time travel

Unprecedented warm temperatures in the High Arctic this past summer were so extreme that researchers with a Queen’s University-led climate change project have begun revising their forecasts.

“Everything has changed dramatically in the watershed we observed,” reports Geography professor Scott Lamoureux, the leader of an International Polar Year project announced yesterday in Nunavut by Indian and Northern Affairs Minister Chuck Strahl. “It’s something we’d envisioned for the future – but to see it happening now is quite remarkable.”

One of 44 Canadian research initiatives to receive a total of $100 million (IPY) research funding from the federal government, Dr. Lamoureux’s new four-year project on remote Melville Island in the northwest Arctic brings together scientists and educators from three Canadian universities and the territory of Nunavut. They are studying how the amount of water will vary as climate changes, and how that affects the water quality and ecosystem sustainability of plants and animals that depend on it.

The information will be key to improving models for predicting future climate change in the High Arctic, which is critical to the everyday living conditions of people living there, especially through the lakes and rivers where they obtain their drinking water.

Other members of the research team include, from the Queen’s Geography Department: Paul Treitz, Melissa Lafreniere and Neal Scott; Myrna Simpson and Andre Simpson from U of T; and Pierre Francus from INRS-ETE, Quebec. Linda Lamoureux of Kingston’s Martello School will work with the scientists to develop learning tools for schools in the north.

From their camp on Melville Island last July, where they recorded air temperatures over 20ºC (in an area with July temperatures that average 5ºC), the team watched in amazement as water from melting permafrost a metre below ground lubricated the topsoil, causing it to slide down slopes, clearing everything in its path and thrusting up ridges at the valley bottom “that piled up like a rug,” says Dr. Lamoureux, an expert in hydro-climatic variability and landscape processes. “The landscape was being torn to pieces, literally before our eyes. A major river was dammed by a slide along a 200-metre length of the channel. River flow will be changed for years, if not decades to come.”

Comparing this summer’s observations against aerial photos dating back to the 1950s, and the team’s monitoring of the area for the past five years, the research leader calls the present conditions “unprecedented” in scope and activity. What’s most interesting, he says, is that their findings represent the impact of just one exceptional summer.

“A considerable amount of vegetation has been disturbed and we observed a sharp rise in erosion and a change in sediment load in the river,” Dr. Lamoureux notes. “With warmer conditions and greater thaw depth predicted, the cumulative effect of this happening year after year could create huge problems for both the aquatic and land populations. This kind of disturbance also has important consequences for existing and future infrastructure in the region, like roads, pipelines and air strips.”

If this were to occur in more inhabited parts of Canada, it would be “catastrophic” in terms of land use and resources, he continues. “It would be like taking an area the size of Kingston and having 15 per cent of it disappear into Lake Ontario.”

The Queen’s-led project is working with other IPY research groups including: Arctic HYDRA, an international group investigating the impact of climate change on water in the Arctic; Science Pub, a Norwegian group working on broad research from science to public education about the impacts of global warming; and CiCAT, a University of British Columbia-led group of 48 researchers investigating the impacts of climate change on tundra vegetation.

International Polar Year (IPY) is the largest-ever international program of coordinated scientific research focused on the Arctic and Antarctic regions and the first in 50 years.

From http://qnc.queensu.ca

Drop in Arctic Sea Ice Raises Questions

Melting Arctic sea ice has shrunk to a 29-year low, significantly below the minimum set in 2005, according to preliminary figures from the National Snow and Ice Data Center, part of the University of Colorado at Boulder. NASA scientists, who have been observing the declining Arctic sea ice cover since the earliest measurements in 1979, are working to understand this sudden speed-up of sea ice decline and what it means for the future of Earth’s northern polar region.

“The decline in the amount of thick ice that survives the summer melt season this year is quite remarkable,” said Josefino C. Comiso, senior scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md. “The extent of this ‘perennial’ sea ice and the area it covers are both nearly 38 percent lower than average. Compared to the record low in 2005, the extent and area are 24 percent and nearly 26 percent lower this year, respectively.”

“From what we know of how Arctic sea ice behaves after nearly 30 years of continuous satellite observations, this kind of drop in sea ice usually takes more than three years to happen. The rapid trend of the perennial ice previously reported in 2002 appears now to be in an accelerated mode,” Comiso observed.

Because Arctic ice cover varies so much year to year, it can be dangerous to look at any one year and draw too much of a conclusion from it,” said Waleed Abdalati, head of Goddard’s Cryospheric Sciences Branch. “But this year, the amount of ice is so far below that of previous years that it really is cause for concern. The trend in decreasing ice cover seems to be getting stronger and stronger as time goes on.”

NASA developed the original capability to observe the extent and concentration of sea ice from space using passive microwave sensors. More recently, NASA launched an advanced microwave instrument in 2002 — the Advanced Microwave Scanning Radiometer (AMSR-E) on the Aqua satellite — that provides a view of sea ice dynamics in greater detail than has ever been seen before. Researchers use this information to study polar bear habitats and the unique movements of sea ice from season to season. AMSR-E is a joint project of NASA and the National Space Development Agency of Japan.

The accelerating decline in sea ice may be due to changes in climate brought on by the lack of sea ice itself, Comiso believes. “When there is less sea ice in the summer, the Arctic Ocean receives more heat. The warmer water makes it harder for the ice to recover in the winter, and, therefore, there is a higher likelihood that sea ice will retreat farther during the summer. This process repeats itself year after year,” Comiso said.

“The longer this process continues, the less likely recovery becomes,” Abdalati believes. “The implications on global climate are not well known, but they have the potential to be quite large, since the Arctic ice cover exhibits a tremendous influence on our climate. It really is imperative that we try to understand the interactions between the ice, ocean and atmosphere. And satellites hold the key to developing this understanding.”

Current satellites, however, can map sea ice in two dimensions, but it is much more difficult to find out how the thickness of the ice contributes to the change in the total volume of the ice. NASA’s ICESat spacecraft (Ice, Cloud, and land Elevation Satellite), launched in 2003, with the primary goal of determining how much ice sheets are contributing to sea-level rise. ICESat is also collecting data that enables scientists to make estimates of sea ice thickness with unprecedented detail.

“What we need to truly understand the interaction of the ice, ocean and atmosphere in the Arctic is sea ice thickness information,” said Abdalati. “The new capability we have with ICESat is expected to be extended into the next decade based on recent recommendations by the National Research Council for a follow-on mission. Ultimately, like the 29-year record we have now of sea ice cover, a long-term ice thickness record will help scientists understand these complex interactions and what the changes in the ice cover will mean to the ecology of the Arctic and to life on Earth.”

Imagine peering down from aboard an airplane flying at 35,000 feet and spotting changes in the thickness of a paper back book on a picnic blanket in New York City’s Central Park. If you believe this impossible, NASA satellites are doing the equivalent of just that. From nearly 400 miles above the Earth, satellites have detected subtle rises and falls in the surface of fast-moving ice streams on the Antarctic ice sheet, a capability that also offers scientists an extraordinary view of interconnected waterways deep below that surface. 

“This exciting discovery of large lakes exchanging water under the ice sheet’s surface has radically altered our view of what’s happening at the base of the ice sheet and how ice moves in that environment,” said Bindschadler.

Fricker, Bindschadler and others spotted intriguing discharges of water from the lakes into the ocean. Their research has also delivered new insights into how much water “leaks” from these waterways, how frequently and how many connect to the ocean. Because Antarctica holds about 90 percent of the world’s ice, and 70 percent of the world’s reservoir of fresh water, “leaks” in this system influence sea level and ice melt worldwide.

The research team combined images from an instrument aboard NASA’s Terra and Aqua satellites and data from NASA’s Ice Cloud and Land Elevation Satellite (ICESat) to unveil a first-ever view of changes in the elevation of the icy surface above a subglacial lake the size of Lake Ontario that took place over a three-year period. Those changes suggest the lake drained and that its water relocated elsewhere.

To the naked eye, the surface of the ice sheet is very cold and stable, but the base of any of its ice streams is warm, enabling water, melted from the basal ice to flow, filling the system’s “pipes” and lubricating flow of the overlying ice. These waterways act as a vehicle for water to move and change its influence on the ice movement, a factor that determines ice sheet growth or decay.

“There’s an urgency to learning more about ice sheets when you note that sea level rises and falls in direct response to changes in that ice,” said Fricker. “With this in mind, NASA’s ICESat, Terra, Aqua and other satellites are providing a vital public service.”

