--------------------------------------------------------------------------- README document for the Multi-Sensor AAI dataset (MS-UVAI) --------------------------------------------------------------------------- This README file provides a very brief description of the various Absorbing Aerosol Index (AAI) product versions that have been produced in the framework of the Aerosol_CCI project. VERSION SUMMARY: --------------------------------------------------------------------------- 1.7 - June 2017 The binning method has been improved, by cutting up the satellite footprint into a number of subpixels, and distributing these onto the grid. The number of such subpixels used for the instruments are: TOMS : 10 x 10 GOME-1 : 64 x 8 SCIAMACHY : 12 x 6 OMI : 8 x 4 GOME-2A : 16 x 8 GOME-2B : 16 x 8 The code now uses an updated (extended) row anomaly filtering for the OMI OMAERO AAI data. This improves the MS-UVAI somewhat in the last two years of the OMI AAI data that are used (2007 and 2008). The improvement would be much larger for the more recent years of OMI AAI, but these years are not included in the MS-UVAI. The quality control of TOMS AAI data was improved, leading to the removal of a few (but strong) anomalies. 1.6 - September 2016 Minor update only. A small bug was removed and some of the names of global attributes in the NetCDF files were changed slightly with respect to the previous version. Some new global attributes were added. The filenames were also changed. This was done to better comply with the format proposed by the "Data Standards Requirements for CCI Data producers" document (ESA Tech. Note CCI-PRGM-EOPS-TN-13-0009). 1.5.7 - March 2016 This is a minor update of the previous version 1.4.7. The dataset now also contains GOME-2 AAI data from MetOp-B: - TOMS Nimbus-7 1978 -- 1993 - GOME-1 ERS-2 1995 -- 2003 - SCIAMACHY Envisat 2002 -- 2012 - OMI Aura 2004 -- 2008 - GOME-2 MetOp-A 2007 -- 2012 - GOME-2 MetOp-B 2013 -- 2015 The GOME-2 AAI data are better than those used in the previous version owing to a better correction for instrument degradation. The format of the NetCDF files has been changed slightly with respect to the previous version 1.4.7, but only in the global attributes. 1.4.7 - June 2015 This dataset contains AAI data from the following instruments: - TOMS Nimbus-7 1978 -- 1993 - GOME-1 ERS-2 1995 -- 2003 - SCIAMACHY Envisat 2002 -- 2012 - OMI Aura 2004 -- 2008 - GOME-2 MetOp-A 2007 -- 2013 The dataset covers nearly the entire time period from 1978 till 2013. The data from the various sensors are merged onto the level-3 grids. OMI data from the years after 2008 are excluded, because of the row anomaly problem. Next to daily and monthly level-3 grids also a 35-year based climatology is provided, provided for each month of the year. Please note that the format of the NetCDF files has been changed completely, in order to better comply with the "Data Standards Requirements for CCI Data producers" (ESA Tech. Note CCI-PRGM-EOPS-TN-13-0009). Images for the monthly fields and for the climatology are also provided. 1.0.1 - March 2013 This dataset contains OMI AAI data from the years 2005 and 2008. The data are provided in level-3 format. Daily and monthly grids. Compared to the previous version 1.0.0 updates on the NetCDF formatting of the global attributes have been made. The data rejection for row anomaly affected data is improved because this dataset is based on OMAERO version 1.2.3 (see details below). Generated from OMAERO version 1.2.3. OMAERO version 1.2.3 is an incremental update to version 1.2 of the OMAERO product. Some changes were made to the handling of snow or ice at the surface within a shared library. This version is used to reprocess the OMAERO for the complete OMI mission. The level-1b used for reprocessing has been post-processed to include updated information on the row anomaly. 1.0.0 - September 2011 This dataset contains OMI AAI data from the year 2008. The data are provided in level-3 format. Daily and monthly grids. Generated from OMAERO version 1.2.0. REFERENCES: --------------------------------------------------------------------------- L.G. Tilstra, M. de Graaf, I. Aben, and P. Stammes, In-flight degradation correction of SCIAMACHY UV reflectances and Absorbing Aerosol Index, J. Geophys. Res. 117, D06209, doi:10.1029/2011JD016957, 2012. 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, Proceedings of the ESA Living Planet Symposium 2013, ESA Special Publication SP-722, 2013. CONTACT: --------------------------------------------------------------------------- L.G. (Gijsbert) Tilstra, KNMI, tilstra@knmi.nl ---------------------------------------------------------------------------