New cause of exceptional Greenland melt revealed

A new study by researchers from Denmark and York University, published in Geophysical Research Letters, has found that the climate models commonly used to simulate melting of the Greenland ice sheet tend to underestimate the impact of exceptionally warm weather episodes on the ice sheet.

Researchers service one of PROMICE’s automatic weather stations on the Greenland ice sheet that was used in the study. Photo by William Colgan, York University

The study investigated the causes of ice melt during two exceptional melt episodes in 2012, which occurred from July 8 to 11 and from July 27 to 28. During these exceptional melt episodes, which can be regarded as an analogue to future climate, unusually warm and moist air was transported onto the ice sheet. During one episode, the researchers measured the ice sheet melting at more than 28 cm per day, the largest daily melt rate ever documented on the ice sheet. While the two brief melt episodes only lasted six days combined, or six per cent of the melt season, they contributed to 14 per cent of the total melt.

Using the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) automatic weather station data, the researchers ranked the energy sources contributing to surface melt during 2012 at twelve PROMICE sites around the ice sheet periphery. While ice sheet melt is usually dominated by the radiant energy associated with sunlight, the researchers found that the energy associated with air temperature and moisture content, rather than radiant energy, was responsible for more melt during the 2012 exceptional melt episodes.

As Robert Fausto of the Geological Survey of Denmark and Greenland, lead author of the study, says, “When we were analyzing our weather station data, we were quite surprised, that the exceptional melt rates we observed were primarily caused by warm and moist air, because ice sheet wide melt is usually dominated by radiant energy from sunlight. “

This finding has implications for how the scientific community projects future ice sheet melt using climate models. In the study, the researchers also show that while the models presently used to project ice sheet melt can accurately simulate melt due to radiant energy, models tend to systematically underestimate melt due to the non-radiant energy processes they document.

“Glaciological instrumentation capable of automatically recording the daily rate of melting in exceptional melt circumstances, where the ice surface lowers by close to 10 m in a few months, has only emerged in the last decade or so, thanks to PROMICE. The detail of PROMICE observations is permitting new insights on brief, but consequential, exceptional melt events,” says William Colgan of the Lassonde School of Engineering at York University, a co-author of the study.

Fausto adds that, “Exceptional melt episodes dominated by non-radiant energy are expected to occur more frequently in the future due to climate change. This makes it critical to better understand the influence of these episodes on ice sheet health.”

William Coglan

Lassonde ESSE alumna contributes to detection of Gravity Waves

Lassonde alumna Dr. Susan McCall’s work played a significant role in the process behind the detection of gravitational waves by Laser Interferometer Gravitational-Wave Observatory (LIGO). This detection, announced last week, was touted as one of the most important scientific discoveries of our time, cementing Albert Einstein’s general theory of relativity and ushering in a new era in science.

Gravitational waves are ripples in the fabric of time and space and are produced by massive objects such as stars and planets.

Dr. Susan McCall received her M.Sc. and Ph.D. from the department of Earth and Space Science and Engineering at York University in 1992 under the supervision of Professor Gordon Shepherd.

Dr. Susan McCall received both her M.Sc. and Ph.D. from York University

Currently, Dr. Susan McCall is the founder and president of Stellar Optics Research International Corporation and a specialist in optical black surfaces/materials and optical scatter data. She also recently founded the York University Science Alumni Network.

Dr. McCall was contracted by Breault Research Organization to provide a list of candidates, glossy black materials and coatings for long-term, vacuum compatible use in the LIGO chambers while meeting the challenging optical scatter requirements of having Bidirectional Reflectance Distribution Function (BRDF) scatter values of less than 0.001, at large backscatter angles, for 0.6328 micrometers.

In addition to these challenging optical requirements, the materials had to be of reasonable cost and easy to install, given that there were to be 100 to 200 panels as large as 12 cm by 383 cm. Dr. McCall provided these samples for the Breault Research Organization and LIGO, thus contributing to the detection of gravity waves.

