The researchers have developed a technique that uses interference patterns created when GPS signals that reflect off of the ground -- called "multipath" signals -- are combined with signals that arrive at the antenna directly from the satellite, said CU-Boulder aerospace engineering sciences Professor Kristine Larson, who is leading the study. Since such multipath signals arrive at GPS receivers "late," they have generally been viewed as noise by scientists and engineers and have largely been ignored, said Larson, who is leading a multi-institution research effort on the project.

In one recent demonstration, the team was able to correlate changes in the multipath signals to snow depth by using data collected at a field site in Marshall, Colo. just south of Boulder, which was hit by two large snowstorms over a three-week span in March and April of 2009. Published in the September issue of Geophysical Research Letters, the snowpack study built on a project Larson and her colleagues have been working on that is funded by the National Science Foundation to measure soil moisture using GPS receivers.

The new study on snow and vegetation moisture will be presented at the fall meeting of the American Geophysical Union being held in San Francisco Dec. 14 to 18.

Larson's group is the first to use traditional GPS receivers -- which were designed for use by surveyors and scientists to measure plate tectonics and geological processes -- to assess snowpack, soil moisture and vegetation moisture. The team hopes to apply the technique to data collected from an existing network of more than 1,000 GPS receivers in place around the West known as the Plate Boundary Observatory, a component of NSF's Earthscope science program.

"By using the Plate Boundary Observatory for double duty, so to speak, we hope this will be a relatively inexpensive and accurate method that can benefit climate modelers, atmospheric researchers and farmers throughout the West," said Larson.

Study collaborators, all from Boulder, include CU-Boulder's Eric Small and Mark Williams, John Braun from the University Corporation for Atmospheric Research, Ethan Gutmann from the National Center for Atmospheric Research and Valery Zavorotny and Andria Bilich from National Oceanic and Atmospheric Administration.

The most recent effort by the team has been conducted in cooperation with Munson Farms of Boulder. The new experiment is designed to analyze how the GPS signals traveling through alfalfa, corn and grass correlate with the amount of water in the vegetation. Small and CU-Boulder students have been cutting and weighing both wet and dry vegetation and matching the sample weights with comparative GPS multipath signal changes using a receiver set up at the farm.

The team is collaborating with Bob Munson, owner of Munson Farms and a former antenna engineer at Ball Aerospace & Technologies of Boulder. Munson holds more than 30 patents related to antenna design, including one of the most widely used antennas for GPS applications like vehicle navigation and recreational applications.

"With this system, the GPS antenna allows us to see across a whole field, unlike individual moisture sensors that are sometimes set up to measure only small, specific areas," Munson said. If a farmer relied on data from only a single soil moisture sensor that happened to be in a particularly dry pocket of his crop field, for example, it could have a negative effect on the timing and quality of the harvest, he said.

Originally developed in the 1970s for military use, GPS technology is in wide use today, telling drivers and hikers their exact position on the planet and providing directions to their destinations by gathering at least four signals simultaneously from the 31 GPS satellites now orbiting Earth.

Braun, who received his doctorate from CU-Boulder in 2004, also is interested in observing water vapor in the atmosphere by measuring the delay of GPS signals as they propagate through the atmosphere. "Water scarcity is going to be a problem for the western United States in the coming century," he said. "Having improved observations of water in all of its phases is going to be an important step as we monitor changes in the environment, which is the most intriguing part of this project for me."

Larson helped to pioneer the use of GPS as a tool to measure the movement of tectonic plates and the crustal deformation associated with earthquakes as a graduate student at the University of California-San Diego in 1980s. "Even then we knew that the data were corrupted by ground reflection, which was really irritating," she said. "But it was only recently that we began to think maybe there was a way to use these ground reflections to our benefit."

All of the team's research efforts revolve around the water cycle, said Larson. "We want to know if the water is in the ground, in the snow or in the vegetation, and how much is evaporating into the atmosphere, since it will ultimately be returned to the Earth's surface through precipitation events."

