OREGON STATE UNIVERSITY

college of earth

Geochemist to present Condon Lecture

CORVALLIS, Ore. – Richard Carlson, a geologist, geochemist, and planetary scientist from the Carnegie Institution in Washington, D.C., will present the 2014 Thomas Condon Lecture at Oregon State University on Wednesday, March 5.

The free public lecture, "A History of Earth Formation," is designed for a non-specialist audience. It begins at 7:30 p.m. in Austin Auditorium of the LaSells Stewart Center on the OSU campus. The Condon Lecture, named after a pioneer of Oregon geology, helps to interpret significant scientific research for non-scientists.

Carlson is a staff scientist at the Department of Terrestrial Magnetism at the Carnegie Institution. He conducts research on the history and evolution of the crust and interior of Earth, Mars, the moon and different asteroids to understand the mechanisms of planet formation and the way in which planets develop habitable surfaces.

He uses isotope geochemistry to study element formation in stars and how those elements are delivered throughout the solar system. His studies have taken to southern Africa, Brazil, the Arctic coast of Hudson’s Bay, eastern Oregon, and most recently, central Mongolia.

The recipient of numerous awards, Carlson was elected to the National Academy of Sciences in 2012.

While at OSU, Carlson will also give a more technical presentation on a related topic. His George Moore Lecture, “Pacific Northwest Volcanism: The Connection of Mantle Dynamics and Continent Formation,”   will be held Thursday, March 6, beginning at 4 p.m. in Kelley Engineering Room 1003.

The presentations are sponsored by the OSU Research Office and the College of Earth, Ocean, and Atmospheric Sciences.

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John Dilles, 541-737-1245 or dillesj@geo.oregonstate.edu

Noted oceanographer to speak Nov. 12 at Hatfield

NEWPORT, Ore. – Don Walsh, a pioneering oceanographer famous for his 1960 dive to the deepest part of the ocean, will visit Newport on Tuesday, Nov. 12.

Walsh will give a free public lecture at Oregon State University’s Hatfield Marine Science Center. His presentation, “Lunch on Board the Titanic: Two Miles Deep in the Atlantic,” begins at 6:30 p.m. In his talk, Walsh will share his experience diving in a submersible down to the Titanic and other adventures from his career of more than 40 years.

A retired captain from the U.S. Navy, Walsh went on to enjoy a lengthy career as an oceanographer and ocean engineer who explored the deep oceans and polar regions. He has commanded submarines as a naval officer and deep-sea submersibles as a researcher.

In 1960, Walsh and Swiss oceanographer Jacques Piccard boarded the bathyscaphe Trieste and descended to the floor of the Mariana Trench in the northern Pacific Ocean – a depth of more than 35,000 feet, or nearly seven miles. It took five hours to reach the seafloor, and at 30,000 feet they heard a loud crack. Upon reaching the bottom, they discovered cracks in the window, and quickly began ascending.

The historic dive received worldwide attention. It also remained a world record dive for 52 years until James Cameron piloted his Deepsea Challenger to the same place in 2012.

Walsh, who has a courtesy appointment in OSU’s College of Earth, Ocean, and Atmospheric Sciences, will also visit schools in Newport during the week and give a seminar at the Hatfield Marine Science Center. That talk, intended for a research audience, is titled “Going the Last Seven Miles – Looking Backwards at the Future.” It begins at 3:30 p.m. on Nov. 12 in the Hennings Auditorium.

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Maryann Bozza, 541-867-0234; maryann.bozza@oregonstate.edu

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Don Walsh

OSU oceanography dean to speak at ARCS Foundation

PORTLAND, Ore. – Mark Abbott, dean of the College of Earth, Ocean, and Atmospheric Sciences at Oregon State University, will give the keynote speech at the Achievement Rewards for College Scientists (ARCS) Foundation scholars luncheon on Tuesday, Oct. 22, in Portland.

The event begins at 11 a.m. at the Portland Art Museum, where 52 ARCS scholars will be honored and present posters of their research. Ticket information is available online at: https://www.arcsfoundation.org/portland/news/portland-chapters-9th-annual-luncheon-celebrates-50-american-science-scholars

Abbott’s talk, “Our Oceans under Pressure,” will outline how human impacts on the world’s oceans are increasing, raising concern for such issues as declining fisheries, sea level rise, pollution, acidification, harmful algal blooms, and marine “dead zones.”

Abbott is president of the Oceanographic Society and a former member of the National Science Board. In 2011, he received the prestigious Jim Gray eScience Award in Stockholm, Sweden, from Microsoft Research for his leadership in blending science and computing technology. He joined the OSU faculty in 1988 and has served as dean of the college since 2001.

Julia Maxson of Oregon Health & Science University will be the featured ARCS Scholar Alumna speaker. Her talk is titled “Using Genetics to Find Better Cancer Treatments.”

Fifty-two scholars at OSU and OHSU will be honored at this ninth annual luncheon.

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Jean Josephson, ARCS president, jeanjosephson@gmail.com

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Mark Abbott
Mark Abbott

Ocean sound: The Oregon Coast rules when it comes to ambient noise

NEWPORT, Ore. – For more than a year, scientists at Oregon State University’s Hatfield Marine Science Center deployed a hydrophone in 50 meters of water just off the coast of Newport, Ore., so they could listen to the natural and human-induced sounds emanating from the Pacific Ocean environment.

Their recently published analysis has a simple conclusion: It’s really noisy out there.

There are ships, including container shipping traffic, commercial fishers and recreationalists. There are environmental sounds, from waves pounding the beach, to sounds generating by heavy winds. And there are biological sounds, especially the vocalizations of blue whales and fin whales. And not only is Oregon’s ocean sound budget varied, it is quite robust.

“We recorded noise generated from local vessels during 66 percent of all hours during the course of a year,” said Joe Haxel, an OSU doctoral student who is affiliated with both the Cooperative Institute for Marine Resources Studies (CIMRS) and NOAA’s Pacific Marine Environmental Laboratory acoustics program at the Hatfield center. “In fact, there is an acoustic spike during the opening of the commercial crabbing season related to the high number of boats working the shallow coastal waters at the same time.

“But, at times, the biggest contributor to the low-frequency sound budget is from the surf breaking on the beach a few kilometers away,” he added. “That’s where Oregon trumps most other places. There haven’t been a lot of studies targeting surf-generated sound and its effect on ambient noise levels in the coastal ocean, but the few that are out there show a lot less noise than we have. Our waves are off the charts.”

The year-long study of noise, which was published in the Journal of the Acoustical Society of America, was supported by the Department of Energy, the Oregon Wave Energy Trust, NOAA and OSU.

The study is about more than scientific curiosity, researchers say. The research was carried out in support of OSU’s Northwest National Marine Renewable Energy Center and will play an important role in determining whether testing of wave energy devices off the Oregon coast may have environmental impacts.

Scientists must know what naturally occurring sounds exist, and at what levels, so when new sounds are introduced, there is some context for evaluating their intensity and impact.

Documenting marine noises for an entire year isn’t easy, the researchers pointed out. First, the equipment must withstand the rugged Pacific Ocean, so the OSU researchers deployed the hydrophone near the seafloor in about 50 meters of water so violent winter storms wouldn’t destroy the instrumentation. They focused on low-frequency sounds, where the majority of noise emitted by wave energy converters is expected to occur.

After combing through an entire year of data, they determined that Oregon’s low-frequency noise budget is often dominated by the constant sounds of breaking surf. These weren’t necessarily the loudest noises, though.

“The strongest signal we got during the course of the year came from a boat that drove right over our mooring,” said Haxel, who is pursuing his doctorate through OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The second loudest sound came from the vocalizations of a blue whale, which can be incredibly loud. We were told by colleagues at the Marine Mammal Institute that blue whales have been sighted close to shore in recent years and it was probably within several kilometers of the hydrophone.”

Haxel said the OSU researchers also recorded numerous vocalizations of fin whales and humpback whales, but a startling omission was that of gray whales, one of the most common West Coast whales.

“We didn’t document a single gray whale sound during the entire year, which was really surprising,” Haxel said. “Even during times when gray whales were visually sighted from shore within close proximity of the hydrophone, we never recorded any vocalizations. One theory is that they are trying to keep as quiet as possible so they don’t give away their location to orcas, which target their calves.”

Another unusual source of noise was the wind. Even at 50 meters below the surface, the hydrophone picked up sound from the wind – but not in the way one might think. It wasn’t the howling of the wind that was noticeable, Haxel said, but the ensuing waves, known as “whitecaps” or “wind chop,” and the clouds of bubbles that were injected into the water column.