“The experience I gained from studying black surfaces for extreme environments, York U’s emphasis on multidisciplinary research, my brilliant mentors Dr. Gordon Shepherd, Dr. Robert Breault, and Dr. J. A. Dobrowolki were the essential keys that paved the way for SORIC’s products, contracts and sales with major companies, space agencies, and astronomical observatories around the world,” said Dr. Susan McCall about her time studying at York University.

Lassonde research team selected by NASA to provide support to the Curiosity mission

Lassonde Professor John Moores and his research team have been selected by NASA to provide scientific and operations support to the Mars Science Laboratory Mission (Curiosity).

The team is comprised of Moores, MSc student Jake Kloos, Postdoctoral Fellow Christina Smith and PhD Student Casey Moore.

From left, Jake Kloos, Professor John Moores, Christina Smith and pictured in front is Casey Moore

The Lassonde team will be part of the mission through 2020 as they help plan out what the $2.5 billion Rover will do each day.

“We’ve been amazed by everything the rover has sent back, but the whole of our team here at Lassonde is looking forward to where Curiosity takes us over the next four years. Who knows what discoveries are still out there over the next ridge line, just waiting to be made,” said Moores.

A total of 28 proposals were selected out of nearly 100 submitted proposals from researchers around the world.

Curiosity is a car-sized robotic rover exploring Gale Crater on Mars as part of NASA’s Mars Science Laboratory mission. As of February 16, 2016, Curiosity has been on Mars for 1255 sols (1289 total days) since landing on August 6, 2012. Self-portrait of Curiosity located at the foothill of Mount Sharp (October 6, 2015). Image: NASA

“It’s amazing to be a part of the MSL team and to see your work realized on such a large project. I can’t describe the feeling of hearing that your contributions are ‘Go’ to run on Mars!” said Smith.In addition to their work with Spacecraft Operations where they represent environmental science in many of the daily planning sessions, the team also makes videos of the movement of clouds and looks at the motion of dust within the Gale crater.The research team has put out five papers on this topic recently, two of which were helmed by the graduate students.

Detection of gravitational waves, and one of our graduates!

What are some of our ESSE graduates doing now? Dr. Susan McCall, an ESSE alumni has done work useful to LIGO, which has recently been in the news for the detection of gravitational waves.

Stellar Optics Research International Coporation’s (SORIC) Founder and President, Dr. Susan McCall is a specialist in optical black surfaces/materials and optical scatter data. She was contracted by a USA Corporation to provide a list of candidate, glossy black materials and coatings for long-term, vacuum compatible use in the LIGO chambers while meeting the challenging optical scatter requirements of having Bidirectional Reflectance Distribution Function (BRDF) scatter values of less than 0.001, at large backscatter angles, for 0.6328 micrometers. In addition to these challenging optical requirements, the materials had to be of reasonable cost, and easy to install, given that there were to be 100 to 200 panels as large as 12cm by 383 cm. Dr. McCall, in her 1995 report, “Unconventional Baffle Materials for the LIGO Experiment”, used SORIC’s internal databank of black surfaces used in aerospace, defense, and astronomy, and selected nineteen practical suggestions encompassing glossy black: flexible films, fabrics and foils; solid glasses and a paint, and provided samples, all for the USA Corporation and LIGO to consider for further study, who then performed experiments for verification and final selection.

Sun dogs versus Rainbows

A Sun Dog captured in Bolton, featured on the Weather Network.

On Friday, our department’s own Dr. Lee witnessed a Sun Dog on her way to York, an atmospheric phenomenon that Dr. Klaassen explains,  “…they form about 22 degrees on either side of a bright sun, due to refraction by ice  crystals. If you are looking at a rainbow, the sun is behind you”.

IMG_3159_sml

A Sun Dog as photographed by ESSE’s Dr. Gary Klaassen.

 

York U researchers help create first map of Greenland ice sheet movement

York U researchers are among a team of scientists that has created the first map showing how the Greenland ice sheet has flowed over time, revealing that ice in the interior is now moving more slowly toward the edges than it has, on average, over the past 9,000 years.

Greenland’s ice sheet

In comparing this paleo-velocity map to modern flow rates, researchers from York University and The University of Texas, as well as other institutions, found the ice sheet’s interior to be moving slower now than it was during most of the Holocene, a geological period that began at the end of the last glacial period roughly 11,700 years ago and runs to the present.

The findings, which researchers said don’t change the fact that the ice sheet is now rapidly losing mass and contributing to sea level rise, was published in the Feb. 5, 2016 issue of the journal Science.

Along Greenland’s periphery, many glaciers are now rapidly thinning. However, the vast interior of Greenland, as it moves more slowly, has been gradually thickening over millennia. This new study documents and describes why this is happening.

“We found three reasons for this gradual slowing and thickening of the ice sheet in the Greenland’s interior,” said William Colgan of York University’s Lassonde School of Engineering, second author of the study.

An increase in snowfall over the last 9,000 years and a gradual stiffening of the ice sheet, are two reasons, he said.

“The ice that formed from snow that fell in Greenland during the last ice age is about three times softer than the ice being formed today,” said Colgan.

This is causing the ice sheet to slowly become stiffer and, as a consequence, flow slower and get thicker over time. This is especially the case in southern Greenland, where higher snowfall rates have led to rapid replacement of ice from the last glacial period with more modern Holocene ice.

“But that didn’t explain what was happening elsewhere in Greenland, particularly the northwest, where there isn’t as much snowfall,” said lead author Joe MacGregor of The University of Texas at Austin’s Institute for Geophysics (UTIG), a research unit of the Jackson School of Geosciences.

It’s the third reason that seems to have had the largest impact in northwest Greenland, said Colgan, citing the collapse of an ‘ice bridge’ that connected Greenland to Ellesmere Island at the end of the last ice age – some 10,000 years ago.

The collapse led first to acceleration in the northwest, but ice flow there has since decreased to a slower pace. These changes affect how the Greenland ice sheet is understood today.

Scientists often use GPS and altimeters aboard satellites to measure the elevation of the ice surface to estimate how much mass is being lost or gained across the ice sheet. But, when correcting for other known effects on the surface elevation, any leftover thickening is often assumed to be due to increasing snowfall. This study shows that that may not be the case.

“The recent increases in snowfall do not necessarily explain present day interior thickening,” said Colgan. “So if you’re using a satellite altimeter to figure out how much mass Greenland is losing, you’re going to get the answer slightly wrong, unless you account for these very long-term signals that are evident in its interior.”

The study builds on earlier UTIG-led research that developed a database of the many layers within Greenland’s ice sheet. Using this database, scientists determined the flow pattern for the past 9,000 years, in effect creating a “paleo-velocity” map.

“Scientists are very interested in understanding how ice sheets flow and how that flow may have been different in the past. Our paleo-velocity map for Greenland allows us to assess the flow of the ice sheet right now in the context of the last several thousand years,” said MacGregor.

The study was supported by the National Science Foundation’s Arctic Natural Sciences Program, the Center for Remote Sensing of Ice Sheets and NASA’s Operation IceBridge.

Colgan is also a guest researcher at the Geological Survey of Denmark and Greenland, where a portion of this research was undertaken.

Lassonde is home to Esri Canada GIS Centre of Excellence

Lassonde School is Engineering has been selected by Esri Canada as a GIS Centre of Excellence. The partnership with Esri Canada means that students will benefit through experiential learning using the ArcGIS platform and faculty will have the opportunity to conduct innovative research.

“The Centre will help our students develop valuable entrepreneurial skills and create new products and services for spatial data management and analysis. As well, it will promote teaching excellence and collaboration with the other GIS Centres of Excellence,” said Costas Armenakis, associate professor, Geomatics Engineering.

Costas Armenakis

The Centres will also provide access to scholarships, conferences and competitions for students.

To enhance further their GIS skills, students from member Centres can participate in an annual app development challenge that focuses on the use of open government data and Esri technology.

