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Environmental Monitoring


September 2012 Issue

US Government, Coast Guard Tests Arctic Operations
The U.S. Coast Guard (USCG) and Department of Defense crews in August completed an oil spill recovery equipment exercise off the coast of Barrow, Alaska, while a team of scientists left for a separate Bureau of Ocean Energy Management (BOEM)-led expedition to study marine life in the Hanna Shoal in the northeast Chukchi Sea.

The three-day USCG exercise—the first of its kind to be held in the Arctic Ocean—evaluated the suitability of new equipment for use in Arctic waters. Normally, oil spill equipment used aboard a USCG buoy tender would be staged while the ship is moored to a pier. With the nearest pier capable of supporting the Coast Guard Cutter Sycamore nearly 600 miles away, a tug and barge were dispatched from Prudhoe Bay to Barrow to serve as a staging platform.

The first day of the exercise, crewmembers on the Sycamore, which served as the exercise platform, tested their onboard spilled oil recovery system. On the second day, the exercise evaluated a U.S. Navy SUPSALV NOFI Current Buster 600 boom system to determine if a USCG buoy tender could be a platform to deploy the boom. Crews tested the DESMI (Nørresundby, Denmark) Polar Bear skimmer, which is designed to recover oil in pockets of water trapped by ice, on the third day.

The next week, scientists from U.S. universities and the Woods Hole Oceanographic Institution departed from Dutch Harbor, Alaska, on the Coast Guard Cutter Healy for a three-week expedition that is part of a long-term study of marine life in the Hanna Shoal area. Information from this study will inform BOEM's future resource management decisions in the Arctic.

Previous studies of Hanna Shoal have documented sustained benthic productivity, with high concentrations of water birds, walruses and whales. This new study, scheduled to run until 2016, will identify and measure physical and biological processes contributing to the area's high concentration of marine life. Work will include documenting physical and oceanographic features, ice conditions and information concerning local species.

At the end of July, NOAA and the Bureau of Safety and Environmental Enforcement released the Arctic version of the Environmental Response Management Application.

GPS Measures Ice Melt, Change In Greenland Over Months
Researchers have found a way to use GPS to measure short-term changes in the rate of ice loss on Greenland, which revealed a surprising link between the ice and the atmosphere above it.

The study, published in the Proceedings of the National Academy of Sciences in July, hints at the potential for GPS to detect many consequences of climate change, including ice loss, the uplift of bedrock, changes in air pressure and possibly sea-level rise.

The team, led by earth scientists at the Ohio State University, used measurements from the Greenland GPS Network (GNET), which consists of more than 50 transmitters, to pinpoint a period in 2010 when high temperatures caused the natural ice flow out to sea to suddenly accelerate, and 100 billion tons of ice melted away from the continent in six months.

They were able to make the measurement because the earth compresses or expands like a spring depending on the weight above it, letting them use the Greenland bedrock like a giant bathroom scale to weigh the ice atop it. As ice accumulates, the bedrock sinks, and as the ice melts away, the bedrock rises. Measurements revealed that Greenland sank by about 6 millimeters over the winter of 2010, and the researchers determined that half of the sinking was actually due to high air pressure above the ice, and the other half was due to ice accumulation.

GPS has been used to study ice loss before, but previously could only detect changes over several years, not months. The team is investigating the possibility of detecting changes in sea-level rise via GPS units planted at coastlines and in small ocean islands.

Earth's Oceans, Ecosystems Still Absorbing Half of CO2 Emissions
Earth's oceans, forests and other ecosystems continue to soak up about half the CO2 emitted into the atmosphere by human activities, even as emissions have increased, said a study by University of Colorado and NOAA scientists published in August in Nature. The remaining CO2 accumulates in the atmosphere, where it is likely to accelerate global warming.

The scientists analyzed 50 years of global CO2 measurements and found that the processes by which the planet's oceans and ecosystems absorb the greenhouse gas are not yet at capacity. Recent studies suggest that natural CO2 sinks might no longer be keeping up with the increasing rate of emissions, which could cause a faster-than-expected rise in atmospheric CO2 and projected climate-change impacts.

The researchers analyzed records of CO2 levels measured at remote sites around the world. Those levels reflect global averages of the greenhouse gas, which are affected by natural cycles as well as people's activities.

Researchers Forecast 3 Feet in Sea-Level Rise for California
Analysis by researchers from the Scripps Institution of Oceanography contains scenarios that sea level along the California coast could reach 3 to 4 feet higher than it was in 2000. Another study in the same report, published in July, concluded that by mid-21st century the number of exceedances over historical extremes of one hour per year would climb to 75 hours per year.

The report, titled 'Our Changing Climate 2012, Vulnerability and Adaptation to the Increasing Risks from Climate Change in California,' is part of the assessments commissioned by the California Energy Commission and the California Natural Resources Agency to plan for the state's climate future.

Computer models suggest an increasing tendency for heightened sea-level events. The most extreme sea-level episodes in the next several decades will follow historical patterns wherein large storms coincide with high tides, often during El Niño years, but will be amplified as mean sea level rises. Relative sea level off the West Coast, which is distinct from global sea level, is the key factor influencing increased flooding potential. Other variables such as the strength of storms or the frequency of large wave events are not expected to increase significantly in this century, the researchers added.


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