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Sen2Cor is a Level-2A processor designed to correct Sentinel-2 Level-1C products from the effects of the atmosphere in order to deliver a Level-2A surface reflectance product. A key-parameter for accurate atmospheric correction is the knowledge of the spatially and temporally very variable aerosol content of the atmosphere The multi-spectral instrument on board Sentinel-2 has the appropriate spectral bands to derive the aerosol optical thickness (AOT) of the atmosphere, provided the image contains reference areas of known reflectance behavior, preferably dense dark vegetation (DDV). If the granule contains no DDV pixels, a fallback solution is required. The former solution was to generate an AOT map based on the start visibility set in the configuration file. In this updated Sen2Cor version, meteorological AOT estimates are retrieved from ECMWF ftp server and pre-processed. The integration and assimilation of ECMWF aerosol estimates into Sen2Cor atmospheric correction is described and recent validation results are presented.

The number of hydrological (flood, mass movement), meteorological (tropical storm, extratropical storm, convective storm, local storm), climatological (extreme temperature, drought, wildfire) and geophysical (earthquake, tsunami, volcanic activity) events continue to increases in the last decades at global level. According to different research, statistics and databases (UNISDR, EM-DAT) floods are the most frequent in the last decades worldwide and especially in Romania. On the other hand, the probabilistic hazard results for Romania indicate that, in the future, the highest damages will be produced by floods and earthquakes. In this context, it has become necessary to develop an emergency response service. The emergency service, named GEODIM, integrates the GIS geodatabases: roads, rivers, administrative units, land cover/land use, satellite data (optical and synthetic aperture radar), in-situ measurements, in order to support the disaster management. The Earth Observations data offers the capabilities to monitor the disasters at a large scale, being able to identify areas where the events are not in-situ observed or to monitor large vulnerable areas potentially affected by disasters. The paper presents the downstream emergency response service for disaster hazard in Romania, based on Earth Observation data and other geo-information information.