Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 3 2 2003 10.5194/acpd-3-1973-2003 http://www.atmos-chem-phys-discuss.net/3/1973/2003/ http://www.atmos-chem-phys-discuss.net/3/1973/2003/acpd-3-1973-2003.html http://www.atmos-chem-phys-discuss.net/3/1973/2003/acpd-3-1973-2003.pdf 1973 1989 2003-04-15 Improving the seasonal cycle and interannual variations of biomass burning aerosol sources S. Generoso F.-M. Bréon Y. Balkanski O. Boucher M. Schulz Laboratoire des Sciences du Climat et de l’Environnement, CEA/CNRS, Gif-sur-Yvette, France Laboratoire d’Optique Atmosphérique, CNRS/Université des Sciences et Technologies de Lille, Villeneuve d’Ascq, France This paper suggests a method for improving current inventories of aerosol emissions from biomass burning. The method is based on the hypothesis that, although the total estimates within large regions are correct, the exact spatial and temporal description can be improved. It makes use of open fire detection from the ATSR instrument that is available for a period of 5 years starting in 1996. Thus, the emissions inventories are re-distributed in space and time according to the occurrence of open fires.<br> <br> The impact of the method on the emission inventories is assessed using an aerosol transport model, the results of which are compared to sunphotometer and satellite data. It is shown that the seasonal cycle of aerosol load in the atmosphere is significantly improved in several regions, in particular South America and Australia. Besides, the use of ATSR fire detection may be used to account for interannual events, as is demonstrated on the large Indonesian fires of 1997, a consequence of the 1997&ndash;1998 El Ni&#241;o. Despite these improvements, there are still some large discrepancies between the simulated and observed optical thicknesses.