Contacts:
Kristine Larson, 303-492-6583
John Braun, UCAR, 303-497-8018

NEWS SOURCE: CU-Boulder News Center

Last month's storm brought anywhere from several inches to a few feet of snow along the Front Range while the most recent storm saw up to a foot of snow in some places. It's a scenario that is typical of El Niño during the fall, said Wolter.

"Four of the last five El Niños have had a snowy October here on the Front Range of Colorado," said Wolter. "In general, it tends to be wetter than average in the fall season -- September through November -- from Arizona through New Mexico and Colorado into the high plains."

But according to Wolter, this year's El Niño most likely will impact Colorado's winter weather in a way many skiers won't like.

"In the high country, and this is essentially everything north of Telluride, the ski resorts at the highest elevations tend to be drier with an El Niño winter."

This doesn't mean that ski areas in Colorado won't get snow, said Wolter, but that they'll get fewer midwinter storms because the storm track will be mostly to the south.

"You get fewer storms, and every once in a while we'll get hit and those storms can be healthy storms, by all means, but you shouldn't expect a lot of powder skiing," he said.

But there is a silver lining to this, said Wolter. While chances are that the state will have fewer snowstorms, temperatures will tend to hover closer to normal and there should be fewer windstorms, especially along the Front Range.

"An El Niño doesn't mean you can't get a windstorm, it just means you don't get high wind speeds like 60 miles per hour for days on end," he said.

But as winter comes to a close, Wolter expects the storm track to move back north and that should bring heavier snowstorms to the Front Range and a few areas of the high country if El Niño is still a factor next spring.

"The Front Range and ski resorts just west of the divide -- Winter Park, Keystone, Arapahoe Basin -- all these places have a tendency to have a wet spring " during an El Niño, he said.

If the current El Niño continues to grow into a "strong event," then Southern California, Arizona and New Mexico will have their best chance in years to get a wetter-than-normal winter, he said. And that would be a good thing because Arizona and California continue to suffer from a prolonged drought.

The last El Niño to influence Colorado's winter weather was in 2006-07, Wolter said. But that one produced an unusually snowy midwinter and he said the state should not expect a repeat of the blizzards that hit the Front Range just before Christmas and that lasted through the first weeks of 2007.

Contacts:

Klaus Wolter, 303-497-6340
Dirk Martin, 303-492-3140

NEWS SOURCE: CU-Boulder News Center

A study by researchers from Purdue University and the universities of Colorado and Maryland concluded that greener land cover contributes to cooler temperatures, and almost any other change leads to warmer temperatures. The study, published on line and set to appear in the Royal Meteorological Society’s International Journal of Climatology later this year, is further evidence that land use should be better incorporated into computer models projecting future climate conditions, said Purdue doctoral student Souleymane Fall, the article’s lead author.

“What we highlight here is that a significant trend, particularly the warming trend in terms of temperatures, can also be partially explained by land-use change,” said Dev Niyogi, a Purdue earth and atmospheric sciences and agronomy professor, and the Indiana state climatologist. He is the study's corresponding author.

The results indicate that "unless these landscape effects are properly considered, the role of greenhouse warming in increasing surface temperatures will be significantly overstated," said Roger Pielke Sr., a study co-author. Pielke is a senior research scientist in atmospheric and oceanic sciences at the Cooperative Institute for Research in Environmental Sciences and the Department of Atmospheric and Oceanic Sciences at the University of Colorado at Boulder.

Niyogi and Fall say the idea that land use helps drive climate change has been poorly understood compared to factors such as greenhouse gas emissions. But that is changing.

“People realize that land use cover also is an important force and not only at the local but also at the regional scale,” said Fall, whose doctoral research focuses on the impacts of land surface properties on near-surface temperature trends.

The researchers used higher resolution temperature data than previous studies, meaning the data was more detailed, Niyogi said. They also employed dynamic data on land-use changes from 1992-2001, which was derived from satellite imagery.

Niyogi said having an understanding of land use's affects on climate change could have climatic and other benefits. For instance, creating green spaces and buffer zones in and around urban areas also could be aesthetically attractive, he said.

Among the study's findings:
* In general, the greener the land cover, the cooler is surface temperature.
* Conversion to agriculture results in cooling, while conversion from agriculture generally results in warming.
* Deforestation generally results in warming, with the exception of a shift from forest to agriculture. No clear picture emerged from the impact of planting or seeding new forests.
* Urbanization and conversion to bare soils have the largest warming impacts.

In general, land use conversion often results in more warming than cooling.

The study took an approach called "observation minus reanalysis," or OMR. Through this process, the researchers used temperature data from local ground observations, observation and computer modeling, Geographic Information Systems (GIS) and statistical methods. They were able to separate the effects of land use or cover from greenhouse warming and isolate the impact from each land use or cover type. The more detailed data provided a clearer picture of the effects of land surface properties on near-surface temperature trends.

“We showed this quantitatively for the first time,” said University of Maryland atmospheric and oceanic science Professor Eugenia Kalnay, who developed the OMR method with Florida State University Professor Ming Cai. She also is a co-author of the study.

While the effects of greenhouses gases like carbon dioxide are clear, Kalnay said, the study does suggest land use needs to be considered carefully as well.

“I think that greenhouse warming is incredibly important, but land use should not be neglected,” she said. “It contributes to warming, especially in urban and desertic areas.”

Purdue's Gilbert Rochon and Alexander Gluhovsky also participated in the study. Rochon is associate vice president for collaborative research for Information Technology at Purdue (ITaP) and director of ITaP's Purdue Terrestrial Observatory satellite and remote sensing data program. Gluhovsky is a Purdue professor in earth and atmospheric sciences and statistics.

The work was supported by the U.S. Department of Energy Atmospheric Radiation Measurement program, NASA, the National Science Foundation, and the National Oceanic and Atmospheric Administration.

Writer:
Greg Kline, 765-494-8167

Sources:
Souleymane Fall, 765-494-9138
Dev Niyogi, 765-494-6574

Purdue News Service, 765-494-2096

NEWS SOURCE: CIRES

Their flights, planned to continue through December, are part of the HIPPO Mission, a multiagency, multiyear effort to paint a three-dimensional portrait of the atmosphere. HIPPO, for HIAPER Pole-to-Pole Observations of Greenhouse Gases, is funded and operated jointly by the National Science Foundation, the National Center for Atmospheric Research, and NOAA. HIAPER – the High-performance Instrumented Airborne Platform – is the NSF's Gulfstream V aircraft.

Steve Wofsy of Harvard University is leading HIPPO with a team of scientists from NOAA, NCAR, Scripps Institution of Oceanography, Jet Propulsion Laboratory, University of Miami, and Princeton University.

"While we have ground-based stations that measure carbon dioxide at specific locations, HIPPO is giving us a view of how carbon dioxide is distributed globally at different altitudes and during different seasons," said Jim Elkins, Ph.D., a NOAA ESRL atmospheric physicist. The team is pleased with the success of the first phase of HIPPO flights last January, which gathered data in cross-sections of the atmosphere from pole to pole, he said.

Information gathered during these flights will be critical for both climate modelers seeking to understand Earth's future and policymakers who rely on accurate science for decision-making. This research and decades of greenhouse gas monitoring are part of NOAA's suite of climate services.

Three more sets of flights are planned over the next two years to fill in additional data during different seasons and from areas where few previous measurements have been made. HIPPO's second phase will cover the central and eastern Pacific, departing from Colorado with stops in Alaska, Hawaii, Rarotonga of the Cook Islands, New Zealand, Australia, and the Solomon Islands. A fly-over of the NOAA American Samoa observatory is also planned.

NOAA scientists have been monitoring greenhouse gases through a ground-based, global network for nearly 40 years. As these gases move up through different layers of the atmosphere, they may persist for a time or be altered or destroyed in the upper atmosphere. The HIPPO Mission flights will give scientists a clearer picture of the distribution of greenhouse gases throughout the atmosphere.

NOAA scientists designed five instruments for analyzing air samples onboard HIPPO flights. They have the ability to detect and measure more than 30 major and minor greenhouse gases as well as water vapor, ozone, and soot particles.

"We are providing flight planning and weather support, measurements of all greenhouse gases and some carbon isotopes, and in-flight measurement of non-carbon dioxide greenhouse gases and black carbon," Elkins said.

Eric Hintsa of CIRES and Elkins will be flying on subsequent legs of HIPPO phase II. Other scientists involved in leadership, flight planning and overall coordination on the ground are Steven Montzka, David Fahey, Ru-shan Gao, and Karen Rosenlof of NOAA, and Geoff Dutton, Molly Heller, Ben Miller, J. David Nance, Eric Ray, Joshua Schwarz, Colm Sweeney, Jack Higgs, and Sonja Wolter of CIRES.

NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

NOAA Media Contact:
Linda Joy 301-734-1165

NEWS SOURCE: CIRES

NEWS SOURCE: College of Arts and Sciences

This award and others will be presented during International Education Week at a special awards ceremony and reception on Tuesday, November 17 from 5:00 to 7:00 p.m. in the British and Irish Studies Room in Norlin Library on the CU-Boulder campus.

This event is planned annually to award outstanding champions of international education, both faculty and students, global citizens, as well as to reveal the winners of the photo contest. The catered reception is open to all. Enjoy talking with students, faculty and staff who are internationally-minded and view the photo submissions for this year's contest.

NEWS SOURCE: Office of International Education

Andrews Hall houses the Engineering Honors Program and the program's director, Associate Professor Scot Douglass, lives in the hall with his wife and two daughters.

The new facility offers engineering students multiple opportunities to learn where they live, said Kambiz Khalili, executive director of Housing and Dining Services. Students experience daily faculty interaction and activities outside the classroom that relate to what is being studied inside the classroom.

"Not only is teaching enhanced, but first-year students benefit from the mentoring relationships and expectations set by upper-division students who have continued in the program," Khalili said. "This is a community of talented individuals coming together to challenge, inspire and learn from each other."

Andrews Hall features two classrooms, one faculty director's office, one staff office and six study rooms. Just over $14 million was spent on the 60,588-gross-square-foot renovation.

The rededication ceremony will include a talk by Douglass, music performed by Andrews Hall residents, tours of the residence hall and refreshments.

Andrews Hall is the second of four buildings being renovated in the Kittredge Complex and is on track to receive Leadership in Energy and Environmental Design, or LEED, Gold certification.

Contacts:
Kambiz Khalili, 303-492-6494
Megan Rose, 303-492-8687

NEWS SOURCE: CU-Boulder News Center

RASEI, a new joint institute between the University of Colorado at Boulder and the U.S. Department of Energy's National Renewable Energy Laboratory in Golden, made the announcement at CU-Boulder's Annual Energy Research Symposium taking place today in Boulder.

"NREL and CU-Boulder, along with research colleagues from Colorado State University and the Colorado School of Mines, are already working together on a variety of critical energy technologies that will help to ensure a clean and sustainable energy supply for our nation's future," said Robert McGrath, NREL deputy laboratory director for science and technology, and one of RASEI's chief architects. "The newly established RASEI significantly strengthens the structural platform enabling CU-Boulder and NREL researchers to take full advantage of the complementary strengths resident within each institution."

A national search will be conducted for RASEI's director. In addition to creating the resources to attract a top candidate to lead the new institute, CU-Boulder plans to designate as many as 10 new faculty hires to RASEI over the next several years, with exact levels of support contingent upon the Colorado economy and the university's budget.

Institute management and decision-making will be coordinated by the new director, a private-sector Leadership Board and a set of prominent research fellows appointed from NREL and CU-Boulder. The initial 34 RASEI fellows named today include 18 from CU-Boulder and 16 from NREL.

"CU has a long history of joint institutes with national laboratories that attract the highest caliber leadership and scientific talent," said CU-Boulder Chancellor Philip P. DiStefano. "With this initiative, CU is fostering an invaluable working relationship with an important partner, and opening up new opportunities for CU researchers to collaborate with Stanford, MIT and other major American Association of Universities research institutions focusing on the development of new energy solutions."

