Lidar-relevant radiative properties of soot fractal aggregate ensembles

Lucas Paulien (1) , Romain Ceolato (1) , Laurent Soucasse (2) , Franck Enguehard (3) , Anouar Soufiani (2)

1 DOTA, ONERA, Université de Toulouse [Toulouse]
2 EM2C - Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion
3 TNR - Thermique aux Nano échelles et Rayonnement [Institut Pprime]

This study presents the averaged lidar-relevant radiative properties of numerically generated soot fractal aggregate ensembles. The radiative properties of these aggregates have been computed using the Superposition T-Matrix Method, with emphasis put on those that are most relevant to lidar application; the backscattering and extinction cross-sections, the Lidar Ratio and the Linear Depolarization Ratio. These lidar-relevant radiative properties have been computed over a broad spectrum, going from the ultraviolet to the near infrared, in order to address lidar instrument need for a priori knowledge in signal inversion procedures and measurement analysis. By averaging the computed radiative properties according to each set of morphological parameters, we obtain statistically representative results and we study the impacts of morphological changes on these lidar-relevant radiative properties. Our results show a strong impact of the primary particle radius on all considered radiative properties, while the number of primary particles induce significant variations on the cross-sections only. The fractal dimension, although being an essential morphological parameter, has a weak influences on the lidar-relevant radiative properties.

Mots clés: Aerosol radiative properties; Modelling; T-Matrix; Soot fractal aggregates; Lidar

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]; Matière Condensée [cond-mat]; Chimie-Physique [physics.chem-ph]

Lucas Paulien, Romain Ceolato, Laurent Soucasse, Franck Enguehard, Anouar Soufiani. Lidar-relevant radiative properties of soot fractal aggregate ensembles. Journal of Quantitative Spectroscopy and Radiative Transfer, 2020, 241, pp.106706. ⟨10.1016/j.jqsrt.2019.106706⟩. ⟨hal-02349170⟩