The significant impact of shape deviations of atmospheric aerosols on light monitoring networks
- Author(s)
- L. Kómar, Stefan Wallner, Miroslav Kocifaj
- Abstract
Aerosol particles are important modulators of night sky brightness (NSB) due to their manifold impacts on spectral and angular properties of scattered light. The majority of radiative transfer models currently in use are based on rigorous Mie theory for spherical homogeneous particles. This fundamental concept enables significant simplifications in theoretical formulae and numerical modelling. However, as known from many studies, spherical shapes are rare for both natural and anthropogenic aerosols. Therefore, the aim of this paper is to analyse the potential magnitude of the subsequent effect in skyglow modelling assuming that the aerosol particles are of different aspect ratios. The zero-order approximation to tackle the problem is to characterize the non-sphericity by the ratio of the largest to smallest size of an ellipsoidal particle. We use T-matrix formalism to perform light scattering calculations on spheroidal particles of arbitrary size, composition, and orientation in respect to the incident light. Results indicate that the particle-shape impact on NSB can be of significant size leading to both positive and negative amplitudes around the zenith. In the most extreme case, an increase of up to 70 per cent in zenithal luminance was displayed. As a consequence, especially light monitoring devices like the sky quality meter, usually measuring the NSB around the zenith, are particularly influenced by this effect. In summary, the paper underlines both the importance of treating non-spherical aerosols in theoretical modelling of skyglow and also the significance of including atmospheric parameters to analyses of light monitoring networks.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Slovak Academy of Sciences (SAS), Comenius University Bratislava
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 512
- Pages
- 1805-1813
- No. of pages
- 9
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stac548
- Publication date
- 05-2022
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103037 Environmental physics, 103004 Astrophysics, 103039 Aerosol physics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/660a0c93-920a-49db-a5f7-598e10dd8d6f