OREGON STATE UNIVERSITY

college of earth

Study finds limit on evaporation to ice sheets, but that may change

CORVALLIS, Ore. – Although the coastal regions of the Greenland Ice Sheet are experiencing rapid melting, a significant portion of the interior of that ice sheet has remained stable – but a new study suggests that stability may not continue.

Researchers found that very little of the snow and ice on the vast interior of the ice sheet is lost to the atmosphere through evaporation because of a strong thermal “lid” that essentially traps the moisture and returns it to the surface where it refreezes.

However, there are signs that this lid is becoming leaky as global temperatures increase. The researchers say there may be a threshold at which warming becomes sufficient to turn on a switch that will destabilize the snow surface.

Results of the study, which was funded by the National Science Foundation, are being published in Science Advances. New measurements from a research tower atop the Greenland ice sheet helped uncovered the mystery of how much snow piles up on this ice sheet.

“Normally, the air temperature goes down as you climb, but near the surface in Greenland, it gets warmer,” said David Noone, an Oregon State University professor who is an atmospheric scientist and principal investigator on the study. “The surface is very cold, but it can be as much as 20 degrees warmer just 30 to 40 feet up in the air. It’s enough that you can feel the difference between your nose and your toes.”

“The temperature difference effectively forms a lid so that there is hardly any evaporation. Warm air likes to rise, but if it is already warmer up above the air is trapped nearer the ground. One consequence is that layers of fog form from water that had recently evaporated. Eventually the small fog water-drops drift back down to the very cold surface where it refreezes onto the ice sheet.”

“It’s a handy little trick of nature.”

Max Berkelhammer, a researcher at the University of Illinois and lead author on the study, said scientists have been aware of “accumulation zones” in high-altitude areas of the ice sheet, but they haven’t been comprehensively measured because of the difficulty in analyzing evaporation and condensation over time.

“Instruments capable of doing this are pretty new and while they have been used before on the ice sheet, they have never been able to run during an entire winter,” said Berkelhammer, who did his post-doctoral work with Noone when both were at the University of Colorado. “I think at this point we are still the only group who has been able to run this type of instrument for an entire year on top of an ice sheet.”

The research aims to better understand how ice cores capture information about past temperatures in Greenland. The snow and ice on Greenland’s interior originated from ocean water far to the south and is transported northward by weather systems and storms, and finally falls as snow on the pristine ice sheet.

The researchers are able to track the origins and fate of the water by the ratio of oxygen and hydrogen isotopes in the water.

Variations in the isotope ratios in layers of snow piled up on the ice sheet provide the team a history of Green climate that helps put recent warming into historical context, the researchers say.

To understand past climate, scientists must know how much precipitation fell and how much evaporated. Without the team’s analysis, what fraction of falling snow accumulates and what fraction evaporates was difficult to determine. When they began to explore evaporation rates, they discovered this unique thermal lid, which effectively “recycles” water back onto the Greenland Ice Sheet.

This finding will allow previous estimates of Greenland’s past water balance to be re-evaluated.

“When thinking about climate change, one often thinks about rising global temperatures,” Noone said. “However in Greenland, as like here in Oregon, climate change is also a story of the changing water cycle and how we lose water because evaporation rates are increasing.

“Climate models suggest that as temperatures increase, more precipitation may actually fall in Greenland because warmer air can hold more water. Taken by itself, that could indicate that parts of the ice sheet may grow. However, if the lid becomes increasingly leaky, the evaporation process has become more effective and moisture will escape to the atmosphere.

“The fate of the ice sheet is in the balance,” Noone said. “It becomes a question of which influence is stronger.”

Story By: 
Source: 

David Noone, 541-737-3629, dcn@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

This photo of fogbows can be downloaded at: https://flic.kr/p/FM1utW

 

 

 

IMG_3025

Summit Station in Greenland

 

David_Noone_Summit2012_IMG_1170

David Noone, OSU, in a snow pit.

 

IMG_2578

Max Berkelhammer measures ice crystals

OSU to issue RFI on ship project after design completion

CORVALLIS, Ore. – The design phase for a project to construct a new regional class research vessel to replenish the United States academic fleet is complete and Oregon State University will issue a request for information (RFI) on Monday, May 2, to shipyards that may be interested in the vessel construction phase.

In January 2013, the National Science Foundation selected Oregon State as the lead institution to finalize the design and coordinate the construction of the vessel – and possibly up to two more – a project considered crucial to maintaining the country’s marine science research capabilities.

The design phase has been completed by The Glosten Associates, a naval architecture firm based in Seattle, and the RFI is a chance to generate market interest and to get feedback from industry on the design and other project documents. OSU plans to issue a Request for Proposals (RFP) in two phases beginning this summer – a technical phase to establish a competitive pool of qualified shipyards and a cost phase to elicit vessel cost proposals.

“The Request for Information issued on May 2 is a chance for us to make final tweaks in the preliminary design and to open up a dialogue with industry about the project,” said Demian Bailey, Oregon State University’s former marine superintendent and a co-leader on the project. “Once we issue the RFP this summer, it will become more difficult to alter the design or other project documents.”

Although similar in size, the new ship will differ greatly from the R/V Oceanus, built in 1975 and operated by OSU, and its sister ships, Endeavor, operated by the University of Rhode Island, and Wecoma (retired), according to Clare Reimers, a professor in the College of Earth, Ocean, and Atmospheric Sciences and project co-leader.

“This class of ships will enable researchers to work much more efficiently at sea because of better handling and stability, more capacity for instrumentation and less noise,” Reimers said. “The design also has numerous ‘green’ features, including an optimized hull form, waste heat recovery, LED lighting, and variable speed power generation.”

These “regional class research vessels” are designed for studying coastal waters out to beyond the continental rise as part of the U.S. academic fleet that is available to all ocean scientists conducting federal and state-funded research and educational programs.

Among the design features:

  • Each regional class research vessel will be 193 feet, with a range of 7,064 nautical miles;
  • Cruising speed is 11 knots with a maximum speed of 13 knots;
  • There are 16 berths for scientists and 13 for crew members;
  • The ships can stay out at sea for 21 days before coming back to port.

The 2017 President’s budget calls for building two RCRVs, but until a final budget is passed by Congress the plan is to make ready a shipyard contract to build one RCRV with options for additional vessels.

After reviewing the proposals from industry, OSU will select a shipyard in early 2017. The NSF will assume ownership of the regional class research vessels, but Oregon State expects to operate the first vessel constructed, which will conduct science missions primarily in the eastern North Pacific Ocean basin.

Additional vessels would be operated in the Atlantic and Gulf regions of the U.S. by other institutions that the NSF would select in late 2017.

“These ships will also have the ability to operate near ice and are considered ‘ice classed,’ although they are not ice-breakers,” Bailey said. The first ship will likely be delivered in 2020.

More information about the project, including renderings, is available at: http://ceoas.oregonstate.edu/ships/rcrv/

Story By: 
Source: 

Demian Bailey, 541-737-0460, dbailey@coas.oregonstate.edu;

Clare Reimers, 541-737-2426, creimers@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

This image of the ship is available at: https://flic.kr/p/FGRCR8

West Coast scientists sound alarm for changing ocean chemistry

CORVALLIS, Ore. – The ocean chemistry along the West Coast of North America is changing rapidly because of global carbon dioxide emissions, and the governments of Oregon, California, Washington and British Columbia can take actions now to offset and mitigate the effects of these changes.

That is the conclusion of a 20-member panel of leading West Coast ocean scientists, who presented a comprehensive report on Monday outlining a series of recommendations to address the increase in ocean acidification and hypoxia, or extremely low oxygen levels.

“Ocean acidification is a global problem that is having a disproportionate impact on productive West Coast ecosystems,” said Francis Chan, an Oregon State University marine ecologist and co-chair of the West Coast Ocean Acidification and Hypoxia Science Panel. “There has been an attitude that there is not much we can do about this locally, but that just isn’t true. A lot of the solutions will come locally and through coordinated regional efforts.”

Ocean acidification and hypoxia are distinct phenomena that trigger a wide range of effects on marine ecosystems. They frequently occur together and represent two important facets of global ocean changes that have important implications for Oregon’s coastal oceans.

Among the panel’s recommendations:

  • Develop new benchmarks for near-shore water quality as existing criteria were not developed to protect marine organisms from acidification;
  • Improve methods of removing carbon dioxide from seawater through the use of kelp beds, eel grass and other plants;
  • Enhance coastal ecosystems’ ability to adapt to changing ocean chemistry through better resource management, including marine reserves, adaptive breeding techniques for shellfish, and other methods.

“Communities around the country are increasingly vulnerable to ocean acidification and long-term environmental changes," said Richard Spinrad, chief scientist for the National Oceanic and Atmospheric Administration, and former OSU vice president for research. “It is crucial that we comprehend how ocean chemistry is changing in different places, so we applaud the steps the West Coast Ocean Acidification and Hypoxia Science Panel has put forward in understanding and addressing this issue. We continue to look to the West Coast as a leader on understanding ocean acidification.”

Chan said regional awareness of the impact of changing ocean chemistry started in Oregon. Some of the first impacts were seen about 15 years ago when the state began experiencing seasonal hypoxia, or low-oxygen water, leading to some marine organism die-offs. Then the oyster industry was confronted with high mortality rates of juvenile oysters because of increasingly acidified water. It turns out that Oregon was on the leading edge of a much larger problem.

“It was a wakeup call for the region, which since has spread up and down the coast,” said Chan, an associate professor in the Department of Integrative Biology in OSU’s College of Science.

California responded to this call, and in partnership with Oregon, Washington and British Columbia, convened a panel of scientific experts to provide advice on the issue. The panel worked with federal and state agencies, local organizations and higher education institutions to identify concerns about ocean acidification and hypoxia, then developed a series of recommendations and actions that can be taken today.

“One of the things all of the scientists agree on is the need for better ocean monitoring or ‘listening posts,’ up and down the West Coast,” said Jack Barth, a professor and associate dean in OSU’s College of Earth, Ocean, and Atmospheric Sciences and a member of the panel. “It is a unifying issue that will require participation from state and federal agencies, as well as universities, ports, local governments and NGOs.”

Barth said one such “listening post” has been the Whiskey Creek Shellfish Hatchery in Netarts Bay, Oregon, which was able to solve the die-off of juvenile oysters with the help of OSU scientists George Waldbusser and Burke Hales, who both served on the 20-member panel. Together, they determined that the ocean chemistry changed throughout the day and by taking in seawater in the afternoon, when photosynthesis peaked and CO2 levels were lower, juvenile oysters could survive.

The West Coast is a hotspot for acidification because of coastal upwelling, which brings nutrient-rich, low-oxygen and high carbon dioxide water from deep in the water column to the surface near the coast. These nutrients fertilize the water column, trigger phytoplankton blooms that die and sink to the bottom, producing even more carbon dioxide and lowering oxygen further.

“We’re just starting to see the impacts now, and we need to accelerate what we know about how increasingly acidified water will impact our ecosystems,” said panel member Waldo Wakefield, a research fisheries biologist with NOAA Fisheries in Newport and courtesy associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

“There’s a lot at stake. West Coast fisheries are economic drivers of many coastal communities, and the seafood we enjoy depends on a food web that is likely to be affected by more corrosive water.”

Last year, OSU researchers completed the deployment of moorings, buoys and gliders as part of the Endurance Array – a component of the $386 million National Science Foundation-funded Ocean Observatories Initiative, created to address ocean issues including acidification.

These and other ocean-monitoring efforts will be important to inform policy-makers about where to best focus their adaptation and mitigation strategies.

“The panel’s findings provide a road map to help us prepare for the changes ahead,” said Gabriela Goldfarb, natural resource policy adviser to Oregon Gov. Kate Brown. “How Oregon and the West Coast address ocean acidification will inform those confronting this issue around the country and world.”

“With the best scientific recommendations in hand from the science panel, we now have the information on which to base our future management decisions,” added Caren Braby, marine resource manager at the Oregon Department of Fish and Wildlife. “These are practical recommendations natural resource managers and communities can use to ensure we continue to have the rich and productive ecosystem Oregonians depend on for healthy fisheries, our coastal culture and economy.”

Story By: 
Source: 

Francis Chan, 541-844-8415, chanft@science.oregonstate.edu;

Jack Barth, 541-737-1607, barth@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

oyster

An oyster at Whiskey Creek Shellfish Hatchery

PNAS Study: Carbon from land played a role during last deglaciation

CORVALLIS, Ore. – As the Earth emerged from its last ice age several thousand years ago, atmospheric carbon dioxide increased and further warmed the planet. Scientists have long speculated that the primary source of this CO2 was from the deep ocean around Antarctica, though it has been difficult to prove.

A new study being published this week in Proceedings of the National Academy of Sciences confirmed that the ocean played a significant role in the rise of atmospheric carbon dioxide, but also documents the signature of land-based carbon sources in Antarctic ice cores that contributed to abrupt increases in CO2.

“There wasn’t a steady rate of rising carbon dioxide during the last deglaciation,” said Edward Brook, an Oregon State University paleoclimatologist and co-author on the PNAS study. “It happened in fits and starts. With the new precise techniques we developed to fingerprint the sources, it is apparent that the early carbon largely came from the ocean, but we think the system got a jolt from an influx of land-based carbon a few times as the climate warmed.”

The study was funded by the National Science Foundation with support from the Marsden Fund Council in New Zealand.

The breakthrough came from the comparison of carbon isotope ratios in pristine samples of ice mined from the Taylor Glacier in Antarctica. Although such isotopic fingerprinting strategies have been attempted before, the key was detailed work both in the field and in the laboratory that improved the precision to read the record in fine detail.

The study found that during the initial rise in atmospheric CO2 – from 17,600 years ago to 15,500 years ago – the light isotope 12-C increased faster than the heavier isotopes, pointing to a release of carbon from the deep ocean. However, at about 16,300 years ago and 12,900 years ago, there were abrupt, century-scale perturbations in the carbon ratio that suggested rapid release of carbon from land sources such as plants and soils.

Although the region of the CO2 source is not clear, the scientists say, at least one of the two events may come from the tropics because methane from tropical swamps rose at the same time.

“One theory,” Brook said, “is that an influx of icebergs in the Northern Hemisphere at about 16,300 years ago – from retreating ice sheets – cooled the North Atlantic Ocean and pushed the tropical rain belt southward over Brazil, expanding the wetlands. Swamps in the Southern Hemisphere, in places like Brazil, may have become wetter and produced methane, while plants and soils in the Northern Hemisphere, in places like China, may have been hit by drought and produced CO2.”

During the next 4,000 years, the continued rise of atmospheric CO2 – by about 40 parts per million – was marked by small changes in the carbon-13 to carbon-12 ratio indicating additional sources of carbon from rising ocean temperatures. This CO2 source, analogous to the bubbles released from warming soda pop, may have added to the biological carbon sources.

