Exploitable results Catalogue of aerosol optical depth A semi-operational ATSR aerosol retrieval algorithm has been developed in the framework of CREATE and the ESA project TEMIS. This algorithm is utilized to retrieve aerosol optical depth (AOD) maps over Europe for the year 2000 from available ATSR-2 data. A cloud-screening algorithm has been automated and implemented as part of the semi-operational ATSR-2 retrieval algorithm. Furthermore, routines were developed to include AERONET sun photometer data of AOD measured within half an hour of the ATSR overpass. AOD maps over Europe for the year 2000 are retrieved from ATSR-2 data, delivered by ESA for the area confined by the latitudinal boundaries (20N, 80N) and the longitudinal boundaries (20W, 40E). Retrieval is done over cloud-free scenes for the 1x1km2 sensor resolution (at nadir). The monthly AOD maps for the European scale are given as a product with a (default) resolution of 10x10km2 (roughly 0.1? x 0.1? over Europe) by means of an automated post-processing step, where the AOD values for the individual ATSR-2 pixels in each 10 x 10km2 area are averaged. This average cannot be considered as monthly averages because the ATSR-2 swath of 512km allows for an overpass over each area in Europe once every third day, at 10:30 in the morning and for many overpasses AOD cannot be retrieved due to the presence of clouds. As a consequence, the data represent a snapshot of the situation during the overpass, and at best each snapshot is available once every third day. Therefore the monthly maps should be considered as composites providing information on the spatial variation of the occurrence of aerosols and hot spots. A further restriction is the solar zenith angle of maximum 81°, which puts a limit to the amount of available data for the Northern part of Europe, in particular in the winter. The results have been delivered to the CREATE database as maps of AOD at 0.55µm and 0.67µm, together with comparisons with AERONET data for validation. Because part of the work was done in the framework of the ESA project TEMIS, and the TEMIS webpage will be maintained for at least several years with likely continuation by the ESA GMES Service Element (GSE) PROMOTE, the results have also been provided to the TEMIS web pages (www.temis.nl) where they are available to the users. The TEMIS web site is linked to the CREATE web site (http://macehead.nuigalway.ie/create/). Single frames or maps over specific areas can be produced for a single overpass with high spatial resolution. This product is useful for application on a local scale, such as urban pollution monitoring or source assessment by inverse modelling. Much effort has been put into developing routines for providing the data for applications that require other spatial resolutions than the default 10x10 km2 or the high resolution 1x1km2 products, such as for the intercomparison of aerosol model results, ground-based and space-based observations. This exercise required binning the high-resolution AOD values in cells of 1? x 1?. Another application is the assimilation of ATSR-2 AOD data in regional and global models in the FP5 GMES targeted project DAEDALUS that has been coupled to CREATE on request of the EU Commission. Catalogue of maps of model data Modelled aerosol maps over Europe for the year 2000 have been assembled using the LMDz-INCA model which couples the Laboratoire de Meteorologie Dynamique general circulation model and the "Interaction with Chemistry and Aerosols" (INCA) module developed at the LSCE, Gis sur Yvette, near Paris. Comparisons between model predictions have been made with aerosol observations made available by CREATE partners and from the AERONET network. The aerosol parameters are: sulfate, black carbon, organic carbon and sea salt surface concentrations, surface concentration of PM10 mass, aerosol optical depth and the Angstrom component. All of these comparisons are available for each month of the year 2000, and for the different seasons of the year. A web interface provides user-friendly access to the results: http://nansen.ipsl.jussieu.fr/AEROCOM/DATA/create.html. The web interface is a major achievement and is a new way to provide insight into aerosol fields over Europe. A similar comparison has been established for global coverage and is accessible through:http://nansen.ipsl.jussieu.fr/AEROCOM/DATA/surfobs.html. Aerosol extinction vertical profiles measured with Raman lidar in the framework of EARLINET in 2000 are compared to profiles modelled by LMDzT-INCA at seven stations in Europe. The comparisons for all observed profiles can be found at the following web site: http://nansen.ipsl.jussieu.fr/AEROCOM/DATA/lidar.html. Information is synthesised from many profiles of vertical aerosol distribution for the first time on this web site interface. The lidar/model comparisons showed that an average vertical profile of aerosol extinction provides a powerful diagnostic tool for the understanding of the vertical distribution of the aerosol. The combination of satellite (MODIS), sun photometer and lidar retrieved aerosol optical depth at a particular EARLINET station (Hamburg) showed that the column-integrated values of different data origin are comparable within a factor of 2. Good agreement is found between column integrated EARLINET measurements and AERONET optical depth. Results also suggest that in-situ ground observations require a denser network than that of AOD, and both spatial and temporal in situ ground data is particularly lacking in south-western and south-eastern Europe. Use can be made of the Model results to provide an assessment on the representativeness of surface aerosol data based on correlations of time series in observations and model outputs. The analysis supports the need for a widespread monitoring network of about 20 super-sites in Europe. Based on this analysis and on the availability of existing suitable sites, 20 super-sites have been selected for ongoing and future aerosol measurements in Europe. A main result of the project: european aerosol database A main result of CREATE is the establishment, use and delivery of an European aerosol database. Through CREATE, agreement has been obtained with NILU to host its database in the European Monitoring and Evaluation Programme (EMEP) -Chemical Coordinating Centre (CCC) database at http://www.nilu.no/projects/ccc/create/database.htm. This website allows for submission of aerosol data (using NASA-AMES 1001 format) to the European aerosol database. A formal cooperative agreement, through CREATE, has been achieved between NILU and JRC, at Ispra, which hosts the WMO-GAW (Global Atmosphere Watch) World Data Centre for Aerosols (WDCA). This means that present and future aerosol data only needs to be submitted to the EMEP-CCC database. The infrastructure for EMEP data flow is used to transfer submitted data seamlessly to the WDCA site as well: http://ies.irc.cec.eu.int/wdca/. This represents a major achievement towards harmonisation for archival of aerosol data at the European level, and it minimises the duplication of databases and effort all round for data providers, and for data users. Aerosol data has been submitted using the agreed common data format (NASA-AMES 1001) to the CREATE database by 10 Atmospheric Research Stations. It represents typically 3-5 years (over the period from about 1995-2003) of hourly values of the following aerosol parameters: number concentration, size distribution, aerosol radiative parameters: light scattering and absorption coefficient, particulate mass (PM) and chemical composition (integrated and size resolved data). Current status is that the Database is operational and can be accessed by users in a user-friendly manner. Data can also be submitted to the Database - use web site: http://www.nilu.no/projects/ccc/create/database.htm. Expected benefits and applications include: Database data can be used for comparison with modelled predictions of air quality levels. Furthermore, data can be used to make predictive assessments of radiative effects. End users include: Scientists; Policy makers; and the General Public Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
