{"id":5844,"date":"2020-06-29T15:14:54","date_gmt":"2020-06-29T14:14:54","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=5844"},"modified":"2020-06-29T15:14:54","modified_gmt":"2020-06-29T14:14:54","slug":"aurora-project-results-new-approach-for-atmospheric-sentinel-data","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/aurora-project-results-new-approach-for-atmospheric-sentinel-data\/5844\/","title":{"rendered":"AURORA project results: new approach for atmospheric Sentinel data"},"content":{"rendered":"
In response to the European Commission\u2019s 2015 Horizon 2020<\/a> Earth Observation call \u2018Stimulating wider research use of Copernicus Sentinel Data<\/a>\u2019 (EO-2-2015), the AURORA (Advanced Ultraviolet Radiation and Ozone Retrieval for Application) began to focus on opportunities that strengthen the outstanding performance expected from the atmospheric Sentinels.1 <\/sup><\/p>\n At the core of AURORA\u2019s work is the investigation of innovative strategies for optimal exploitation of complementary information on the vertical distribution of the atmospheric ozone<\/a>. This data is then retrieved from measurements acquired at different frequencies and observation geometries by the Sentinel-4 and Sentinel-5 missions of Copernicus.<\/p>\n A major outcome achieved by the project has been the ability to demonstrate the technical feasibility of the novel approach to synergistically use data from multiple independent sources of observations of a given target, based on the sequential operation of data fusion techniques and data assimilation models.<\/p>\n In fact, the AURORA Consortium tested the performance of this new concept by using synthetic ozone products from simulated observations as conducted onboard geostationary (GEO, Sentinel-4) and Low Earth Orbit (LEO, Sentinel-5) in the Ultraviolet (UV), Visible (VIS) and Thermal Infrared (TIR) spectral regions. State-of-the-art radiative transfer models generated simulated measurements based on an atmospheric scenario built from climatological data for four months (April to July 2012).<\/p>\n Collocated measurements of Sentinel-4, as well as of Sentinel-5, were merged in fused ozone profiles by using the Complete Data Fusion (CDF) method and subsequently fed into ECMWF and KNMI Data Assimilation Systems (DAS). For example, the Integrated Forecasting System in two configurations (i.e., IFS and C-IFS) and the Transport Model version 5 (TM5).2-4<\/sup><\/p>\n Significant steps forward have been necessary in order to apply the CDF method to the atmospheric Sentinel data in question. As a result, they proved successful in providing fused products of higher quality (i.e. smaller difference from the true value, smaller errors, improved vertical resolution) with respect to the simulated ozone profiles and columns retrieved from Sentinel-4 and Sentinel-5.<\/p>\n Demonstration of the feasibility of the assimilation of fused data was obtained by running a series of seven assimilation experiments, where each of the above-mentioned DASs assimilated incremental amounts of information. The process started from a base run where no data was assimilated, and then proceeded with the assimilation of UV, VIS and TIR LEO data. Then the process fused LEO, followed by fused LEO and fused GEO. The fifth experiment assimilated fused LEO and fused GEO products, along with data from the geostationary air quality missions TEMPO (Tropospheric Emission Monitoring of Pollution<\/a>) and GEMS (Geostationary Environmental Monitoring Spectrometer), which are planned to fly in constellation with Sentinel-4, over North America and Asia-Pacific.5,6<\/sup><\/p>\n Finally, the series was closed by the assimilation of fused LEO and GEO products and the assimilation of UV, VIS and TIR LEO and GEO data. Cross-comparisons of the results from a specific couple of experiments aimed to estimate the impact of corresponding set of measurements or of fused products, even though this idea turned out to be applicable only to a limited extent due to the inconsistencies introduced by the use of simulated data together with real data in the assimilation experiments. The consequent degradation prevented the possibility for an appropriate comparative assessment of the assimilated products that remains to this day, one of the key issues to address in desirable follow-ons of the scientific effort of AURORA.<\/p>\nThe assimilation of fused data<\/h3>\n