Pollution events observed during CARIBIC flights in the upper troposphere between South China and the Philippines S. C. Lai1, A. K. Baker1, T. J. Schuck1, P. van Velthoven2, D. E. Oram3, A. Zahn4, M. Hermann5, A. Weigelt5, F. Slemr1, C. A. M. Brenninkmeijer1, and H. Ziereis6 1Max Planck Institute for Chemistry, Air Chemistry Division, J.-J.-Becherweg 27, 55128, Mainz, Germany 2Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, 3730 AE, de Bilt, The Netherlands 3National Centre for Atmospheric Science, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK 4Institut für Meteorologie und Klimaforschung (IMK), Forschungszentrum Karlsruhe, Weberstr. 5, 76133 Karlsruhe, Germany 5Leibniz-Institut für Troposphärenforschung (IFT), Permoserstr. 15, 04318 Leipzig, Germany 6Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, 82230 Wessling, Germany
Abstract. A strong pollution episode in the upper troposphere between South China and
the Philippines was observed during CARIBIC flights in April 2007. Five
pollution events were observed, where enhancements in aerosol and trace gas
concentrations including CO, CO2, CH4, non-methane hydrocarbons
(NMHCs) and halocarbons were observed along the flight tracks during four
sequential flights. The importance of the contribution of biomass/biofuel
burning was investigated using chemical tracers, emission factor analysis,
back-trajectory analysis and satellite images. The Indochinese peninsula was
identified as the probable source region of biomass/biofuel burning.
However, enhancements in the urban/industrial tracer C2Cl4 during
the events also indicate a substantial contribution from urban anthropogenic
emissions. An estimation of the contribution of fossil fuel versus
biomass/biofuel to the CO enhancement was made, indicating a biomass/biofuel
burning contribution of ~54 to ~92% of the observed CO
enhancements. Biomass/biofuel burning was found to be the most important
source category during the sampling period.
Citation: Lai, S. C., Baker, A. K., Schuck, T. J., van Velthoven, P., Oram, D. E., Zahn, A., Hermann, M., Weigelt, A., Slemr, F., Brenninkmeijer, C. A. M., and Ziereis, H.: Pollution events observed during CARIBIC flights in the upper troposphere between South China and the Philippines, Atmos. Chem. Phys., 10, 1649-1660, doi:10.5194/acp-10-1649-2010, 2010.