HR: 0800h
AN: A21C-0870    [Abstracts]
TI: Measurement of the Impact of Halogen Atom Chemistry on Volatile Organic Compounds in the Arctic
AU: * Cavender, A
EM: acavende@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive , West Lafayette, IN 47907
AU: Tackett, P
EM: ptackett@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive , West Lafayette, IN 47907
AU: Keil, A
EM: keilad@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive , West Lafayette, IN 47907
AU: Shepson, P
EM: pshepson@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive , West Lafayette, IN 47907
AU: Shepson, P
EM: pshepson@purdue.edu
AF: Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907
AU: Young, V
EM: valy@bobcat.ent.ohiou.edu
AF: Department of Chemical Engineering, Ohio University, Stocker Engineering Center 179, Athens, OH 45701
AB: It is well known that ozone and mercury depletion events occur in the Arctic during spring, around the time of polar sunrise. It has been suggested that halogen atoms, in particular bromine, play an important role in the onset of these depletion events, during which chlorine chemistry is also occurring. A variety of carbonyl compounds are produced when chlorine atoms react with VOCs, and destruction of aldehydes is seen as a result of bromine atom chemistry. Thus, these two halogen atoms impact the distribution of carbonyl compounds, and the ketone/aldehyde ratio is sensitive to the levels of chlorine and bromine that are present. During a field study in Barrow, Alaska, January - March of 2005, a variety of alkanes, ketones and aldehydes were measured using a preconcentrating autosampler-gas chromatograph-mass spectrometer from an inland site, and via Tenax-based sampling and GC-FID analysis in the vicinity of the Barrow lead. Additionally, ambient samples were collected in canisters and analyzed off-site, and the results from those canisters were used to evaluate the data collected with the instruments mentioned above. Here we discuss what can be learned about the sources and reactions of these compounds by examining the relationships between these species and ozone during a time period ranging from pre-polar sunrise, when ozone is not depleted, to post-polar sunrise, when substantial surface halogen chemistry is occurring.
DE: 0736 Snow (1827, 1863)
DE: 0750 Sea ice (4540)
DE: 0794 Instruments and techniques
DE: 9315 Arctic region (0718, 4207)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005