HR: 1330h
AN: A52A-0777    [PDF]
TI: Using Stable Carbon Isotope Ratios to Determine Mean Photochemical Ages of Ethane and Benzene in the Arctic Troposphere
AU: * Thompson, A E
AF: Centre for Atmospheric Chemistry, York University, 4700 Keele St, Toronto, ONT M3J1P3 Canada
AU: Rudolph, J
AF: Centre for Atmospheric Chemistry, York University, 4700 Keele St, Toronto, ONT M3J1P3 Canada
AU: Anderson, R S
AF: Centre for Atmospheric Chemistry, York University, 4700 Keele St, Toronto, ONT M3J1P3 Canada
AU: Rohrer, F
AF: ICGII: Troposphere, Forschungszentrum Juelich, Juelich, 54825 Germany
AU: Stein, O
AF: ICGII: Troposphere, Forschungszentrum Juelich, Juelich, 54825 Germany
AU: Huang, L
AF: Meteorological Service of Canada, 4905 Dufferin St, Downsview, ONT M3H5T4 Canada
AB: Between July 1999 and March 2001 fortnightly samples of ambient background air were collected at Alert (Canada $82.5\deg$N, $62.3\deg$W) and analysed for the concentrations and stable carbon isotope ratios of ethane and benzene. The results of these measurements are compared with the predictions of a 3D isotopic inclusive chemical tracer model using the EDGAR V.2 emission database. The model reproduces the shape of the seasonal variations of the concentrations of ethane and benzene, but the concentration levels calculated by the model are on average a factor of two too low, indicating a significant underestimation of the emission rates in the EDGAR V.2 database. Model predicted and observed seasonal variation of the stable carbon isotope ratio of ethane agree very well. However the observed benzene isotopic compositions in summer imply lower mean photochemical ages than predicted by the model. This finding can be explained by the existence of benzene sources at high northern latitudes which are not included in the emission database.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0345 Pollution--urban and regional (0305)
DE: 1040 Isotopic composition/chemistry
DE: 9315 Arctic region
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting