Posts tagged increase
NASA-CU Boulder mission discovers particle accelerator in heart of Van Allen radiation
Jul 26th
The new results from NASA’s Van Allen Probes mission show the acceleration energy is in the belts themselves. Local bumps of energy kick particles inside the belts to ever-faster speeds, much like a well-timed push on a moving swing. Knowing the location of the acceleration within the radiation belts will help scientists improve predictions of space weather, which can be hazardous to satellites near Earth. The results were published July 25 in the journal Science.
“Until the 1990s, we thought the Van Allen belts were pretty well-behaved and changed slowly,” says Geoff Reeves, lead author on the paper and a radiation belt scientist at Los Alamos National Laboratory in Los Alamos, N.M. “With more and more measurements, however, we realized how quickly and unpredictably the radiation belts change. They are basically never in equilibrium, but in a constant state of change.”
In order for scientists to understand such changes better, the twin Van Allen Probes fly straight through this intense area of space. One of the top priorities for the mission, launched last August, is to understand how particles in the belts are accelerated to ultra-high energies.
“We see case after case where the very high energy electrons appear suddenly right in the heart of the outer belt,” said CU-Boulder Professor Daniel Baker, director of the Laboratory for Atmospheric and Space Physics and a study co-author. “But now we can prove where the electrons originate from and we can see the waves — and the lower energy ‘seed’ particles — from which the relativistic electrons grow. We can essentially peer into the inner workings of our local cosmic accelerator with unprecedented clarity.”
By taking simultaneous measurements with advanced technology instruments, the Van Allen Probes were able to distinguish between two broad possibilities on what accelerates the particles to such amazing speeds. The possibilities are radial acceleration or local acceleration. In radial acceleration, particles are transported perpendicular to the magnetic fields that surround Earth, from areas of low magnetic strength far from Earth to areas of high magnetic strength closer to Earth.
Physics dictates particle speeds in this scenario will increase as the magnetic field strength increases. The speed of the particles would increase as they move toward Earth, much the way a rock rolling down a hill gathers speed due to gravity. The local acceleration theory proposes the particles gain energy from a local energy source, similar to the way warm ocean water can fuel a hurricane above it.
Reeves and his team found they could distinguish between these two theories when they observed a rapid energy increase in the radiation belts Oct. 9, 2012. The observations did not show an intensification in particle energy starting at high altitude and moving gradually toward Earth, as would be expected in a radial acceleration scenario. Instead, the data showed an increase in energy that started right in the middle of the radiation belts and gradually spread both inward and outward, implying a local acceleration source. The research shows this local energy comes from electromagnetic waves coursing through the belts, tapping energy from other particles residing in the same region of space.
“These new results go a long way toward answering the questions of where and how particles are accelerated to high energy,” said Mona Kessel, Van Allen Probes program scientist in Washington. “One mission goal has been substantially addressed.”
The challenge for scientists now is to determine which waves are at work, according to the science team. The Van Allen Probes, which are designed to measure and distinguish between many types of electromagnetic waves, will tackle this task, too.
Baker said the new findings would not have been possible without the Relativistic Electric Proton Telescope, or REPT, developed by a team at CU-Boulder’s LASP and which is riding on the Van Allen Probes. CU-Boulder will receive more than $18 million from NASA over the Van Allen Probes mission lifetime for REPT and an electronics package known as the Digital Fields Board, said Baker, who led the LASP team that developed REPT.
“I think we are now getting a crash course in true radiation belt physics,” said Baker. “While before we were nibbling at the edges or looking through a cloudy screen, things are incredibly clear now. With our beautiful new sensors, we can see almost every ‘thumbprint’ of every large solar storm that has impressed itself on the Earth’s radiation belts.”
The Johns Hopkins University Applied Physics Laboratory in Laurel, Md., built and operates the twin Van Allen Probes for NASA’s Science Mission Directorate. The Van Allen Probes are the second mission in NASA’s Living With a Star program, managed by NASA’s Goddard Space Flight Center in Greenbelt, Md. The program explores aspects of the connected sun-Earth system that directly affect life and society.
For more information about the Van Allen Probes visit:
http://www.nasa.gov/vanallenprobes. For more information on LASP visit http://lasp.colorado.edu/home/.
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Graduating seniors give CU Boulder high marks
May 8th
The 2012 study is the latest edition of the senior survey, conducted 11 times since 1985 by CU-Boulder’s Office of Planning, Budget and Analysis, or PBA.
“The survey data clearly demonstrate that these students, from their perspective as seniors, judge the university in overwhelmingly positive terms,” said Michael Grant, CU-Boulder associate vice chancellor for undergraduate education. “CU-Boulder routinely invests a lot of time and energy in polling our senior students about their experiences, academic and otherwise, in order to continuously work toward improving those experiences.”
The online questionnaire was sent to 7,646 degree-seeking seniors and was completed by 2,890, or 38 percent, of the recipients. Comprising about 200 scaled items, plus four open-ended questions, the survey collected a massive amount of information including nearly 7,900 written comments.
The 2012 seniors’ ratings of CU-Boulder advising services were higher than those from any previous senior survey. The seniors’ satisfaction with numerous other CU-Boulder services, from libraries to information technology, was high and generally comparable to that of earlier cohorts.
