases of magnetic energy in the Sun’s corona that dispatch energized particles capable of penetrating Earth’s atmosphere within an hour and disrupting orbiting satellites and electronic communications on the ground.

    Recent images captured by the university’s 1.6-meter New Solar Telescope at Big Bear Solar Observatory (BBSO) have revealed the emergence of small-scale magnetic fields in the lower reaches of the corona the researchers say may be linked to the onset of a main flare.


    NJIT Big Bear Solar Observatory

    The study also includes the first scientific contributions from NJIT’s newly commissioned Extended Owens Valley Solar Array (EOVSA).


    NJIT Owens Valley Solar Array

    “These smaller magnetic fields appear as precursors to the flare by reconnecting with each other – breaking apart and forming new connections – in an already stressed magnetic environment. This sets the stage for a larger energy release,” notes Haimin Wang, distinguished professor of physics at NJIT and the leading author of a paper published this week in the magazine Nature Astronomy. The study, funded by the National Science Foundation and NASA, was conducted in collaboration with colleagues in Japan and China.

    “Through our measurements, we are able to see the emergence of fine magnetic channel structures prior to the flare, which contain mixed positive and negative magnetic polarities,” Wang adds. “We then see a strong twist in the magnetic lines that creates instability in the system and may trigger the eruption.”

    While solar flares are generally believed to be powered by what is known as free energy – energy stored in the corona that is released by twisting magnetic fields – the authors suggest that the build-up of coronal energy in the upper atmosphere alone may not be sufficient to trigger a flare. In their study of a prolonged flare on June 22, 2015, they observed in unprecedented detail the emergence in the lower atmosphere of what they call precursors, or “pre-flare brightenings,” in various wavelengths.

    There are well-documented periods in which flares occur more frequently than the norm, but it has been difficult thus far to determine exactly when and where a particular flare might be initiated. The BBSO’s recent study of a flare’s magnetic evolution, enhanced by simultaneous microwave observations from EOVSA, has been able to pin down the time and location of the magnetic reconnection prior to the flare.

    “Our study may help us predict flares with more precision,” Wang says.

    A co-author of the article, Kanya Kusano of Nagoya University, compared BBSO’s observations with his numerical simulation of the triggering process of solar flares.

    “I found that the observational result is very well consistent with the simulation,” he notes. “This clearly indicates that these mixed-polarity magnetic channel structures are typical of the stressed magnetic field that triggers solar flares.”

    See the full article .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NJIT campus

    Welcome to the New Jersey Institute of Technology. We’re proud of our 130 years of history, but that’s only the beginning of our story – we’ve doubled the size of our campus in the last decade, pouring millions into major new research facilities to give our students the edge they need in today’s demanding high-tech marketplace.

    NJIT offers 125 undergraduate and graduate degree programs in six specialized schools instructed by expert faculty, 98 percent of whom hold the highest degree in their field.

    Our academic programs are fully accredited by the appropriate accrediting boards, commissions and associations such as Middle States, ABET, and NAAB.

     
  • richardmitnick 4:48 pm on December 3, 2015 Permalink | Reply
    Tags: , , NJIT, ,   

    From NJIT: “NJIT Scientists Shed Light on How Solar Flares Accelerate Particles to Nearly the Speed of Light” 

    NJIT Bloc

    New Jersey Institute of Technology

    Dec 3 2015
    Tracey Regan

    1
    Image shows the speed of fast plasma outflows produced by the flare. The termination shock is shown as a transition layer where the colors change abruptly from red/yellow to blue/green. At bottom is the Karl G. Jansky Very Large Array, which captured the termination shock in action using radio observations. Image credits: SDO/AIA data is from NASA. VLA image courtesy of NRAO/AUI. Image prepared by Chen, Jibben, and Samra.

    For scientists studying the impacts of space weather, one of the central mysteries of solar flares – the colossal release of magnetic energy in the Sun’s atmosphere that erupts with the force of millions of hydrogen bombs – is the means by which these explosions produce radiation and accelerate particles to nearly the speed of light within seconds. The most powerful blasts dispatch energized particles that can penetrate Earth’s atmosphere within an hour, disrupting orbiting satellites and electronic communications on the ground.

    In an article published in Science magazine this week, Particle acceleration by a solar flare termination shock, solar scientists at several institutions, including NJIT, have shed light on an elusive structure known as a termination shock that is believed to play a key role in converting released magnetic energy from flares into kinetic energy in accelerated particles. Through a recent set of observations captured by a large radio telescope, the Jansky Very Large Array [VLA], they have imaged a shock and its time evolution during a long-lasting solar flare and demonstrated its role in accelerating particles.

    NRAO VLA
    NRAO VLA

    “Although predicted by theoretical models, this is the first time we have had direct images and movies showing the repeated formation, disruption, and reformation of a termination shock, enabling us to link it directly to particle acceleration,” said Dale Gary, distinguished professor of physics at NJIT and one of the authors of the article. Bin Chen, an astrophysicist at the Harvard Smithsonian Center for Astrophysics who will join NJIT next January, is the article’s lead author.

    The powerful shocks occur when high-speed jets expelled from the explosive energy-release site of a solar flare collide with stationary plasma below. One surprising result is that, occasionally, some jets can disrupt the shock, after which the shock takes time to reform. During the disruptions, radio and X-ray emission due to accelerated particles is observed to decrease not just at the shock, but throughout the emitting region, showing that the shock is at least partly responsible for accelerating those particles.

    The observations were made possible by the ability of the newly enhanced Karl G. Jansky Very Large Array (VLA) in New Mexico to acquire the more than 40,000 individual images per second of observation needed to resolve the rapidly varying emission features produced by the termination shock. This level of resolved detail allowed the firm identification of the radio source as a shock and revealed its dynamic evolution. Chen, who took part in significant upgrades of the VLA which made these observations possible, developed the technique to visualize the shock dynamics from the millions of images taken during the event.

    “We have been studying the Sun for many years using observations of its light in a broad range of wavelengths, but we have been unable to observe some of its activities in detail, including those related to particle acceleration,” Chen said. “Radio telescopes, which are now able to capture tens of thousands of images per second through various frequencies, are giving us much more information on what was previously hidden.”

    Solar flares erupt when stored magnetic energy is suddenly released and converted to other forms, such as high-energy particles, hot plasma at millions of degrees, intense electromagnetic radiation and plasma eruptions called coronal mass ejections (CMEs). Solar radiation from the primary flare and that generated secondarily from CMEs can affect Earth in many ways. The high-energy particles can destroy the electronic systems in satellites used in telecommunications, weather forecasting and navigation systems, among other services. The electromagnetic radiation can interfere directly with communication and navigation signals, ionize the atmosphere, and cause short-wave radio black-outs. Associated magnetic disturbances can also affect devices on the ground such as power transformers.

    The study of flares began in 1859 following what is known as the Carrington Event, a solar flare and associated geomagnetic storm so powerful that it electrified telegraph wires, causing spark discharges that caught paper on fire, caused world-wide magnetic disturbances, and was visible across the globe in the form of auroras. That storm was by some estimates four orders of magnitude stronger than the flare described in the Science article.

    “A flare the size of the Carrington event would pose real danger today because of our increasing reliance on susceptible technology,” Gary said. “Big events are difficult to predict, however. We have ways of measuring energy build-up, but sometimes when we think a large flare will occur, the energy dissipates quietly or in a series of smaller events instead. Studies like ours provide better understanding of the fundamental processes occurring in flares, and may one day lead to better predictions.”

    NJIT is expanding its own, solar-dedicated radio telescope, the Expanded Owens Valley Solar Array [EOVSA}, to observe the Sun every day with many of the same observational capabilities.

    NJIT Owens Valley Solar Array
    NJIT EOVSA

    Multi-frequency imaging with high frequency and time resolution will become a standard method of studying solar flares in the near future.

    “The VLA observes all sorts of astronomical targets and so the amount of time allotted to focus on the Sun amounts to less than a week per year. Owens Valley observes the Sun 24 hours a day,” said Chen, who called the star – “reasonably close” at 93 million miles away – “the best laboratory for studying a broad range of physical processes that occur across the Universe.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NJIT campus

    Welcome to the New Jersey Institute of Technology. We’re proud of our 130 years of history, but that’s only the beginning of our story – we’ve doubled the size of our campus in the last decade, pouring millions into major new research facilities to give our students the edge they need in today’s demanding high-tech marketplace.

    NJIT offers 125 undergraduate and graduate degree programs in six specialized schools instructed by expert faculty, 98 percent of whom hold the highest degree in their field.

    Our academic programs are fully accredited by the appropriate accrediting boards, commissions and associations such as Middle States, ABET, and NAAB.

     
  • richardmitnick 8:42 am on April 30, 2015 Permalink | Reply
    Tags: , , NJIT, ,   

    From phys.org: ” New solar telescope unveils the complex dynamics of sunspots’ dark cores” 

    physdotorg
    phys.org

    NJIT Bloc

    April 29, 2015
    No Writer Credit

    NJIT Big Bear Solar Observatory
    NJIT Big Bear Solar Observatory Interior
    NJIT Big Bear Solar Observatory

    1

    Groundbreaking images of the Sun captured by scientists at NJIT’s Big Bear Solar Observatory (BBSO) give a first-ever detailed view of the interior structure of umbrae – the dark patches in the center of sunspots – revealing dynamic magnetic fields responsible for the plumes of plasma that emerge as bright dots interrupting their darkness. Credit: NJIT’s Big Bear Solar Observatory

    Their research is being presented this week at the first Triennial Earth-Sun Summit meeting between the American Astronomical Society’s Solar Physics Division and the American Geophysical Union’s Space Physics and Aeronomy section in Indianapolis, Ind.

    The high-resolution images, taken through the observatory’s New Solar Telescope (NST), show the atmosphere above the umbrae to be finely structured, consisting of hot plasma intermixed with cool plasma jets as wide as 100 kilometers.

    NJIT Big Bear Solar Observatory New Solar Telescope
    NST

    “We would describe these plasma flows as oscillating cool jets piercing the hot atmosphere. Until now, we didn’t know they existed. While we have known for a long time that sunspots oscillate – moderate resolution telescopes show us dark shadows, or penumbral waves, moving across the umbra toward the edge of a sunspot – we can now begin to understand the underlying dynamics,” said Vasyl Yurchyshyn, a research professor of physics at NJIT and the lead author of two recent journal articles based on the NST observations.

    Called spikes, the oscillating jets result from the penetration of magnetic and plasma waves from the Sun’s photosphere – the light-giving layer of its atmosphere – into the abutting chromosphere, which they reach by traveling outward along magnetic tubes that serve as energy conduits. “This process can be likened to a blowhole at a rocky beach, where relentless onshore waves jet sea water high into the air,” Yurchyshyn said.

    Sunspots are formed when strong magnetic fields rise up from the convection zone, a region beneath the photosphere that transfers energy from the interior of the Sun to its surface. At the surface, the magnetic fields concentrate into bundles, which prevent the hot rising plasma from reaching the surface. This energy deficit causes the magnetic bundles to cool down to temperatures about 1,000 degrees lower than their surroundings. They therefore appear darker against the hotter, brighter background.

    “But the magnetic field is not a monolith and there are openings in the umbra from which plasma bursts out as lava does from a volcano’s side vents. These plumes create the bright, nearly circular patches we call umbral dots,” Yurchyshyn noted. “Sunspots that are very dark have strong magnetic fields and thus fewer openings.”

    Compact groups of fast-changing sunspots create tension in their magnetic systems, which at some point erupt to relieve the stress. It is those eruptions that cause intense “space weather” events in the Earth’s magnetosphere affecting communications, power lines, and navigation systems.

    “We had no sense of what happens inside an umbra until we were able to see it in the high-resolution images obtained with the world’s largest solar telescope. These data revealed to us unprecedented details of small-scale dynamics that appear to be similar in nature to what we see in other parts of the Sun,” Yurchyshyn said. “There is growing evidence that these dynamic events are responsible for the heating of coronal loops, seen in ultraviolet images as bright magnetic structures that jet out from the Sun’s surface. This is a solar puzzle we have yet to solve.”

    Since it began operating in 2009, Big Bear’s NST has given scientists a closer look at sunspot umbrae, among other solar regions. It has also allowed them to measure the shape of chromospheric spectral lines, enabling scientists to probe solar conditions.

    “These measurements tell us about the speed, temperature, and pressure of the plasma elements we are observing, as well as the strength and the direction of the solar magnetic fields,” said Yurchyshyn, who is also a distinguished scholar at the Korea Astronomy and Space Science Institute. “Thus we were able to find that spikes, or oscillating jets, are caused by chromospheric shocks, which are abrupt fluctuations in the magnetic field and plasma that constantly push plasma up along nearly the same magnetic channels.”

    The study on umbral spikes was published in the Astrophysical Journal in 2014.

    In a second paper published in the Astrophysical Journal in 2015, he is presenting another set of NST observations, taking a closer look at the sunspot oscillations that occur every three minutes and are thought to produce bright umbral flashes – emissions of plasma heated by shock waves.

    The NST takes snapshots of the Sun every 10 seconds, which are then strung together as a video to reveal fast-evolving small explosions, plasma flows and the movement of magnetic fields. “We were able to obtain photographs of these flashes of unique clarity that allowed us to follow their development inside the umbra,” he said. Previously believed to be diffuse patches randomly distributed over the umbra, the researchers found their location is in fact not random. They mainly form along so-called sunspot umbral light bridges, which are very large openings in the sunspot magnetic fields that often split an umbra into two or more parts.

    “Even more importantly, we found that umbral flash lanes tend to appear on the side of light bridges that face the center of the sunspot,” he added. “This finding is significant because it indicates that sunspot oscillations may be driven by one energy source located under the umbra. There are simulations that appear to reproduce what we have observed, which is very encouraging. We, as a community, are finally in the position to be able to directly compare the observations and the state-of-the-art simulation results, which is the key to making further progress in our field.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
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