High-performance computer modeling to tackle fisheries future
Timely forecasts of storms and effective management of commercial fishing are essential in the wake of extreme weather events and unprecedented warming in the Gulf of Maine.
Damian Brady, University of Maine assistant professor in the School of Marine Sciences at the Darling Marine Center, is working to advance both of those goals.
The National Science Foundation recently awarded Brady and colleagues a $266,309 grant to advance UMaine high-performance computer modeling tools to do just that.
The project — “Major Research Instrumentation Program Track 1: Acquisition of High Performance Computing to Model Coastal Responses to a Changing Environment” — includes buying a system that nearly triples computing power at the university and acquiring an off-site backup system for project data.
The project is ideal because it joins world-class researchers and experts in cyberinfrastructure to create a platform that advances goals of the research and creates a platform that benefits research and education across all disciplines, says Bruce Segee, the Henry R. and Grace V. Butler Professor of Electrical and Computer Engineering and director of the Advanced Computing Group.
“Computing and storage are the test tubes and microscopes of the 21st century. They support the creation of knowledge, collaboration, communication and economic growth,” he says.
“Maine is fortunate to have a High Performance Computation facility available to its researchers and students, and this grant will help significantly increase the complexity of the questions that can be asked and the number of users it can support. Demand for computing resources is growing at a rapid pace, and this grant provides a great step forward to help meet the demand.”
The tools will help scientists better predict climate changes and extreme weather, as well as understand ensuing ecological and physical consequences, and weigh costs and benefits of adaptation or mitigation.
“The effects of climate change are not likely to be straightforward. There are species and ecosystems that will benefit and those that will not,” says Brady.
“The purpose of running computer models is that they ask the really tough questions like: What will happen to the lobster industry under a 1-, 2-, or 3-degree (temperature) increase? What will the impact of increased rainfall be on shellfish along the coast? Although models will not perfectly predict the consequences of these changes, they can give us a range of potential futures.”
Maine is uniquely positioned physically and economically to be affected by climate change, Brady says. The state is on one of the sharpest latitudinal temperature gradients in the world and has one of the longest coastlines in the United States.”
And the potential impacts of climate change are significant for Maine, where the economy is linked to marine resources and infrastructure. The aquaculture industry (predominantly salmon and shellfish) doubled in value from 2005 to 2013. And Maine’s commercial fisheries were valued at a record $585 million in 2014, says Brady.
Boosting computing capacity at UMaine will allow coastal modelers to inform local decisions and increase undergraduate and graduate student access to high-performance computing, Brady says.
UMaine colleagues Huijie Xue, professor of oceanography; Fei Chai, professor of oceanography; Qingping Zou, assistant professor of coastal engineering, and Sean Birkel, research assistant professor with the Climate Change Institute, are taking part in the three-year project with Brady and Segee.
Contact email@example.com with open GA positions
Is your department looking for a Graduate Assistant? Contact Lauren Dupee (firstname.lastname@example.org) to post on the Graduate School website!
New England Future Faculty Workshop For Women to be held August 10, 2017
The New England Future Faculty Workshop For Women (NE-FWW) in STEM fields is being held August 10, 2017, at Northeastern University in Boston, MA. This exciting opportunity is for female postdocs and advanced graduate students interested in faculty careers. Learn more about the workshop.
If you are interested in participating in the NE-FFW, you must complete the following steps:
- Apply online by May 26th
- Submit a 300 word statement about why you want to participate
- Submit your CV
- Accepted applicants will be notified by June 5th
- Confirm participation by:
- Paying a $25 registration fee by July 1, 2017
- Uploading a research statement
Call for Judges: 2017 Maine State Science Fair
From Mike McKernan, Program Director of STEM and Undergraduate Education, The Jackson Laboratory:
As you may know, The Jackson Laboratory is an organizer of the Maine State Science Fair. This year’s fair will be held on Saturday, March 25, at Colby College, in Waterville, ME.
The 2017 Fair will be the largest Maine State Science Fair to date, including 250 students from 28 Maine high schools. Given this outstanding response, additional judges are needed to help evaluate student research and engineering projects including all STEM categories: natural sciences, social sciences, mathematics, computer sciences, etc. All projects will be scored using a standardized rubric (very similar to a poster session), and the top scoring projects will be recognized within their STEM category. The top three projects, overall, will represent Maine at the Intel Science and Engineering Fair to be held in Los Angeles in May. In addition to these awards, we plan to award a number of full-tuition scholarships to The University of Maine, the University of Southern Maine, and College of the Atlantic.
Several of you have served as judges in prior years and are returning to the 2017 MSSF (and have already registered to do so). We are looking to recruit a few more individuals willing to help out this year. Judge registration begins at 8 am and the judging rounds begin at 9 am. Scores are tallied during a working lunch and judges are typically free to go by 1 – 1:30 pm.
If you are interested, please register online: https://www.jax.org/education-and-learning/high-school-students-and-undergraduates/maine-state-science-fair/judges/judge-registration-form
Questions? Don’t hesitate to ask.
Program Director, STEM and Undergraduate Education
207.288.6806 t | 207.610.0684 m
The Jackson Laboratory
Bar Harbor, ME | Farmington, CT | Sacramento, CA www.jax.org
Researchers help salmon farmers confront threat to their industry
It’s a mystery that has puzzled University of Maine assistant professor of marine biology and aquaculture Heather Hamlin and the salmon farming industry in New England: the decline in egg survival.
The survival rate of fertilized salmon eggs had been as high as 80 percent. But beginning in 2000, salmon embryos began dying in large numbers and the average survival rate fell to around 50 percent.
Previous studies have shown that a range of factors can negatively impact egg quality and production, including nutrition, stress, temperature and the endocrine status of the female. Until recently, businesses such as New Brunswick-based Cooke Aquaculture, which runs farming operations at several sites in Maine, knew little about why some of its eggs were dying and others were surviving, despite having come from same strain females, cultured under similar conditions.
Now a UMaine study has found that two hormones may play significant roles in achieving an 80 percent embryo survival rate. Hamlin and LeeAnne Thayer, a UMaine Ph.D. candidate in marine sciences, wrote about their findings in the journal Aquaculture Research.
For the past five years, Hamlin and Thayer have been taking tissue samples from Atlantic salmon ages 2–4 at three sites: the National Coldwater Marine Aquaculture Center run by the U.S. Department of Agriculture at UMaine’s Center for Cooperative Aquaculture Research in Franklin; and two sites owned by Cooke Aquaculture — a fresh-water breeding site in Bingham and a sea cage site in Eastport.
In their research, Hamlin and Thayer incubated fertilized eggs and monitored their development. What they watched for was the development of the embryos’ eyes in the bright orange eggs — a good indication that the egg will ultimately hatch.
For Hamlin and Thayer, a major focus of their research has been the endocrine system, which includes the hormones, the tissues that produce them and the genes that regulate them. Because hormones regulate much of reproduction and embryonic development and many other systems, the researchers wanted to determine if there was a difference in the hormone profiles of the females producing batches of eggs with high and low survival rates.
Hamlin and Thayer found that female Atlantic salmon with the highest levels of 11-ketotestosterone, an androgen, and 17-beta estradiol, an estrogen, were more likely to produce embryos with an 80 percent survival rate.
The project was a natural next step in Hamlin’s research career focused on the intersection of endocrinology and reproductive health. The Hampden, Maine native received her bachelor’s and master’s degrees from UMaine. She was an assistant professor in the department of obstetrics and gynecology at the Medical University of South Carolina before returning to her alma mater in 2011.
“How do I use what I’ve done in the past to address problems that are important to Maine?” says Hamlin. “It’s a really important part of our scholarship and research. It has less utility, in my opinion, if it can’t benefit the people of Maine.”
Hamlin found the research project that would allow her to fulfill this goal a few months before beginning her job in Orono. That spring, she was invited to a salmon hatchery roundtable in Bangor. Commercial aquaculture producers, marine scientists and state and federal officials gather biannually to discuss challenges facing hatcheries in New England. At the meeting, Hamlin learned about declining embryo survival rates in farmed Atlantic salmon.