RASEI will operate much like CU-Boulder's other independent research institutes, including JILA, which collaborates with the National Institute of Standards and Technology, and the Cooperative Institute for Research in Environmental Sciences, which collaborates with the National Oceanic and Atmospheric Administration.

According to McGrath, "RASEI will expand and build upon the work already initiated under the Center for Revolutionary Solar Photoconversion, the Colorado Center for Biorefining and Biofuels, the Center for Research and Education in Wind and other research centers affiliated with the Colorado Renewable Energy Collaboratory."

The Collaboratory's partners include CU-Boulder, CSU, the Colorado School of Mines and NREL.

"Colorado's new energy economy is leading America toward a new energy future, and collaborations between our universities and national laboratories such as RASEI are leading the way," said Colorado Gov. Bill Ritter. "RASEI is poised to attract the best and brightest new research talent to the state of Colorado, which will also bring good jobs and advance clean energy technologies."

And with ConocoPhillips, a member of RASEI's industry-driven Leadership Board, building a new global technology center and corporate learning center at the Sun Microsystems/StorageTek site in Louisville, the new institute will spur greater overall investment in new energy development in Colorado, now seen as a national hub for clean energy technology creation. The new ConocoPhillips center will handle research and development of renewable energy and high-tech carbon fuels recovery.

"One of the key reasons ConocoPhillips plans to locate its new global technology center and corporate learning center in Colorado is the exceptional research talent pool in close proximity to our proposed campus," said Stephen Brand, ConocoPhillips' senior vice president for technology. "As a long-time collaborator with CU-Boulder, and member of the RASEI Leadership Council, ConocoPhillips is committed to making this new institute a world-class success."

NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy, LLC, comprised of the Midwest Research Institute, Battelle Memorial Institute, CU-Boulder, CSU, Colorado School of Mines, MIT and Stanford.

CU-Boulder is a leading U.S. public research university and the only American Association of Universities Tier One research institution in the Rocky Mountain region. CU-Boulder has four Nobel laureates, seven MacArthur "genius grant" winners, numerous Fulbright, Guggenheim and Packard fellows, 38 members of the National Academies and world-renowned joint research institutes with national labs such as NIST and NOAA.

RASEI, an interdisciplinary joint research effort between CU-Boulder and NREL located on the CU campus, is advancing solutions for producing energy economically from low-carbon sources and using energy more efficiently to meet the global energy challenge.

More information about RASEI.

Contacts:
Stein Sture, CU interim provost, 303-492-5537
Carl Koval, RASEI faculty director, 303-506-7042
Elaine Tucci, RASEI, 303-328-7368

NEWS SOURCE: CU-Boulder News Center

"As a founding member of RASEI's Leadership Council, we see this as a natural fit for Toyota," said Chris Hostetter, Toyota Motor Sales group vice president, advanced product strategy and product planning. "Future customers will have high expectations for these emerging technologies. Demonstration programs like this will ensure that the vehicles we bring to market will not just meet customer expectations, but exceed them."

RASEI faculty director Carl Koval added, "This is a perfect illustration of how collaborative research from universities and federal laboratories combined with industry leadership can address the energy and technology challenges of the future."

The SmartGridCity project is the first fully functioning smart grid enabled city in the world. Its goal is to provide increased grid reliability and energy use information. It will also allow participating customers to remotely control in-home energy management devices.

RASEI, Xcel Energy and Toyota Motor Sales will use this program to gather data on vehicle performance and charging patterns, consumer behavior and preferences, as well as electric utility/customer interactions. The locale offers the additional benefit of monitoring high-altitude, cold climate performance of Toyota's first-generation lithium-ion battery.

"We know that PHVs coupled with smart charging techniques can reduce carbon emissions," said Jay Herrmann, regional vice president for Xcel Energy. "Partnerships like this can bring us closer to delivering new solutions that can conserve energy, save natural resources and reduce dependence on foreign oil."

The 10 vehicles participating in the project are part of a 150 vehicle demonstration fleet arriving in the U.S. in early 2010. The Prius PHV is targeted to achieve a maximum electric only range of approximately 12 miles and will be capable of achieving highway speeds in electric only mode. For longer distances, the PHV concept reverts to "hybrid mode" and operates like a regular Prius.

The vehicles are targeted for delivery in March 2010.

Contacts: Contact: Toyota Environmental, Safety and Quality Communications
Jana Hartline (310) 468-7977
Amy Taylor (310) 468-6237

NEWS SOURCE: CU-Boulder News Center

An analysis of sediment cores indicates that biological and chemical changes occurring at a remote Arctic lake are unprecedented over the past 200,000 years and likely are the result of human-caused climate change, according to a new study led by the University of Colorado at Boulder.

While environmental changes at the lake over the past millennia have been shown to be tightly linked with natural causes of climate change -- like periodic, well-understood wobbles in Earth's orbit -- changes seen in the sediment cores since about 1950 indicate expected climate cooling is being overridden by human activity like greenhouse gas emissions. The research team reconstructed past climate and environmental changes at the lake on Baffin Island using indicators that included algae, fossil insects and geochemistry preserved in sediment cores that extend back 200,000 years.

"The past few decades have been unique in the past 200,000 years in terms of the changes we see in the biology and chemistry recorded in the cores," said lead study author Yarrow Axford of CU-Boulder's Institute of Arctic and Alpine Research. "We see clear evidence for warming in one of the most remote places on Earth at a time when the Arctic should be cooling because of natural processes."

The study was published Oct. 19 in the Proceedings of the National Academy of Sciences. The study included researchers from CU-Boulder, the State University of New York's University at Buffalo, the University of Alberta, the University of Massachusetts and Queen's University in Kingston, Ontario.

The sediment cores were extracted from the bottom of a roughly 100-acre, 30-foot-deep lake near the village of Clyde River on the east coast of Baffin Island, which is several hundred miles west of Greenland. The lake sediment cores go back in time 80,000 years beyond the oldest reliable ice cores from Greenland and capture the environmental conditions of two previous ice ages and three interglacial periods.

The sediment cores showed that several types of mosquito-like midges that flourish in very cold climates have been abundant at the lake for the past several thousand years. But the cold-adapted midge species abruptly began declining in about 1950, matching their lowest abundances of the last 200,000 years. Two of the midge species adapted to the coldest temperatures have completely disappeared from the lake region, said Axford.

In addition, a species of diatom, a lake algae that was relatively rare at the site before the 20th century, has undergone unprecedented increases in recent decades, possibly in response to declining ice cover on the Baffin Island lake.

"Our results show that the human footprint is overpowering long-standing natural processes even in remote Arctic regions," said co-author John Smol of Queen's University. "This historical record shows that we are dramatically affecting the ecosystems on which we depend."

The ancient lake sediment cores are the oldest ever recovered from glaciated parts of Canada or Greenland. Massive ice sheets during ice ages generally scour the underlying bedrock and remove previous sediments.

"What is unique about these sediment cores is that even though glaciers covered this lake, for various reasons they did not erode it," said study co-author Jason Briner of the University at Buffalo. The result is that we have a really long sequence of sediment that has survived Arctic glaciations."

Axford emphasized the multiyear research project required expertise from each of the five institutions involved in the PNAS study. "This was a team effort all the way around, and each of the institutions has a unique set of skills that allowed us to carry out this study," she said. "We needed people who understood algae, insects, glaciers and geochemistry, not to mention how to drive snowmobiles and extract the cores."

The study was funded by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada and the Geological Society of America.

A study published in Science magazine last month that involved CU-Boulder researchers and reconstructed past temperatures in the Arctic using ice cores, tree rings and lake sediments concluded that recent warming around the Arctic is overriding a cooling trend caused by Earth's periodic wobble. Earth is now about 0.6 million miles further from the sun during the Northern Hemisphere summer solstice than it was in 1 B.C. -- a trend that has caused overall cooling in the Arctic until recently.

INSTAAR researcher and CU-Boulder geological sciences Professor Gifford Miller was a co-author on both the PNAS study and the recent Science study.

Contacts:

Yarrow Axford, 303-492-7641
Gifford Miller, 303-492-6962
Jim Scott, 303-492-3114

NEWS SOURCE: CU-Boulder News Center