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
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 plumes were intersected and 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 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 in the plumes also indicate a substantial contribution from anthropogenic emissions. An estimation of the anthropogenic component of CO shows that biomass/biofuel burning contributed 44–63% to the intersected plumes.