The application of this carbon isotope technique became possible because of a unique site along the margin of the Antarctic ice sheet where old ice that flowed from the interior is exposed at the surface of a large glacier – Taylor Glacier – named for a geologist on an early expedition to the frozen continent. Ice that normally would be a mile or more below the surface is available to easily sample in large quantities.

These large samples, laboriously cut from the exposed ice layers, allowed the precise measurements, the  researchers report.

“The isotope ratio technique gives us a sort of ‘return address’ for carbon dioxide,” noted Thomas Bauska, a former Ph.D. student and post-doctoral researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences, who was lead author on the PNAS study.  “The technique is new, extremely precise and gives us one of the best windows into the Earth’s past climate.”

Bauska is now a post-doctoral researcher at the University of Cambridge in England.

That window into the past may provide hints at what may happen in the future under a new global warming regime, noted Alan Mix, an Oregon State oceanographer and co-author on the study. However, he cautioned, it isn’t always simple to predict the future based on past events.

“The rise of CO2 is a complicated beast, with different behaviors triggered at different times,” Mix said. “Although the natural changes at the end of the ice age are not a direct analogy for the future, the rapid changes do provide a cautionary tale. Manmade warming from CO2 pollution may trigger further release from ‘natural sources,’ and this could exacerbate greenhouse gases and warming.”

Other authors on the PNAS study include Daniel Baggenstos and Jeffrey Severinghaus, Scripps Institution of Oceanography; Shaun Marcott, University of Wisconsin-Madison; Vasillii Petrenko, University of Rochester; Hinrich Schaefer, National Institute of Water and Atmospheric Research in New Zealand; and James Lee, Oregon State University.

Story By: 
Source: 

Ed Brook, 541-737-8197, brook@geo.oregonstate.edu;

Thomas Bauska, +44 1223 764917, tkb28@cam.ac.uk;

Alan Mix, 541-737-5212, amix@coas.oregonstate.edu

Extreme events show signal of climate change

CORVALLIS, Ore. – The rapid warming of Earth may not have directly caused all of the extreme weather events that have taken place in the past two decades – from the European heat wave of 2003 to Hurricane Katrina – but climate change has in some way had an impact on them, a new report concludes.

A 10-person committee of the National Research Council issued a report on Friday that examined the influence of humans on recent extreme weather events. Though the committee stopped short of saying that climate change is causing more frequent and severe events – a link difficult to prove in a short time frame – the connection, it acknowledges, is unmistakable.

“Scientists used to say that we can’t attribute any one event to climate change,” said Philip Mote, an Oregon State University climatologist and co-author on the report. “But that is a copout. Every extreme weather event has the fingerprint of climate change. The question is not whether global warming caused Hurricane Sandy; but rather how much stronger it was because of global warming.

“There is little doubt that Hurricane Sandy would have had less impact without climate change.”

The committee issued its report today in the National Academies Press, published by the National Academies of Science, Engineering and Medicine.

Humans’ use of fossil fuel since the start of the Industrial Revolution has begun to modify the Earth’s climate in many ways, said David W. Titley, who chaired the Committee of Extreme Weather Events and Climate Change Attribution.

“The consequences of this change to the climate are seemingly everywhere: average temperatures are rising, precipitation patterns are changing, ice sheets are melting and sea levels are rising,” Titley noted in the report’s preface. “These changes are affecting the availability and quality of water supplies, how and where food is grown, and even the very fabric of ecosystems on land and in the sea.”

Despite progress on understanding these changes, scientists are still trying many different approaches to understanding the causes of extreme events.

Since 2012, the number of research groups issuing studies on the attribution of extreme weather events has exploded, shedding new light on the external “forcing” mechanisms of events and how they are similar or different from other events.

This is allowing scientists to get a better feel for the impact of climate change on extreme events, Mote pointed out.

“The clearest tie between climate change and weather is in heat-related events,” said Mote, who wrote the sections on heat and drought in the report. “Droughts are getting worse and some aspect of every major heat-related event is stronger today because of climate change. In fact, most types of extreme events are getting stronger or more frequent, except those related to cold events, which are weaker or less frequent.”

Mote said he understands public skepticism over the link between global warming and weather in places like the East Coast of the United States, which has suffered through strong blizzards in the past two to three winters – a brief return to a climate of decades past. A warming planet does not affect every region uniformly, he added, nor does it make every season warmer than average.

On the other side of the country the three Pacific coast states – California, Oregon and Washington – experienced major drought in 2014-15.

“I’m frequently asked if we can expect more of the same in the future for the West Coast,” said Mote, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The answer is yes. The weather we had this past year, which was the warmest on record in Oregon, is the type of year we can expect to call ‘norm’ in the decade of the 2040s.”

Story By: 
Source: 

Phil Mote, 541-913-2274

Multimedia Downloads
Multimedia: 

5261
Phil Mote

Mariana Trench: Seven miles deep, the ocean is still a noisy place

NEWPORT, Ore. – For what may be the first time, scientists have eavesdropped on the deepest part of the world’s oceans and instead of finding a sea of silence, they discovered a cacophony of sounds both natural and caused by humans.

