ross different states. Back in the laboratory, the scientists dried samples of corn leaves and husks, then converted them to graphite using a series of chemical reactions. The graphite then was analyzed in the W.M. Keck Carbon Cycle Accelerator Mass Spectrometer, which measures a rare isotope of carbon, called radiocarbon. Carbon dioxide derived from fossil fuels contains no radiocarbon so it is easily distinguishable from other sources. With measurements from this machine, scientists calculated overall levels of carbon dioxide produced by fossil fuels at the location where the corn samples were collected.
California and the Ohio Valley had the most fossil-fuel-emitted carbon dioxide, while the Colorado region had the least. The scientists expected pollution from California and other western coastal states to drift east, but they found that the Rocky Mountains appeared to provide a barrier for the movement of carbon dioxide from fossil fuels.
Air in the Mountain West, including Colorado, Idaho and New Mexico, was the cleanest, with about 370 parts per million of carbon dioxide. Air in the Eastern United States, which includes Massachusetts, New Hampshire and New York, contained an additional 2.7 parts per million of carbon dioxide from fossil fuel sources. Air in Maryland, Ohio, Pennsylvania and West Virginia had nearly twice as much additional carbon dioxide from fossil fuels, 4.3 parts per million.
"We have to better understand emission patterns and changes in the atmosphere in order to better regulate fossil fuels," said Susan Trumbore, also a professor of Earth system science and co-author of the study. "This is a direct way to measure the release of carbon dioxide emissions that are contributing to climate warming."
'"/>Contact: Jennifer Fitzenberger
jfitzen@uci.edu
949-824-3969
University of California - Irvine 22-Jan-2007Page: 1 2 Related biology news :1.
Scientists show that mitochondrial DNA variants are linked to risk factors for type 2 diabetes2.
Scientists prove that disputed Korean stem cell line comes from an unfertilized egg and not cloning3.
Scientists move closer to bio-engineered bladders4.
Scientists find stem cell switch5.
Scientists discover new way to study nanostructures6.
Scientists a step closer to understanding how anaesthetics work in the brain7.
Scientists to make news at Computational Biology Conference8.
Accident-prone? Scientists link brain function to knee injuries9.
Scientists take next step in understanding potential target for ovarian cancer treatment10.
Scientists find brown fat master switch11.
Scientists identify 2 distinct Parkinsons networks