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


Lidar measurements of the vertical distribution of the aerosol optical properties are performed in the frame of AQuA-GRO project in three selected sites: Athens, the island of Evia (measurements during selected time frames) and the region south of Bucharest.

These measurements will be used to identify the main air pollution/aerosols sources, over Europe and NE Africa, which affect the air quality over these regions. In parallel, meteorological data will be used to study the long-range transport of air pollution, the transportation mechanisms and to identify the main aerosol sources which influence the atmospheric quality over SE Europe (Athens, Evia island/Central Aegean Sea and the region south of Bucharest).


Systematic measurements

Systematic lidar measurements are performed three times per week (Monday at 13:00 and 19:00 UT, Thursday at 19:00 UT) for a time period of 2 hours at least. Measurements are processed in order to retrieve aerosol optical parameters (backscatter and extinction coefficients). Final products are submitted to  the EARLINET-ACTRIS joint database.

At the end of the project a statistical database will be established concerning the vertical distribution of aerosol optical properties over the area of SE Europe.

The systematic lidar measurements are used to identify the main air pollution/aerosol sources over Europe and NE Africa affecting the air quality over the SE European region. Using meteorological data and the Hysplit model, the long-range transport mechanisms of the polluted air masses is under investigation.

1st AQUA-GRO campaign

In order to investigate the aerosol vertical distribution, the vertical distribution of the aerosol optical-chemical properties, the climatology and the transport processes of aerosols over the South-Eastern Europe and especially, over Athens / Evia island / Aegean Sea (Greece) and Bucharest / Iasi / Timisoara (Romania), an intensive lidar measurements campaign was organized between 15-29 September, 2012.

Synchronized and regular aerosol lidar observations were performed for the first time on the axis: N Africa - Greece - Romania, at 5 lidar stations: Athens (Lat: 37.96N, Lon: 23.78E, Elev: 220m), Oxylithos (Lat: 38.57N, Lon: 24.13E, Elev: 110m), Bucharest (Lat: 44.348N, Lon: 26.029E, Elev: 93m), Iasi (Lat: 47.166N. Lon: 27.566E, Elev: 200m), Timisoara (Lat: 45.733N. Lon: 21.216E, Elev: 102m).

The campaign was organized to perform regular measurements, 2 sessions per day:

  • (a) daytime: 06:00 – 09:00 UT;
  • (b) night time: 16:00 UT – 20:00 UT.

Weather and dust forecasts were issued each day prior to the measurements. During alerts, daily sessions were extended to:

  • (a) daytime: 06:00 – 13:00 UT;
  • (b) night time: 16:00 UT – 21:00 UT.

A total number of 282 hourly profiles were measured, out of 412 scheduled. The difference is mainly due to rain and low clouds conditions, when lidar measurements are not possible. Range corrected lidar time series were computed and made freely available on line at:

These describe the temporal evolution of the atmospheric structure, and are generally used to assess the aerosol layers altitude.