Evaluación de datos satelitales del sensor de calidad de aire TROPOMI - SENTINEL 5P para el Ecuador entre los años 2018 a 2020

Abstract

Currently, Ecuador does not have a study that evaluates the reliability of satellite data with ground data, so this study shows the comparison between measurements obtained by the TROPOMI sensor on board Sentinel 5P and REMMAQ measurements in the city of Quito Ecuador, in the period between August 2018 and December 2020. In order to develop an alternative methodology for air quality monitoring that covers more ground and can be replicable in other provinces of Ecuador. For this, with the Google Earth Engine platform, we proceeded to obtain satellite images provided by the TROPOMI sensor in real time, and the data generated by REMMAQ for CO, NO2 and O3 pollutants on the page of the Secretariat of Environment of Quito.To find the relationship between satellite and terrestrial data, a correlation of the variables CO_ SATELITE vs CO_SATELITE, NO2_ SATELITE vs NO2_ SATELITE and O3_ SATELITE vs O3_SATELITE was performed, where it was found that there is a statistically significant correlation. In addition, to verify the similarity in the behavior of the data obtained, a descriptive statistical analysis was performed, which determined that the spatial and terrestrial measurements have similarity in their behavior. To visualize this, graphs were made with the normalized data of each pollutant versus time, where it was shown that there is a relationship in the decrease of CO, NO2 and O3 concentrations during the period of mandatory quarantine by Covid-19 and the sanitary emergency in Ecuador. The results obtained are also shown in spatio-temporal maps made for each pollutant where the areas of greatest contamination in the Metropolitan District of Quito are identified. As a final result, a web application was developed in Google Earth Engine, which shows mosaics of the observations provided by the TROPOMI sensor on board the Sentinel 5P, the user can select the date at will, the pollutant and the province of Ecuador where he/she wants to see the behavior of the analyzed pollutants.