Haxel compared his data on Oregon sounds to a handful of studies in the literature associated with high-energy environmental conditions to see how the region fared. All of the other studies were limited: a Monterey Bay, Calif., survey focused only on surf noises. A study off the Florida coast examined wind-generated sounds. And a study of the Scotia Shelf in Canada looked at wind and surf.

Oregon noise levels were similar to other regions for frequencies above 100 Hz, Haxel said, but rose sharply for frequencies affected by surf-generated noise – generally below 100 Hz.

“The bottom line is that the Pacific Ocean in the Northwest can be a remarkably loud environment and our wave climate in particular is amazing,” Haxel said. “That’s why wave energy is being targeted for this region in the first place. The study will provide some valuable information as the wave energy industry goes forward.

“We will be able to measure noise levels from the testing, or even the loading and unloading of equipment from the vessels, and compare those measurements with the range of background ambient sound levels already occurring in the area,” he added.

“It is a balancing act as some noise from the testing sites may serve as a warning signal for whales and other animals to avoid the area, helping to reduce the risk for collision or entanglement,” Haxel said. “But adding too much noise can be harmful, disrupting their communication or navigation.”

Media Contact: 
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Joe Haxel, 541-867-0282; joe.haxel@oregonstate.edu

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Tail of the whale
Blue whale vocalizations
are second loudest


 Coastal waves
Breaking surf tops
the charts for noise

 

Sound file of breaking surf:

http://oregonstate.edu/dept/ncs/media/wave-breaking.wav

 

Sound file of boat motors:

http://oregonstate.edu/dept/ncs/media/boat-noise.wav

Study documents early warming of West Antarctica at end of last ice age

CORVALLIS, Ore. – West Antarctica began emerging from the last ice age about 22,000 years ago – well before other regions of Antarctica and the rest of the world, according to a team of scientists who analyzed a two-mile-long ice core, one of the deepest ever drilled in Antarctica.

Scientists say that changes in the amount of solar energy triggered the warming of West Antarctica and the subsequent release of carbon dioxide (CO2) from the Southern Ocean amplified the effect and resulted in warming on a global scale, eventually ending the ice age.

Results of the study were published this week in the journal Nature. The authors are all members of the West Antarctic Ice Sheet Divide project, which was funded by the National Science Foundation.

The study is significant because it adds to the growing body of scientific understanding about how the Earth emerges from an ice age. Edward Brook, an Oregon State University paleoclimatologist and co-author on the Nature study, said the key to this new discovery about West Antarctica resulted from analysis of the 3,405-meter ice core.

“This ice core is special because it came from a place in West Antarctica where the snowfall is very high and left an average of 20 inches of ice or more per year to study,” said Brook, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Not only did it allow us to provide more accurate dating because we can count the layers, it gave us a ton more data – and those data clearly show an earlier warming of the region than was previously thought.”

Previous studies have pointed to changes in the Earth’s orbit around the sun as the initial trigger in deglaciation during the last ice age. An increase in the intensity of summer sunlight in the northern hemisphere melted ice sheets in Canada and Europe starting at about 20,000 years ago and is believed to have triggered warming elsewhere on the globe.

It previously was thought that Antarctica started its major warming a few thousand years later, at about 18,000 years before present. However, the new study shows that at least part of Antarctica started to warm 2,000 to 4,000 years before this. The authors hypothesize that changes in the total amount of sunlight in Antarctica and melt-back of sea ice caused early warming at this coastal site – warming that is not recorded by ice cores in the interior of the continent.

“The site of the core is near the coast and it conceivably feels the coastal influence much more so than the inland sites where most of the high-elevation East Antarctic cores have been drilled,” Brook said. “As the sunlight increased, it reduced the amount of sea ice in the Southern Ocean and warmed West Antarctica. The subsequent rise of CO2 then escalated the process on a global scale.”

“What is new here is our observation that West Antarctica did not wait for a cue from the Northern Hemisphere before it began warming,” Brook said, “What hasn’t changed is that the initial warming and melting of the ice sheets triggered the release of CO2 from the oceans, which accelerated the demise of the ice age.”

Brook said the recent increase in CO2 via human causes is also warming the planet, “but much more rapidly.”

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

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ice core wintering

 

drilled ice core

 

HZBS400B

Study finds novel worm community affecting methane release in ocean

CORVALLIS, Ore. – Scientists have discovered a super-charged methane seep in the ocean off New Zealand that has created its own unique food web, resulting in much more methane escaping from the ocean floor into the water column.

Most of that methane, a greenhouse gas 23 times more potent than carbon dioxide at warming our atmosphere, is likely consumed by biological activity in the water, the scientists say. Thus it will not make it into the atmosphere, where it could exacerbate global warming. However, the discovery does highlight scientists’ limited understanding of the global methane cycle – and specifically the biological interactions that create the stability of the ocean system.

Results of the study, which was funded primarily by the National Oceanic and Atmospheric Administration and the Federal Ministry of Education and Research in Germany, have just been published online in the journal Limnology and Oceanography.

“We didn’t discover any major ‘burps’ of methane escaping into the atmosphere,” said Andrew R. Thurber, a post-doctoral researcher at Oregon State University and lead author on the study. “However, some of the methane seeps are releasing hundreds of times the amounts of methane we typically see in other locations, so the structure and interactions of this unique habitat certainly got our attention.

“What made this discovery most exciting was that it is one of the first and best examples of a direct link between a food web and the dynamics that control greenhouse gas emissions from the ocean,” Thurber added.

The scientists first discovered this new series of methane seeps in 600 to 1,200 meters of water off North Island of New Zealand in 2006 and 2007. The amount of methane emitted from the seeps was surprisingly high, fueling a unique habitat dominated by polychaetes, or worms, from the family Ampharetidae.

"They were so abundant that the sediment was black from their dense tubes,” Thurber pointed out.

Those tubes, or tunnels in the sediment, are critical, the researchers say. By burrowing into the sediment, the worms essentially created tens of thousands of new conduits for methane trapped below the surface to escape from the sediments. Bacteria consumes much of the methane, converting it to carbon dioxide, and the worms feast on the enriched bacteria – bolstering their healthy population and leading to more tunnels and subsequently, greater methane release.

The researchers say that there is one more critical element necessary for the creation of this unique habitat – oxygen-rich waters near the seafloor that the bacteria harness to consume the methane efficiently. The oxygen also enables the worms to breathe better and in turn consume the bacteria at a faster rate.

“In essence, the worms are eating so much microbial biomass that they are shifting the dynamics of the sediment microbial community to an oxygen- and methane-fueled habitat – and the worms’ movements and grazing are likely causing the microbial populations to eat methane faster,” said Thurber, who works in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “That process, however, also leads to more worms that build more conduits in the sediments, and this can result in the release of additional methane.”

Methane seeps and worm communities are present in many other areas around the world, the researchers point out, including the Pacific Northwest. However, the deep water in many of these locations has low levels of oxygen, which the scientists think is a factor that constrains the growth of the worm populations. In contrast, the study sites off New Zealand are bathed in cold, oxygen-rich water from the Southern Ocean that fuels these unique habitats.

“The large amounts of methane consumed by bacteria have kept it from reaching the surface,” Thurber said. “Those bacteria essentially are putting the pin back in the methane grenade. But we don’t know if the worms ultimately may overgraze the bacteria and overtax the system. It’s something we haven’t really seen before.”

Also participating in the study were scientists from Scripps Institution of Oceanography, the National Institute of Water and Atmospheric Research in Wellington, New Zealand, and the Helmholtz Centre for Ocean Research in Germany.

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Andrew Thurber, 541-737-8251; athurber@coas.oregonstate.edu

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Poly_red Ampharetid_feeding

Worm feeding

 

Poly_red Ampharetid_pic3

Worm outside its tube

 

AmphBeds

Worm bed off coast

of New Zealand

Oregon State University students produce interactive iBook Atlas of the Columbia River Basin

Another version of this story is available on Terra magazine at Oregon State.

CORVALLIS, Ore. — The Columbia River Basin comes to life in a new digital atlas produced by Oregon State University cartography students. Starting with ArcMap, they created an iBook — accessible via Apple’s iPad — which combines the look and feel of a traditional paper book with the touch-screen features of a tablet computer.

Through colorful maps, animations, photos and video, the new atlas allows users to explore the basin’s geology, climate, social history and land use. It shows the location and extent of historical and current tribal lands — Kootenai, Nez Perce, Umatilla and others — the region’s population centers and a time-lapse display of dam construction from 1900 to the present. Maps also show the location of salmon runs, recreation sites and public lands. 

Under the guidance of Bernhard Jenny, cartographer and assistant professor in the College of Earth, Ocean, and Atmospheric Sciences, 17 graduate and undergraduate students published the Atlas of the Columbia River Basin. It can be downloaded free as a PDF or iBook from the cartography and visualization group at Oregon State. Jenny has submitted it to Apple’s iTunes library.

