Remote Sensing

High school students explore remote sensing at the Mountain Research Station

Anonymous — Tue, 13 Aug 2019 06:00:00 +0000

High school students explore remote sensing at the Mountain Research Station Anonymous (not verified) Tue, 08/13/2019 - 00:00

Jeff Zehnder

Tomoko Matsuo leading a discussion about infrared, visible, and ultraviolet light.

Science, engineering and nature are coming together for Colorado high school students at a unique summer camp.

The 2019 CU Science Discovery Mountain Research Experience, a weeklong sleepaway camp program held at the University of Colorado Boulder Mountain Research Station, north of Nederland, is a chance for kids to learn about the possibilities of scientific research outside the traditional school setting.

Remote sensing is the science of investigating aspects of the environment from a distance, typically using instruments aboard aircraft or satellites. It often involves monitoring conditions not visible to the naked eye. That is where the camp project comes in. Working from the Mountain Research Station’s Megaron Cabin, a one-room log cabin that is simultaneously rustic and technology-rich, the students are building special digital cameras to explore the world in visible, infrared and ultraviolet light.

Hands On Learning

“They’re going to learn a little about microcontrollers, programming, working in the terminal and how things look outside the visible light spectrum,” said Tomoko Matsuo, who is leading the day’s lesson.

Two students taking a selfie with their camera.

Matsuo is an assistant professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences at CU Boulder whose research is in remote sensing.

“We want to give them an appreciation of the science and technology and the hands-on work that you can do. We also want them to know that anyone has the capability to do this,” said Nick Dietrich, an aerospace PhD student, one of several undergraduate and graduate students advised by Matsuo assisting with the camp for the day.

While the high schoolers are there to learn and have fun, Matsuo has brought her college students to help them sharpen their skills as educators.

“I want them to have experience interacting with high school students,” Matsuo said. “I want them to be able to explain things. If you understand the material really well, you should be able to explain it to others in simple terms.”

Investigating flowers in ultraviolet light with PhD student Clayton Cantrall.

Inside and Out

After a brief lesson on remote sensing, the students assembled their cameras - comprised of ultra-tiny handheld Raspberry Pi Linux computers, batteries, a camera lens, and additional filters for UV and infrared light. They then set out to explore a series of stations around the cabin and surrounding alpine forest to see how things appear using the different filters.

“Part of the fun is just troubleshooting,” said Valerie Svaldi, a Colorado School of Mines metallurgical engineering senior who is completing a summer research program with Matsuo. “We want the kids to do as much problem-solving as possible when something goes wrong or isn’t working -- that's part of engineering.”

Inside the cabin, the students snap photos of objects ranging from sunscreen to dollar bills in UV and infrared. Once outdoors, they explore the appearance of flowers, other plants and minerals. There are many things in nature that glow in ultraviolet light, including some insects and arachnids - scorpions are likely the best known, although the Mountain Research Station is at a high enough elevation they are thankfully not much of a worry.

The day’s program was just one part of a weeklong experience for the high school students, who spent time each day with an array of scientists and researchers to learn more about what they do.

Matsuo working with two high school students.

“�鶹��Ժ get reasonable exposure to science in their high school classes, but it’s limited to science in a laboratory,” said Alexandra Rose, CU Science Discovery’s Broader Impacts Liaison and Institute of Arctic and Alpine Research Ecologist. “There is very little outdoor work. This camp is about exposing them to as many different ways of doing science out-of-doors as possible.”

For Kara Jansen, a rising senior at Peak to Peak Charter School in Lafayette, it was an exciting summer experience.

“I want to be outside and connecting with people who have the same passions for nature and environmental biology that I do,” Jensen said. “I wanted to be part of a group that wasn't just playing video games all summer.”

Science, engineering and nature are coming together for Colorado high school students at a unique summer camp. The 2019 CU Science Discovery Mountain Research Experience, a weeklong sleepaway camp program is a chance for kids to learn about the possibilities of scientific...

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Observations Show Gravity Waves Above Antarctica Dance in Winter

Anonymous — Tue, 05 Feb 2019 16:40:48 +0000

Observations Show Gravity Waves Above Antarctica Dance in Winter Anonymous (not verified) Tue, 02/05/2019 - 09:40

New research by Xinzhao Chu, a professor of Smead Aerospace and the Cooperative Institute for Research in Environmental Sciences, and her team shows gravity waves above Antarctica exhibit seasonal patterns that peak in winter, which could help researchers trace the source of the mysterious phenomenon.

Gravity waves are enormous vertical oscillations of air that propagate through the atmosphere like ripples in quiet water, and they are perpetually present in the Antarctic atmosphere.

Because these waves can create air turbulence and affect weather and climate by transporting energy and momentum between atmospheric layers, researchers have diligently searched for their sources.

Any gravity wave source must be constrained by wave properties observed in the atmospheric layers between 50 and 115 kilometers above Earth’s surface, where persistent gravity waves were first documented, and in the underlying stratosphere, where gravity waves have not yet been rigorously characterized.

To help fill this gap, Chu et al. report the results of a detailed statistical analysis of gravity wave characteristics in the stratosphere. Their data, which span from 2011 to 2015, are derived from the first multiyear, year-round measurements of temperature fluctuations made using an iron Boltzmann lidar system at the Arrival Heights observatory near Antarctica’s McMurdo Station. Read the full story at Earth & Space Science News.

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The Buffs Who Summer in Antarctica

Anonymous — Fri, 07 Dec 2018 19:56:15 +0000

The Buffs Who Summer in Antarctica Anonymous (not verified) Fri, 12/07/2018 - 12:56

Antarctica is one of Earth’s most forbidding places. That’s why CU researchers keep going back.

Ian Geraghty (AeroEngr’18) spent his first season in Antarctica in 2017. Now a research assistant at CU, he’s part of an engineering team using laser equipment to study the mysteries of Earth’s atmosphere, including persistent gravity waves that could influence air circulation and weather patterns worldwide.

To obtain the most precise measurements, the delicate setup must be operated by hand around the clock, he said. This would be a true feat in Boulder, let alone at the ends of the earth. Geraghty and a colleague work in shifts, squeezing themselves into narrow alleys between banks of machinery filling an entire shack.

"It’s good to bring spare parts,” he said. “Because you can’t just go to the hardware store.”

Geraghty marvels over the many quirks of life at McMurdo. Hiking trails abound with curious penguins, and the night sky dazzles with aurora. Communication with the outside world is limited, and internet bandwidth is late ’90s-era slow. The accommodations are akin to army barracks or college dorms, with bunk beds and shared bathrooms down the hall

Researchers invariably lament the scarcity of fresh produce. When fruit and vegetables arrive by plane — infrequently, given weather patterns — it’s instantly the talk of camp.

But the rest of the menu is surprisingly good: Contractors in the restaurant-quality mess hall prepare impressive rotating fare such as Mongolian barbecue, Italian pasta and burgers. (The late celebrity chef Anthony Bourdain paid a visit in 2017.)

Much like summer camps elsewhere, there is a certain unshakable camaraderie among the 500 or so people who return to populate McMurdo every year.

“It’s funny because you’ll hear someone say they’re not coming back, and then you’ll see them next year, as usual,” says Xinzhao Chu, a professor and researcher at CU’s Cooperative Institute for Research in Environmental Sciences (CIRES). She has led the atmospheric laser project since 2010 and has been traveling to Antarctica since 1999.

Chu marvels at her students’ willingness to travel so far and endure so much in the name of research that can only be accomplished in polar conditions.

“Everything that they are doing contributes to getting a bigger picture of the makings of the atmosphere,” she said.

Standing at the base of an Antarctic glacier in 2016, Pacifica Sommers watched the transport helicopter fly away, leaving her and a few fellow CU biologists all alone in one of the coldest and most remote places on Earth.

