HR: 0800h
AN: A51C-0793    [Abstracts]
TI: Capturing the Signatures of the 1997 Indonesian Wildfires Present in the CARIBIC Observations With a Global Chemistry Transport Model
AU: * Meijer, E
EM: meijere@knmi.nl
AF: Royal Netherlands Meteorological Institute, P.O. Box 201, De Bilt, NL-3730 AE Netherlands
AU: van Velthoven, P
EM: velthove@knmi.nl
AF: Royal Netherlands Meteorological Institute, P.O. Box 201, De Bilt, NL-3730 AE Netherlands
AU: Brenninkmeijer, C
EM: carlb@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AB: In the CARIBIC project, several flights with a passenger aircraft sampled air exposed to biomass burning events. One of these events includes the Indonesian wildfires of 1997. During flights from Munich to Male in November and December 1997, peak values of 230 ppbv were observed at cruising altitudes. Biomass burning is a major source of ozone precursors and aerosols, both major drivers of changes in radiative forcing. As biomass burning exhibits a large spatial and temporal variability that depends mostly on natural factors, its description poses a challenge for global chemistry transport models. Rather recently, several satellite observational products, such as active fire counts, aerosol absorbing index, and burned area, have become available that allow adequate description of the variability of biomass burning (e.g. Schultz, 2002; Duncan et al., 2003; Van der Werf et al., 2003). In this study we perform model simulations with the Tracer Model Version 4 (TM4) chemistry transport model to interprete the CARIBIC CO measurements. With a tagging technique we distinguish between industrial, biogenic, and biomass-burning contributions. We will test different (published) descriptions of biomass burning CO emissions based on the ATSR-2 fire count product. We will show that TM4 captures the signatures of the 1997 Indonesian wildfires rather well with these descriptions, and that the model results improve further if we apply a "daily" resolved biomass-burning emissions instead of the commonly used monthly resolved emissions. This "daily" resolution has been obtained by calculating 10-days backward moving-averages of the ATSR fire counts product.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting