To assess information about the optical, microphysical, and radiative properties of aerosol particles the lidar technique and sun photometers are commonly used. Information that result from both lidar and sun photometer data can provide a distinct image of the vertical aerosol properties. The algorithm developed at the Institute of Physics of the National Academy of Science of Belarus (IPNASB) uses lidar measurements at the three wavelengths 355, 532, and 1064 nm and mean backscatter and extinction coefficients retrieved from radiometric data to obtain profiles of fine-mode and coarse-mode concentrations. Within the master thesis the IPNASB algorithm was tested for specific aerosol situations. Three cases are considered representing Saharan dust, smoke and industrial aerosol from East Europe, and volcanic aerosol from the Eyjafjallajokull eruption. The retrieved microphysical aerosol properties are in good to acceptable agreement with findings of well-established methods.

To assess information about the optical, microphysical, and radiative properties of aerosol particles the lidar technique and sun photometers are commonly used. Information that result from both lidar and sun photometer data can provide a distinct image of the vertical aerosol properties. The algorithm developed at the Institute of Physics of the National Academy of Science of Belarus (IPNASB) uses lidar measurements at the three wavelengths 355, 532, and 1064 nm and mean backscatter and extinction coefficients retrieved from radiometric data to obtain profiles of fine-mode and coarse-mode concentrations. Within the master thesis the IPNASB algorithm was tested for specific aerosol situations. Three cases are considered representing Saharan dust, smoke and industrial aerosol from East Europe, and volcanic aerosol from the Eyjafjallajokull eruption. The retrieved microphysical aerosol properties are in good to acceptable agreement with findings of well-established methods.

Aerosols are small, micrometer-sized particles, whose optical effects coupled with their impact on cloud properties is a source of large uncertainty in climate models. While their radiative forcing impact is largely of a cooling nature, there can be significant variations in the degree of their impact, depending on the size and the nature of the aerosols. The radiative and optical impact of aerosols are, first and foremost, dependent on their concentration or number density (an extensive parameter) and secondly on the size and nature of the aerosols (intensive, per particle, parameters). We employed passive (sunphotmetry) and active (backscatter lidar) measurements to retrieve extensive optical signals (aerosol optical depth or AOD and backscatter coefficient respectively) and semi-intensive optical signals (fine and coarse mode OD and fine and coarse mode backscatter coefficient respectively) and compared the optical coherency of these retrievals over a variety of aerosol and thin cloud events (pollution, dust, volcanic, smoke, thin cloud dominated). The retrievals were performed using an existing spectral deconvolution method applied to the sunphotometry data (SDA) and a new retrieval technique for the lidar based on a colour ratio thresholding technique. The validation of the lidar retrieval was accomplished by comparing the vertical integrations of the fine mode, coarse mode and total backscatter coefficients of the lidar with their sunphotometry analogues where lidar ratios (the intensive parameter required to transform backscatter coefficients into extinction coefficients) were (a) computed independently using the SDA retrievals for fine mode aerosols or prescribed for coarse mode aerosols and clouds or (b) computed by forcing the computed (fine, coarse and total) lidar ODs to be equal to their analog sunphotometry ODs. Comparisons between cases (a) and (b) as well as the semi-qualitative verification of the derived fine and coarse mode vertical profiles with the expected backscatter coefficient behavior of fine and coarse mode aerosols yielded satisfactory agreement (notably that the fine, coarse and total OD errors were <~ sunphotometry instrument errors). Comparisons between cases (a) and (b) also showed a degree of optical coherency between the fine mode lidar ratios.