“You do sort of realize at that point that a rescue wouldn’t be cheap or easy,” the postdoctoral researcher said.

It was quite a change of scenery for Sommers, who had completed her doctoral studies in the Arizona desert. She remembers standing sideways next to a Saguaro cactus to make use of its narrow band of shade in 100-plus-degree heat.

Now, she was strapping on crampons and setting up camp in the McMurdo Dry Valleys, the only area of Antarctica that isn’t permanently covered by snow. The dark, exposed soil on the hillsides resembles Colorado’s alpine landscapes: beautiful, rugged, desolate.

But while the world’s coldest, windiest, driest continent may appear hostile to life, Sommers knows it’s quite the opposite. Small pockets in the surface known as cryoconite holes teem with microorganisms, all of which have adapted to survive an extreme environment. These naturally occurring test tubes could help scientists better understand evolutionary selection on Earth and even life on other planets.

“Ecosystems depend on historical contingency and randomness,” Sommers said. “We want to study how chance affects what biological communities look like and how they assemble.”

Antarctica’s 5.4 million square miles make for a pristine, if imposing, natural laboratory: All but 2 percent of the surface is covered in thick ice. The vast continent, nearly one and a half times the size of the contiguous U.S., has little in the way of commerce, government or human habitation. At the summer peak, in January, around 5,000 scientists and contractors occupy a handful of international stations near the coasts. In winter, when temperatures reach 50 degrees below zero, that population drops to roughly 1,000.

The thrill of scientific discovery in a place most people will never visit is matched by its challenges. The months-long work is grueling, the isolation is daunting and the days are long — literally, since the polar summer months bring near-constant sunshine. And yes, it’s pretty cold.

In Sommers’ first season on the ice, she wasn’t sure what to expect and admits she might have overpacked. By year two, she was a seasoned pro reveling in the occasionally balmy December weather.

“It can get up to 30 degrees or so,” she said. “We took our shoes off and played frisbee.”

CU researchers usually begin arriving in November. Their first stop after a six-hour military aircraft flight from Christchurch, New Zealand, is McMurdo Station, the continent’s population hub, known colloquially as “town.” Year after year, this international outpost becomes a temporary home away from home.

Engineering professor Michael Gooseff (CivEng’98) is another Antarctic long-timer. He’s been making the trip annually for over two decades, first as a CU graduate student, now as principal investigator of the National Science Foundation’s Long-Term Ecological Research (LTER) project, which studies the unique Dry Valleys ecosystem.

“Every time I go in the Valleys, it feels like a place where no one has been before,” Gooseff says. “There’s an obvious Martian analogue here. You fly over and see no sign of life, but on the ground and in the streams and lakes, you see beautiful microbial mats filled with color.”

Gooseff lauds CU’s commitment to Antarctic studies and cites scientific operations on the continent broadly as a model of international collaboration. New Zealand, China, Italy and South Korea all have stations within an hour of McMurdo by helicopter, and it’s not uncommon for the scientists of several nations to help each other out — a kind of United Nations on ice.

“I think we all realize that it takes a lot of investment to work down here,” Gooseff said. “That raises the requirement on us to produce as much quality research as we can and get the results out there to the public in a relatable way.”

This year, Geraghty is headed back for another tour of duty. Except this time, when the last summer transport leaves in February, he won’t be on it. He and graduate student Zimu Li, will stay at McMurdo through October 2019 with a skeleton crew to manage the laser equipment in winter’s pervasive darkness.

“It’s a lot of responsibility,” he said. “But it feels good to work really hard and contribute to a big project with some of the most interesting people I’ve ever met.”

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Uneven Rates of Sea Level Rise Tied to Climate Change

Anonymous — Tue, 04 Dec 2018 16:52:10 +0000

Uneven Rates of Sea Level Rise Tied to Climate Change Anonymous (not verified) Tue, 12/04/2018 - 09:52

The pattern of uneven sea level rise over the last quarter century has been driven in part by human-caused climate change, not just natural variability, according to a new study.

The findings suggest that regions of the world where seas have risen at higher than average rates — including the Eastern Seaboard of the United States and the Gulf of Mexico — can expect the trend to continue as the climate warms.

The study, published today in the Proceedings of the National Academy of Sciences, was authored by scientists John Fasullo at the National Center for Atmospheric Research (NCAR) and Steve Nerem at the University of Colorado Boulder.

“By knowing that climate change is playing a role in creating these regional patterns, we can be more confident that these same patterns may linger or even intensify in the future if climate change continues unabated,” Fasullo said. “With sea levels projected to rise a couple of feet or more this century on average, information about expected regional differences could be critical for coastal communities as they prepare.”

The research was funded by the National Science Foundation, which is NCAR's sponsor, the NASA Sea Level Change Team, and the U.S. Department of Energy.

Finding the signal of climate change

For the study, Fasullo and Nerem, both members of the NASA Sea Level Change Team, analyzed the satellite altimetry sea level record, which includes measurements of sea surface heights stretching back to 1993. They mapped global average sea level rise as well as how particular regions deviated from the average.

For example, the oceans surrounding Antarctica and the U.S. West Coast have had lower-than-average sea level rise, while the U.S. East Coast and Southeast Asia, including the Philippines and Indonesia, have experienced the opposite. In some parts of the world, the rate of local sea level rise has been as much as twice the average.

Regional differences in sea level rise are influenced by where heat is stored in the ocean (since warm water expands to fill more space than cold water) and how that heat is transported around the globe by currents and wind. Uneven sea level rise is also influenced by ice sheets, which lose mass as they melt and shift the gravitational forces affecting regional sea surface height.

Regional sea level trends in millimeters per year from 1993 through mid-2018 with the global average rate removed. Red colors indicate that the local rate of sea level rise was greater than average, and blue colors indicate the opposite. (Image: PNAS)

Natural shifts in ocean cycles — including the Pacific Decadal Oscillation, a pattern of sea surface temperatures similar to El Niño but longer lasting — are therefore known to affect sea levels. So scientists were not surprised to find that as the ocean rises, it rises unevenly. But it's been difficult to say whether these natural cycles were the dominant influence on regional differences

To investigate the role of climate change, the scientists turned to two sets of climate model runs, known as “large ensembles”: one created using the NCAR-based Community Earth System Model and one created using the Earth System Model at the National Oceanic and Atmospheric Administration. These large ensembles — many model simulations by the same model, describing the same time period — allow researchers to disentangle natural variability from the impacts of climate change. With enough runs, these impacts can be isolated even when they are relatively small compared to the impacts from natural variability.

The climate models suggest that in regions that have seen more or less sea level rise than average, as much as half of that variation may be attributed to climate change. The scientists also found that the impacts from climate change on regional sea level rise sometimes mimic the impacts from natural cycles.

"It turns out the sea level rise response to climate change in the Pacific resembles what happens during a particular phase of the Pacific Decadal Oscillation," Fasullo said. "This explains why it's been so difficult to determine how much of the pattern was natural or not, until now."

Improving forecasts

The research findings have implications for local officials, who are interested in improved forecasts of sea level rise for the areas they oversee. In the past, forecasters have had to rely on the global rate of change — about 3 millimeters a year and accelerating — and knowledge of the uneven regional impacts associated with continued melting of the ice sheets covering Greenland and Antarctica.

The findings add the possibility that the regional patterns of sea level rise tied to climate change can also be included, because the models predict that the regional patterns observed in the satellite measurements will continue into the future.

"We now have a new tool — long-term satellite altimeter measurements — that we can use to help stakeholders who need information for specific locations," said Nerem, a fellow of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder and a professor of aerospace engineering.

About the article

Title: Altimeter-Era Emergence of the Patterns of Forced Sea Level Rise in Climate Models and Implications for the Future

Authors: John T. Fasullo and R. Steven Nerem

Journal: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1813233115

About UCAR/NCAR: The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation.

CIRES is a partnership of NOAA and CU Boulder.

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Recruiting PhD students for world-class LIDAR team

Anonymous — Wed, 02 May 2018 17:11:20 +0000

Recruiting PhD students for world-class LIDAR team Anonymous (not verified) Wed, 05/02/2018 - 11:11

CIRES’ Chu research group poses with CU Boulder emblems during LIDAR deployment in Antarctica.

For more information, contact
Xinzhao Chu
Professor, Smead Aerospace Engineering Sciences
CU Boulder

Download recruiting flyer

University of Colorado Boulder Smead Aerospace professor Xinzhao Chu is seeking PhD students to join her LIDAR research team at the Cooperative Institute for Research in Environmental Sciences (CIRES).

CU Boulder is home to a vibrant community of scientists and engineers and houses some of the world’s most renowned environmental science institutes and facilities.

Scientists at CIRES explore advanced spectroscopy principles, develop new LIDAR technologies, study the fundamental physical and chemical processes that govern the whole atmosphere, and make new discoveries in the atmosphere-space sciences.

CIRES is recruiting PhD students in:

laser spectroscopy, optics and photonics
atmospheric and space physics
electrical and aerospace engineering

Current research projects:

exploration of space-atmosphere interactions with LIDAR in Antarctica
Na and Fe Doppler LIDAR observations of the mid-latitude atmosphere
collaborative research of LIDAR with rocket at Wallops Island
measurements of new metal species in space with laser spectroscopy

Chu has led several teams to Antarctica, including during the current 2017-2018 academic year, when her group successfully installed a new Na Doppler LIDAR to collocate with an Fe Boltzmann LIDAR at the Arrival Heights Lidar Observatory near McMurdo, Antarctica.

Simultaneous Na and Fe LIDAR observations have been made since mid-January 2018. The Fe Boltzmann LIDAR was deployed during a previous trip she led in 2010 with students Zhibin Yu, John A. Smith, and Weichun Fong.

Yu subsequently became the first winter-over LIDAR student at McMurdo, and he also became the first grantee to winter-over in Antarctica in 23 years.

Including Yu, the McMurdo LIDAR campaign has now featured eight CU Boulder aerospace graduate students who have wintered-over Antarctica and collected tons of invaluable data.

Both LIDAR projects were funded by the National Science Foundation through the the United States Antarctic Programs (USAP), but are housed in the Antarctica New Zealand (AntNZ) building at Arrival Heights. The CU LIDAR team received support from both McMurdo Station (run by USAP) and Scott Base (run by AntNZ).

Chu and a team of International scientists at the Arrival Heights Observatory in Antarctica

Many new science discoveries and breakthroughs have resulted from the data, opening a new door to observe and understand the Earth’s space-atmosphere interaction region.

So far, the McMurdo LIDAR projects have led to four PhD degrees: Zhibin Yu, John A. Smith, Weichun Fong, and Cao Chen, and two MS degrees: Brendan Roberts and Ian Barry.

Furthermore, Cao Chen, Zhibin Yu, and Weichun Fong earned first place prizes in 2012, 2013, and 2015, respectively, in the students' poster competitions at the CEDAR workshop hosted by the National Science Foundation (NSF).

A new era of LIDAR observations has just begun, and the CU Boulder LIDAR team members and their collaborators are working hard to collect simultaneous Na and Fe LIDAR data and make new discoveries via data analysis and numerical modeling.

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Shoebox-sized cube satellite to study Earth's inner radiation belt

Anonymous — Wed, 14 Mar 2018 21:00:09 +0000

Shoebox-sized cube satellite to study Earth's inner radiation belt Anonymous (not verified) Wed, 03/14/2018 - 15:00

A NASA-funded cube satellite built and operated by CU Boulder researchers will study the inner radiation belt of Earth’s magnetosphere, providing new insight into the energetic particles that can disrupt satellites and threaten spacewalking astronauts.

CU Boulder Professor Xinlin Li holds up a model of the CSSWE cube satellite that studied energetic particles in Earth's magnetosphere. The new CIRBE cube satellite will build on the success of the CSSWE. Photo: LASP

The $4 million Cubesat: Inner Radiation Belt Experiment (CIRBE) mission, tentatively slated for a 2021 launch, will provide some of the first advanced resolution of one of Earth’s two Van Allen belts, a zone that traps energetic particles in the planet’s magnetic field. This powerful radiation, known to physicists since the late 1950s, poses a hazard to solar panels, electronic circuitry and other hardware aboard spacecraft traveling at and beyond a low Earth orbit.

“CIRBE will provide sophisticated, fine-grain measurements of this Van Allen belt like never before,” said principal investigator Professor Xinlin Li of the Laboratory for Atmospheric and Space Physics (LASP) and the Ann and H.J. Smead Department of Aerospace Engineering Sciences (AES). “We will study the distribution of these particles and how they become so energized.”

Cube satellites are breadbox-sized satellites that can be built economically in order to achieve specific scientific objectives. CU Boulder students (including undergraduates) have worked on several successful cube satellite missions in recent years, and the campus currently has more than eight cube satellite projects in operation or in development across its various departments and research institutes.

“CU Boulder is clearly recognized as a world leader in cube satellite technology,” said Professor Scott Palo of AES, a co-investigator on the project. “We’ve seen tremendous growth over the past five or six years. Industry partners and science organizations see a huge value in these small satellites.”

CIRBE is poised to build on the success of the Colorado Student Space Weather Experiment (CSSWE), a cube satellite that launched in 2012 to study the Van Allen belt and operated for over two years. CSSWE’s data resulted in over 21 peer-reviewed publications in major scientific journals, including Nature. The mission also helped solve a longstanding astronomical mystery.

In the years since CSSWE’s launch, the researchers have further improved their ground station, which is located on the roof of the LASP building on CU Boulder’s campus. By the time CIRBE launches, the station will be able to collect data 100 times faster than before.

The CIRBE mission will include collaborations with Colorado’s aerospace industry, including Boulder-based Blue Canyon Technologies, which will manufacture the cube satellite’s bus system. The overall system design, science instrument development, integration, test, mission operation, data analysis and modeling will be done at CU by LASP and AES faculty, engineers and graduate students. The project also features a partnership with the Air Force Research Laboratory and NASA's Goddard Spaceflight Center.

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Sea Level Rise Accelerating

Anonymous — Tue, 13 Feb 2018 18:28:13 +0000

Sea Level Rise Accelerating Anonymous (not verified) Tue, 02/13/2018 - 11:28

A research team led by aerospace professor Steve Nerem detects an acceleration in the 25-year satellite sea level record.

Global sea level rise is not cruising along at a steady 3 mm per year, it’s accelerating a little every year, like a driver merging onto a highway, according to a powerful new assessment led by CIRES Fellow Steve Nerem. He and his colleagues harnessed 25 years of satellite data to calculate that the rate is increasing by about 0.08 mm/year every year—which could mean an annual rate of sea level rise of 10 mm/year, or even more, by 2100.

“This acceleration, driven mainly by accelerated melting in Greenland and Antarctica, has the potential to double the total sea level rise by 2100 as compared to projections that assume a constant rate—to more than 60 cm instead of about 30.” said Nerem, who is also a professor of Aerospace Engineering Sciences at the University of Colorado Boulder. "And this is almost certainly a conservative estimate," he added. "Our extrapolation assumes that sea level continues to change in the future as it has over the last 25 years. Given the large changes we are seeing in the ice sheets today, that's not likely."

If the oceans continue to change at this pace, sea level will rise 65cm (26 inches) by 2100—enough to cause significant problems for coastal cities, according to the new assessment by Nerem and several colleagues from CU Boulder, the University of South Florida, NASA Goddard Space Flight Center, Old Dominion University, and the National Center for Atmospheric Research. The team, driven to understand and better predict Earth’s response to a warming world, published their work today in the journal Proceedings of the National Academy of Sciences.

Rising concentrations of greenhouse gases in Earth’s atmosphere increase the temperature of air and water, which causes sea level to rise in two ways. First, warmer water expands, and this "thermal expansion" of the oceans has contributed about half of the 7 cm of global mean sea level rise we've seen over the last 25 years, Nerem said. Second, melting land ice flows into the ocean, also increasing sea level across the globe.

These increases were measured using satellite altimeter measurements since 1992, including the U.S./European TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3 satellite missions. But detecting acceleration is challenging, even in such a long record. Episodes like volcanic eruptions can create variability: the eruption of Mount Pinatubo in 1991 decreased global mean sea level just before the Topex/Poseidon satellite launch, for example. In addition, global sea level can fluctuate due to climate patterns such as El Niños and La Niñas (the opposing phases of the El Niño Southern Oscillation, or ENSO) which influence ocean temperature and global precipitation patterns.

So Nerem and his team used climate models to account for the volcanic effects and other datasets to determine the ENSO effects, ultimately uncovering the underlying sea-level rate and acceleration over the last quarter century. They also used data from the GRACE satellite gravity mission to determine that the acceleration is largely being driven by melting ice in Greenland and Antarctica.

The team also used tide gauge data to assess potential errors in the altimeter estimate. “The tide gauge measurements are essential for determining the uncertainty in the GMSL (global mean sea level) acceleration estimate,” said co-author Gary Mitchum, USF College of Marine Science. “They provide the only assessments of the satellite instruments from the ground.” Others have used tide gauge data to measure GMSL acceleration, but scientists have struggled to pull out other important details from tide-gauge data, such as changes in the last couple of decades due to more active ice sheet melt.

“This study highlights the important role that can be played by satellite records in validating climate model projections,” said co-author John Fasullo, a climate scientist at the National Center for Atmospheric Research. “It also demonstrates the importance of climate models in interpreting satellite records, such as in our work where they allow us to estimate the background effects of the 1991 eruption of Mount Pinatubo on global sea level.”

Although this research is impactful, the authors consider their findings to be just a first step. The 25-year record is just long enough to provide an initial detection of acceleration—the results will become more robust as the Jason-3 and subsequent altimetry satellites lengthen the time series.

Ultimately, the research is important because it provides a data-driven assessment of how sea level has been changing, and this assessment largely agrees with projections using independent methods. Future research will focus on refining the results in this study with longer time series, and extending the results to regional sea level, so they can better predict what will happen in your backyard.

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Larson awarded honorary doctorate for groundbreaking GPS research

Anonymous — Fri, 17 Feb 2017 17:07:44 +0000

Larson awarded honorary doctorate for groundbreaking GPS research Anonymous (not verified) Fri, 02/17/2017 - 10:07

Congratulations to CU Boulder aerospace professor Kristine Larson for being awarded an honorary doctorate from the Chalmers University of Technology!

Located in Gothenburg, Sweden, Chalmers is known for its engineering education and research programs. Larson is receiving the doctorate in recognition of her groundbreaking research using GPS signals to measure soil moisture, snow depth, vegetation, and sea level. Her work has contributed to improved hydrological studies, weather forecasting, climate models, and sea level rise estimates.

Larson served as a visiting professor at Chalmers in 2010-2011 and maintains an ongoing collaboration with researchers there. She has been an aerospace faculty member at CU Boulder since 1990.

