Abstract
ABSTRACT Night-time monitoring of the aerosol content of the lower atmosphere is a challenging task, because appropriate reference natural light sources are lacking. Here, we show that the anthropogenic night-sky brightness due to city lights can be successfully used for estimating the aerosol optical depth of arbitrarily thick atmospheric layers. This method requires measuring the zenith night-sky brightness with two detectors located at the limiting layer altitudes. Combined with an estimate of the overall atmospheric optical depth (available from ground-based measurements or specific satellite products), the ratio of these radiances provides a direct estimate of the differential aerosol optical depth of the air column between these two altitudes. These measurements can be made with single-channel low-cost radiance detectors widely used by the light pollution research community.
Highlights
Monitoring the aerosol content of the lower atmosphere is relevant for characterizing the atmospheric boundary layer dynamics
We describe here a new application, namely a practical approach for determining the difference in aerosol optical depth (∆AOD) between two altitudes in the nocturnal air column, based on differential photometry of the artificial skyglow. ∆AOD could be derived from ground AOD if the aerosol scale height for the exponential atmosphere were known
The AOD was obtained from the AERONET station located in Poprad-Ganovce
Summary
Monitoring the aerosol content of the lower atmosphere is relevant for characterizing the atmospheric boundary layer dynamics. Sanchez de Miguel et al (2020) have shown that their scattered upward radiance is correlated with the downward one, and with the light perceived by ground-based observers as anthropogenic skyglow, providing a feasible tool for wide-area light pollution monitoring Analysing these halos, Kocifaj and Bara (2020) developed a method for estimating the number-size distribution of aerosol particles in the nocturnal air column from the angular distribution of the upward scattered light. The method here described allows estimating ∆AOD from measurements of the zenith sky brightness made at two different altitudes, in the vicinity of the urban centres, and having a good estimate of the total AOD The ratio between these radiances provides a good estimate of the fraction of the total AOD that is due to the aerosols in the layer between the two measuring heights. We expect this method can contribute to increase the amount and the quality of aerosol data in the nocturnal atmosphere
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Monthly Notices of the Royal Astronomical Society: Letters
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
