HR: 1340h
AN: B13B-0225    [Abstracts]
TI: Disjunct Eddy Accumulation Measurements of Organic Nitrate Fluxes Over a Forest Site in Northern Michigan
AU: * Martins, D K
EM: dmarti18@purdue.edu
AF: Department of Chemistry, Purdue University 560, Oval Drive, West Lafayette, In 47905 United States
AU: Edwards, G D
EM: gdedward@purdue.edu
AF: Department of Chemistry, Purdue University 560, Oval Drive, West Lafayette, In 47905 United States
AU: Starn, T
EM: tstarn@comcast.net
AF: Department of Chemistry, West Chester University of Pennsylvania, West Chester, Pa 19383 United States
AU: Shepson, P B
EM: pshepson@purdue.edu
AF: Department of Chemistry, Purdue University 560, Oval Drive, West Lafayette, In 47905 United States
AU: Shepson, P B
EM: pshepson@purdue.edu
AF: Department of Earth and Atmospheric Science, Purdue University, 550, Stadium Mall Drive, West Lafayette, In 47907 United States
AB: Fluxes of organic nitrates have been measured at the PROPHET tower site in northern Michigan by the technique of disjunct eddy accumulation (DEA). This relatively new method involves conditional sampling into up and down cartridge-based reservoirs, from a disjunct sample container. In this experiment, air parcels containing target species were sampled at rates proportional to the magnitude and direction of the vertical wind vector. One disjunct sample was taken every 30 seconds by drawing ambient air into analysis tubes containing a sorbent material (Tenax-TA) for a period of one hour. These sorbet tubes were then analyzed by thermal desorption/GC-ECD. The performance of the DEA instrument and GC during their first field deployment is evaluated and the overall flux for several organic nitrate molecules will be reported. Using these data and the gas phase concentrations, dry deposition velocities of these organic nitrates can be calculated and will be discussed here. The potential role and relative importance (compared to other sources of nitrogen) of these molecules in biosphere-atmosphere exchange within a nitrogen limited forest will also be discussed.
DE: 1806 Chemistry of fresh water
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical processes (4805)
DE: 0315 Biosphere/atmosphere interactions
DE: 0345 Pollution--urban and regional (0305)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting