Examinando la relación de la profundidad óptica de aerosoles derivada de imágenes MODIS con contagios por COVID-19 en Santiago, Chile

Abstract

Here, the relationship between the MAIAC (Multi-Angle Implementation of At-mospheric Correction) aerosol optical depth (AOD) product, derived from MODIS (Moderate Resolution Imaging Spectroradiometer) satellite images, and COVID-19 infections is examined. This research field still remains unexplored in the international state-of-the-art, whose approach will contribute to understand the incidence of air pollution on the occurrence of the disease cases over large cities. For this, daily AOD data, acquired at ~18:00 local time, and COVID-19 reproduction number (R0) from the Metropolitan Area of Santiago, Chile, were aggregated and correlated on a weekly epidemiological basis (SE) in a period embracing from March to December 2020, within four zones that divided the study area. The highest correlations were obtained when AOD was lagged by one week regarding R0s lower than 120 per 100 thousand inhabitants. This temporal range accounts for the virus incubation period, as well as the delay at which air pollution exposure affects human health when transmission has not yet become community-acquired. The northeast and southeast areas showed clearer correlations between both data sources (r= 0.57 and 0.47, respectively), than those north-west and south-west (r= 0.3). This finding is closely related to the atmospheric dynamics characterizing the valley where Santiago city is located, determining the movement of pollutants towards its highest sector (east) at afternoon. It is expected that this work will constitute a first approach to the construction of causal and predictive AOD-based models on the spatiotemporal behavior of the disease at issue.