(UV, VIS) Laboratory evaluation of the lidar depolarization ratio of freshly emitted soot aggregates from pool fire in ambient air at exact backscattering angle

Abstract In this paper, a controlled-laboratory experiment is carried out to evaluate the lidar depolarization ratio of freshly emitted soot aggregates in exact backward scattering direction at 180.0°. The performed two wavelengths simultaneously, namely 355 and 532 nm, often used polarimetric remote sensing. are generated from kerosene JET A-1 pool fire laboratory ambient air microscopic images confirm fractal morphology aggregates. Then, Superposition T-Matrix (STM) method applied numerically simulate backscattering properties for different particles refractive indices, monomer radii numbers. range these parameters which ensures lowest discrepancy between measurement STM-computations discussed within experimental numerical error bars. We find that polydisperse monomers model gives an overall better evaluation F22(π)/F11(π). case, our findings agree both index m = 2.65 + i1.32 number Nm > 40 mean radius rp = 30 nm (Nm 160 rp = 27.5 nm). believe work may be useful light sensing communities also help future studies aimed understanding impact particle on Earth's climate, still needs precisely quantified.