Sulfur, the tenth most abundant element in the universe, is part of many inorganic and organic compounds. Sulfur cycles sulfur through the land, atmosphere and living things and plays critical roles in both climate and in the health of organisms and ecosystems.
"Dimethylsulfide emissions play a role in climate regulation through transformation to aerosols that are thought to influence the earth's radiation balance," says Oduro, who conducted the research while completing a Ph.D. in geology & earth system sciences at Maryland and now is a postdoctoral fellow at the Massachusetts Institute of Technology. "We show that differences in isotopic composition of dimethylsulfide may vary in ways that will help us to refine estimates of its emission into the atmosphere and of its cycling in the oceans."
As with many other chemical elements, sulfur consists of different isotopes. All isotopes of an element are characterized by having the same number of electrons and protons but different numbers of neutrons. Therefore, isotopes of an element are characterized by identical chemical properties, but different mass and nuclear properties. As a result, it can be possible for scientists to use unique combinations of an element's radioactive isotopes as isotopic signatures through which compounds with that element can be traced.
"What Harry did in this research was to devise a way to isolate and measure the sulfur isotopic composition of these two sulfur compounds," says Farquhar, a professor in the University of Maryland's department of geology. "This was a very difficult measurement to do right, and his measurements revealed an unexpected variability in an isotopic signal that appears to be related to the way the sulfur is metabolized.
"Harry's work establishes that we should expect to see variability in the sulfur isotope signatures o
|Contact: Lee Tune|
University of Maryland