Hamlin’s Ph.D. research at the University of Florida had examined how pesticides, nitrates and chemicals in plastics affected the reproductive health of alligators, sharks, chickens, Siberian sturgeon and turtles. Later, in South Carolina, the reproductive endocrinologist worked at the Hollings Marine Laboratory, where she did research on marine animals in an effort to learn more about problems impacting maternal fetal health.
In the declining survival rates of salmon embryos in New England, Hamlin saw an opportunity to use her expertise in endocrinology and reproduction to help solve a major problem facing an industry vital to Maine’s economy.
Cooke Aquaculture operates salmon farming operations in New Brunswick, Nova Scotia, Newfoundland, Chile, Scotland, Maine and Washington and sea bass and sea bream farming operations in Spain. The Cooke family of companies now includes wild salmon and groundfish processing, through Icicle Seafoods, Inc. in Alaska, as well as shrimp, oyster, scallop, king crab and other products through the Virginia-based Wanchese Fish Company and a hake fishery and processor, Cooke Uruguay (formerly Fripur).
Cooke representatives were among the industry officials at the salmon hatchery roundtable in Bangor. Hamlin introduced herself after hearing about the salmon embryo survival problem, and proposed working together to solve the issue.
The declining embryo survival rate creates unpredictability, which means the company must produce more eggs than needed to ensure a consistent supply of salmon for the marketplace.
Hamlin will now turn her attention to hormonal processes related to egg assembly, ovulation or post-ovulatory aging. In the next phase of her research, Hamlin plans to analyze arrays of mRNA transcripts, or transcriptomes, in the tissues of farmed Atlantic salmon to see which systems inside the fish are the most stressed.
“That could really help us sort of identify that needle in the haystack,” says Hamlin. “We can start to identify very specific pathways that might be affected. Then we might be able to definitively identify causes. That’s a relatively new area of research.”
Contact: Jay Field, 207.581.3721; 207.338.8068
From UMaine News.
Official Graduate Student Government Statement on Immigration Executive Order
Below is a message directly from the leadership of the Graduate Student Government concerning the Immigration Executive Order:
January 30, 2017
We have received numerous requests for information from graduate students in regard to the Executive Order on Immigration signed by the President of the United States on Friday. This email is to assure you that the University of Maine administration, the Graduate School, the Graduate Student Government, and the University of Maine System leadership and Board of Trustees serve as allies, resources, and advocates for all UMS students.
UMS Counsel is in the process of determining next steps for students and organizing a forum for questions alongside the UMS campus Student Governments. Details about these meetings will be emailed soon.
We have been assured that Congress has not changed the immigration laws of the United States and that all legal guarantees of freedom and protection of religion, race, and country of origin are still maintained by the Constitution.
If there are any questions in regards to next steps, or if any graduate student has concerns about safety or comfort, please reach out to any of the GSG representatives https://umaine.edu/gsg/executive-committee/ or to the Graduate School (207) 581-3291 or email@example.com.
Below is a list of additional on-campus resources:
Counseling Center (Free & Confidential): (207) 581-1392
Office of Multicultural Student Life: (207) 581-1428
Office of International Programs: (207) 581-3437
Dean of Student’s Office: (207) 581-1406
University of Maine Police Department: (207) 581-4040
Office of Community Standards, Rights, & Responsibilities: (207) 581-1409
Again, please do not hesitate to reach out. You are not alone.
Shane J. Cushing, GSG President
Kimberley Rain Miner, BOT Representative
Gill examines plants encased in tar pits to reconstruct ice age ecosystem
For tens of thousands of years, the warm, sticky natural asphalt that occasionally bubbled to the Earth’s surface in the area now called Los Angeles was a death sentence for some ice age animals.
Woolly mammoths, camels, rabbits, horses, bison, sloths, rodents, snails, turtles, birds and saber-toothed cats perished after becoming mired in the liquid asphalt — sometimes referred to as tar pits.
For Jacquelyn Gill, the fossils, twigs and plants encased in this sticky petroleum at the La Brea Tar Pits and Museum in downtown Los Angeles provide opportunities to examine the climate and flora and fauna of the past and observe evolutionary changes.
The University of Maine paleoecologist’s findings will be added to the broader mosaic of what’s already known about the very large animals of that era.
Gill and other scientists involved with Project 23, as it’s called, intend to reconstruct the food web — from mastodons and bison to rodents and plants — during 2,000- to 5,000-year snapshots across an approximate 50,000-year period.
“Most of these are ice age survivors,” Gill says of the animals and plants trapped in the oil seeps. “What made them so resilient to climate change and extinction?”
By reconstructing the food web, Gill and the team of researchers will learn how various species were connected for extended periods of time when they were not under climate stress.
Understanding those connections could help protect today’s biodiversity in a changing climate, she says.
“We can see how species relied on each other, and use those relationships to predict extinction risk based on food web connections,” says Gill. “It’s a useful model to apply to our modern ecosystems.”
Fossils in the tar pit tombs were unearthed recently when the Los Angeles County Museum of Art, which is adjacent to La Brea Tar Pits and Museum, excavated a site to build an underground parking garage.
Salt Lake Oil Field, a large petroleum reservoir below the Earth’s surface, is nearby. For tens of thousands of years, oil — formed from marine plankton deposited in an ocean basin 5–25 million years ago — has seeped to the surface.
The National Science Foundation funds Gill’s nearly $300,000 portion of the $1.2 million three-year project.
Gill conceived of the project when she delivered a lecture about ice age ecosystems and extinction at the Natural History Museum of Los Angeles County, which manages the Tar Pits.
“For the first time, we can look at the entire ice age ecosystem of Rancho La Brea, instead of just the largest herbivores and predators,” Gill says.
Thus far, Gill says the plants that have been identified in asphalt chunks from Los Angeles now grow in Oregon and at higher elevations in the southern Sierra Nevada mountains.
This indicates the late Pleistocene climate at La Brea Tar Pits was cooler and wetter than it is now, she says.
UMaine undergraduate Chason Frost, an environmental horticulture major from Gardiner, Maine, is assisting Gill with research.
University of California Merced professors Jessica Blois and Justin Yeakel and several graduate students there also are taking part in the project, as is Emily Lindsey, a curator at the La Brea Tar Pits and Museum.
In Maine, the grant includes funding for middle school student-centered citizen science activities as well as for training of middle school educators.
Gill is a frequent source for The New York Times, Slate, The Atlantic, National Geographic and other national media for articles on climate and ecosystem change, extinction and past and modern ecosystems.
She co-hosts Warm Regards, a podcast about the warming planet created by Eric Holthaus, a meteorologist and writer. Andy Revkin, a senior reporter at ProPublica, also is a co-host.
Recent topics, which can be heard on SoundCloud, iTunes and Twitter, include “The year in review,” “On humanizing science” and “Climate anxiety in the Trump era.”
As a researcher and educator at a public university, Gill says she’s sensitive to her responsibility to think about ways in which science influences policy.
Gill also is active on Twitter. “I’m passionate about how my work connects with the public and about standing up for science and publicly funded science,” she says.
Having conversations — in class, on podcasts and on social media — amplifies the messages, she says, and helps people make meaningful connections with science.
Contact: Beth Staples, 207.581.3777
From UMaine News.
Professor examines 100 years of rural education research
What can you learn by studying 100 years of academic writing about rural education in the United States? For Catharine Biddle, assistant professor of educational leadership at the University of Maine, it’s this: the more things change, the more they stay the same.
“If you look at the case we follow, it’s like the conversations are almost exactly the same. The circumstances around them maybe have changed, but the core is the same,” says Biddle, who co-authored an article published last month in the Review of Research in Education titled “Constructing and Reconstructing the ‘Rural School Problem’: A Century of Rural Education Research.”
Biddle and co-author Amy Price Azano, an assistant professor of adolescent literacy at Virginia Tech, trace the origins the “rural school problem” to the progressive education reformers of the early 20th century. Ellwood Cubberley was the first to use the phrase, writing in response to a landmark report on rural America issued by President Theodore Roosevelt’s U.S. Commission on Country Life. The commission’s report included details on the poor condition of rural schools, many of which were still one-room schoolhouses. Biddle and Azano write that Cubberley and like-minded reformers sought to modernize rural schools over concerns “about the provinciality of rural life and people, the administrative inefficiency of rural schools, and the lack of adequate preparation for rural teachers.”
Biddle says one of the most interesting discoveries for her were how, after attracting a lot of attention in the first half of the 20th century, interest in rural education as a topic of academic research in the U.S. started to wane by the 1950s. She speculates that school consolidation and modernization in the early part of the century led many researchers to believe the “rural school problem” had been solved.
“There were fewer and fewer one-room schoolhouses, even though the actual problems hadn’t necessarily gone away,” Biddle says.
Biddle and Azano examined nearly 150 academic articles published between 1910 and 2015. Rather than study the totality of rural education research over that period, they looked at one aspect in particular: rural teacher recruitment, retention and training. Taking a long view of this one topic, says Biddle, shows how little changed in terms of the issues facing rural education.
“Rural schools have always had a hard time attracting teachers, and then the teachers they do attract have to do a wide variety of things and teach a wide variety of subjects, which they wouldn’t necessarily have to do in a more specialized urban environment,” she says.
As changing economic conditions, such as free trade and globalization, began to leave their mark on rural areas, Biddle says there was a renaissance in rural education research beginning in the late 20th century. Even here she sees parallels to the issues discussed by education reformers a century earlier.
“In rural America around the turn of the 20th century, you had these huge infrastructure challenges. You know, electrification and trying to connect telephone lines to all of these areas. Today, we’re talking about fiber optic cables and high-speed internet access and that kind of thing,” she says.
An aspect that has changed, Biddle says, is that rural America has lost population since the early 20th century. That’s had a negative impact on the political capital of rural communities and, in turn, rural schools, she says.
Biddle and Azano conclude their article by cautioning researchers against seeing rurality itself as a cause of the problems facing rural schools. They recommend education researchers take a more holistic look at issues of place.
“A lot of literature at the turn of the century focused on the things that rural schools lack, and there’s a tendency to still do that today. That’s kind of the echo forward of the ‘rural school problem,’” Biddle says. “But there’s all this literature now talking about the dangers of deficit-based approaches to education — just looking at what schools don’t have, or what communities don’t have — rather than an asset-based approach or looking at the strengths of those places.”
In their next project, Biddle and Azano are comparing early 20th-century literature on education to research from the turn of the 21st century to see how the perspectives on the deficiencies or assets of rural schools evolved. They plan to present that research at the American Educational Research Association’s annual meeting in late April.
Contact: Casey Kelly, 581.3751
From UMaine News.
UMaine engineers make waves in naval architecture
A tiny storm rages at the University of Maine’s Advanced Structures and Composites Center.
Simulated wind and waves beat against the hull of a model FPSO vessel in conditions comparable to a 100-year storm off the coast of western Africa.
Watching from the side of the wind-wave basin in the Alfond W2 Ocean Engineering Laboratory, Razieh Zangeneh, a UMaine Ph.D. student in mechanical engineering, closely monitors the three-meter-long model’s movement as it rises and falls over the swells.
Floating Production, Storage and Offloading vessels, also known as FPSOs, have become a primary method for extracting, processing and storing offshore oil and gas in many areas around the world. Hydrocarbons from beneath the seafloor are transported to the vessel through a network of undersea pipelines and wells. Once onboard, the oil is processed and stored until it can be offloaded onto small shuttle tankers and transported to coastal refineries.
The floating production vessels are often retrofitted oil tankers. However, unlike their mobile counterparts, they are permanently moored to the sea floor for long periods of time. As a result, they endure a wide variety of ocean conditions, including extreme storms.
Zangeneh, who came to UMaine after finishing a master’s degree at the Amirkabir University of Technology in Tehran, Iran, is studying the performance of FPSO hull shapes and the deep-water mooring systems that hold them in place in offshore environments, where two different wave systems moving in uncorrelated directions — or bidirectional waves — combine with wind to produce complex ocean conditions.
FPSO vessels are commonly held stationary by a turret mooring system, which is attached to the hull at or near the bow of the ship. It allows the vessel to freely swivel, or weathervane, in response to the prevailing ocean conditions, keeping the vessel’s bow pointed into oncoming wind and waves. This orientation helps reduce the strain on the mooring system, production equipment and crew during heavy seas and storm events.
However, in some parts of the world, local wave systems and wind combine with swells borne from distant ocean storms and produce bidirectional wave patterns. These patterns have been shown to cause heading instability in moored FPSOs, which can have a tremendous impact on the stability of the vessel.
The wind-wave basin at the Alfond W2 Ocean Engineering Lab is one of the few facilities in the world that can model both wind and bidirectional wave patterns and simulate some of the worst and most dynamic ocean conditions on the planet.
The 1/120-scale FPSO hull was built at the UMaine Marine Ocean and Offshore Research (MOOR) Laboratory with help from graduate and undergraduate mechanical engineering students. While the model is just over 9 feet in length, it represents a ship more than 1,000 feet long, 190 feet tall and weighing 3,000 tons.
The 100-year storm conditions in the waters off western Africa, while relatively tame compared to other regions of the world, are often comprised of long-period swells and local waves with varying degrees of severity and direction, combined with sudden changes in wind speed and direction. The area is home to a growing number of FPSO vessels.
“FPSO mooring systems should be designed for the different environmental conditions they will be used in,” says Zangeneh, adding that the data they’re generating at the Alfond W2 Ocean Engineering Lab will be very useful in informing these designs. She also is testing the model in the more extreme storm conditions of the Campos Basin, another deepwater oil reserve off the coast of Brazil.
Zangeneh’s research is helping to verify and validate the simulation and testing capacity of the Alfond W2Ocean Engineering Lab.
“The W2 data is in great agreement with computational models and other scale model experiments at other facilities around the world,” says Krish Thiagarajan, Presidential Chair in Energy, professor of mechanical engineering and Zangeneh’s academic adviser.
“I really can’t think of any other facility in the world like the one we have here at the University of Maine,” says Thiagarajan.
Thiagarajan leads the MOOR group and works with students researching how human-made structures interact with the complex, and often chaotic, ocean environment. Their focus spans offshore wind and wave energy systems, coastal infrastructure and naval architecture.
Zangeneh’s research is helping to open the door for future collaboration between the University of Maine and the offshore oil and gas industry, and her work has already gained the attention of commercial and naval shipbuilders.
Zangeneh and the MOOR research group are currently working with General Dynamics Bath Iron Works (BIW) to test a U.S. Navy Combatant model. The model DTMB 5415 hull will be built at the UMaine Composites Center and tested on the lab’s soon to be implemented tow carriage.
“The primary goals of this project are to foster a working relationship between the Advanced Structures and Composites Center and BIW as well as to further validate the testing capacity of the Alfond W2 Ocean Engineering Lab,” says Zangeneh.
Zangeneh says that the lab is capable of providing unique research opportunities for Maine’s shipbuilding industry as well as for the many undergraduate and graduate students that work at the facility.
Contact: Walter Beckwith, 581.3729
From UMaine News.
National Communication Association Honors Scott-Pollock’s Article as One of Year’s Best
Julie-Ann Scott-Pollock, associate professor of communication studies, was formally honored with the award for Best Ethnographic Journal Article by the National Communication Association at the NCA’s annual meeting in Philadelphia in November.
“Narrative Performance Research: Co-Storying “Almost Passing,” was originally published in the Departures in Critical Qualitative Research journal in 2015. “Ethnography” is research that describes a culture, while ethnographers investigate cultural meanings and practices through observation and interviews.
“Through this auto-ethnographic essay, I explore how a critical qualitative researcher’s disclosure of her personal reactions to participants’ narratives can offer an opportunity to resist cultural marginalization,” said Scott-Pollock. She explains that this requires a level of vulnerability and disclosure that can feel risky but is often necessary in the pursuit of identification and transformative understanding in daily performance.
“Scott-Pollock’s article is exceptionally well-written and superlative in all aspects,” one reviewer noted. “But its greatest merit comes from disrupting the apparent dichotomy of the researcher and researched. She productively disturbs this binary and exposes intersections between these elements of ethnographic research.”
Scott-Pollock received the UNCW Distinguished Award for Scholarly Engagement and Public Service in 2015 and was recognized as a “Woman to Watch” in Education by Wilma Magazine. She was also nominated by the Wilmington YWCA as a 2015 Woman of Achievement.
Scott-Pollock earned a Ph.D. in communication from the University of Maine. She teaches courses in performance studies, storytelling and qualitative research methods. A faculty member at UNCW since 2010, she also directs the UNCW Storytellers and Hawk Tale Players, two UNCW performance troupes that perform in K-8 classrooms.
— Caroline Cropp
NASA technology key to Boss’ exploration of polar phytoplankton dynamics
Free-floating ocean phytoplankton, often too small to be seen without a microscope, are a big deal.
The tiny marine plants consume carbon dioxide and produce half of all the oxygen molecules that people and animals breathe. And, as the base of the ocean food web, they’re nourishment for zooplankton, fish, seabirds and whales.
To gain greater understanding of the annual cycles of these life-sustaining organisms in the Arctic and Antarctic, University of Maine oceanographer Emmanuel Boss and colleagues from around the country utilized NASA’s Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument.
Lidar is an active sensor that emits a pulse of light and measures, as a function of time, the return signal due to interaction with matter along the light path. Return signals from the ocean measured by CALIOP have only recently been found to provide a good predictor of particle concentration in the upper ocean, Boss said.
Return signals are similar to fields generated with passive satellite sensors, with the added advantage that measurements can be taken at night and through thin and broken clouds.
With this technology, the team examined a decade of uninterrupted growth-decay cycles of polar phytoplankton biomass (microscopic algae), including when no light was available during polar winters.
Boss said the project yielded several important takeaways.
One is that if NASA optimizes lidar technology for ocean measurements (CALIOP was designed for atmospheric measurements), quantifying phytoplankton vertical distribution on a global scale will be possible.
CALIOP’s vertical resolution is 100 feet but an ocean-optimized lidar could have a vertical resolution as short as 5 feet. This could revolutionize knowledge about plankton distribution, which have strong vertically varying distribution at certain places, including near sea ice and river mouths.
Second, Boss and his colleagues concluded the annual cycle of plankton biomass can be explained as a slight imbalance in herbivore-phytoplankton dynamics.
High-latitude phytoplankton accumulate when their growth rate consistently improves, with maximal biomass occurring when they grow the fastest. Once their growth rate stays the same or slows, their concentrations start dropping, most likely due to predation and viruses.
Third, the team learned that during the last 10 years, ice cover changes dominated the variability in Antarctic phytoplankton stocks and that ecological processes —light, nutrients and grazing — predominantly drove changes in Arctic phytoplankton stocks.
The team’s findings were published in the Dec. 19 online article “Annual boom-bust cycles of polar phytoplankton biomass revealed by space-based lidar” in Nature Geoscience.
In addition to lead author Michael J. Behrenfeld of Oregon State University and Boss, co-authors are: Robert T. O’Malley and Jennifer Schulien at OSU; Yongxiang Hu, Chris A. Hostetler, Johnathan Hair, Xiaomei Lu, Sharon Rodier and Amy Jo Scarino at NASA Langley Research Center; David A. Siegel of the University of California, Santa Barbara; and Jorge Sarmiento at Princeton University.
This team also is collaborating on the five-year North Atlantic Aerosols and Marine Ecosystem Study (NAAMES) NASA Venture project. UMaine’s portion of the project’s $30 million award is $1.5 million.
During four, targeted monthlong expeditions, a lidar optimized for ocean exploration flies over a research vessel and in-water robots to study a subarctic North Atlantic phytoplankton bloom and its multiple links to atmospheric processes, such as providing a source for aerosol and cloud condensation nuclei.
Contact: Beth Staples, 207.581.3777
From UMaine News.