Excerpt From Nasa

A new wind turbine blade design that researchers at Sandia National Laboratories developed in partnership with Knight & Carver (K&C) of San Diego promises to be more efficient than current designs. It should significantly reduce the cost-of-energy (COE) of wind turbines at low-wind-speed sites.Named “STAR” for Sweep Twist Adaptive Rotor, the blade is the first of its kind produced at a utility-grade size. Its most distinctive characteristic is a gently curved tip, termed “sweep,” which unlike the vast majority of blades in current use, is specially designed for low-wind-speed regions like the Midwest. The sites targeted by this effort have annual average wind speeds of 5.8 meters per second, measured at 10-meter height. Such sites are abundant in the U.S. and would increase by 20-fold the available land area that can be economically developed for wind energy.

Sized at 27.1 meters — almost three meters longer than the baseline it will replace — the blade improves energy capture at lower wind speeds. Instead of the traditional linear shape, the blade features a curvature toward the trailing edge, which allows the blade to respond to turbulent gusts in a manner that lowers fatigue loads on the blade. It is made of fiberglass and epoxy resin.

“This design allows the blade to twist more than traditional designs, thus relieving some of the effects of gusty turbulent wind on blade life,” says Tom Ashwill, who leads Sandia’s blade research efforts. “This then allows us to grow the blade length for the same rotor, providing for increased energy capture of 5-10 percent and yet retaining the same expected fatigue life.”

Sandia is a National Nuclear Security Administration (NNSA) laboratory.

The K&C contract is part of the Low Wind Speed Technology (LWST) project that targets wind sites that are not the strongest but plentiful. In late 2005 the Department of Energy (DOE) and Sandia awarded Knight & Carver the $2 million contract that includes $800,000 in K&C cost share. Because of budget reallocations, this project was the only one of several LWST projects to receive 2007 funding.

Sandia’s role in the project has been in directing design and test planning. The K&C team provided the detailed design and blade fabrication.

The first STAR blade was tested in January at Knight & Carver’s fabrication facility in San Diego to determine its bending and twist behavior due to static loads. Natural frequencies were also measured. This data will be compared to design simulations to determine how well the design concept performs. Four additional blades will be fabricated in the first quarter of 2007 — three of which will be flight-tested on a turbine in Iowa.

Other members of the design team are Dynamic Design of Davis, Calif.; MDZ Consulting of Clear Lake Shores, Texas; University of California, Davis; and NSE Composites of Seattle, Wash.

“The DOE interest and funding are a big step for us,” Ashwill says. “We’ve been pushing for the incorporation of innovative concepts into utility-scale blades for some time now as a way of reaching program goals of lowered cost of energy.”

He adds that the continued increase in the average size of utility-grade wind turbines may come to an end before all efficiencies are wrung out unless blade weight growth (which is nonlinear) can be reined in. The challenge is to develop new concepts that reduce the rate of weight growth, such as the swept STAR blade.

Other weight-reducing concepts such as carbon spar caps, off-axis carbon fibers that facilitate bend-twist coupling, and new “structural” airfoils have been incorporated at a smaller scale in 9-meter-long prototype blade being flight-tested at Sandia’s test site in Bushland, Texas, at the U.S. Department of Agriculture ARS (Agriculture Research Station) facility.

From SANDIA

Forests of spruce trees and shrubs in parts of northern Canada are taking over what were once tundra landscapes–forcing out the species that lived there. This shift can happen at a much faster speed than scientists originally thought, according to a new University of Alberta study that adds to the growing body of evidence on the effects of climate change.

The boundary, or treeline, between forest and tundra ecosystems is a prominent landscape feature in both Arctic and mountain environments. As global temperatures continue to increase, the treeline is expected to advance but the new research shows that this shift will not always occur gradually but can surge ahead.

“The conventional thinking on treeline dynamics has been that advances are very slow because conditions are so harsh at these high latitudes and altitudes,” said Dr. Ryan Danby, from the Department of Biological Sciences. “But what our data indicates is that there was an upslope surge of trees in response to warmer temperatures. It’s like it waited until conditions were just right and then it decided to get up and run, not just walk.”

Danby and Dr. David Hik, also from the Faculty of Science, reconstructed changes in the density and altitude of treeline forests in southwestern Yukon over the past 300 years. Using tree rings, they were able to date the year of establishment and death of spruce trees and reconstruct changes in treeline vegetation. The study is published in the “Journal of Ecology.”

They found that a rapid change in response to climate warming during the early mid 20th century was observed at all locations. Treeline advanced considerably—as much as 85 metres elevation—on warm, south-facing slopes and tree density increased significantly—as much as 65 per cent—on cooler, north-facing slopes.

“The mechanism of change appears to be associated with occasional years of extraordinarily high seed production—triggered by hot, dry summers—followed by successive years of warm temperatures favourable for seedling growth and survival,” said Danby.

Widespread changes to treelines could have significant impacts, says Danby. As tundra habitats are lost and fragmented, species and habitats are forced to move upwards as well. “The problem is that in mountainous areas you can only go so high so they get forced into smaller and smaller areas,” said Danby.

These changes are of particular importance in these northern regions where First Nation people still rely heavily on the land, says Danby. Tundra species like caribou and sheep populations, which are important parts of that lifestyle, have declined across southwestern Yukon. As treeline advance, the reflectance of the land surface declines because coniferous trees absorb more sunlight than the tundra. This light energy is then re-emitted to the atmosphere as heat. This sets up a “positive feedback,” the same process that is associated with the rapidly decaying Arctic ice cap.

“These results are very relevant to the current debate surrounding climate change because they provide real evidence that vegetation change will be quite considerable in response to future warming, potentially transforming tundra landscapes into open spruce woodlands,” said Danby, who will also be participating in an International Polar Year project that will be examining treeline dynamics across the circumpolar north.

From University of Alberta

Solar energy has the power to reduce greenhouse gases and provide increased energy efficiency, says a scientist at the U.S. Department of Energy’s Argonne National Laboratory, in a report (view it online) published in the March issue of Physics Today.

Last month, the Intergovernmental Panel on Climate Change (IPCC) of the United Nations released a report confirming global warming is upon us and attributing the growing threat to the man-made burning of fossil fuels.

Opportunities to increase solar energy conversion as an alternative to fossil fuels are addressed in the Physics Today article, co-authored by George Crabtree, senior scientist and director of Argonne’s Materials Science Division, and Nathan Lewis, professor of Chemistry at Caltech and director of its Molecular Materials Research Center.

Currently, between 80 percent and 85 percent of our energy comes from fossil fuels. However, fossil fuel resources are of finite extent and are distributed unevenly beneath Earth’s surface. When fossil fuel is turned into useful energy through combustion, it often produces environmental pollutants that are harmful to human health and greenhouse gases that threaten the global climate. In contrast, solar resources are widely available and have a benign effect on the environment and climate, making it an appealing alternative energy source.

“Sunlight is not only the most plentiful energy resource on earth, it is also one of the most versatile, converting readily to electricity, fuel and heat,” said Crabtree. “The challenge is to raise its conversion efficiency by factors of five or ten. That requires understanding the fundamental conversion phenomena at the nanoscale. We are just scratching the surface of this rich research field.”

Argonne carries out forefront basic research on all three solar conversion routes. The laboratory is creating next-generation nanostructured solar cells using sophisticated atomic layer deposition techniques that replace expensive silicon with inexpensive titanium dioxide and chemical dyes. Its artificial photosynthesis program imitates nature using simple chemical components to convert sunlight, water and carbon dioxide directly into fuels like hydrogen, methane and ethanol. Its program on thermoelectric materials takes heat from the sun and converts it directly to electricity.

The Physics Today article is based on the conclusions contained in the report of the Basic Energy Sciences Workshop on Solar Energy Utilization sponsored by the U.S. Department of Energy. Crabtree and Lewis served as co-chairs of the workshop and principal editors of the report. The key conclusions of the report identified opportunities for higher solar energy efficiencies in the areas of:

Electricity – important research developments lie in the development of new, less expensive materials for solar cells, including organics, thin films, dyes and shuttle ions, and in understanding the dynamics of charge transfer across nanostructured interfaces.

Fuel – solar photons can be converted into chemical fuel more resourcefully by breeding or genetically engineering designer plants, connecting natural photosynthetic pathways in novel configurations and using artificial bio-inspired nanoscale systems.
Heat – controlling the size, density and distribution of nanodot inclusions during bulk synthesis could enhance thermoelectric performance and achieve more reliable and inexpensive electricity production from the sun’s heat.

The nation’s first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Since 1990, Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America’s scientific leadership and prepare the nation for the future. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

From Argonne National Laboratory