Intergovernmental GR-RO research Programme

Air Quality assessment and study of transport processes along the axis Athens-Aegean sea (Greece) and Bucharest (Romania) using lidar techniques


The present knowledge of the aerosol distribution is far from sufficient to properly estimate the role of aerosols in changes of the global and regional environmental conditions and climate. 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). Since the information on the vertical distribution is particularly lacking, advanced laser remote sensing is the most appropriate tool to close the observational gap.

Lidar networks are fundamental to study aerosol on large spatial scale and to investigate transport and modification phenomena. For this, the European Aerosol Research Lidar Network EARLINET was established in 2000. NTUA and INOE's lidar stations are both contributing members of EARLINET.

EARLINET consists at present of 27 lidar stations which perform coordinated measurements to investigate aerosol properties, transport and modification phenomena. A comprehensive and homogeneous database was created, hosting more than 36,664 profiles. This is relevant for climatology, but also for special events: Saharan dust outbreaks, forest-fire smoke plumes, photochemical smog and volcano eruptions.

EARLINET is now the lidar component of ACTRIS which aims at integrating European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds and short-lived gas-phase species. ACTRIS also includes EUSAAR (European Supersites for Atmospheric Aerosol Research), the distributed infrastructure on aerosol – cloud interaction CLOUDNET, and a group of existing EU ground-based monitoring capacity for short-lived trace gases.

This global aerosol observing system should be dedicated in supporting studies in specific areas such as long range transboundary air pollution, weather-climate and water resources. Specific targets to be addressed should include: defining observational gaps and the filling of those gaps; standardization of measurement methods; standardization of data archival protocols; improvement of data quality including uncertainties; improvement of data delivery/data management system to multiple users including researchers.

This observing system should foster aerosol-related process studies, validation of satellite sensors, model development and evaluation, assimilation of aerosol data into operational models, and build a comprehensive aerosol climatology on a global scale.

At international level, ACTRIS operates in strong cooperation with the Global Atmospheric Watch Program of the WMO, the ARM Climate Research Program and all the relevant research networks as (i.e. AERONET, GALION, NDACC, etc.) for the establishment of the ground-based component of the Global Earth Observation System of Systems.