Nighttime monitoring of the aerosol content of the lower atmosphere by differential photometry of the anthropogenic skyglow

TL;DR

This paper presents a novel method using anthropogenic skyglow measurements from low-cost detectors to estimate aerosol optical depth in the lower atmosphere at night, overcoming the lack of natural reference sources.

Contribution

It introduces a new technique that leverages city light brightness measurements to determine aerosol content at different atmospheric layers.

Findings

Method successfully estimates aerosol optical depth using sky brightness ratios.

Applicable with low-cost radiance detectors widely used in light pollution studies.

Provides a practical approach for nighttime atmospheric monitoring.

Abstract

Nighttime 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.