When Glaciers Melt, What's in the Water?

Measuring the movement of nutrients in Alaska's glacial streams is a "hot topic" for an NSF-supported research team

Being on top of an Alaskan glacier was not as cold as Michael Nassry expected.

Nassry grew up hunting, fishing, hiking and camping in western Pennsylvania, near his home in Hopwood. "I like the outdoors," he said.

With that motivation, he decided he wanted to be an environmental engineer, and found himself in the agricultural and biological engineering program at Penn State University, where he focused on soils and water research. Now a doctoral student in biological systems engineering at Virginia Tech, he has fine-tuned his interest to nutrient transport in rivers and streams.

"I look at what is taken up, what is used, what is passed through to down-river systems," he said, referring to the nutrients in waterways that exercise tremendous control over whether aquatic life thrives, or collapses. He is guided in this focus by his advisor, Durelle "Scotty" Scott.

"Scotty has a lot of projects going on, but I was attracted to the Alaska project because I haven't had a lot of exposure to glacial systems," Nassry said. "What is happening to these watersheds is a hot topic."

"Within a small area, you can examine watersheds that range in glacial coverage," Scott said. "This allows us to look at how these systems respond to climate change."

Nassry traveled to Alaska with Scott and undergraduate student Andrew Jeffrey, who has since graduated, to join Eran Hood, associate professor of hydrology at the University of Alaska Southeast, and his two students, for two weeks in July 2009. It was all part of Scott's NSF-funded research to measure the movement of nutrients out of glaciers.

All of the study sites were close to, and accessible from, Juneau, and the July period, when the glaciers are melting, offered better weather for the helicopters carrying the researchers to the glacier tops.

In addition to the milder-than-expected temperatures, Nassry was surprised at how quickly the ice melted around the ground covers the scientists slept on. "When we picked up the tarp, the ice underneath was about an inch higher than the surrounding ice." Nassry also noticed a lot of streams on top of the glacier, some of them large. "I didn't expect so much surface flow," he added. "I thought more melt would be through the ice."

The research team was atop the ice to perform an injection experiment. First, they put dye in a stream so they could measure its speed. The next day, for three hours straight, they injected a salt solution and several other solutions containing nutrients into the stream. The team then collected water samples at three downstream locations, after the injection pumps were turned off, to determine what flowed out and what was absorbed. Nassry's jobs were to calibrate the injection pumps and collect background samples above the injection point.

The task and clean-up took until 10 or 11 p.m., by which time the helicopters had quit for the day, so the researchers slept on the ice--or not. "It was so bright, I couldn't sleep at all," Nassry said. Hood had been prepared for the overnight and provided the sleeping bags. The one Nassry used came complete with teddy bear, having previously been used by Hood's young daughter.

The next task was to sample the base of the different watersheds, some of which had more glacial coverage than others. "For the Lemon Glacier, Andrew, Eran, Scotty and I were dropped at the face by a helicopter early in the morning; then, we sampled and hiked the whole length of Lemon Creek--six to eight hours," Nassry said.

"Scotty and Andrew biked up a path to the Herbert glacier and sampled the stream on the way back. And Eran and I hiked a trail at Montana Creek and sampled on the way down. That only took a few hours," Nassry said. The Mendenhall River is shrinking at a far more rapid pace, as evidenced by data from its stream gauges.

"Eran analyzed samples for carbon in his lab and shipped us the remaining samples," Nassry said. "In Scotty's lab, we're measuring nutrients, carbon, anions and water isotopes. We used a U.S. Geological Survey computer model, called OTIS, to simulate the downstream flow of water and salts along the reach. Once we achieved a calibrated model for the salts, we knew the hydrology--or what the water was doing. Our next step is to apply the model to each of the biologically available nutrients added during the injection experiment."

In summer 2010, the researchers, including Nassry, will work in streams between the glaciers and the gulf. "This spring," Nassry said, "I'll be designing those experiments and testing them in Stroubles Creek [near the Virginia Tech campus]."

And when they head back, the summer 2010 team will include a local K-12 teacher so that she can learn what it's like to do environmental research--experiences she can share with other teachers and her students.

-- Susan Trulove, Virginia Tech, STrulove@vt.edu

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.

Investigators
Michael Nassry
Durelle Scott
Eran Hood
http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=116555&org=NSF

Kewl Mary008

I was starting to wonder?  

 

Also fun, the sheer amount af data that is available on the subject is amazing, especially in the last 6 months to a year.

Illustration depicting the overturning circulation of the global ocean. Throughout the Atlantic Ocean, the circulation carries warm waters (red arrows) northward near the surface and cold deep waters (blue arrows) southward. Image credit: NASA/JPL

PASADENA, Calif. – New NASA measurements of the Atlantic Meridional Overturning Circulation, part of the global ocean conveyor belt that helps regulate climate around the North Atlantic, show no significant slowing over the past 15 years. The data suggest the circulation may have even sped up slightly in the recent past.

The findings are the result of a new monitoring technique, developed by oceanographer Josh Willis of NASA's Jet Propulsion Laboratory in Pasadena, Calif., using measurements from ocean-observing satellites and profiling floats. The findings are reported in the March 25 issue of Geophysical Research Letters.

The Atlantic overturning circulation is a system of currents, including the Gulf Stream, that bring warm surface waters from the tropics northward into the North Atlantic. There, in the seas surrounding Greenland, the water cools, sinks to great depths and changes direction. What was once warm surface water heading north turns into cold deep water going south. This overturning is one part of the vast conveyor belt of ocean currents that move heat around the globe.

Without the heat carried by this circulation system, the climate around the North Atlantic -- in Europe, North America and North Africa -- would likely be much colder. Scientists hypothesize that rapid cooling 12,000 years ago at the end of the last ice age was triggered when freshwater from melting glaciers altered the ocean's salinity and slowed the overturning rate. That reduced the amount of heat carried northward as a result.

Until recently, the only direct measurements of the circulation's strength have been from ship-based surveys and a set of moorings anchored to the ocean floor in the mid-latitudes. Willis' new technique is based on data from NASA satellite altimeters, which measure changes in the height of the sea surface, as well as data from Argo profiling floats. The international Argo array, supported in part by the National Oceanic and Atmospheric Administration, includes approximately 3,000 robotic floats that measure temperature, salinity and velocity across the world's ocean.

With this new technique, Willis was able to calculate changes in the northward-flowing part of the circulation at about 41 degrees latitude, roughly between New York and northern Portugal. Combining satellite and float measurements, he found no change in the strength of the circulation overturning from 2002 to 2009. Looking further back with satellite altimeter data alone before the float data were available, Willis found evidence that the circulation had sped up about 20 percent from 1993 to 2009. This is the longest direct record of variability in the Atlantic overturning to date and the only one at high latitudes.

The latest climate models predict the overturning circulation will slow down as greenhouse gases warm the planet and melting ice adds freshwater to the ocean. "Warm, freshwater is lighter and sinks less readily than cold, salty water," Willis explained.

For now, however, there are no signs of a slowdown in the circulation. "The changes we're seeing in overturning strength are probably part of a natural cycle," said Willis. "The slight increase in overturning since 1993 coincides with a decades-long natural pattern of Atlantic heating and cooling."

If or when the overturning circulation slows, the results are unlikely to be dramatic. "No one is predicting another ice age as a result of changes in the Atlantic overturning," said Willis. "Even if the overturning was the Godzilla of climate 12,000 years ago, the climate was much colder then. Models of today's warmer conditions suggest that a slowdown would have a much smaller impact now.

"But the Atlantic overturning circulation is still an important player in today's climate," Willis added. "Some have suggested cyclic changes in the overturning may be warming and cooling the whole North Atlantic over the course of several decades and affecting rainfall patterns across the United States and Africa, and even the number of hurricanes in the Atlantic."

With their ability to observe the Atlantic overturning at high latitudes, Willis said, satellite altimeters and the Argo array are an important complement to the mooring and ship-based measurements currently being used to monitor the overturning at lower latitudes. "Nobody imagined that this large-scale circulation could be captured by these global observing systems," said Willis. "Their amazing precision allows us to detect subtle changes in the ocean that could have big impacts on climate."

For more information about NASA and agency programs, visit: http://www.nasa.gov .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

Interesting article on the bees, boy do we need to find out the answer to this one. Not just the bees but bats and other polinators.

Mysterious bat-killing illness previously seen in the U.S. now in Ontario

19/03/2010 4:04 PM |

Sometimes its just an amazing shot

DEFENSE: Accelerating Arctic changes pose long-term risks for the U.S. Navy (03/24/2010)

Lauren Morello, E&E reporter

LAUREL, Md. -- Climate change is poised to turn the Arctic into a new military frontier, but that doesn't mean it's likely thaw out as a new "Wild West."

A Russian expedition made headlines in 2007 when it planted a Russian flag in an Arctic seabed, spurring headlines suggesting a new Cold War was imminent. But for the U.S. Navy, Marine Corps and Coast Guard, the challenge posed by climate change -- in the Arctic and beyond -- is more complex, long-term and tinged with uncertainty.

"For the U.S. Navy, climate change is a challenge -- and not a crisis," said Rear Adm. David Titley, who is leading the Navy's Task Force Climate Change. "I would say that my Russian friends probably did us more help than anything by putting that flag on the North Pole. It got us to focus on the Arctic. But there was a great article in National Geographic that indicates that was kind of a tourist expedition."

That doesn't mean there isn't reason for concern about changes in the high North.

"The thing is that the Arctic is not a vacuum," Titley said yesterday at a conference at Johns Hopkins University's Applied Physics Lab. "What happens there will have repercussions in mid-latitude, and vice versa."

That holds true for changes in the Arctic atmosphere and its geopolitics. Results from Navy war games suggest conflicts that arise in the far North may spread beyond the Arctic Circle, Titley said.

But there are some factors that may temper the pace of change -- and its political and national security fallout.

Take talk about new shipping routes that are likely to emerge as the Arctic thaws. In 2008, the long-sought Northwest Passage and Northern Sea Route were open simultaneously -- though briefly -- for the first time in recorded history.

Search-and-rescue capability may set the pace

Some cruise ships and even a few sailboats have been sighted in the Arctic in recent years. But Richard Engel, a retired Air Force major general who leads the National Intelligence Council's climate change program, said that even if Arctic summers are free of sea ice in the 2030s, shippers may not pounce immediately.

Their operations will depend on putting in place infrastructure -- like search-and-rescue capability -- that is now absent.

"It won't be quite as fast as people lead you to believe," Engel said. "It's commercial and economic interests that may slow it up a little bit."

Debate over just how climate change will play out in the Arctic highlights the uncertainty faced by military planners who recognize climate change's disruptive potential.

The Navy last year commissioned its first ship bearing a hybrid gas-electric drive, the USS Makin Island. And next month, on Earth Day, the force will conduct an airborne test of an F/A-18 aircraft powered by biofuels -- the "Green Hornet."

But amid those concrete steps to reduce its dependence on fossil fuels that contribute to climate, the Navy is wrestling with more fundamental questions posed by climate change.

"Uncertainty is very tightly linked with risk," said Jay Gulledge, senior scientist at the Pew Center on Global Climate Change. "And that's what the security implications of climate change is about -- risk, and how we're going to manage that risk."

Generation-spanning issues

Climate change is a complex problem that involves predicting changes in nonlinear systems, where even slight shifts in key variables can cause major shifts in outcomes. Adding to that, Gulledge said, is the fact that climate change is a problem that spans generations.

The temptation for many people is ignoring the problem, because the risk seems hard to define or far off. Tackling that uncertainty head-on isn't simple.

For Titley, who's heading a Navy task force shaping that force's response to climate change, one major problem is that current climate models make predictions on a continent-by-continent, not region-by-region, basis, at time scales well beyond the Navy's planning horizon.

"The paradox with climate is, in some ways, the forecasts for 2100 are a lot more confident than the forecasts for 2013," he said.

And science is developing rapidly.

Last month, the Pentagon's Quadrennial Defense Review made headlines with its assessment that climate change has become a "threat multiplier" for the nation's armed forces.

But experts noted that that review, mandated by Congress in the 2008 defense authorization bill, relied on middle-range predictions of future warming taken from the 2007 report by the Intergovernmental Panel on Climate Change.

That science, in many cases, is already out of date.

The IPCC predicted the world's seas would rise between 7 and 23 inches by 2100 -- but issued a giant caveat. The IPCC cautioned that an additional rise could come from rapid and unpredictable melting of massive ice sheets in Greenland and Antarctica, which it didn't attempt to estimate.

Three years later, a crop of new scientific analyses paint a picture of 1 to 2 meters of sea level rise -- roughly 3 to 7 feet -- by the end of the century.

Predictions become more severe

But the quadrennial review, directed by Congress to rely on the IPCC's mid-range projections, didn't capture those recent scientific advances. The IPCC report, published in 2007, relied on analyses from 2005 or earlier.

"Climate risks are loaded to the more severe side," Gulledge said. "It's more likely that we're underestimating than overestimating at this point."

There are risks that may be overstated -- and potential threats that are true wild cards.

Dabelko said he puts climate migration in the first category, as something that is frequently sensationalized.

"There's a very large uncertainty with migration, but it can be a good thing," Dabelko said. "It can defuse conflict when people move. It really matters how it's done."

"We are pushed to oversimplify," he said, offering blunt advice: "Embrace the uncertainty. The mindset and tools that the security community brings to this are very well positioned in terms of planning for the worse and hoping for the best."

Meanwhile, there are the wild cards. One of them, according to the Navy's Titley, is shifting ocean chemistry.

The world's seas help sop up carbon dioxide emissions, but as output of the greenhouse gas has risen, that has made ocean water more acidic. Scientists say that will cause problems for marine species -- including shellfish, corals, plankton and other marine animals -- that grow hard shells made of a chalky mineral called calcium carbonate. If ocean water becomes too acidic, it can begin dissolving those shells, sometimes faster than the creatures can rebuild them.

Scientists at sea on ocean chemistry change

"It's a wild card as to whether or not, or how, the living ecosystem, from tiny critters to big fish, is going to adapt," Titley said. "If they don't, we have to start asking ourselves where the 1 billion people today who get protein from the ocean are going to get that from."

Experts also said they are eyeing talk of geoengineering closely, figuring that many of the proposed schemes to engineer a cooler planet have the potential to spark geopolitical havoc.

One oft-mentioned geoengineering approach is to mimic the cooling effects of a volcano by spraying sulfate particles into the upper atmosphere, where they would increase the amount of sunlight reflected away from Earth.

Scientists say it's cheap enough that a very wealthy individual or an individual nation might be able to act unilaterally and deploy the scheme without international oversight.

"We know very little about this," said Geoff Dabelko, director of the Environmental Change and Security Program at the Woodrow Wilson Center. "It holds big potential for challenges in the political realm, the security realm, that we have not fully grappled with. ... It's not a stretch that the Navy would be asked to monitor or interdict these activities."

Other potential wild cards, experts at the conference said, include the possibility that a climate-related push for new technology and new forms of energy will spur demand for a new set of natural resources in short supply.

Increased production of electric car batteries, for example, is driving a new global hunger for lithium. Half the world's supply is found in Bolivia, whose president, Evo Morales, is an outspoken critic of the United States.

Water Supply Forecasts

Key to Successful Water Management

People who live in the semi-arid western United States often refer to water as the lifeblood of their land. And there’s a delicate balance between water supply and snow fall. Nearly all water used to supply cities, farms, and industry in the West comes from melting snow in the high mountains.

NOAA’s vigilance in monitoring and understanding mountain snow pack helps the agency forecast the availability of water resources for the upcoming year. Managers of this precious resource rely on NOAA forecasts when making decisions about water allocation and management.

NOAA leads the National Integrated Drought Information System, which is a collaborative effort between federal, state, and local governments tasked to ensure a high level of drought-related information sharing and awareness. The National Integrated Drought Information System maintains a Web portal where water management officials access current drought status, forecasts, effects and planning information.

Managing Water Supplies in Drought

As shown by the U.S. Drought Monitor, drought occurred in every Western state last year. And drought conditions in the West will continue to be a major concern in the future. Increasing population in Western cities has further stressed water management and has added concern to the already dry region.

Before the snow melts each spring, NOAA’s National Weather Service River Forecast Centers project how much water the melting snow will supply to hundreds of river basins in the western United States. Coordinating with many other agencies, NOAA scientists generate water supply forecasts monthly between December and June for the western United States.

Water supply forecasters use mathematical models of the mountain snow pack, water flow, soil infiltration, evaporation, and precipitation to develop forecasts. These models are based on scientific understanding of snow and the land surface coupled with forecasts for weather and climate.

Forecasters create detailed water supply forecasts using observations of precipitation, snow totals, temperatures, and stream flow from networks operated by NOAA, the U.S. Geological Survey, the Natural Resources Conservation Service, and state and local agencies.

More Effective Resource Management

With this combined information, NOAA scientists provide forecasts that are essential for helping water resource managers keep water flowing in homes and communities throughout the western United States.

NOAA scientists post seasonal water supply forecasts on their Water Resource Forecasts Web site. This Web site not only gives residents in the western United States a glimpse of the expected water supply in their area, but it also houses useful information to help water resource managers do their job. 

A large number of federal and state agencies and interest groups are responsible for managing the physical, legal, and economic constraints of the water supply. The starting point for these efforts begins with an accurate water supply forecast from NOAA’s National Weather Service.

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