HR: 1340h
AN: A53B-1154    [Abstracts]
TI: Atmospheric Deposition of Iron and Phosphorus to Greenland over the 20th- Century
AU: * Edwards, R
EM: redwards@dri.edu
AF: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, United States
AU: McConnell, J R
EM: Joe.McConnell@dri.edu
AF: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, United States
AU: Banta, J R
EM: Ryan.Banta@dri.edu
AF: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, United States
AB: The atmospheric supply of iron (Fe) and phosphorus (P) to nitrogen rich aquatic and terrestrial ecosystems may limit primary production and carbon cycling. During recent centuries, climate change, changes in land use, and industrial activities are thought to have altered the natural variability and atmospheric chemistry of these elements. In order to investigate the sources and perturbation of the atmospheric Fe and P over the 20th century, we have determined Fe and P in ice-cores and snow from the Greenland ice cap. Two ice –cores, D4 (71.4N, 44W) and, Basin 9 (65N, 44.9 W) and snow samples from the Greenland summit were analyzed by high resolution inductively coupled plasma mass spectrometry. Mean iron and phosphorus concentrations over the 20th century were found to be ~ 1 and 0.25 ppb respectively. Over the past 50 years, snow iron concentrations at the ice core sites displayed no significant trend, while phosphorus increased dramatically from 1990 to 2005. Comparison with black carbon records from the same ice cores suggest that boreal forest fires may be the source of the increase in phosphorus.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
DE: 0724 Ice cores (4932)
DE: 0736 Snow (1827, 1863)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting