________________________________________________________________________ Absorbing Aerosol Index and residues from ERS-2/GOME-1 ________________________________________________________________________ The following datasets are available: ../daily/data/YYYY/ESACCI-AEROSOL-L3-AAI-GOME-1D-YYYYMMDD-fv1.9.nc NetCDF file with gridded daily ERS-2/GOME-1 residues from year YYYY, month MM, and day DD. The data in this NetCDF file are contained in a 2-dimensional grid (with cells of 1 x 1 degrees). Longitude: 360 bins centered on 179.5 W to 179.5 E (1 degree steps) Latitude : 180 bins centered on 89.5 S to 89.5 N (1 degree steps) The average residue is provided, along with the number of measurements for each of the grid cells. The average AAI is also provided. This is an average of the *positive* residues only. ------------------------------------------------------------------------ ../monthly/data/YYYY/ESACCI-AEROSOL-L3-AAI-GOME-1M-YYYYMM-fv1.9.nc NetCDF file with gridded monthly ERS-2/GOME-1 residues from year YYYY and month MM. The format is the same as for the daily gridded data. ------------------------------------------------------------------------ ../daily/lv2data/YYYY/YYMMDD_gome_aai.tar.gz, containing: YYMMDD_HHMM_gome_sc.aai ASCII files with ERS-2/GOME-1 level-2 residue data for each of the orbits from year YYYY, month MM, and day DD. The HH and MM relate to the time of first measurement of the particular orbit. Residue, time, and geolocation information are given in the files. A tool to extract the data in IDL exists and can be downloaded. ________________________________________________________________________ Some tools are available for handling the data in IDL: ../tools/read_aai_level2.pro READ_AAI_LEVEL2 This procedure will read level-2 AAI data. See the source code for the calling sequence and the list of returned parameters. ________________________________________________________________________ The following image files are available: ../daily/images/YYYY/YYMMDD.gif Image files of the daily residue are available in GIF format. The files present the daily residue of year YYYY, month MM, and day DD projected onto the world map. ------------------------------------------------------------------------ ../monthly/images/YYYY/GOME-1_AAI_map_YYYYMM.png Image files of the gridded monthly averaged AAI are available in PNG format. These files present the monthly averaged AAI of year YYYY and month MM projected onto the world map. ________________________________________________________________________ Daily log files are available for each processed day: ../daily/logs/YYYY/YYMMDD.log These files contain all processing information. Log files are also available for days where no GOME-1 data were available. ________________________________________________________________________ References (follow the links on the webpage to download): [01] M. de Graaf, P. Stammes, O. Torres, and R.B.A. Koelemeijer, Absorbing Aerosol Index: Sensitivity analysis, application to GOME and comparison with TOMS, JGR 110, 2005. [02] L.G. Tilstra, O.N.E. Tuinder, and P. Stammes, GOME-2 Absorbing Aerosol Index: Statistical analysis, comparison to GOME-1 and impact of instrument degradation, Proceedings of the 2010 EUMETSAT Meteorological Satellite Conference, 2010. [03] L.G. Tilstra, M. de Graaf, O.N.E. Tuinder, R.J. van der A, and P. Stammes, Studying trends in aerosol presence using the Absorbing Aerosol Index derived from GOME-1, SCIAMACHY, and GOME-2, EUMETSAT P.59, 2011. [04] L.G. Tilstra, M. de Graaf, O.N.E. Tuinder, R.J. van der A, and P. Stammes, Monitoring aerosol presence over a 15-year period using the Absorbing Aerosol Index measured by GOME-1, SCIAMACHY, and GOME-2, ESA SP-722, 2014. ________________________________________________________________________