HR: 10:20h
AN: A42B-01    [Abstracts]
TI: Halogen Activation from Heterogeneous Uptake of N₂O₅
AU: Roberts, J M
EM: James.M.Roberts@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: * Osthoff, H D
EM: hostoff@ucalgary.ca
AF: Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, ALB T2N 1N4, Canada
AU: Bates, T S
EM: Tim.Bates@noaa.gov
AF: Atmospheric Chemistry Program, Pacific Marine Laboratory, NOAA, 7600 Sand Point Way, Seattle, WA 98115, United States
AU: Coffman, D
EM: Derek.Coffman@noaa.gov
AF: Atmospheric Chemistry Program, Pacific Marine Laboratory, NOAA, 7600 Sand Point Way, Seattle, WA 98115, United States
AU: Quinn, P K
EM: Patricia.K.Quinn@noaa.gov
AF: Atmospheric Chemistry Program, Pacific Marine Laboratory, NOAA, 7600 Sand Point Way, Seattle, WA 98115, United States
AU: Williams, E J
EM: Eric.J.Williams@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Williams, E J
EM: Eric.J.Williams@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AU: Lerner, B M
EM: Brian.Lerner@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Lerner, B M
EM: Brian.Lerner@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AU: Stark, H
EM: Harald.Stark@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Stark, H
EM: Harald.Stark@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AU: Sommariva, R
EM: Roberto.Sommariva@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Sommariva, R
EM: Roberto.Sommariva@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AU: Ravishankara, A R
EM: A.R.Ravishankara@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Ravishankara, A R
EM: A.R.Ravishankara@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AU: Brown, S S
EM: Steven.B.Brown@noaa.gov
AF: Chemical Sciences Division, Earth System Research Laboratory, NOAA, 325 Broadway, Boulder, CO 80305, United States
AU: Brown, S S
EM: Steven.B.Brown@noaa.gov
AF: Cooperative Institute for Research in the Environmental Sciences, University of Colorado, CB 216, Boulder, CO 80309, United States
AB: The nitrate radical, NO₃, formed from reaction of NO₂ with O₃, and dinitrogen pentoxide, N₂O₅, formed from subsequent reaction of NO₃ with NO₂, drive several important nocturnal chemical processes, including oxidation of VOCs (by NO₃) and removal of NOx (= NO + NO₂) by the heterogeneous reaction of N₂O₅ to form either nitric acid, HNO₃, and/or aerosol nitrates. Laboratory studies have shown that heterogeneous uptake of N₂O₅ on sea salt and chloride containing aerosol produces nitryl chloride, ClNO₂. After sunrise, photolysis of ClNO₂ provides a source of Cl atoms, an important oxidant of VOCs in the marine boundary layer. In spite of the potential importance of this halogen activation mechanism, field investigations have yet to directly confirm it. We have measured NO₃ and N₂O₅, by cavity ring-down spectroscopy, and ClNO₂, by I^- chemical ionization mass spectrometry, on board the NOAA research vessel Ronald H. Brown during the Texas Air Quality Study - Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) 2006. In this presentation, a few aspects of the interaction between nitrogen oxide and halogen cycles in the subtropical marine boundary layer are highlighted, including efficient ClNO₂ production from N₂O₅ uptake on mixed continental and marine aerosol.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0317 Chemical kinetic and photochemical properties
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting