Effects of the COVID-19 Lockdown on Urban Light Emissions: Ground and Satellite Comparison

Abstract

‘Lockdown’ periods in response to COVID-19 have provided a unique opportunity to study the impacts of economic activity on environmental pollution (e.g., NO2, aerosols, noise, light). The effects on NO2 and aerosols have been very noticeable and readily demonstrated, but that on light pollution has proven challenging to determine. The main reason for this difficulty is that the primary source of nighttime satellite imagery of the earth is the SNPP-VIIRS/DNB instrument, which acquires data late at night after most human nocturnal activity has already occurred and much associated lighting has been turned off. Here, to analyze the effect of lockdown on urban light emissions, we use ground and satellite data for Granada, Spain, during the COVID-19 induced confinement of the city’s population from 14 March until 31 May 2020. We find a clear decrease in light pollution due both to a decrease in light emissions from the city and to a decrease in anthropogenic aerosol content in the atmosphere which resulted in less light being scattered. A clear correlation between the abundance of PM10 particles and sky brightness is observed, such that the more polluted the atmosphere the brighter the urban night sky. An empirical expression is determined that relates PM10 particle abundance and sky brightness at three different wavelength bands.

Impacts of the COVID‐19 pandemic on human–nature interactions: Pathways, evidence and implications

“…ity and human mobility (e.g Bustamante-Calabria et al, 2021;Chen et al, 2020;Derryberry et al, 2020;Mandal & Pal, 2020;Venter, Aunan, et al, 2020;Venter, Barton, et al, 2020),. and in some there has been a reduction in management (e.g.…”

Light pollution affects West Nile virus exposure risk across Florida

“…Previous experimental studies measured ALAN in units of lux using handheld light metres in enclosed facilities, which served as the foundation for our hypotheses [50]. Whereas others have emphasized that data from the new world atlas of artificial night sky brightness that we chose to use here are highly related to light pollution levels at ground level [55,69], a critical component to future work involving ALAN will be understanding how remotely sensed values translate to other common metrics for quantifying light exposure, such as lux [70]. Thus, although our models suggest that WNV risk increases from the darkest sites in our dataset to peak in areas exposed to some degree of light pollution, we are limited by the current availability of data, namely, that our ALAN measure captures only the artificial component of night sky brightness.…”

Lockdown induced night-time light dynamics during the COVID-19 epidemic in global megacities

“…In the future, multi-source data can be combined to evaluate its impact more comprehensively, such as, electricity consumption data, human mobility data, etc. ( Bustamante-Calabria et al, 2021 , Demirguc-Kunt et al, 2020 , Li et al, 2020 , Ruan et al, 2020 ). Lastly , this study selects limited samples; it does not take into account the differences between small and medium cities.…”