Phys.org published an article on research conducted by a University of Maine team that found stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling 12,900 to 11,600 years ago in the Northern Hemisphere. Prevailing scientific understanding has been that glaciers advanced in the Northern Hemisphere throughout most of the Younger Dryas Stadial (YDS) — a 1,300-year period of dramatic cooling. However, the researchers determined carbon-dated bog sediment indicates the 9,500-square-kilometer ice cap over Rannoch Moor in Scotland retreated at least 500 years before the end of the YDS.
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A University of Maine research team says stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling 12,900 to 11,600 years ago in the Northern Hemisphere.
Prevailing scientific understanding has been that glaciers advanced in the Northern Hemisphere throughout most of the Younger Dryas Stadial (YDS) — a 1,300-year period of dramatic cooling.
But carbon-dated bog sediment indicates the 9,500-square-kilometer ice cap over Rannoch Moor in Scotland retreated at least 500 years before the end of the YDS, says Gordon Bromley, a postdoctoral associate with UMaine’s Climate Change Institute (CCI).
“Our new record, showing warming summers during what traditionally was believed to have been an intensely cold period, adds an exciting new layer of complexity to our understanding of abrupt events and highlights the fact that there is much yet to learn about how our climate can behave,” Bromley says.
“This is an issue that is becoming ever more pressing in the face of global warming, since we really need to know what Earth’s climate system is capable of. But first we have to understand the full nature of abrupt climate events, how they are manifest ‘on the ground.’ And so we were compelled to investigate the terrestrial record of the Younger Dryas, which really is the poster child for abrupt climate change.”
Glaciers, says Bromley, respond to sea surface temperatures and Scotland is immediately downwind of the North Atlantic Ocean.
“Scotland was the natural choice as it lies within the North Atlantic Ocean — widely believed to be a driver of climatic upheaval — and thus would give us a robust idea of what really transpired during that critical period,” he says.
What the team found was that amplified seasonality driven by greatly expanding sea ice resulted in severe winters and warm summers.
While sea ice formation prevented ocean to atmosphere heat transfer during winters, melting of sea ice during summers created a stratified warmer freshwater cap on the ocean surface, he says. The increased summer sea surface temperature and downwind air temperature melted the glaciers.
Bromley says this research highlights the still-incomplete understanding of abrupt climate changes throughout Earth’s history.
“Ever since the existence of abrupt climate change was first recognized in ice-core and marine records, we’ve been wrestling with the problem of why these tumultuous events occur, and how,” he says.
Kurt Rademaker, Brenda Hall, Sean Birkel and Harold W. Borns, all from UMaine’s Climate Change Institute and School of Earth and Climate Sciences, are part of the research team. So too is Aaron Putnam, previously from CCI and now with Lamont-Doherty Earth Observatory at Columbia University/Earth Institute. Joerg Schaefer and Gisela Winckler are also with Lamont-Doherty Earth Observatory and Thomas Lowell is with the University of Cincinnati.
The team’s research paper, Younger Dryas deglaciation of Scotland driven by warming summers, was published April 14 on the “Proceedings of the National Academy of Sciences” website.
Contact: Beth Staples, 207.581.3777
Third-year marine sciences major Ian Jones of Canton, Conn., is studying how ocean acidification impacts lobster larvae, an important resource for the Maine economy.
Jones works with American lobsters raised at UMaine’s Aquaculture Research Center (ARC). The lobster larvae were raised last summer at various pH levels, replicating natural environments and the impact of ocean acidification. Jones weighed and photographed approximately 700 lobster larvae to monitor their growth in these different environments. The hypothesis: slower growth and more irregular development occur at lower pH. This creates adaptation problems for lobsters dealing with increased environmental CO2 levels.
“We will certainly see greater ocean acidification in the future as an effect of climate change. As atmospheric levels of CO2 continue to increase from human input, so do the CO2 levels of the upper ocean,” says Jones.
Along with lobster larvae, Jones also monitored seahorses in Tim Bowden’s lab. The seahorses, which were dealing with a mycobacterial infection, were in the care of Jones while an antibiotic treatment was created. He also raised juvenile seahorses last year. Through this experience, Jones learned about seahorse aquaculture, proper feeding protocols, tank chemistry and more.
“Not much is known about seahorse aquaculture relative to raising other fish, so although information on raising newborns was limited, it was a fun challenge figuring out our own system that worked.”
This fall, Jones will travel to the Darling Marine Center on the Damariscotta River, where he and other UMaine students will further the hands-on work they do in the classroom through the Semester By the Sea program.
Jones plans to attend graduate school to study sensory biology and/or the effect of climate change on marine animals.
Why is your lobster research important?
Research on American lobster growth at lowered pH is incredibly important first, because there has been little climate change study on this particular species and second, any slowing or other adverse effects on lobster growth could have serious impacts on the health of the lobster fishery, which Maine, of course, greatly depends on. Delayed lobster larvae development means it will take longer for lobsters to get to market size, and predation risk may increase as well, causing fewer individuals to grow into adults and lowering the overall abundance of adult lobsters. Changes in lobster abundance can in turn upset ecosystem balance by changing the abundance of organisms that depend on lobster as prey and organisms lobsters prey on. These trophic cascades have the power to reduce the presence of many species in addition to just the lobster, consequently reducing biodiversity.
Are you excited about heading to the Darling Marine Center in the fall?
I am really excited to be able to SCUBA dive in the area on the weekends; there is a dive locker on campus. I’m also excited for many of the courses offered this fall, such as the scientific diving course and the marine invertebrate biology course. I look forward to the seminar class, which teaches students how to tackle job interviews and graduate school applications for pursuing a career post graduation. Generally, I look forward to interacting with the marine environment on a near daily basis as I learn more about it and gain skills for marine research.
Why did you choose UMaine?
My primary reason for choosing UMaine was their excellent marine science program, which was more attractive than those at other colleges due to its emphasis on hands-on experience, such as through their Semester by the Sea program, expert faculty and it covers fundamentals of marine biology, chemistry and physics, not just the area you choose to concentrate in. Also driving me to UMaine were the strong nondiscriminatory policies and minority services on campus, making me confident that I can be myself at UMaine and face minimal to no prejudice, especially from faculty and administrators.
Have you worked closely with a mentor, professor or role model who has made your UMaine experience better, if so how?
Working with Tim Bowden has greatly improved my experience here, and the opportunities he’s granted me to assist with seahorse aquaculture and lobster larvae research have not only been very enjoyable but have helped define my research interests and add to my qualifications for future research experience. Additionally, his constructive feedback on my performance in his lab has allowed me to improve as a researcher.
What difference has UMaine made in your life, helping you reach your goals?
My professors at UMaine have made a major impact on what it means to have a career in science and beyond. They share advice on the mentality, skills and process necessary toward being successful in particular research fields. Also, the abundance of research facilities here, such as the Aquaculture Research Center, has allowed me to build a lot of hands-on experience that I can apply to future positions in marine biological research.
What advice do you have for incoming students?
I advise students to get involved with at least a couple student organizations that suit their interests. There’s a club for almost anything you could think of, from fencing to SCUBA diving to various political, academic and religious and social groups. Also I recommend science students look for work in a faculty member’s lab as soon as possible, even if it’s just volunteer work. You don’t need to know what your interests are yet, but any research and lab experience gained early can really help you in the long run. Just ask around.
What is your favorite place on campus?
My favorite place is the Littlefield Garden on the north end of campus. The garden is especially nice to study in, or to just hang out and have a picnic at — given warm weather of course.
Have you had an experience at UMaine that has shaped the way you see the world?
Unrelated to marine science, I took the Intro to LGBT studies course offered by the Women’s, Sexuality and Gender Studies department, which vastly increased my understanding of the complexity of the LGBT community. I knew a fair amount about LGBT culture and identities going into the course but I did not realize how much I didn’t know until taking the class. For example, I didn’t know that there is opposition to same-sex marriage within members of the LGBT community and that historically there has been plenty of conflict of interest between feminist and lesbian organizations, as well as lesbian and gay people who have spearheaded “LGBT” movements that often leave the B (bisexual) and T (transgender) out of the equation. I now view the LGBT community differently than before, recognizing that people won’t always get along or share common goals just because they all belong to a minority. I also better understand the importance of full inclusiveness in LGBT organizations, due the diversity and intersectionalities with race, class, etc., of LGBT people.
The Huffington Post reported on maple syrup research being conducted by Jenny Shrum, a Ph.D. candidate in the ecology and environmental sciences graduate program in the University of Maine School of Biology and Ecology. Shrum is researching the biophysical relationships between weather and sap flow. Her goal is to better understand what drives flow and how expected trends in climate may affect the processes and harvesters in the future. Shrum said she’s also trying to understand the links between people’s relationship with their land, where they get their information from, how they perceive climate change, and their motivation for harvesting. “I’m trying to piece together how those four things are related. I think that also plays into whether people will want to collect maple syrup in the future, and which people,” she said.
The Morning Sentinel and Kennebec Journal reported on the Maine Water & Sustainability Conference held at the Augusta Civic Center and organized by the Senator George J. Mitchell Center at the University of Maine. Several hundred people who work with or are interested in water resources and environmental sustainability, such as water resource professionals, engineers and environmental advocates, attended the conference. Session topics included the effect of water withdrawals on water supply and quality, lake management strategies, Maine’s energy future, climate-related trends, safe beaches and shellfish beds, and management approaches for sustainable urban streams.
The Free Press reported the University of Maine Cooperative Extension and Maine Sea Grant will offer free training sessions for Signs of the Seasons, a program for volunteers to contribute local plant and animal life-cycle data for climate change research. Sessions are open to all interested volunteers, and registration is required. Sessions in the midcoast area will be held March 22 in Newcastle, March 25 in Belfast and April 5 in Boothbay.
The Kennebec Journal and Morning Sentinel previewed the Maine Water & Sustainability Conference to be held April 1 at the Augusta Civic Center. The conference, organized by the Senator George J. Mitchell Center at the University of Maine, will focus on the future of energy, clean water and safe beaches and shellfish beds. The annual event, founded in 1994 as the Maine Water Conference, was renamed the Maine Water & Sustainability Conference to reflect the addition of sustainability science research. The conference has become one of the largest environmentally related conferences in Maine attracting more than 350 attendees each year.
The Senator George J. Mitchell Center at the University of Maine invites the public to attend a series of informative sessions on Maine water and sustainability issues from 7:30 a.m. to 4 p.m. April 1 at the Augusta Civic Center.
The Maine Water & Sustainability Conference will include several sessions on sustainability science research in Maine, as well as sessions with a joint focus on water resources and sustainability.
The Maine Water Conference was founded in 1994 by the Senator George J. Mitchell Center at the University of Maine as an annual forum for water resource professionals, researchers, consultants, citizens, students, regulators and planners to exchange information and present new findings on water resource issues in Maine. The conference has grown to become one of the largest environmentally related conferences in Maine attracting more than 350 attendees each year. The Maine Water Conference Steering Committee is made up of key water resource stakeholders from across the state.
Cost to attend is $55. More information, including how to register and session times, is online.
The Fogler Library at the University of Maine will display a “Human Dimensions of Climate Change” exhibit in late March and early April. The exhibit, in Fogler’s first floor hallway, highlights a selection of the library’s books, government documents and films that emphasize potential impacts of climate change on populations throughout the world.
The exhibit corresponds with the “Human Dimensions of Climate Change” film series. Upcoming films, which are shown in Fogler’s CETA room, include “Climate Refugees” at 6 p.m. March 25 and “There Once Was an Island” at 6 p.m. April 1.
Paul Mayewski, director of the Climate Change Institute, will facilitate discussion following “Climate Refugees”. Discussion after “There Once Was an Island” will feature Jim Roscoe, professor of anthropology.
The Bangor Daily News reported Charles Porter, a research associate for the University of Maine’s Climate Change Institute and well-known mountain climber, passed away Feb. 23, 2014 at the age of 63. Paul Mayewski, director and distinguished professor of the Climate Change Institute, and Brenda Hall, a professor in the institute and UMaine’s School of Earth and Climate Sciences, shared their memories of Porter with the BDN. Mayewski said, “Charlie had a very rare ability and a staunch drive to understand as much as he could about the physical, chemical, biological and socio-cultural aspects of some of Earth’s most remote places.” Hall called Porter a “one-of-a-kind person” who was always up for an adventure.