OREGON STATE UNIVERSITY

environment and natural resources

Study: Forested riparian zones important to nitrogen control, stream health

CORVALLIS, Ore. – Human activities from agriculture to fossil fuel consumption have resulted in high levels of nitrates in many streams and rivers; now a new study suggests that nurturing riparian zone forests may be a key in maintaining healthy waterways.

Streams flowing through urban areas and agricultural lands may have some of the same ability to process nitrates as healthy forest streams – if they have adequate forest buffer zones along their banks, the researchers say.

Results of the research were just published the professional journal, Ecosystems.

“There are many important ways in which streamside trees help maintain healthy river systems,” said lead author Daniel Sobota, who conducted the research as part of his doctoral studies at Oregon State University. “The shade they offer may reduce the amount of sunlight reaching the stream, preventing excessive algae growth.

“Additionally, the leaves and woody debris generated by streamside forests hold the nitrogen and prevent it from being released downstream all at once,” added Sobota, whose Ph.D. was in fisheries and wildlife at OSU. “This ability of a stream to ‘take up’ the nitrogen can help reduce the impacts of nitrogen enrichment in human-altered river basins.”

In the study, which was funded by the National Science Foundation, Sobota and his colleagues looked at nine streams in Oregon’s Willamette Valley that flowed through forest, agricultural or urban landscapes. Among their goals was to discover how much nitrogen was absorbed by the streams near the source, and how much went downriver.

In tests in Willamette Valley streams, the researchers discovered that 21 to 72 percent of nitrates entering the waterway could be stored in leaves, wood and aquatic mosses within one kilometer downstream.

The inability of a stream or river to hold nitrogen can cause “eutrophication,” or excess algae growth that can die and lead to low-oxygen waters. Eutrophication has caused significant problems in the Gulf of Mexico where the Mississippi River drains, as well as in the Chesapeake Bay.

“Forested riparian buffers can help delay nitrogen from going downstream so there isn’t a large influx at one time that could trigger harmful algal blooms,” Sobota said. “From a management perspective, that is a desirable trait.”

Rivers also can process nitrogen naturally through a process called “denitrification.” When oxygen levels in the water are low, bacteria will consume nitrogen instead and release it into the atmosphere – mostly as a harmless gas, Sobota pointed out. However, previous studies by researchers at OSU and the U.S. Forest Service found that the Oregon streams in their study have lower-than-average rates of denitrification.

The reason is a combination of high-gradient streams, oxygenated water and porous streambeds, which are not conducive to denitrification, said Sherri Johnson, a research ecologist with the U.S. Forest Service and a courtesy professor of fisheries and wildlife at OSU.

“A lot of streams in Oregon have subsurface water flowing beneath the streambed through the gravel,” said Johnson, also an author on the Ecosystems article. “This ‘hyporheic’ flow intermixes with the river water and limits the anaerobic processes.”

Linda Ashkenas, a senior faculty research assistant in the Department of Fisheries and Wildlife at OSU and an author on the study, said maintaining complex river channels is also important to stream health.

“Human impacts on rivers have eliminated many of the braids and channels that existed naturally, causing water to flow downstream faster, carrying nitrates with it,” Ashkenas said. “River systems that are more complex slow the water down and give organisms time to filter out the nitrogen.”

Sobota is working with the U.S. Environmental Protection Agency office on the OSU campus as a National Research Council post-doctoral researcher. The Ecosystems study is part of a large, multi-institution project called Lotic Intersite Nitrogen Experiment II, or LINX II.

Media Contact: 
Source: 

Daniel Sobota, 541-754-4833

Corvallis Science Pub to feature Engineers Without Borders, Beavers Without Borders

CORVALLIS, Ore. – At the Oct. 10 Corvallis Science Pub, two Oregon State University groups will describe their efforts to bring shelter and clean water to people in developing countries.

Jordan Machtelinckx, emeritus president of OSU’s Engineers Without Borders chapter, will discuss the challenges of providing safe drinking water to rural communities in El Salvador and Kenya. Taylor Kavanaugh, a 2010 OSU engineering graduate and representative of Beavers Without Borders, will describe the group’s effort to build housing in Guatemala, Macedonia and other countries.

The program begins at 6 p.m. at the Old World Deli, 341 Second St., in downtown Corvallis. It is free and open to the public.

In much of the world, lack of access to potable water is a major public health problem. More than a million children die annually from water-related diseases, according to the World Health Organization. “Engineers Without Borders is a chance for students to combine technical and social knowledge to provide basic human needs to some of the more remote communities around the world,” Machtelinckx said.

Starting in 2006, OSU students undertook the challenge of providing clean water to a remote mountain village in El Salvador. They installed a rainwater catchment system and a gravity-fed network that delivers filtered spring water to a school. In 2010, they shifted their focus to Lela, Kenya, a community of about 400 people who lack access to clean water year around. During annual droughts, they must walk for miles to reach available supplies.

Beavers Without Borders, sponsored by the OSU Department of Intercollegiate Athletics, got under way in 2010, when athletes representing soccer, gymnastics, football, basketball and other sports traveled to Alotenango, Guatemala, to build a new house for a family living in a make-shift shelter. The organization sent another group to Macedonia last spring and has plans to do construction projects in Haiti, Cambodia and Ethiopia.

Sponsors of Science Pub include Terra magazine at OSU, the Downtown Corvallis Association and the Oregon Museum of Science and Industry.

-30-

Media Contact: 
Source: 

Jordan Machtelinckx, 503-734-7929

Insect identification website takes wing at OSU

CORVALLIS, Ore. – A new online tool being developed at Oregon State University uses interactive pattern recognition technology to help researchers quickly and accurately identify species of moths and butterflies.

Jeff Miller, a professor in OSU's College of Agricultural Sciences, and colleague Hans Luh, a senior research associate with the university's Integrated Plant Protection Center, are the creators of the tool, called Lepidoptera Wing Pattern Identification System, or LepWing ID. This pilot project allows users to compare a digital image of a specimen against a library of more than 1,600 photos.

Those images are just a fraction of the roughly 150,000 species of moths and butterflies that have been identified worldwide, but LepWing ID (http://ipmnet.org/lepid) still represents a significant improvement in identification. Compared to thumbing though a paper field guide to put a name to a particular species, the system offers a much faster and more accurate way of identifying moths and butterflies, Miller said. It is the first free, digital tool for identification available to both scientists and the general public.

Though still in its early phases, LepWing ID will be a valuable resource for scientists, as the winged insects are an indicator species of overall ecosystem health. Once the library is expanded, the system also has the potential to be used for non-research purposes. For instance, an agricultural inspector who finds a moth in a load of imported fruit could look up the insect in LepWing ID and determine if it is new to the region, and whether it is a pest or a beneficial.

"It would expedite the response to finding a new insect, perhaps by as much as one whole season, which could make a big difference in responding with appropriate management tactics," Miller said.  

LepWing ID works by matching a color pattern on a specific section of the wing to the same wing section in library images. Users also have the option of selecting certain traits, such as the dominant color of the specimen, from a menu to narrow down possible matches. Results are displayed in descending order, with the most probable matches displaying first. Because there are multiple photos of most species, the system might return the same species several times. But that's a good thing, Miller said, because it reassures the user that the results are accurate.

Users don't even need to have the specimen in hand to use the system: they can upload a computer-made illustration or even a hand-drawn cartoon of what they've glimpsed and LepWing ID will be able to search for potential matches, Miller said.

Miller took many of the photographs of moths and butterflies that make up the system's library, and he continues to add images to increase the tool's accuracy. He hopes LepWing ID will someday have tens of thousands of images to match against an uploaded photo of an unknown species.

Because LepWing ID is free, it's also a tool for the casual gardener or naturalist who is curious about the butterfly out in the garden.

In the future, Miller and Luh envision the LepWing ID model could be used to identify species of stink bugs, beetles, ticks, bees – even plants.

"I think the use is wide-reaching in biology," Miller said.

Source: 

Jeffrey Miller, 541-737-5508

New Western Region Sun Grant Director named

CORVALLIS, Ore. – Oregon State University has named John Talbott as the new director of the Western Region Sun Grant program, through which he will oversee Sun Grant operations in nine states and several Pacific islands. His appointment is effective immediately.

The Sun Grant Initiative is a national network of land grant universities researching the development of bioenergy – energy derived from agricultural products instead of petroleum. OSU coordinates the Western Region Center.

Sun Grant's goal is to increase environmental sustainability, economic development, and national energy security. The organization awards competitive grants to researchers for projects to develop renewable alternative bio-based energies. Bill Boggess has directed the western region since 2008, while maintaining his position as executive associate dean of the College of Agricultural Sciences. He will remain involved with Sun Grant at the national level.

"One of the drivers for bringing John in is that the Sun Grant program has matured; it's ready for a full-time director," Boggess said. "We're expecting John to do things we've never had the resources to do, such as building our working partnerships with federal research agencies, private firms, and related state agencies throughout the western region."

Talbott, who is finishing his public policy Ph.D. dissertation at Virginia Tech, has a diverse background that includes time as a wildlife ecologist, ranch hand, private consultant and county and state agency administrator. For the past five years, he has been deputy director and project manager of the Big Sky Carbon Sequestration Partnership headquartered at Montana State University, a partnership with the U.S. Department of Energy working to find ways to capture and permanently store greenhouse gasses.

Priorities for the Western Region Sun Grant program include enhancing and developing alternative feedstock, the plant material used to make bioenergy; creating energy-efficient agricultural operations; and producing sustainable aviation biofuels. Boggess said there has been a renewed demand for both commercial and military aviation biofuels.

OSU recently participated in an effort, led by several major airlines and other aviation stakeholders, which resulted in an outline to develop a sustainable aviation biofuels industry in the Pacific Northwest.

Talbott's work in his new position may be driven by this increase in interest.

"It's going to be incumbent on Sun Grant, OSU and the other universities to work with producers themselves," Talbott said. "How do we supply them with the knowledge and economic security necessary to change their agricultural operations to focus on feedstock for biofuel?"

As an avid outdoorsman, Talbott is familiar with rural communities and the challenges they face.  He said the Sun Grant position will allow him to have a stake in aiding those places.

"Here's a chance to do something both for the environment and the environmental policy and at the same time really spur some sustainable economic growth in these rural communities," he said. "I find that really intriguing and a really exciting challenge."

Source: 

Bill Boggess, 541-737-1395

Analysis of 500-year-old salmon finds importance of smaller juveniles

NEWPORT, Ore. – Chinook salmon reared in the upper stretches of the Columbia River watershed 250 to 500 years ago used to leave their freshwater habitat and enter the estuary – and possibly even the Pacific Ocean – when they were smaller and younger than most of their contemporary counterparts.

Researchers tracking the life history of salmon long before dams were built on the Columbia say the finding suggests that fisheries leaders may need to manage for a diversity of life histories.

Results of the research have been published in the Canadian Journal of Fisheries.

“The Columbia River estuary is an amazingly productive system and there clearly are advantages for fish to enter into that environment,” said Jessica Miller, an Oregon State University ecologist and lead author on the study. “Yet today fish remain in fresh water for a longer period of time – possibly because they must navigate past the dams, and because river flows during their ocean migration have been reduced with the development of the hydropower system.

“Chinook salmon have a more diverse portfolio than other salmon species, which may be one reason some of their populations are doing so well,” Miller added. “Managing the resource to retain that diversity seems like a logical strategy.”

“We know there are advantages for the salmon to reach a certain size before entering the ocean, especially in avoiding prey,” Miller pointed out. “But there may be long-term advantages to having individuals that migrate at a diversity of sizes.”

To learn more about ancient salmon runs, the researchers worked with the Confederated Tribes of the Colville in Washington, where they obtained the skeletal remains of salmon from a former archaeological site just downriver from Grand Coulee Dam. The fish, which the scientists dated to 250-500 years ago, were in an area of the Columbia River which is no longer accessible to migrating fish because of the dams.

One goal of the research was to see if fish that used to go upstream of Chief Joseph Dam – the farthest upriver that salmon and steelhead return – had different characteristics than present-day fish. To do this, they looked at the bony structure within the salmon’s ears called an “otolith,” which accretes calcium carbonate and forms growth rings. By examining the growth rings and isotopes within otoliths, scientists can ascertain the age of a fish, where it lived and sometimes what it has eaten.

“It’s pretty amazing that we can look at the otolith of a 500-year-old fish and determine which river it likely originated in and at what size it entered marine waters,” said Miller, an assistant professor of fisheries and wildlife who works out of OSU’s Hatfield Marine Science Center in Newport.

They do this by analyzing the ratio of strontium-to-calcium isotopes in the otolith. A high ratio indicates a fish has been living in salt water, while a lower ratio suggests recent freshwater history. They also can examine two isotopes of strontium, which can provide information on the river of origin.

“We can also estimate where in the river system they were, because as you move east to west, the rocks get younger and the strontium values change,” Miller said. “In most cases, the isotopic signature is extraordinarily revealing.”

Miller also was lead author on another study, published in the Marine Ecology Progress Series, which examined diversity of fish runs in modern populations. Focusing on Central Valley (California) Chinook salmon, the study determined that adult fish typically had begun their juvenile migration in two “pulses.”