Creating the interactive and static maps required the use of three different software packages, says Jenny. Students used ArcMap to merge geospatial data from different sources and design the maps. They reprojected the maps to a local coordinate system that was optimized for the portrayal of the transboundary Columbia Basin. After exporting the maps from ArcMap into Adobe Illustrator, they fine-tuned symbolization, labeling and layout. The last step consisted of placing the maps in iBooks Author, the authoring software for creating eBooks for the iPad. The maps were combined with interactive features, text, diagrams and other elements and laid out in this authoring software.

Unlike most atlases that are restricted by national and state borders, this atlas crosses the boundary between Canada and the United States, says Kimberly Ogren, an Oregon State Ph.D. student. Ogren helped to develop the 33-page document as a student in Jenny’s course on computer-assisted cartography.

“If you apply cartography concepts in the right way,” she says, “you will create a map that draws people to the information and conveys it effectively. People will want to learn more. That’s our hope for this atlas.”

Not Just Another Digital Map

More than a useful resource about the Columbia basin, the new atlas is also a milestone in cartography. “Cartographers haven’t used these new formats with all their features,” says Jenny. He notes that the first digital map (The Electronic Atlas of Canada) was created in 1981, but it and its successors have been more useful for specialists than for the general public.

“Those atlases don’t have individual page layouts or elements like diagrams and pictures,” he says. “They’re more standardized in their appearance and functionality.” In essence, most digital atlases provide a visual interface for viewing and analyzing data rather than an educational resource for the public.

In contrast, the Atlas of the Columbia River Basin presents information in a format that is accessible. It includes a table of contents and chapters. It integrates digital data with other book-like features and touch-screen functions that are familiar to any smart phone or tablet computer user.

The advantage for mapmakers, says Jenny, lies in the ease with which such atlases can be created. The downside is that creativity in terms of interactivity is limited to what the authoring software allows. In addition, e-books cannot be exported to multiple brands of devices. Apple’s iBook authoring software, for example, creates e-books only for Apple devices.

The evolution of atlases to tablet computers follows the growth in sales of iPads, Amazon’s Kindle and other tablets in the last few years. In 2014, says Jenny, sales of tablet computers are expected to outpace sales of desktop and notebook PCs combined. E-books have grown in popularity as well and accounted for about 20 percent of publishers’ revenues in 2012. In 2011, sales of e-books outpaced sales of hardcover adult fiction.

Jenny plans to continue incorporating iBook publishing in his cartography classes. Both he and Ogren say that students in the cartography class benefited by creating a product that they could show to future employers as well as family and friends.

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Bernhard Jenny, 541-737-1204

Climate center at OSU gets major grant to study forest mortality

CORVALLIS, Ore. – Oregon State University has received a five-year, $4 million grant from the United States Department of Agriculture to investigate increasing impacts of drought, insect attacks and fires on forests in the western U.S., and to project how the influence of climate change may affect forest die-offs in the future.

The researchers will also enhance an earth system model to allow them to predict when forests are becoming vulnerable to physiological stress and then create strategies to minimize impacts of climate, insects and fire.

“The western United States has gone through two decades of devastating forest loss and we don’t even fully know why it happened, much less how to predict these events,” said Philip Mote, director of the Oregon Climate Change Research Institute at OSU and a principal investigator on the grant. “Certainly wildfire, bark beetle infestation and drought play a role, but the intersection of these factors with forest management decisions hasn’t been well-explored.

“A change in severity of drought, for example, can make the difference between trees losing some needles and wiping out the entire stand,” added Mote, a professor in the College of Earth, Ocean, and Atmospheric Sciences at OSU. “The margin between life and death in the forest can be rather small.”

Other lead investigators from OSU on the project include Beverly Law, a professor in the Department of Forest Ecosystems and Society, who will focus on modeling forest processes with the Community Land Model; and Andrew Plantinga, a professor in the Department of Applied Economics, whose expertise is on the economics of land use, climate change and forests.

“Climate variation and extremes can impact trees differently depending on species-specific traits that determine how they compete and respond to environmental conditions,” Law said. “We know little about how physiological limits vary by species, and have not incorporated such knowledge in earth system models.”

