Emissions from biomass burning Contact: thomas.diehl@nasa.gov Description of the biomass burning files We compiled a gridded inventory of monthly means of dry mass burned due to biomass burning for each month of the time period 1979-2007. The inventory is derived from two sources. The time frame from 1997 to 2007 is based on the monthly carbon emissions from the Global Fire Emissions Database version2 (GFEDv2) (Randerson 2007 and Van der Werf 2006). We computed dry mass burned (DM) as DM=C/0.45. The time frame from 1979 to 1996 is based on an inventory from Duncan et al. (2003), which was generated using fire data from AVHRR and ATSR and the Aerosol Index from the TOMS instrument to estimate the dry mass burned in eight regions. The original Duncan dataset is available up to 1999. For the overlap period 1997 to 1999, we determined a 3-year average of scaling factors for each month and region as DMtot_gfed/DMtot_bd. These scaling factors are then applied to all files of the Duncan dataset to generate a scaled version for the period 1979 to 1996. The naming convention for the biomass burning files is DM_BD_SCALED_yyyymm.nc for the time frame 1979 to 1996 and DM_yyyymm.nc for years after 1996, where yyyy is the year and mm denotes the month. The horizontal resolution of the dataset is 1x1. The following variables are included in each file: * lon: longitude at grid cell midpoints * lat: latitude at grid cell midpoints * ilon: longitude at grid cell interfaces * ilat: latitude at grid cell interfaces * dm: rate of dry mass burned in kg/m2/month Recommendations regarding the usage of the inventory We use the following emission factors in GOCART to convert dry mass burned (DM) to black carbon (BC), organic carbon (OC), and SO2: efBC=0.001 kgC/kgDM, efOC=0.008 kgC/kgDM, and efSO2=0.00112 kgSO2/kgDM. 80% of BC and 50% of OC is emitted as hydrophobic, the rest as hydrophilic. Currently, we are evenly distributing the emissions among all vertical levels located within the boundary layer. For regridding purposes, we recommend the NCREGRID tool, but any other code, which is mass conserving will of course be adequate as well. References: Duncan, B. N., R. V. Martin, A. C. Staudt, R. Yevich, and J. A. Logan, Interannual and seasonal variability of biomass burning emissions constrained by satellite observations, J. Geophys. Res., 108(D2), 4100, doi:10.1029/2002JD002378, 2003. Randerson, J. T., G. R. van der Werf, L. Giglio, G. J. Collatz, and P. S. Kasibhatla, Global Fire Emissions Database, Version 2 (GFEDv2.1), Data set, Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A, doi:10.3334/ORNLDAAC/849, 2007. Van der Werf, G. R., J. T. Randerson, L.Giglio, G. J. Collatz, and P. S. Kasibhatla, Interannual variability in global biomass burning emission from 1997 to 2004, Atmospheric Chemistry and Physics, 6, 3423-3441, 2006.