A Technique to Retrieve Vertical Concentration Profiles of Individual Aerosol-species Based on the Synergy of Lidar and Spectrophotometer Measurements.

In this study, we present the concept of a synergistic algorithm to retrieve the vertical concentration profiles of individual aerosol species using lidar and spectrophotometer measurements. Synergies among the following instruments will be deployed: a depolarization Raman lidar, a double monochromator Brewer and a DOAS/MAX-DOAS spectrophotometer installed at the Laboratory of Atmospheric Physics in Thessaloniki, Greece. The aerosol species are modeled with the Optical Properties of Aerosols and Clouds (OPAC) database which provides the optical properties per aerosol mode. They are calculated from Mie theory assuming spherical particles with the exception of mineral dust species for which spheroid particles are assumed. Hygroscopic growth calculations are included and the corresponding optical properties are selected using relative humidity profiles currently from radiosondes and in the future from models as well. The algorithm currently compiles a lookup table of mixtures that constitute of up to four aerosol modes and identifies the mixture/mass concentration combinations that best describe the lidar attenuated backscatter profiles. In the next phase, these profiles will be imported to a radiative transfer model and the combination that best reproduces ratios between the direct solar radiance, sky radiance, and irradiance spectra measured from the spectrophotometers will be
isolated.