Remote Sensing        INOE

Long term measurements have clearly shown that human activities are changing the composition of the Earth’s atmosphere. Chemical species in the atmosphere are key elements of the Earth system and of the public concern about the anthropogenic impact. In the first decade of the 21^st century, a revolution is taking place in the approach to manage and use global Earth observations coupled with weather and climate models to address societal needs. A single type of observational platform cannot, by itself, provide sufficient data to fulfil our current observational needs.

Each of the existing observational systems has specific advantages and therefore applications:

• Extensive ground-based measurements (in-situ and remote sensing) including balloons: accuracy, long-term history, validation source, local/regional relevance
• Systematic aircraft measurements: high-resolution tropospheric profiles; tropopause measurements, history
• Satellite observations: global coverage, uniform data quality
• Chemical models and data assimilation tools: integration, data analysis and exploitation

A combination of surface-based (in situ and remote sensing), sub-orbital (aircraft and balloons), and satellite observations are needed. Efforts are being made to implement global observational systems, for example through the Integrated Global Observing Strategy (IGOS), and the Global Earth Observation System of Systems (GEOSS).

Ground-based remote sensing data forms the ideal link between in situ surface concentration and satellite column data. They are extremely important in providing missing information on the vertical distribution of aerosols, gases and clouds, as well as for the necessary calibration and validation of satellite-based remote sensing instruments. Globally, the monitoring stations are organized as The Network for the Detection of Atmospheric Composition Change (NDACC) and The Global Atmospheric Watch (GAW), which are also in direct cooperation. Both are important ingredients for IGACO, and main partners for the long-term validation of the satellite atmospheric products. Currently, the remote sensing part of NDACC refers to the NDACC-NORS (Network Of ground-based Remote Sensing observations), currently focusing on trace gases. On the other hand, the most representative remote sensing part of the GAW is the GALION (GAW Aerosol LIdar Observation Network), currently focusing on aerosols. As a member of EARLINET, the European part of GALION, the Remote Sensing Dept. in INOE received the status of GAW regional station. Recent cooperation with BIRA-IASB opens new opportunities to become also a NDAC-NORS station.

CARESSE represents an initiative to concentrate and organize existing capacities for atmospheric remote sensing in Romania, in order to become a relevant and competent partner for ESA’s EO missions. Its field of expertise covers atmospheric composition and processes, which recommends it for participation in Ground Segment activities (e.g. validation of retrieval algorithms or products for Sentinels, EarthCARE and ADM-Aeolus).