Preliminary results from the new multiwavelength aerosol lidar scanning system in Turkey

Aerosols affect the radiation budget of the Earth by scattering and absorbing the incoming solar radiation, and by acting as cloud condensation nuclei (CCN) to form clouds and/or change their properties. Because of their high spatio-temporal variability and remote nature, investigations of aerosols physical properties have been rather limited until the last few decades. Lately, multiwavelength Raman lidars became an important tool for the measurements of aerosol physical parameters. Such lidars allow to get three aerosol backscattering and two extinction coefficients (so called 3β+2α) and from these optical data the particle microphysical parameters such as number, surface area and volume concentrations, effective radius, particle size distribution, particle and volume polarizations and complex refractive index can be retrieved through inversion with regularization, principle component analysis and linear estimation techniques. During 2009-2011, using a homemade multiwavelength Raman lidar with a Quantel BrilliantB Nd:YAG laser generating also the 2nd and the 3rd optical harmonics, the spatial and temporal distribution of aerosols and their microphysical properties have been measured and evaluated in various seasons, meteorological conditions and with different horizontal measurement angles. Reliability of our results have been confirmed with the synergistic measurements done with lidars located in Greece, the EUFAR aircraft (European Facility for Airborne Research, FAAM-Bae146 aircraft), ACEMED campaign (Evaluation of CALIPSO’s (Cloud-aerosol Lidar and Infrared Pathfinder Satellite Observation) aerosol classificatiomn scheme over Eastern Mediterranean) and GOSAT (Global Greenhouse Gas Observation by Satellite project). In early 2012, the addition of the scanning module mounted on the top of the telescope, allowed to obtain information about the aerosol distribution within fixed and regular time intervals in a given time frame and from various measurement angles, and thus it made possible to cover a large spatial area and to evaluate the changes in the aerosol microphysical properties in space and time. It uses Newport ESP301 Motion Controller allowing to make measurements in 340° azimuthal and ± 15° vertical scanning angles by a 300 x 600 mm plane mirror. In this paper, the description of the new multiwavelength aerosol lidar scanning system installed in the Scientific and Technological Research Council of Turkey (TUBITAK) Marmara Research Center (MRC), KA09 Laser and Lidar Laboratory is explained, and the first results obtained from the data acquired during Spring and Summer 2012 are presented by integrating the results with a geographical map of Gebze Area.