The OSU researchers note that forest management decisions could potentially play a role during periods of drought, for example. Drought-stressed trees become vulnerable when they experience vapor pressure deficits – and cannot take in enough water to sustain them, or to remain vigorous enough to help repel invading bark beetles, said Law, who is co-lead principal investigator on the project.

An excess of trees in an area of limited water might benefit from targeted thinning so fewer trees remain to compete for the same amount of water, Law noted. However, forests that already have low densities “are not expected to respond well,” she said.

“What we don’t know,” Mote said, “is what the threshold is between stress and mortality, which trees to thin and how many, and whether such a strategy not only works, but is economically feasible for landowners.”

Law said the intervention strategies “should not result in potentially harmful ecological impacts on habitat and soil quality.”

Among the goals of the project are to:

  • Improve the ability of a leading land surface model to predict tree mortality;
  • Map the vulnerability of western forests to mortality under present and future climate conditions,  particularly in Oregon, Washington, California and Idaho;
  • Apply forest vulnerability data to forest sector models to help land managers better predict ecological and economic outcomes, including timber production, forest recreation and water use.

As part of the study, the researchers will run computer models that will utilize a crowd-sourced computing effort called Weatherathome.net, through which a network of thousands of volunteers will use their home computers to run climate model scenarios. Such a network can equal or exceed the output of a supercomputer.

The OSU grant is part of the inter-agency Decadal and Regional Climate Prediction Using Earth System Models Program, which is coordinated by the National Science Foundation and includes USDA and the Department of Energy.

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Phil Mote, 541-737-5694

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Dying trees

Forest die-off

Global warming to cut snow water storage 56 percent in Oregon watershed

The study this story is based on is available online: http://bit.ly/13ZLzl1

CORVALLIS, Ore. – A new report projects that by the middle of this century there will be an average 56 percent drop in the amount of water stored in peak snowpack in the McKenzie River watershed of the Oregon Cascade Range -  and that similar impacts may be found on low-elevation maritime snow packs around the world.

The findings by scientists at Oregon State University, which are based on a projected 3.6 degree Fahrenheit temperature increase, highlight the special risks facing many low-elevation, mountainous regions where snow often falls near the freezing point. In such areas, changing from snow to rain only requires a very modest rise in temperature.

As in Oregon, which depends on Cascade Range winter snowpack for much of the water in the populous Willamette Valley, there may be significant impacts on ecosystems, agriculture, hydropower, industry, municipalities and recreation, especially in summer when water demands peak.

The latest study was one of the most precise of its type done on an entire watershed, and was just published in Hydrology and Earth System Sciences, with support from the National Science Foundation. It makes it clear that new choices are coming for western Oregon and other regions like it.

“In Oregon we have a water-rich environment, but even here we will have to manage our water resources differently in the future,” said Eric Sproles, who led this study as a doctoral student at OSU.

“In the Willamette River, for instance, between 60-80 percent of summer stream flow comes from seasonal snow above 4,000 feet,” he said. “As more precipitation falls as rain, there will more chance of winter flooding as well as summer drought in the same season. More than 70 percent of Oregon’s population lives in the Willamette Valley, with the economy and ecosystems depending heavily on this river.”

Annual precipitation in the future may be either higher or lower, the OSU researchers said. They did calculations for precipitation changes that could range 10 percent in either direction, although change of that magnitude is not anticipated by most climate models.

The study made clear, so far as snowpack goes, that temperature is the driving force, far more than precipitation. Even the highest levels of anticipated precipitation had almost no impact on snow-water storage, they said.

“This is not an issue that will just affect Oregon,” said Anne Nolin, a professor in the College of Earth, Ocean, and Atmospheric Sciences, and co-author of the study. “You may see similar impacts almost anywhere around the world that has low-elevation snow in mountains, such as in Japan, New Zealand, Northern California, the Andes Mountains, a lot of Eastern Europe and the lower-elevation Alps.”

The focus of this study was the McKenzie River, a beautiful, clear mountain river that rises in the high Cascade Range near the Three Sisters volcanoes, and supplies about 25 percent of the late summer discharge of the Willamette River. Researchers said this is one of the most detailed studies of its type done on a large watershed.

Among the findings of the study:

  • The average date of peak snowpack in the spring on this watershed will be about 12 days earlier by the middle of this century.
  • The elevation zone from 1,000 to 1,500 meters will lose the greatest volume of stored water, and some locations at that elevation could lose more than 80 days of snow cover in an average year.
  • Changes in dam operations in the McKenzie River watershed will be needed, but will not be able to make up for the vast capability of water storage in snow.
  • Summer water flows will be going down even as Oregon’s population surges by about 400,000 people from 2010 to 2020.
  • Globally, maritime snow comprises about 10 percent of the Earth’s seasonal snow cover.
  • Snowmelt is a source of water for more than one billion people.
  • Precipitation is highly sensitive to temperature and can fall as rain, snow, or a rain-snow mix.

The model developed for this research, scientists said, could be readily adapted to help other regions in similar situations determine their future loss of snow water in the future.

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Eric Sproles, 541-729-1377

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McKenzie River watershed

McKenzie River watershed


McKenzie River

McKenzie River

Study explains Pacific equatorial cold water region

CORVALLIS, Ore. – A new study published this week in the journal Nature reveals for the first time how the mixing of cold, deep waters from below can change sea surface temperatures on seasonal and longer timescales.

Because this occurs in a huge region of the ocean that takes up heat from the atmosphere, these changes can influence global climate patterns, particularly global warming.

Using a new measurement of mixing, Jim Moum and Jonathan Nash of the College of Earth, Ocean, and Atmospheric Sciences at Oregon State University have obtained the first multi-year records of mixing that permit assessment of seasonal changes. This is a significant advance beyond traditional shipboard measurements that are limited to the time that a ship can be away from port. Small instruments fueled by lithium batteries were built to be easily deployed on deep-sea equatorial moorings.

Moum employs a simple demonstration to show how mixing works.

He pours cold, white cream into a clear glass mug full of hot, black coffee, very carefully, using a straw to inject the heavier cream at the bottom of the mug, where it remains.

“Now we can wait until the cream diffuses into the coffee, and we’ll have a nice cuppa joe,” Moum says. “Unfortunately, the coffee will be cold by then. Or, we can introduce some external energy into the system, and mix it.”

A stirring spoon reveals motions in the mug outlined by the black/white contrasts of cream in coffee until the contrast completely disappears, and the color achieves that of café au lait.

“Mixing is obviously important in our normal lives, from the kitchen to the dispersal of pollutants in the atmosphere, reducing them to levels that are barely tolerable,” he said.

The new study shows how mixing, at the same small scales that appear in your morning coffee, is critical to the ocean. It outlines the processes that create the equatorial Pacific cold tongue, a broad expanse of ocean near the equator that is roughly the size of the continental United States, with sea surface temperatures substantially cooler than surrounding areas.

Because this is a huge expanse that takes up heat from the atmosphere, understanding how it does so is critical to seasonal weather patterns, El Nino, and to global climate change.

In temperate latitudes, the atmosphere heats the ocean in summer and cools it in winter. This causes a clear seasonal cycle in sea surface temperature, at least in the middle of the ocean. At low latitudes near the equator, the atmosphere heats the sea surface throughout the year. Yet a strong seasonal cycle in sea surface temperature is present here, as well. This has puzzled oceanographers for decades who have suspected mixing may be the cause but have not been able to prove this.

Moum, Nash and their colleagues began their effort in 2005 to document mixing at various depths on an annual basis, which previously had been a near-impossible task.

“This is a very important area scientifically, but it’s also quite remote,” Moum said. “From a ship it’s impossible to get the kinds of record lengths needed to resolve seasonal cycles, let alone processes with longer-term cycles like El Nino and La Nina. But for the first time in 2005, we were able to deploy instrumentation to measure mixing on a NOAA mooring and monitor the processes on a year-round basis.”

The researchers found clear evidence that mixing alone cools the sea surface in the cold tongue, and that the magnitude of mixing is influenced by equatorial currents that flow from east to west at the surface, and from west to east in deeper waters 100 meters beneath the surface.

“There is a hint – although it is too early to tell – that increased mixing may lead, or have a correlation to the development of La Niña,” Moum said. “Conversely, less mixing may be associated with El Niño. But we only have a six-year record – we’ll need 25 years or more to reach any conclusions on this question.”

Nash said the biggest uncertainty in climate change models is understanding some of the basic processes for the mixing of deep-ocean and surface waters and the impacts on sea surface temperatures. This work should make climate models more accurate in the future.

The research was funded by the National Science Foundation, and deployments have been supported by the National Oceanic and Atmospheric Administration. Continued research will add instruments at the same equatorial mooring and an additional three locations in the equatorial Pacific cold tongue to gather further data.

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Source: 

Jim Moum, 541-737-2553

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