Vertical profile of polarization over Vladivostok using horizon shadowing: Clues to understanding the altitude variation of reflectance of aerosol particles

Characterizing atmospheric aerosols using polarimetry and shadow hiding

“…For instance, instead of the log-normal size distribution that is often considered in application to atmospheric aerosols (e.g., Willeke and Brockmann, 1977;Dubovik et al, 2006), we use the power-law size distribution r -n that is formally characterized by only three parameters: the minimum radius of aerosol particles r min , their maximum radius r max , and the power index n. It is worth noting that aerosol particles sampled previously in situ in the atmosphere were successfully characterized in terms of the power-law size distribution (e.g., Junge et al, 1961). Another important feature to emphasize is an equivalence of the polarimetric response produced by polydisperse particle systems obeying a log-normal size distribution and a power-law size distribution (see Pavlov et al, 2018 and therein for review). Therefore, a log-normal size distribution does not produce a unique polarimetric response that cannot be reproduced with a power-law size distribution.…”

“…Twilight phenomena in the atmosphere have been studied by means of different techniques (see Rozenberg, 1966 for review). In particular, it has been investigated by means of polarimetry (e.g., Fesenkov, 1966;Pavlov et al, 2018;Ugolnikov et al, 2021). It is worth noting that the polarimetric response from the atmosphere during daylight is somewhat different from what emerges in twilight; nevertheless, there also is a great deal of qualitative similarity between them (Rozenberg, 1966).…”

“…Fesenkov (1966) proposed a polarimetric method to estimate the contribution of multiple scattering in the twilight atmosphere. Today, polarimetry is considered to be a powerful tool for studying the microphysics of atmospheric aerosols (e.g., Pavlov et al, 2018;Ugolnikov et al, 2021).…”

Circularly and elliptically polarized light under water and the Umov effect

“…In this work, we study the visibility of CP and EP light under water for objects of different albedos and show that a high degree of circular polarization (DoCP) can be observed in the region outside Snell’s window 16 , which is caused by a polarization-dependent phase shift from TIR. The well-known Umov effect, which applies to linear polarization (LP) states of light by relating the albedo of an object to the degree of linear polarization (DoLP), has been used for albedo 19 and particle density estimation 20 , atmospheric measurements in twilight 21 and the retrieval of the size of near-Earth asteroids 22 . A similar variation in the DoCP is observed when an object is illuminated with polarized light.…”