README -- describes contents of HEMCO/GFAS/v2018-09 directory 24 September 2018 GEOS-Chem Support Team geos-chem-support@g.harvard.edu Overview: ================================================================================ This directory contains CAMS Global Fire Assimilation System estimated biomass burning emissions, including information about injection heights derived from fire observations and meteorological information from the operational weather forecasts of ECMWF. FRP observations currently assimilated in this data set are the NASA Terra MODIS and Aqua MODIS active fire products - (http://modis-fire.umd.edu/pages/ActiveFire.php) This data set includes: Fire Radiative Power (FRP), dry matter burnt and biomass burning emissions. Citation: -------------------------------------------------------------------------------- Contains modified Copernicus Atmosphere Monitoring Service Information 2018 Please acknowledge the use of this data set according to the terms of the Copernicus CAMS License agreement: "Where the Licensee makes or contributes to a publication or distribution containing adapted or modified CAMS Information, the Licensee shall provide the following or any similar notice:" 'Contains modified Copernicus Atmosphere Monitoring Service Information [Year]'; Reference: -------------------------------------------------------------------------------- Francesca Di Giuseppe, Samuel Rémy, Florian Pappenberger, and Fredrik Wetterhall: Combining fire radiative power observations with the fire weather index improves the estimation of fire emissions, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-790 Rémy, S., Veira, A., Paugam, R., Sofiev, M., Kaiser, J. W., Marenco, F., Burton, S. P., Benedetti, A., Engelen, R. J., Ferrare, R., and Hair, J. W.: Two global data sets of daily fire emission injection heights since 2003, Atmos. Chem. Phys., 17, 2921-2942, https://doi.org/10.5194/acp-17-2921-2017, 2017 N. Andela (VUA), J.W. Kaiser (ECMWF, KCL), A. Heil (FZ Jülich), T.T. van Leeuwen (VUA), G.R. van der Werf (VUA), M.J. Wooster (KCL), S. Remy (ECMWF) and M.G. Schultz (FZ Jülich), Assessment of the Global Fire Assimilation System (GFASv1) Kaiser, J. W., Heil, A., Andreae, M. O., Benedetti, A., Chubarova, N., Jones, L., Morcrette, J.-J., Razinger, M., Schultz, M. G., Suttie, M., and van der Werf, G. R. (2012). Biomass burning emissions estimated with a global fire assimilation system based on observed fire radiative power. BG, 9:527-554 Xu et al. (2010) New GOES imager algorithms for cloud and active fire detection and fire radiative power assessment across North, South and Central America. RSE Vol. 114 Heil et al. (2010) Assessment of the Real-Time Fire Emissions (GFASv0) by MACC, ECMWF Tech. Memo No. 628 Di Giuseppe, F, Remy, S, Pappenberger, F, Wetterhall, F (2016): Improving GFAS and CAMS biomass burning estimations by means of the Global ECMWF Fire Forecast system (GEFF), ECMWF Tech. Memo No. 790 Files: ================================================================================ YYYY/GFAS_YYYYMM.nc -- Gridded plume rise model parameters, GFAS analysis surface parameters, gridded satellite parameters Resolution : 0.1 x 0.1 Units : m (plume rise model parameters), kg/m^2/s (GFAS analysis surface parameters), unitless (wildfire fraction of area observed), W/m^2 (wildfire radiative power) Timestamps : Monthly, 2003/01 through present month Compression : Level 4 (i.e. nccopy -d4) Exhaustive data set information can be found on the CAMS GFAS page in the ECMWF wiki: https://confluence.ecmwf.int/ How the NetCDF files were created: ================================================================================ The data set files were created as follows. 1) Retrieve NetCDF format data in half month chunks from ECMWF. 2) Create new NetCDF format data file to contain entire month's worth of data, setting 'title', 'conventions', and 'history' attributes as per COARDS. 3) Create output dimensions, converting 'time' from hours since 1900-01-01 00:00:0.0 to hours since 1970-01-01 00:00:0.0 and reversing the sequence of latitude values. NOTE: The units string of seconds must be 00 rather than 0.0 for use in GCHP. The string change to 00 was applied to all files in January 2022 to fix this. - Lizzie Lundgren (GCST), January 23 2002 4) For each data set variable: - set 'units', 'long_name', 'missing_value' - set the modal value in each input half-monthly variable to zero (if it is an emission variable), or the output missing value otherwise. There does not appear to be a consistent missing value in the output from the ECMWF data API for this data set in NetCDF format; as this is sparse data, the modal value will be missing data - concatenate input half-monthly data, reversing the latitude dimension 4) For the mean altitude of maximum injection variable: - where there is no CO emission, i.e. no fire, set mean altitude of maximum injection value to the output missing value - where is CO emission, i.e. fire, and the mean altitude of maximum injection value is between -1.0 and 1.0 (exclusive), set mean altitude of maximum injection value to 0.0 (i.e. surface) - the above two steps were taken to further clean up inconsistencies in missing value in the output from the ECMWF data API for this data set in NetCDF format All variables were compressed at NetCDF 'level 4' when created. Variables were chunked with the following sizes: time/1, lat/1800, lon/3600 as suggested by the GEOS-Chem wiki.