Advantages of an Additional Raman Channel in Laser Sounding at Wavelengths of 355–1064 nm for Retrieving Microphysical Parameters of Atmospheric Aerosol

• Published in: Atmospheric and oceanic optics Vol. 36; no. 6; pp. 701 - 715
• Main Authors: Samoilova, S. V., Kokhanenko, G. P., Balin, Yu. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2023; Springer Nature B.V
• Subjects: Aerosols; Algorithms; Atmospheric models; Distribution functions; Inverse Problems of Atmospheric and Ocean Optics; Lasers; Lidar; Optical Devices; Optics; Parameters; Particle size distribution; Photonics; Physics; Physics and Astronomy; Refractive index; Refractivity; Size distribution; Wavelengths; optical parameters; inverse problem; lidar; microphysical characteristics; aerosol
• ISSN: 1024-8560; 2070-0393
• DOI: 10.1134/S1024856023060179

The potential and advantages of an additional Raman channel in the IR spectral region for the determination of microphysical parameters of aerosol are studied. Features of the joint retrieval of the complex refractive index m = m real + i × m image and the bimodal spherical particle size distribution function U ( r ) from lidar data are considered. A possibility of estimating m + U ( r ) is studied for weakly absorbing particles for m image  ≤ 0.010 when m fine ≠ m coarse . The algorithms are tested for one m fine = 1.50 + i × 0.01 and nine m coarse ( m real = 1.40, 1.50, and 1.60; m image = 0.0001, 0.001, and 0.01). In order to take into account the influence of the contribution from the modal particles to the total concentration, 462 empirical models of U ( r ) are used.