For three weeks, a titanium-encased hydrophone recorded ambient noise from the ocean floor at a depth of more than 36,000 feet in a trough known as Challenger Deep in the fabled Mariana Trench near Micronesia. The team of researchers from the National Oceanic and Atmospheric Administration, Oregon State University and the U.S. Coast Guard expected to hear little. They were surprised.

“You would think that the deepest part of the ocean would be one of the quietest places on Earth,” said Robert Dziak, a NOAA research oceanographer and chief scientist on the project. “Yet there really is almost constant noise from both natural and man-made sources. The ambient sound field at Challenger Deep is dominated by the sound of earthquakes, both near and far was well as the distinct moans of baleen whales and the overwhelming clamor of a category 4 typhoon that just happened to pass overhead.

“There was also a lot of noise from ship traffic, identifiable by the clear sound pattern the ship propellers make when they pass by,” added Dziak, who has a courtesy appointment in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. “Guam is very close to Challenger Deep and is a regional hub for container shipping with China and The Philippines.”

The project, which was funded by the NOAA Office of Ocean Exploration and Research, was designed to establish a baseline for ambient noise in the deepest part of the Pacific Ocean. Anthropogenic, or human-caused noise has increased steadily over the past several decades and getting these first recordings will allow scientists in the future to determine if the noise levels are growing.

Getting those first sounds wasn’t easy.

The bottom of the Challenger Deep trough is roughly seven miles below the ocean’s surface. In fact, you could put the world’s tallest peak – Mount Everest – in the trench and its top would still be more than a mile from the surface.

The pressure at that depth is incredible, said Haru Matsumoto, an Oregon State ocean engineer who along with NOAA engineer Chris Meinig helped to develop a hydrophone capable of withstanding such pressure. In the average person’s home or office, the atmospheric pressure is about 14.7 pounds per square inch; at the bottom of the Mariana Trench, it is more than 16,000 PSI.

“We had never put a hydrophone deeper than a mile or so below the surface, so putting an instrument down some seven miles into the ocean was daunting,” Matsumoto said. “We had to drop the hydrophone mooring down through the water column at no more than about five meters per second. Structures don’t like rapid change and we were afraid we would crack the ceramic housing outside the hydrophone.”

Partnering with the U.S. Coast Guard, the researchers deployed the hydrophone from the Guam-based cutter Sequoia in July 2015. It took more than six hours for the instrument package to free-fall to the bottom of the Mariana Trench. Its recordings filled the flash drive in about 23 days, but the researchers had to wait until November to retrieve the hydrophone because of ships’ schedules and persistent typhoons.

Once back on site, they recovered the hydrophone mooring by sending an acoustic signal from the ship above, triggering its release from the seafloor. Attached floats allowed it to gradually ascend to the surface.

“It is akin to sending a deep-space probe to the outer solar system,” Dziak said. “We’re sending out a deep-ocean probe to the unknown reaches of inner space.”

For the past several months, Dziak and his colleagues have been analyzing the sounds and differentiating natural sounds from ships and other human activities.

“We recorded a loud magnitude 5.0 earthquake that took place at a depth of about 10 kilometers (or more than six miles) in the nearby ocean crust,” Dziak said. “Since our hydrophone was at 11 kilometers, it actually was below the earthquake, which is really an unusual experience. The sound of the typhoon was also dramatic, although the cacophony from big storms tends to be spread out and elevates the overall noise for a period of days.”

Matsumoto said the hydrophone also picked up a lot of noise from the surface of the ocean – some seven miles above – including waves and winds disturbing the surface.

“Sound doesn’t get as weak as you think it does even that far from the source,” he said.

Another OSU co-investigator on the project, Joe Haxel, will lead a planned return to Challenger Deep in 2017, where the researchers will deploy the hydrophone for a longer period of time and attach a deep-ocean camera.

Dziak, Matsumoto and Haxel are affiliated with the Acoustics Program in the NOAA/Pacific Marine Environmental Laboratory and work at OSU’s Hatfield Marine Science Center in Newport, Ore. The project in Challenger Deep is one of a number of projects in which the U.S. Coast Guard partners with NOAA to sponsor scientific research.

Story By: 
Source: 

Bob Dziak, 541-867-0175, Robert.P.Dziak@noaa.gov;

Haru Matsumoto, 541-867-0272; haru.matsumoto@oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

 

A link to sound files, images and a video can be found at: http://bit.ly/1QSb8Mv

 

 

Deep trench

 

ChallengerDeep

 

CD-hydrophone-close

Scientists say window to reduce carbon emissions is small

CORVALLIS, Ore. – At the rate humans are emitting carbon into the atmosphere, the Earth may suffer irreparable damage that could last tens of thousands of years, according to a new analysis published this week.

Too much of the climate change policy debate has focused on observations of the past 150 years and their impact on global warming and sea level rise by the end of this century, the authors say. Instead, policy-makers and the public should also be considering the longer-term impacts of climate change.

“Much of the carbon we are putting in the air from burning fossil fuels will stay there for thousands of years – and some of it will be there for more than 100,000 years,” said Peter Clark, an Oregon State University paleoclimatologist and lead author on the article. “People need to understand that the effects of climate change on the planet won’t go away, at least not for thousands of generations.”

The researchers’ analysis is being published this week in the journal Nature Climate Change.

Thomas Stocker of the University of Bern in Switzerland, who is past-co-chair of the IPCC’s Working Group I, said the focus on climate change at the end of the 21st century needs to be shifted toward a much longer-term perspective.

“Our greenhouse gas emissions today produce climate-change commitments for many centuries to millennia,” said Stocker, a climate modeler and co-author on the Nature Climate Change article. “It is high time that this essential irreversibility is placed into the focus of policy-makers.

“The long-term view sends the chilling message (about) what the real risks and consequences are of the fossil fuel era,” Stocker added. “It will commit us to massive adaptation efforts so that for many, dislocation and migration becomes the only option.”

Sea level rise is one of the most compelling impacts of global warming, yet its effects are just starting to be seen. The latest IPCC report, for example, calls for sea level rise of just one meter by the year 2100. In their analysis, however, the authors look at four difference sea level-rise scenarios based on different rates of warming, from a low end that could only be reached with massive efforts to eliminate fossil fuel use over the next few decades, to a higher rate based on the consumption of half the remaining fossil fuels over the next few centuries.

With just two degrees (Celsius) warming in the low-end scenario, sea levels are predicted to eventually rise by about 25 meters. With seven degrees warming at the high-end scenario, the rise is estimated at 50 meters, although over a period of several centuries to millennia.

“It takes sea level rise a very long time to react – on the order of centuries,” Clark said. “It’s like heating a pot of water on the stove; it doesn’t boil for quite a while after the heat is turned on – but then it will continue to boil as long as the heat persists. Once carbon is in the atmosphere, it will stay there for tens or hundreds of thousands of years, and the warming, as well as the higher seas, will remain.”

Clark said for the low-end scenario, an estimated 122 countries have at least 10 percent of their population in areas that will be directly affected by rising sea levels, and that some 1.3 billion – or 20 percent of the global population – live on lands that may be directly affected. The impacts become greater as the warming and sea level rise increases.

“We can’t keep building seawalls that are 25 meters high,” noted Clark, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Entire populations of cities will eventually have to move.”

Daniel Schrag, the Sturgis Hooper Professor of Geology at Harvard University, said there are moral questions about “what kind of environment we are passing along to future generations.”

“Sea level rise may not seem like such a big deal today, but we are making choices that will affect our grandchildren’s grandchildren – and beyond,” said Schrag, a co-author on the analysis and director of Harvard’s Center for the Environment. “We need to think carefully about the long time-scales of what we are unleashing.”

The new paper makes the fundamental point that considering the long time scales of the carbon cycle and of climate change means that reducing emissions slightly or even significantly is not sufficient. “To spare future generations from the worst impacts of climate change, the target must be zero – or even negative carbon emissions – as soon as possible,” Clark said.

“Taking the first steps is important, but it is essential to see these as the start of a path toward total decarbonization,” Schrag pointed out. “This means continuing to invest in innovation that can someday replace fossil fuels altogether. Partial reductions are not going to do the job.”

Stocker said that in the last 50 years alone, humans have changed the climate on a global scale, initiating the Anthropocene, a new geological era with fundamentally altered living conditions for the next many thousands of years.

“Because we do not know to what extent adaptation will be possible for humans and ecosystems, all our efforts must focus on a rapid and complete decarbonization –the only option to limit climate change,” Stocker said.

The researchers’ work was supported by the U.S. National Science Foundation, the U.S. Department of Energy, the Natural Sciences and Engineering Research Council of Canada, the German Science Foundation and the Swiss National Science Foundation.

Story By: 
Source: 

Peter Clark, 541-737-1247, clarkp@geo.oregonstate.edu;

Thomas Stocker, +41 31 631 44 62, stocker@climate.unibe.ch;

Daniel Schrag, 617-233-2554, schrag@eps.harvard.edu

Multimedia Downloads
Multimedia: 

 

 

Rising sea levels will threaten residents of many countries.

Study: Fish assemblages can change rapidly along coast as water warms

CORVALLIS, Ore. – A modest warming of coastal waters can have a significant impact on juvenile fish assemblages in a period of just a few years, a newly published study has found, raising concern about the potential effects of climate change.

Such a shift is taking place on the Skagerrak coast of Norway, where more warm-water fish species have begun appearing over the past two decades while many populations of resident cold-water fish species have declined.

Results of the study have just been published in the journal Global Change Biology.

Studying the potential impact of climate change on coastal fishes has been difficult, researchers say, because few long-term records adequately address species diversity. But researchers at Norway’s Institute of Marine Research have been conducting what has to be one of the longest, most consistent surveys of near-shore waters ever undertaken – a key to understanding climate change effects.

“What we’re seeing is a clear influence of ocean temperature on the region’s juvenile fish community, which has changed in what is a very important fish nursery area,” said Caren Barceló, an Oregon State University doctoral candidate and lead author on the study. “It has implications for nursery habitats that have been around for decades.”

Barceló, who worked with Norwegian researchers on their beach seine surveys, said no new species had appeared in the waters of Skagerrak for nearly three decades beginning in the mid-1960s. Within the next 15 years, however, several pelagic, planktivorou species more characteristic of the Mediterranean arrived – for example, European anchovy (Engraulis encrasicolus) and European pilchard (Sardina pilchardus).

Other warm-water species of fish present now were documented once before in the area, such as juvenile horse mackerel (Trachurus trachurus), when the water warmed in the 1930s and ‘40s and then became less prevalent when it cooled. The corkwing wrasse (Symphodus melops) is another fish species that appeared during the earlier warm period, then became less prevalent for more than half a century – before returning during the latest warming.

Cold-water species that have been caught less frequently in this dataset over the past two decades include cod (Gadus morhua), pollack (Pollachius pollachius), and European eel (Anguilla anguilla).

One concern, the researchers say, is that the present warming is not an anomaly, rather a symptom of climate change that may worsen instead of going away. There may be other factors involved in the introduction of new species, noted Lorenzo Ciannelli, an Oregon State marine ecologist and co-author on the study.

“There are some unique elements happening today that distinguish the situation from the 1930s and ‘40s,” Ciannelli said. “Winds and currents are pushing warm water into the area in such a way that it suggests the pattern might be here to stay.

“Some fish will move into a new area as adults, while other species disperse their eggs or larva and they then ride into new regions on the currents,” he added. “To make them ‘stick’ there may need to be a seeding process that allows the local population to develop.”

The key to understanding the assemblage shift in Norway is the extraordinary data set collected by Norwegian researchers. For the past 96 years, they have conducted an extensive coast-wide seine survey during the last two weeks of September, using the same style boats, the same locations and nets that were exactly the same size.

Only five survey leaders have coordinated the effort over 96 years, each one having trained with the previous leader for at least 10 years on the operation of setting and hauling the beach seine before taking over the project themselves.

“It began as a project to analyze the recruitment of juvenile cod in the region,” Barceló said, “but someone had the foresight a century ago to document all of the species  brought up in the nets – and they’ve kept it up ever since.”

Barceló, who worked with the Norwegians over two summers, is also analyzing fish surveys off the Oregon coast, investigating the long-term environmental variability and shifting marine fish assemblages.

She and Ciannelli are in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Story By: 
Source: 

Caren Barceló, 541-737-3965, caren.barcelo@gmail.com;

Lorenzo Ciannelli, 541-737-3142, lciannelli@coas.oregonstate.edu

Multimedia Downloads
Multimedia: 

 

 

 

 

 

 

 

 

 

 

 

strandnot2012-20

Caren Barcelo works with Norwegian researchers.

2015 goes down as the warmest in Oregon history

CORVALLIS, Ore. – A mild winter, an early spring and warmer-than-average temperatures every season have contributed to a record-breaking year, as 2015 will go down as the warmest in Oregon since state records began in 1895.

Oregon’s previous record high average temperature of 49.9 degrees was set in 1934 – the height of the Dust Bowl – when the entire country was plagued by hot, dry weather.

Despite a cold, icy end to December in Oregon, the average temperature in 2015 was 50.4 degrees, not only a record but far above the average yearly temperature for the 20th century, which was 47.8 degrees, according to Oregon State University’s Philip Mote, who directs the Oregon Climate Change Research Institute on campus.

“In previous years, we’ve had periods where the weather was warmer for differing spells,” Mote said. “In 2015, though, it was warmer than average almost all the way through the year.” A combination of meteorological conditions and greenhouse gases led to the record warm year, he added.

The statistics are from the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information.

Oregon was not alone in experiencing a warm 2015, according to Kathie Dello, deputy director of the Oregon Climate Service at OSU. Washington, Montana and Florida also experienced record high temperatures, and in several other states 2015 went down in the top five of all time.

It appears this will be yet another record warm year for average global temperature, Dello pointed out, and it is officially the second warmest year in the United States, despite blizzards and Arctic temperatures in the Northeast.

“If you are 31 years of age, you have not lived through a single month in which the global temperature was below average,” Dello said. “And if you are 31 and living in Oregon, you have only experienced three years here that were cooler than the 20th-century average.”

Researchers calculate the average temperature for each day by looking at the highest and lowest temperatures. If the high reaches 90 degrees and the low is 60, that day’s average temperature is 75 degrees. They then calculate the average monthly temperature, and finally, the average yearly temperature.

The average for the state is done by analyzing temperatures at a series of long-established weather stations throughout the state.

 “We had a ridge of high pressure that set up and kept the weather warm and dry throughout most of the summer and fall,” Mote said. “That followed a winter in which we got nearly average precipitation, but much of it came from the south and it fell as rain instead of snow.”

Mote said the record-setting 2015 weather was a combination of meteorological phenomena and the Earth gradually getting warmer because of human activities.

Through rigorous statistical analysis, scientists are able to tease out the impacts of El Niño, greenhouse gas emissions, volcanic activity and solar activity on temperatures. Mote said 2015 would have been a warm year because of meteorological conditions, but the 1-2 degrees (F) attributable to greenhouse gases pushed temperatures into record territory.

“There’s little doubt that the insulation of the planet from greenhouse gas emissions played a role in the warming throughout the year,” he said.

The OSU researchers say expect more of the same in 2016.

“With El Niño and the remnants of The Blob (a huge warm patch of water in the North Pacific Ocean), it should be another warm year for the Earth, and for Oregon,” Dello said.

Story By: 
Source: 

Phil Mote, 541-737-5694, pmote@coas.oregonstate.edu;

Kathie Dello, 541-737-8927, kdello@coas.oregonstate.edu

 

 

 

 

 

A 72-degree day in January (2015) at Yachats on the Oregon Coast. (photo by Theresa Hogue)

OSU/NOAA study: Warm-water years are tough on juvenile salmon

NEWPORT, Ore. – A new analysis of juvenile Chinook salmon in the Pacific Ocean documents a dramatic difference in their foraging habits and overall health between years of warm water and those when the water is colder.

The study found that when the water is warmer than average – by only two degrees Celsius – young salmon consume 30 percent more food than during cold-water regimes. Yet they are smaller and skinnier during those warm-water years, likely because they have to work harder to secure food and the prey they consume has less caloric energy.

Results of the research, conducted by researchers from Oregon State University and the National Oceanic and Atmospheric Administration, are being published this week in the journal PLOS One.

“When young salmon come out to sea and the water is warm, they need more food to keep their metabolic rate up, yet there is less available food and they have to work harder,” said Elizabeth Daly, an Oregon State senior faculty research assistant with the Cooperative Institute for Marine Resources Studies, a joint program of OSU and NOAA.

“Our long-term data set contradicts the long-held assumption that salmon eat less during warm-water regimes,” Daly added. “They actually eat more. But they still don’t fare as well. When the water is warm, salmon are smaller and thinner.”

Daly teamed with Richard Brodeur, a NOAA Northwest Fisheries Science Center researcher, to examine 19 years of juvenile salmon surveys, from 1981-85 and 1998-2011. The rich, long-term data set revealed the trophic habits, size and condition of yearling Chinook salmon caught soon after they migrated to the ocean. The researchers found that during both warm- and cold-water regimes, the diet of the salmon is primarily fish, but when the water is cold, they also consume more lipid-rich krill and Pacific sand lance. When the water is warmer, the salmon’s diet had more juvenile rockfish and crab larvae.

Previous research led by Bill Peterson, a NOAA fisheries biologist and courtesy professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences (CEOAS), found that the makeup of copepods during cold-water years differs greatly than during warm-water years. In cold years, these small crustaceans drift down from the north and are lipid-rich, with much higher nutrient levels than copepods from the south.

And though salmon may not directly consume these copepods, they are eating the fish that do consume them, noted Brodeur, also a courtesy faculty member in CEOAS.

“The warm years typically have less upwelling that brings the cold, nutrient-rich water to the surface,” Brodeur said. “Or in the case of 2005, the upwelling was so late that many of the salmon died because there was no food when they entered the ocean.”

“Salmon populations may be able to handle one year of warm temperatures and sparse food,” Brodeur added. “But two or three years in a row could be disastrous – especially for wild fish populations. They may have to travel much farther north to find any food.”

Hatchery-raised salmon that are released in similar numbers in warm- or cold-water years may fare slightly better during bad ocean conditions, the researchers noted, because they tend to be larger when they enter the marine environment.

Daly and Brodeur, who work out of OSU’s Hatfield Marine Science Center in Newport, Oregon, said that the 19 survey years they analyzed included 10 warm-water years and nine cold-water years. In some cases, the warm water was a result of an El Niño, while in other years it was a lack of upwelling.

During the last two years, an unusually large, warm body of water has settled into the ocean off the Pacific Northwest that scientists have dubbed “The Blob,” which is forecast to be followed this winter by a fairly strong El Niño event. Though recent spring Chinook salmon runs have been strong due to cooler ocean conditions in 2012-13, the impact of this long stretch of warm water on juvenile fish may bode poorly for future runs.

“So far this year, we’ve seen a lot of juvenile salmon with empty stomachs,” Daly said. “The pressure to find food is going to be great. Of those fish that did have food in their stomachs, there was an unusual amount of juvenile rockfish and no signs of Pacific sand lance or krill.

“Not only does this warm water make it more difficult for the salmon to find food, it increases the risk of their own predation as they spend more time eating and less time avoiding predators,” she added.

Story By: 
Source: 

Elizabeth Daly, 541-867-0404; elizabeth.daly@oregonstate.edu;

Ric Brodeur, 541-867-0335, Richard.Brodeur@noaa.gov

Multimedia Downloads
Multimedia: 

OLYMPUS DIGITAL CAMERA