A majority of adults had begun their seaward migration as larger juveniles (75 millimeters or longer), which typically leave rivers in mid-April to May. But the adult sample also contained fish that had begun their emigration as smaller fish (less than 55 mm). Though fewer in numbers, these smaller fish were still significant and typically left rivers in February and March.

“In the Central Valley, the vast majority of hatchery production is focused on larger juveniles, whereas most of the naturally produced fish appear to emigrate at a smaller size,” Miller said. “Similar to the variation in adult run timing – which may protect runs against catastrophic floods, drought or disease – variation in the timing of juvenile migration to the ocean may be important for long-term survival.”

Other researchers on the Canadian Journal of Fisheries study include Virginia Butler, Portland State University; Charles Simenstad, University of Washington; David Backus, Williams College; and Adam Kent, OSU.

Media Contact: 
Source: 

Jessica Miller, 541-867-0381

Earth-friendly technologies to be discussed at Greener Nano conference

CUPERTINO, Calif – Despite increasing awareness of the demand for environmentally safe consumer products, barriers for commercial production remain – a dichotomy especially severe in the rapidly growing field of nanotechnology.

To address this situation, the Oregon Nanoscience and Microtechnologies Institute (ONAMI) and the Safer Nanomaterials and Manufacturing Initiative (SSNI) will host the Greener Nano 2011 Conference and Workshop May 1-3 in California. The events will be at the Hotel Valencia in San Jose and Hewlett-Packard Co.'s site in Cupertino.

"There is a national push to think about the safe development of nanotech from its conception," said Robert Tanguay, a professor of molecular toxicology in Oregon State University's College of Agricultural Sciences, and a leader in national initiatives for safety in nanotechnology. "There is a shift toward greening the technology right out of the gate, rather than as an afterthought. It's the difference in proactive versus reactive design in safer technologies."

Nanotechnologies have experienced rapid growth in the last decade, and nanoparticles are now found in consumer products ranging from laundry soap to eyeliner. However, their environmental impact is largely unknown, and increasingly controversial.

A recent study from Queen's University found that the silver nanoparticles used in many consumer products may harm beneficial soil bacteria, potentially resulting in a hostile environment for plants. While it remains unclear if these effects were directly caused by silver nanoparticles, it is known that most products in commerce have not had the advantage of being designed from the ground up with a mind toward greener innovation, said Tanguay.

The upcoming workshop and conference will bring together policymakers, industry, students and researchers to discuss advancing a "greener" nanotechnology. Plenary speaker for the conference is  Stanley Williams, senior fellow at Hewlett-Packard Laboratories and founding director of the HP Quantum Science Research Group. He will discuss the sustainable development of nanotechnology in the next decades.

More information on the conference is available at http://oregonstate.edu/conferences/event/greenernano/index.htm

About the Oregon Nanoscience and Microtechnologies Institute: ONAMI is the first Signature Research Center for the advancement of research toward the commercialization of innovative technology within Oregon and the Northwest. It represents an unprecedented collaboration between Oregon's three public research universities - University of Oregon, Oregon State University, Portland State University - and the Pacific Northwest National Laboratory, the state of Oregon, and the region's high-technology industries.

Source: 

Robert Tanguay, 541-737-6514

Bill Gates Sr. to speak at Oct. 19 ARCS Foundation Scholar Awards Luncheon in Portland

PORTLAND, Ore. -- Bill Gates, Sr., co-chair of The Bill and Melinda Gates Foundation, will be the keynote speaker for the ARCS Foundation Portland Chapter’s 2010 Scholar Awards Luncheon Oct. 19 at the Portland Art Museum.

Gates will speak on “Making a Difference: The Value of Philanthropy in Education,” particularly fitting as the Portland Chapter of ARCS (Achievement Rewards for College Scientists) will cross the $1-million mark for awards to graduate students in science and engineering at Oregon Health & Science University and Oregon State University this year.

“Gates has been a long-time supporter of ARCS both in Seattle and nationally,” said Caron Ogg, president of the Portland Chapter of ARCS . “In fact, it was a grant from the Gates Foundation that helped to launch the Portland Chapter six years ago.”

Also speaking will be Clayton Winkler, an ARCS Scholar and Ph.D. candidate in the Department of Neuroscience at OHSU, who will discuss his research on treating progressive neurological disease with a simple sugar.

At the Oct. 19 luncheon, 10 new ARCS Scholar Awards will be given to OHSU students and five to OSU students.  These scholars join 77 outstanding men and women ARCS scholars, collectively, currently studying at both institutions.

“The ARCS Foundation’s engagement with OSU and support of our students has been both gratifying and of great benefit to some very worthy young scholars ,” said Edward J. Ray, president of Oregon State University. “We are proud to be partners with the Portland Chapter and, along with OHSU, to be beneficiaries of the chapter’s vision and generosity in advancing scientific education and innovation.”

The ARCS Foundation was established in 1958 in Los Angeles by a group of women committed to keeping American technologically strong and internationally competitive. There currently are 17 ARCS chapters nationwide – all dedicated to advancing science in America through the provision of financial support to outstanding U.S. citizens completing graduate degrees in natural science, medicine and engineering.

For further information about the ARCS Foundation Portland Chapter or the October 19 luncheon, call (503) 297-8603 or email Portland@arcsfoundation.org.

Source: 

Creative writers sought for fall residency at Andrews Forest

CORVALLIS, Ore. – Applications are being sought from writers interested in a one-week fall residency at the H.J. Andrews Experimental Forest.

The residency is part of the Long-Term Ecological Reflections program, which brings together writers, humanists and scientists to create a living, growing record of the forest and the relation of people to the forest.

Creative writers whose work in any genre reflects a keen awareness of the natural world and an appreciation for both scientific and literary ways of knowing are invited to apply. In 2003, the Spring Creek Project at Oregon State University, in collaboration with the Andrews Forest Long-Term Ecological Research Group, began inviting writers to spend weeklong residencies at the forest in order to provide ways of observing the land that complement the ways of science.

Last year’s writer-in-residence, Scott Russell Sanders, wrote an essay called “Mind in the Forest” during his stay. That essay, published in Orion magazine, was recently awarded the John Burroughs Award for an Outstanding Published Nature Essay.

Two earlier pieces of writing inspired by the Andrews Forest residencies also have appeared in Orion: Robert Michael Pyle’s “The Long Haul” (September/October 2004) and Alison Hawthorne Deming’s “The Web” (March/April 2007).

For the Andrews Forest residencies, writers are provided an apartment, access to the ancient forest and well-known research site, interaction with scientists, opportunities to have their writings included in The Forest Log, and an honorarium of $250. Specific dates for week-long residencies during September, October, or November can be negotiated around the writer’s schedule and availability of space. 

The application deadline is May 15. For complete application requirements, go to http://springcreek.oregonstate.edu/residencies.html#AndrewsResidency

Information about the Andrews Experimental Forest is available at http://andrewsforest.oregonstate.edu/

Media Contact: 
Source: 

Charles Goodrich, (541) 737-6198

Talk on ‘Where Does Our Food Come From?” held Tuesday, Dec. 1

CORVALLIS, Ore. – Ethno-botanist and author Gary Nabhan and local seed grower Frank Morton will explore the stories and cultural practices of food and seed production during a benefit event, on Tuesday, Dec. 1, beginning 7 p.m. at Mary’s River Grange in Philomath.

In their talk, “Where Does Our Food Come From?”, Nabhan and Morton will talk about what food production and supply systems reveal about a relationship to the land and to food. They also will explore other ways of imagining those relationships.

Their presentation is sponsored by Oregon State University’s Spring Creek Project for Ideas, Nature, and the Written Word, and is a benefit for Ten Rivers Food Web.

Nabhan is an award-winning ethno-botanist, author, poet and local foods advocate who learns from gardening and caring for his heritage breeds of sheep and turkeys. Some of his popular books include, “Arab/American: Landscape, Culture and Cuisine in Two Great Deserts,” Why Some Like It Hot: Food, Genes and Cultural Diversity,” and “Coming Home to Eat: The Pleasure and Politics of Local Foods.” Nabhan is a tenured research social scientist at University of Arizona.

Nabhan will be in Oregon as writer-in-residence at the H.J. Andrews Experimental Forest as part of the Long-Term Ecological Reflections program, with funding from the U.S. Forest Service.

Joining Nabhan will be local seed grower Frank Morton of Wild Garden Seeds. Morton brings almost 30 years of experience growing organic seeds for farmers, gardeners and Gathering Together Farm in Philomath.

Mary’s River Grange is located on Grange Hall Road south of Philomath (near Gathering Together Farm, at 25159 Grange Hall Road, Philomath).

Advance tickets (sliding scale, $7 to $20) are available at Corvallis Brewing Supply, 119 S.W. 4th St., Corvallis; and at GrassRoots Books and Music, 227 S.W. 2nd  St., Corvallis.

Media Contact: 
Source: 

Charles Goodrich, 737-6198

Satellite Studies of Ship Tracks Show Complex Influence of Pollution on Clouds

SAN FRANCISCO – New satellite studies analyzing the impact on clouds from ocean-going ships suggest that airborne particles from pollution or other causes can have a drying effect on some clouds, and a saturating effect on others, complicating global climate change models.

The key difference is what kind of clouds become “perturbed” by the pollution and what the overlying atmospheric conditions may be, the researchers say.

“One significant impact is that our observations suggest clouds affected by haze will offer less reflectivity and less of a cooling effect than most global climate change models suggest,” said Jim Coakley, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and principal investigator in the study.

Coakley presented the findings today at the annual meeting of the American Geophysical Union in San Francisco.

The ships are not necessarily a major cause of pollution, but the particles they emit into the air affect the overlying clouds and these effects can be easily tracked by NASA satellites. The impact of those emissions on the clouds is providing researchers with new information about cloud “behavior.”

Previous studies by Coakley and OSU graduate student Matt Segrin found that particles emitted by ships led to smaller water droplets and a general drying out of the clouds. Yet most models suggested just the opposite – that increasing the number of particles should lead to more liquid in the droplets.

“What we found was that most of those earlier satellite observations were taken off the coast of California and Oregon, where the marine cloud bank was heavy and the air above it comparatively dry,” Coakley said. “The clouds tend to suck down the drier air above them and because the droplets are smaller than normal from the pollution, they evaporate more readily. That evaporation cools the dry air which then sinks, drawing in more air from above, and the pollution clouds end up drying themselves out.

“In our latest studies, using NASA’s Aqua and Terra satellites, we followed the ships past the marine deck and out to where the nearby pristine clouds are dissipating,” Coakley said. “There the ships’ emissions actually create a cloud where clouds would not otherwise appear. We think that the atmosphere above these regions isn’t as dry so that the polluted clouds with their smaller droplets survive, while the nearby unpolluted clouds dissipate because their larger droplets and the support of the relatively moist air aloft grow to form drizzle and fall from the sky.”

When water molecules condense, they attach to a particle and make droplets. When there are few particles in the air, the droplets are bigger and more likely to reach the saturation point and fall as precipitation. Where there is pollution, more particles are in the air and the droplets become smaller, making it harder for them to grow to drizzle-sized droplets.

Because the pollution generates more particles and the water molecules adhere to them, many scientists have speculated that the clouds would become brighter and more reflective. And since burning fossil fuels would likely result in more particles, overall reflectivity would be higher. But the ship track research points out that isn’t necessarily the case. Those same droplets draw in the warmer air above and essentially evaporate, actually lowering the reflectivity to levels below that predicted by climate models.

“Cloud formation and response to pollution and environmental conditions is the weakest part of global climate change studies,” Coakley said. “What we are learning from our studies of polluted clouds is helping us better understand how all clouds behave.”

The researchers use near-infrared radiation to identify exactly where clouds have been polluted from the ships’ emissions then look at either side of the cloud to see the impact of that interaction on the nearby pristine clouds. The ships act as a kind of laboratory, creating tracks of pollution emissions easily visible via satellite imagery.

Ships are not alone in their impacts on clouds, Coakley pointed out, they are merely a convenient tool for research. Coal plants, automobiles and other pollution-causing agents also send particles into the air that can have an effect on cloud formation and behavior.

“You should see the pollution plumes from Los Angeles and San Francisco in the satellite images,” Coakley said. “They are so intense it’s difficult to follow the ship tracks in those locations.”

Coakley has been studying ship tracks and their impacts on clouds for more than 15 years and says the research provides data that should be helpful to climate modelers. It is premature to jump to too many conclusions about how clouds will react to global climate change without more years of research, he emphasized.

“These impacts from the ship tracks are local,” he said, “and we’re just discovering how important the air above the clouds is to their response. There may be many other factors that affect how particles form droplets, how the clouds respond, and what the result is in terms of reflectivity.”

 

Media Contact: 
Source: 

Jim Coakley,
541-737-5686

Multimedia Downloads
Multimedia: 

Ship clouds

This satellite image shows the clear path of a ship. Particles expelled by the ship’s engines pollute the clouds and cause them to have smaller droplets, affecting their reflectivity and behavior.