ACPD Atmospheric Chemistry and Physics Discussions ACPD Atmos. Chem. Phys. Discuss. 1680-7375 Göttingen, Germany 10.5194/acpd-6-12155-2006 SAWA experiment – properties of mineral dust aerosol as seen by synergic lidar and sun-photometer measurements Kardas A. E. 1 Markowicz K. M. 1 Malinowski S. P. 1 Karasiński G. 2 Stacewicz T. 2 Stelmaszczyk K. 3 Hochhertz C. 3 Woeste L. 3 Institute of Geophysics, Warsaw University, Poland Institute of Experimental Physics, Warsaw University, Poland Free University of Berlin, Germany 28 11 2006 6 6 12155 12178 Copyright: © 2006 A. E. Kardas et al. 2006 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://acp.copernicus.org/preprints/6/12155/2006/acpd-6-12155-2006.html The full text article is available as a PDF file from https://acp.copernicus.org/preprints/6/12155/2006/acpd-6-12155-2006.pdf

We propose a method of retrieving basic information on mineral dust aerosol particles from synergic sun-photometer and multi-wavelength lidar measurements as well as from the observations of lidar light depolarisation. We use this method in a case study of mineral dust episode in Central Europe. <br><br> Lidar signals are inversed with a modified Klett-Fernald algorithm. Aerosol optical depth measured with the sun-photometer allows to reduce uncertainties in the inversion procedure through which we estimate vertical profile of aerosol extinction. <br><br> Next we assume that aerosol particles may be represented by ensemble of randomly oriented, identical spheroids. Having calculated vertical profiles of aerosol extinction coefficients for lidar wavelengths, we compute the profiles of local Angstrom exponent. We use laser beam depolarisation together with the calculated Angstrom exponents to estimate the shapes (aspect ratios) and sizes of&nbsp;the spheroids. Numerical calculations are performed with the&nbsp;transition matrix (T-matrix) algorithm by M.&nbsp;Mishchenko. <br><br> The proposed method was first used during SAWA measurement campaign in Warsaw, spring 2005, to characterise the particles of desert dust, drifting over Poland with a southern-eastern wind (13&ndash;14 April). Observations and T-matrix calculations show that mode radii of spheroids representative for desert aerosols' particles are in the range of 0.15&ndash;0.3 &mu;m, while their aspect ratios are lower than 0.7 or larger than 1.7.