Spatial-temporal analysis of NO2 in the metropolitan region of São Paulo

Abstract

Nowadays, several methods of monitoring air pollutants exist, however few still allow a large spatial and temporal coverage. Sentinel-5P is a satellite dedicated to atmospheric monitoring with high spatial and temporal resolutions, offering a large data of miscellaneous chemical species. Nitrogen oxides (NO and NO₂), emitted by anthropogenic activities into the atmosphere - in large urban centers their main emitting source is vehicles - need particular attention, in addition to being primary pollutants, they are precursors for formation of other chemical species due to photochemical reactions, mainly tropospheric ozone. These photochemical interactions of NO_x stimulate to reduce its lifetime in the atmosphere. Furthermore, these pollutants are used as air quality indexes. The Metropolitan Region of São Paulo (MRSP) has more than 30 cities, being an important economic center for the state of São Paulo, Brazil. The MRSP has a vehicular circulation mesh with a high presence of light and heavy vehicles, besides industries and bears a high population density. Such factors make this region a favorable area for a satellite study given its complexity. Thus, the present work uses Sentinel-5P NO₂ L2 data in order to analyze the evolution of concentrations throughout  the year of 2019.