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Knipp: Global Positioning System Sparks New Data Revolution

Anonymous — Thu, 02 Feb 2017 18:57:46 +0000

Knipp: Global Positioning System Sparks New Data Revolution Anonymous (not verified) Thu, 02/02/2017 - 11:57

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Researchers dial in to 'thermostat' in Earth’s upper atmosphere

Anonymous — Fri, 16 Dec 2016 17:14:15 +0000

Researchers dial in to 'thermostat' in Earth’s upper atmosphere Anonymous (not verified) Fri, 12/16/2016 - 10:14

A team led by CU Boulder has found the mechanism behind the sudden onset of a “natural thermostat” in Earth’s upper atmosphere that dramatically cools the air after it has been heated by violent solar activity.

Scientists have known that solar flares and coronal mass ejections (CMEs) – which release electrically charged plasma from the sun – can damage satellites, cause power outages on Earth and disrupt GPS service. CMEs are powerful enough to send billions of tons of solar particles screaming toward Earth at more than 1 million miles per hour, said CU Boulder Professor Delores Knipp of the Department of Aerospace Engineering Sciences.

Now, Knipp and her team have determined that when such powerful CMEs come off the sun and speed toward Earth, they create shock waves much like supersonic aircraft create sonic booms. While the shock waves from CMEs pour energy into Earth’s upper atmosphere, puffing it up and heating it, they also cause the formation of the trace chemical nitric oxide, which then rapidly cools and shrinks it, she said.

“What’s new is that we have determined the circumstances under which the upper atmosphere goes into this almost overcooling mode following significant heating,” said Knipp, also a member of CU Boulder’s Colorado Center for Astrodynamics Research. “It’s a bit like having a stuck thermostat – it’s really a case of nature reining itself in.”

Knipp gave a presentation at the 2016 fall meeting of the American Geophysical Union being held in San Francisco Dec. 12-16. The presentation was tied to an upcoming paper that is slated to be published in the journal Space Weather.

Solar storms can cause dramatic change in the temperatures of the upper atmosphere, including the ionosphere, which ranges from about 30 miles in altitude to about 600 miles high – the edge of space. While CME material slamming into Earth’s atmosphere can cause temperature spikes of up to 750 degrees Fahrenheit, the nitric oxide created by the energy infusion can subsequently cool it by about 930 F, said Knipp.

The key to solving the mystery came when Knipp was reviewing satellite data from a severe solar storm that pounded Earth in 1967. “I found a graphic buried deep in a long forgotten manuscript,” she said. “It finally suggested to me what was really happening.”

Because the upper atmosphere expands during CMEs, satellites in low-Earth orbit are forced to move through additional gaseous particles, causing them to experience more drag. Satellite drag – a huge concern of government and aerospace companies – causes decays in the orbits of spacecraft, which subsequently burn up in the atmosphere.

As part of the new study, Knipp and her colleagues compared two 15-year-long satellite datasets. One was from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument riding on NASA’s TIMED satellite. The other was from data collected by U.S. Department of Defense satellites.

“We found that the fastest material streaming off the sun was triggering these shockwaves, causing the atmosphere to heave up and heat up,” she said. “But it became very clear that these shock waves were at the root of creating the nitric oxide, which caused the atmosphere to shed energy and cool.”

SABER has been collecting data on nitric oxide in the atmosphere since its launch in 2001, following on the heels of another nitric oxide-measuring satellite known as the Student Nitric Oxide Explorer (SNOE). Launched in 1998, SNOE involved more than 100 CU Boulder students, primarily undergraduates, in its design and construction. Once in orbit, SNOE was controlled by students on campus 24 hours a day for nearly six years.

Geomagnetic storms have had severe impacts on Earth. A 1989 storm caused by a CME resulted in the collapse of the Hydro-Quebec’s electricity transmission system, causing six million Canadians to lose power. In 1859 a solar storm called the Carrington Event produced auroras from the North Pole to Central America and disrupted telegraph communications, even sparking fires at telegraph offices that caused several deaths.

In addition to Knipp, CU Boulder graduate students Dan Pette and Alfredo Cruz participated in the research, as did undergraduate Tristan Isaacs through CU Boulder’s Research Experience for Undergraduates (REU) program.

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