The addition of the University of New Brunswick and York University to our network will further strengthen the community of researchers using GIS to create innovative applications and solve problems.”
The addition of the University of New Brunswick and York University to our network will further strengthen the community of researchers using GIS to create innovative applications and solve problems.”
The addition of the University of New Brunswick and York University to our network will further strengthen the community of researchers using GIS to create innovative applications and solve problems.”
The addition of the University of New Brunswick and York University to our network will further strengthen the community of researchers using GIS to create innovative applications and solve problems.”
The addition of the University of New Brunswick and York University to our network will further strengthen the community of researchers using GIS to create innovative applications and solve problems.”

Launched in 2014, Esri Canada GIS Centres of Excellence in Higher Education are aimed at encouraging innovation in GIS research and promoting teaching excellence in spatial data management and analysis in higher education across Canada.

STEMinism: Lassonde 50:50 Gender Initiative recognized in Ontario Professional Magazine

The Lassonde School of Engineering at York University is Canada’s first engineering school to set a goal of 50:50 gender balance

“By twelve years old, most girls can’t do math.”
“If they study science, they will have to give-up arts or
sports.”
“High school physics is too hard for girls anyways.”
It is not uncommon to hear these statements from parents, teachers, friends, relatives, classmates and girls themselves. Possibly without realizing it, an unconscious bias has been established in Canadian society dissuading girls from the fields of math and science. It’s no wonder that so few girls and women become engineers. In 2015, women held only 12 per cent of licenses to work in the engineering profession across Canada. Almost 25 years ago, I was part of a speaker’s panel that discussed how to encourage more women into professions. I spoke about engineering, and recent female graduates of law and medicine spoke about their respective professions. Today, the professions of medicine and law are leaders in inviting and encouraging women into their fields, but engineering has barely made a dent. From 1991 to 2013, the undergraduate enrolment of women in engineering programs across Canada went from 16.1 per cent to 19.0 per cent, an increase of just 2.9 per cent over a 22 year period.

A tremendous amount of outreach and effort by numerous organizations over these years has been focused on drawing girls into engineering with programs like science camps, coding sessions and robotics clubs. As valuable as these activities are, the profession has seen little change in its gender split. Canada needs more women in engineering. Research has shown that if a group includes more women, its collective performance rises. Gender diversity also shows a positive effect on team innovation in ground-breaking research. With Canada ranking just 26’h globally for business innovation, this is clearly an opportunity to drive economic growth with a diverse set of contributions. It is predicted that Canada is facing major impending labour shortages in fields like engineering. By excluding women from the engineering profession, a highly competent and productive segment of the labour market is currently underutilized. Thus, promoting women’s advancement in engineering would diversify this field that is expected to power much of Canada’s economic engine, meet projected labour demands, and boost innovation and productivity.
The Lassonde School of Engineering at York University has taken a leadership role to address this complex problem of women’s underrepresentation in engineering. On March 3, 2015, it made a bold announcement during National Engineering Month and ahead of International Women’s Day. The School launched the Lassonde 50:50 Challenge to become the first engineering school in Canada to reach a 50:50 gender balance. “Achieving a 50:50 gender balance should be a necessity for every engineering school. It is the single most significant change we can make to improve engineering education in Canada,” said Janusz Kozinski, founding Dean of the Lassonde School of Engineering at the time of the launch. The Lassonde 50:50 Challenge is the first of its kind in Canada. I was selected as the School’s first Assistant Dean, Inclusivity and Diversity to lead this project. Alongside me are two honourary co-chairs, Silicon Valley entrepreneur and philanthropist Sandra Bergeron, and Katty Kay, journalist and coauthor of The Confidence Code and Womenomics. It is a real honour to be a part of this team affecting change on an issue so close to my heart. I believe achieving this goal calls for a comprehensive approach including changing cultural biases and beliefs about what men and women do best throughout their education, training and professionalization. At the public and high school level, we will support initiatives that help girls view themselves as competent in math and science, and help girls associate their desire to help people and society with being an engineer. For example, girls are interested in solving climate change, ending poverty and designing tools that help people – all outcomes that an engineer can contribute to. So we will focus on programming that helps girls find a fit between their own values and what they perceive engineers do. The Lassonde School has been created to be the home of Rennaissance Engineering: a place where students are free to explore their passions and gain different perspectives from the world around them. Our Renaissance undergraduate curriculum will give students a truly multi-disciplinary education. With the opportunity to take courses in law, business and international development alongside engineering, students can explore ideas such as social entrepreneurship. We will experiment with the teaching environment to support female students’ full participation. The “flipped classroom” model at Lassonde encourages students to discover answers in small groups working collaboratively with professors and classmates. This marks a shift away from traditional lectures and textbook learning, toward a focus on problem-solving and hands-on learning. In addition, inclusivity training for professors and students will create an “identity safe” climate to allow for the full participation of everyone regardless of their gender identity.

Our co-op and internship programs will provide specialized training to help students prepare, before entering the workplace, how to confront gender bias and encourage gender inclusive policies at the companies where they work. Our goal is to create allies in men and women within the engineering profession to reduce stereotype threats that can discourage women from staying in engineering, as their profession of choice, after their education. Lastly, we will review the pathways for women into post-graduate studies and professorships to increase the role models for female students and the research
outcomes for the School.

The Lassonde School of Engineering is grateful for the leadership of the Association of Ontario Land Surveyors (AOLS) in helping us reach the goal of gender balance. In addition to the eleven financial awards that the AOLS currently provides for Lassonde students, this fall the AOLS introduced two new Women in Geomatics Engineering Entrance awards designed specifically for female high school graduates. The inaugural winners are Amelia Kishlyansky and Krystel Reyes. Now is the time for all of us to embrace this challenge. I look forward to working with the many experts and engineering schools that are also committed to this long overdue social change. Reaching 50:50 is a bold ambition and one that I am confident we will achieve, together.

York U-led laser instrument to help bring home asteroid sample by NASA mission

The OSIRIS REx Laser Altimeter OLA undergoing testing

Michael Daly, a York University researcher, is the lead scientist on a laser altimeter that will map the surface and create a 3D model of the asteroid Bennu during a NASA mission launching in 2016.

The instrument will also help to guide the spacecraft on the OSIRIS-REx Asteroid Sample Return Mission to a safe spot, where it will grab a sample to bring back to Earth.

“From a science perspective, we need to understand the current state and the evolution of the asteroid,” said Daly, a Lassonde School of Engineering professor, noting one of the goals of the mission is to understand the organic material content of asteroids.

“The sample will provide a snapshot of materials available during the formation of the solar system.”

The OSIRIS REx Laser Altimeter (OLA)

By contributing the instrument – the OSIRIS-REx Laser Altimeter (OLA), an advanced LIDAR (Light Detection And Ranging) – to the mission, Canada will get a portion of that sample. The mission is expected to return 60 grams of the asteroid, but more than a kilogram is hoped for. It will provide Canadian scientists the first-ever direct access to a pristine asteroid sample, according to the Canadian Space Agency (CSA), which funded the instrument.

OLA is more accurate and has a higher resolution than previous altimeters that have been aboard any previous planetary missions, which means better mapping of the asteroid’s topography.

“A lot of LIDARs stare straight and depend on the spacecraft to move around and provide mapping, but we actually do a raster scan, like the way an old cathode-ray tube TV works,” said Daly. “It’s more like taking a range picture than getting a single measurement. The fidelity of information will be higher.”

Bennu, which is about 500 metres in diameter, is of particular interest because it is one of the most potentially hazardous asteroids presently identified, with a small chance of hitting Earth in the 22nd century. The mission will allow the team to study and track the asteroid’s orbit, as OLA will provide precise distance measurements from the spacecraft to the rocky surface.

Michael Daly

“That’s important, as an asteroid’s orbit is difficult to predict over the long term; because asteroids are so small, they get pushed around by small forces,” said Daly. “Understanding how this asteroid has been pushed around, along with its surface and shape properties, will help us to track asteroids better in the future. And thereby we can provide improved predictions about probability of collisions with the Earth.”

OLA, about the size of two bread boxes, will also help navigate the spacecraft to the best location for grabbing a sample. But that won’t happen for a while.

“The main part of the mission, the proximity operation, starts seven or eight kilometres from the asteroid,” said Daly. “Then, it’s a long process of getting to know the asteroid well enough and its non-uniform gravity field well enough to be able to get down and touch the surface and grab a sample.”

That phase will start in late 2018.

As the prime contractor for the CSA, MacDonald, Dettwiler & Associates (MDA), together with its industrial partner Optech, designed, built and tested the instrument.

York University’s Daly is the lead instrument scientist for OLA. The team also includes professors Alan Hildebrand, University of Calgary; Ed Cloutis, University of Winnipeg; Rebecca Ghent, University of Toronto; and Catherine Johnson, University of British Columbia.

Recently delivered to Lockheed Martin in Denver, OLA will now be integrated with the NASA spacecraft for launch in September.

Climate change altering Greenland ice sheet and accelerating sea level rise, says York U professor William Colgan

Professor William Colgan. Photo credit: YFile news.

The Greenland ice sheet has traditionally been pictured as a bit of a sponge for glacier meltwater, but new research has found it is rapidly losing the ability to buffer its contribution to rising sea levels, says a York University researcher.

York University Professor William Colgan, a co-author on the study published Jan. 4 in the journal Nature Climate Change, helped analyse data from three expeditions to the Greenland ice sheet in 2012, 2013 and 2015. The research was done in conjunction with lead researcher Horst Machguth of the Geological Survey of Denmark and Greenland, Mike MacFerrin of the University of Colorado at Boulder and Dirk van As of the Geological Survey of Denmark and Greenland Copenhagen, Denmark.

In 2013, Colgan spent five weeks with the team drilling firn cores in the interior of the Greenland ice sheet. Firn is multi-year compacted snow that is not as dense as glacier ice. Instead, it forms a porous near-surface layer over the ice sheet. Dropped off by a ski-equipped US Air National Guard C-130 Hercules in minus 40 degrees Celsius weather, with 6,000 kilos of supplies and equipment, the team set up several camps and drilled a series of shallow firn cores about 20 metres deep during their time on the ice sheet.

“We were interested in the thin porous near-surface firn layer, and how its physical structure is changing rapidly with climate change,” said Colgan, a professor in the Lassonde School of Engineering at York University. “The study looked at very recent climate change on the ice sheet, how the last couple of years of melt have really altered the structure of the ice sheet firn and made it behave differently to future melt.”

Ice sheet

The researchers also towed a radar unit behind their skidoos to gather profiles between core sites along a 100-kilometre path from the low elevation ice sheet margin into the high elevation ice sheet interior. They analysed the firn cores on the spot by cutting them into small sections to quantify their properties, such as their density, so they could compare them with samples collected the following year. “The year-on-year firn changes were quite dramatic,” said Colgan.

The team was surprised by what they found. An extreme melt that occurred in 2012 caused a layer of solid ice, several metres thick, to form on top of the porous firn in the low elevation areas of the ice sheet. “In subsequent years, meltwater couldn’t penetrate vertically through the solid ice layer, and instead drained along the ice sheet surface toward the ocean,” said Colgan. “It overturned the idea that firn can behave as a nearly bottomless sponge to absorb meltwater. Instead, we found that the meltwater storage capacity of the firn could be capped off relatively quickly.”

As Machguth said, “Basically our research shows that the firn reacts fast to a changing climate. Its ability to limit mass loss of the ice sheet by retaining meltwater could be smaller than previously assumed.”

Because the models scientists use to project Greenland’s sea level rise contribution do not presently take firn cap-off into consideration, it means that Greenland’s projected sea level rise due to meltwater runoff is likely higher than previously predicted. Getting this newly observed physical process into these models is an important next step for the team.

Using unmanned aerial vehicles, Colgan also plans to begin surveying the changes in ice sheet surface reflectance caused by the development of massive ice layers associated with firn cap-off. There are preliminary indications that firn cap-off is also occurring in the ice caps of the Canadian High Arctic.