“We use the survey results extensively to look at what’s popular and working well, to set goals to improve services, and even to pass along advice,” said Jim Davis Rosenthal, CU-Boulder director of orientation and director of the Office of Student Affairs Assessment. “Based on one of the survey questions, we are able to let incoming freshmen know what outgoing seniors wished they had gotten involved in. Other departments also use the results to encourage students to try opportunities they might not otherwise have considered. In a way, it’s like older siblings giving advice to their younger siblings.”
Large proportions of seniors said that if they were to start over at CU-Boulder, they would put more effort toward or spend more time on interacting with faculty (60 percent), career exploration (51 percent), and campus-related research projects, internships and applied experiences (45 percent).
Nearly two-thirds of seniors who expected to graduate by summer 2012 reported that their principal activity in fall 2012 was most likely to be paid employment, either full time (48 percent) or part time (15 percent). A combined 15 percent said they were most likely to be enrolled in graduate studies, professional school or other coursework. A combined 13 percent expected to go into military service, or pursue volunteer service, an internship, student teaching or travel.
The thousands of student comments included praise for various aspects of their major programs, suggestions for ways to enhance and improve major programs, and descriptions of ways in which their major program did or did not meet their educational goals.
One student wrote, “I feel that I am prepared to be an exceptional teacher after I graduate. The school had a lot to do with my preparedness.” Another wrote, “Excellent material, mostly great professors, and fantastic facilities all add up to a well-rounded education.”
The survey collects information on seniors’ satisfaction with their educational experiences at CU-Boulder and about their post-graduation plans. The survey’s findings are used primarily to provide systematic information for academic and service units to use in planning and improvement, and for use by prospective and current students, their advisers, and their families.
Preliminary results for the Seniors’ Future Plans Survey, which is separate from the comprehensive senior survey and which has been conducted each year since 2009, show a jump in full-time employment expectations. The initial data show that 54 percent of CU-Boulder seniors in 2013 expect full-time employment to be their principal activity after graduation, an increase from 48 percent in 2012. Expectations for part-time employment were reported by 15 percent of the 2013 seniors.
The 2012 questionnaire and comprehensive data from the senior survey, including summary reports from students in each of CU-Boulder’s schools and colleges and nearly 50 departments, are available athttp://www.colorado.edu/pba/surveys/senior/12/index.htm.
-CU-
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Noxious weeds on the city’s “hit” list
May 2nd
As a result of a state mandate to eliminate “List A” noxious weed species from all public and private property in Colorado communities, the City of Boulder is proposing an update to its existing weed ordinance to require property owners to remove the weeds from all properties.
“List A” weed species, as provided in the Colorado Noxious Weed Act, are plants that have yet to be well established in Colorado but are either present in small populations or are invasive in nearby states. There are two species of “List A” weeds that are of most concern within Boulder’s city limits: myrtle spurge and Japanese knotweed. The city was awarded a grant through the Colorado Department of Agriculture Noxious Weed Management Fund to assist in an educational plan.
“Early detection and eradication of these particular species can prevent them from becoming a major problem in Colorado,” said city Integrated Pest Management Coordinator Rella Abernathy. “Most of these plants are ‘escaped’ ornamental plants and many residents may not realize that they present a threat to the natural lands surrounding Boulder and are illegal to grow here.”
These noxious, invasive plants can negatively impact biodiversity, threaten endangered species, degrade native habitat, displace wildlife, increase soil erosion, damage streams and other wetlands and increase the risk and frequency of wildfires if allowed to spread. Boulder is in compliance with the Colorado Noxious Weed Act on city-owned properties but has not been enforcing the statue on private property.
The city will focus on education and outreach to notify the public of the requirements and to provide information for identification, environmentally-sound weed removal and suggested replacement plant options.
“A soft enforcement approach is being implemented with voluntary compliance being the goal and enforcement action being a last resort,” said Code Enforcement Supervisor Jennifer Riley. “However, ticketing is possible if property owners do not comply with repeated requests from officers to address illegal weeds.”
Education will begin with a “Purge Your Spurge” event on May 18 where residents are encouraged to pull their myrtle spurge and exchange it for free native plants. This event will occur as part of Boulder Community Day at the East Boulder Community Center, 5660 Sioux Drive, from 10 a.m. to 2 p.m. Other education efforts will include a webpage; fact sheets; media engagement; outreach to nurseries, landscapers and lawn care companies; and code enforcement officers who assist with education in the field.
“Identifying and removing noxious weeds from private property can take some effort, but it’s important to prevent these weeds from spreading to our neighbors’ yards and ultimately to natural areas,” said Abernathy. “Fortunately, only two of the weeds from the list are widespread within the Boulder city limits, myrtle spurge being the most common. We want to make sure people can easily identify the weeds, know how to remove them safely and know what native plants can be used to replace them.”
Myrtle spurge has been commonly used as a decorative plant. People should be aware that it contains a white sap that can cause skin irritation including blistering if touched. Those removing it should wear long sleeves, long pants, gloves and eye protection. Removing at least four inches of the root is recommended to prevent its return. It should be placed in a plastic bag and tightly fastened. DON’T compost noxious weeds as that will cause the weed to spread.
The city’s weed ordinance is expected to be modified through a City Manager rule change, which will be published in the Daily Camera on May 3, as well as on the city’s website. Public feedback will be accepted until May 20. The rule is anticipated to go into effect on June 1, 2013.
For more information or to provide feedback on the proposed City Manager’s rule, contact Rella Abernathy at 303-441-1901.
— CITY OF BOULDER NEWS RELEASE –
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