HR: 0800h
AN: A51C-0066    [Abstracts]
TI: Measurements of Bromoform and Dibromomethane in the Seacoast Region of NH, 2002-2004
AU: * Zhou, Y
EM: yzhou@gust.sr.unh.edu
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824 United States
AU: Russo, R
EM: rrusso@gust.sr.unh.edu
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824 United States
AU: Varner, R
EM: ruth.varner@unh.edu
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824 United States
AU: Wingenter, O
EM: Oliver@nmt.edu
AF: New Mexico Institute of Mining and Technology, Department of Chemistry, Socorro, NM 87001 United States
AU: Blake, D
EM: dblake@orion.oac.uci.edu
AF: University of California, Irvine, Department of Chemistry, Irvine, CA 92697 United States
AU: Talbot, R
EM: robert.talbot@unh.edu
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824 United States
AU: Sive, B
EM: bcs@ccrc.sr.unh.edu
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824 United States
AB: Relatively short-lived halocarbons, such as bromoform and dibromomethane, have been shown to be sources of the halogen oxide radical BrO to the atmosphere which can influence tropospheric oxidation processes in both polar and temperate regions. Under strong convective conditions, which are predominate in the tropics, relatively short lived gases can be transported to the stratosphere or reach it as inorganic bromine, thus contributing to ozone depletion. In addition, short-lived marine halocarbons have been frequently used as tracers to investigate the marine influence on air masses. Measurements of these marine tracers are important for improving our understanding of the atmospheric processes that control the production and distribution of air pollutants along coastal marine regions. Halocarbons were measured at two AIRMAP monitoring sites, Thompson Farm (TF), 25 km inland in Durham, NH from 2002-2004 and Appledore Island (AI), 10 km off the coast of NH during the ICARTT 2004 campaign. For this work, we present measurements of bromoform and dibromomethane made at TF, NH (June 1-August 31, 2002, July 3-September 17, 2003, and July 1-August 15, 2004) and at AI, ME (July 2-August 13, 2004). Additionally, results from measurements of these two gases onboard the NASA DC-8 as part of INTEX-A as well as surface seawater measurements of bromoform made onboard the NOAA ship Ronald H. Brown as part of the NEAQS 2002 campaign are presented. Average mixing ratios of bromoform and dibromomethane at AI (14 and 3 pptv, respectively) were higher than at TF in 2002, 2003, and 2004 (5-9 pptv for bromoform and 1-2 pptv for dibromomethane). Mixing ratios of bromoform and dibromomethane at Appledore Island were significantly higher and more variable than those observed at Thompson Farm, indicating the influence of the local marine sources. Thompson Farm and Appledore Island were significantly impacted by coastal sources of marine halocarbons. At both sites, higher mixing ratios of bromoform and dibromomethane were observed when winds were from coastal marine areas. Vertical distributions of bromoform and dibromomethane and surface seawater concentrations of bromoform suggest that the coastal region of the Gulf of Maine is a significant source of marine derived halocarbons.
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4504 Air/sea interactions (0312, 3339)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005