Berlin 2014 – scientific programme

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UP: Fachverband Umweltphysik

UP 10: Atmosphäre - Aerosole

UP 10.6: Talk

Wednesday, March 19, 2014, 16:15–16:30, MAG 100

Polarization-resolved exact light backscattering by an ensemble of particles in the atmosphere — Elodie Coillet, Gregory David, •Alain Miffre, and Patrick Rairoux — Institut Lumière Matière (ILM), Université Lyon 1, CNRS, Lyon, France

Exact backscattering of light by an ensemble of particles in ambient air has been observed in the laboratory. The experimental set-up operates in the far-field single scattering approximation, covers the exact backscattering direction with accuracy (θ = π +/- ε with ε = 3.5 x 10-3 rad) and efficiently collects the particles backscattering radiation, while minimizing any stray light. By using scattering matrix formalism, the observation of the particles UV-backscattering signal allowed to measure the particles diagonal scattering coefficient (depolarization) of water droplets and salt particles in air, for the first time, in the exact backscattering direction [1]. These results may be useful for comparison with the existing numerical models, for remote sensing field applications [2], in radiative transfer and climatology and for further laboratory experiments on chemical and physical properties of aerosols. References [1] G. David, B. Thomas, E. Coillet, A. Miffre, P. Rairoux, Polarization-resolved exact light backscattering by an ensemble of particles in air, Opt. Ex., 21,18624-18639, (2013). [2] G. David, B. Thomas, T. Nousiainen, A. Miffre, and P. Rairoux, Retrieving volcanic, desert dust, and sea-salt particle properties from two/three-component particle mixtures after long-range transport using UV-VIS polarization Lidar and T-matrix, Atmos. Chem. Phys. (2013).