HR: 0800h
AN: A11C-0609    [Abstracts]
TI: The temporal and spatial variability of halogenated trace gases in the upper troposphere.
AU: Oram, D
AF: University of East Anglia, Earlham road, Norwich, NR4 7TJ, United Kingdom
AU: * O'Sullivan, D
EM: debbie.osullivan@metoffice.gov.uk
AF: University of East Anglia, Earlham road, Norwich, NR4 7TJ, United Kingdom
AU: * O'Sullivan, D
EM: debbie.osullivan@metoffice.gov.uk
AF: now at Met Office, Fitzroy road, Exeter, EX1 3PB, United Kingdom
AU: Brenninkmeijer, C
AF: Max-Planck Institute for Chemistry, Bercherweg, Mainz, D-55128, Germany
AU: van Velthoven, P
AF: KNMI, Royal Dutch Meteorological Institute, NL-3730 AE, de Blit, PO Box 201, Netherlands
AU: Sturges, W
AF: University of East Anglia, Earlham road, Norwich, NR4 7TJ, United Kingdom
AB: Halogenated trace gases play an important role in stratospheric and tropospheric chemistry, particularly affecting ozone concentrations. In addition they have direct and indirect effects on radiative forcing, and impact on tropospheric reactivity. Data from the CARIBIC project (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumented Container) have been used in conjunction with back-trajectory analysis to further our understanding of the chemical composition, inter-hemispheric distribution and source regions of halogenated compounds in the upper troposphere and lower stratosphere. Whole air samples collected within CARIBIC, have been analyzed using gas chromatography mass spectrometry for around 35 halocarbons and related trace gases, among them many potent greenhouse gases and species important for ozone depletion. The large spatial and temporal coverage of the CARIBIC project has enabled new work to be done investigating recent inter-annual trends in the CFCs, halons, and other anthropogenic halocarbons, as well as identifying clear inter-hemispheric and seasonal variability for a number of species, such as methylene chloride, HCFCs, methyl chloride, methyl bromide, methyl iodide and several reactive short lived bromo and chloro carbons. In this paper results from the CARIBIC flights to China and the Philippines will be highlighted, to discuss anthropogenic emissions of ozone depleting and greenhouse gases, from Asia and Africa. Data from flights to South America will also be presented. As production and consumption of many of these substances are being phased out in Europe and North America, emissions from Asia, Africa and also South America are becoming increasingly more important. Emissions from these regions are also of interest, as the most significant sources are often collocated with regions of convection in the tropics and sub-tropics. Thus enabling a greater proportion of the substances emitted to reach the stratosphere, where they have the largest impact on ozone.
DE: 0322 Constituent sources and sinks
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0365 Troposphere: composition and chemistry
DE: 0490 Trace gases
DE: 4854 Physical chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting