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Ocean Research


October 2011 Issue

Grant Works to Bolster Expertise on Coast Guard Research Icebreakers
A $2.1 million National Science Foundation grant to the Scripps Institution of Oceanography and Oregon State University (OSU) will supply experts on U.S. Coast Guard icebreaking research vessels like Healy, Polar Sea and Polar Star.

The new grant will fund technicians from Scripps' Shipboard Technical Support department and OSU's Marine Technician Group to serve as the research backbone aboard polar research vessels. They will coordinate scientific operations of dozens of research scientists who collaborate aboard the ships during summer field programs. These technicians will also be responsible for the safe and accurate operation of shipboard instruments.

Research marine technicians oversee operation of various oceanographic instruments and equipment at sea, including CTD instruments, multibeam swath sonar, echosounders for seafloor mapping and seafloor coring instruments used to analyze long-term changes in the ocean.

The grant also could be a model for improving the quality of scientific support within federal science budgets. Marine technicians have typically worked aboard their own institutional research vessels. The new program combines existing oceanographic institutions to support polar research aboard Coast Guard vessels. For more information, visit http://scrippsnews.ucsd.edu.

Scientists Embark on Survey to Monitor Changing Arctic Conditions
Scientists from the U.S. Geological Survey (USGS), hoping to determine trends in ocean acidification from the least explored ocean in the world, embarked in August on a research cruise to the Arctic Ocean.

For the second year, researchers will set sail aboard the U.S. Coast Guard vessel Healy. What they learn from data collected during the seven-week cruise will provide an understanding of how the Arctic Ocean chemistry is changing and will detail potential implications for carbonate species vulnerable to a more acidic ocean.

The research is taking place during the 2011 U.S.-Canada Extended Continental Shelf Survey research expedition, a joint mission between the U.S. Coast Guard, the USGS and the Canadian Coast Guard.

During this voyage, the USGS scientists, along with researchers from the University of South Florida, will collect and analyze water samples using an array of specialized instruments, including sampling bottles that can collect water from as deep as 3,500 meters. Instruments will also pick up measurements of dissolved oxygen content, and conductivity, temperature and depth in the water column. For more information, visit www.usgs.gov.

Coral Dating Method Suggests a Less Stable Sea Level
New evidence of sea-level oscillations during a warm period that started about 125,000 years ago raises the possibility of a similar scenario if the planet continues warming, says a research team led by the Woods Hole Oceanographic Institution (WHOI).

The study, published online in Nature Geoscience in September, used a new method of dating fossil coral reef skeletons in the Bahamas. By calculating more accurate ages for the coral samples, the study found sea levels were considerably less stable than earlier believed, oscillating up and down by four to six meters over a few thousand years about 120,000 years ago during the last interglacial period.

"This was the last time that climate was as warm as—or warmer than—today," said WHOI geochronologist William Thompson, lead author of the study. "If today's ice sheets continue to melt, we may be headed for a period of ice sheet and sea-level change that is more dynamic than current observations of ice sheets suggest."

To get more accurate age estimates from the geological record, Thompson developed an new way of interpreting uranium and thorium isotope ratios in coral. Until now, scientists attempting to date last interglacial coral reefs concluded erroneously that sea level was relatively stable during this period, the study said.

The finding of a significant sea-level oscillation 120,000 years ago is in sharp contrast to the last 5,000 years, a period of relative sea-level stability. For more information, visit www.whoi.edu.

Arctic Ice Melt Could Pause in Coming Decades, Study Finds
Despite the rapid retreat of Arctic sea ice in recent years, the ice may temporarily stabilize or somewhat expand at times over the next few decades, a new study suggests.

Published in August in Geophysical Research Letters, the study found that Arctic ice under current climate conditions is as likely to expand as it is to contract for periods of up to about a decade.

"The computer simulations suggest that we could see a 10-year period of stable ice or even an increase in the extent of the ice," said Jennifer Kay, lead author and a scientist at the National Center for Atmospheric Research.

Kay said variations in atmospheric conditions such as wind patterns could, for example, temporarily halt the sea ice loss. Still, she said, the ultimate fate of the ice in a warming world is clear. "When you start looking at longer-term trends, 50 or 60 years, there's no escaping the loss of ice in the summer."

Kay and her colleagues also ran computer simulations to answer a fundamental question: Why did Arctic sea ice melt far more rapidly in the late 20th century than projected by computer models? By analyzing multiple realizations of the 20th century from a single climate model, they attributed approximately half of the observed decline to human emissions of greenhouse gases and the other half to climate variability.

To simulate what is happening with the ice, the team used an updated version of one of the world's most powerful computer climate models, the Community Climate System Model.

The simulations indicated Arctic sea ice is equally likely to expand or contract over short time periods under the climate conditions of the late 20th and early 21st century.

Though this provides new insights, the authors cautioned that more modeling studies and longer-term observations are needed. The authors said it is difficult to disentangle the variability of weather systems and sea-ice patterns from the impacts of human emissions of greenhouse gases. For more information, visit www.nsf.gov.


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