photo: Duke University
In The New York Times on Thursday, I write about how scientists are using machines designed to measure greenhouse gas emissions to fingerprint the Gulf oil spill to calculate its size and movements:
Scientists from Texas A&M and the University of California, Santa Barbara, will try to measure the size of the gulf oil spill more precisely by taking continuous measurements of methane with machines that can also fingerprint deep-water oil plumes to track their dispersal.
“What’s coming out of the spill currently is 40 percent methane by weight,” Dr. John Kessler, an assistant professor of oceanography at Texas A&M, said in an interview. “We’ll be measuring methane in the water and the atmosphere every 10 seconds, which will gives us an unprecedented amount of data.”
After sailing to Gulfport, Miss., on their research vessel, the Cape Hatteras, Dr. Kessler’s team and a group of researchers from the University of California, Santa Barbara, are scheduled to set out on Saturday to conduct measurements. The voyage is being financed by a $160,000 grant from the National Science Foundation.
Other expeditions, including one led by Samantha Joye of the University of Georgia, have been measuring the extent of the oil spill and taking methane measurements. The difference in Texas A&M’s approach is in technology and technique, Dr. Kessler said.
As the Cape Hatteras travels around the gulf, water will be pumped into a device called a seawater equilibrator in which gases in the water are equalized with air. An analyzer made by Picarro, a Silicon Valley company, will then continuously measure the methane concentrations.
The $50,000 Picarro machines are about the size of a desktop computer and take precise, real-time measurements of greenhouse gases like carbon dioxide and methane. The company has sold its analyzers to the National Oceanic and Atmospheric Administration, governments in China and California, and to academic scientists.
A conventional gas chromatograph allows measurements to be taken only every 5 to 10 minutes, Dr. Kessler said.
You can read the rest of the story here.
Green Wombat 
It should be noted that the expedition is also using a novel laser-based “Fast Greenhouse Gas Analyzer” made by Los Gatos Research (www.LGRinc.com) that simultaneously measures the concentrations of methane, carbon dioxide and water vapor at data rates up to 10 Hz. Although typically used by atmospheric scientists for precise measurements of trace gases in the atmosphere, LGR instruments can also report accurate measurements over the extremely wide range of gas concentrations that may be present in ambient air and dissolved in the water near the oil spill and Gulf environment at this time.
Similar to the Fast Greenhouse Gas Analyzer, the LGR Methane Carbon Isotope Analyzer, which simultaneously measures the concentrations of both 13CH4 and 12CH4, is presently used by energy exploration and mud-logging companies worldwide to quickly identify the origins of oil and gas deposits at the drilling site and for on-line monitoring of biogas reactors and of other anaerobic digestion processes. This instrument may also serve to track the fate of the methane emanating from the oil spill. Both of these instruments can help allow scientists to identify and quantitatively map the extent of the leak quickly and accurately.