Understanding the local and remote source contributions to ambient O during a pollution episode using a combination of experimental approaches in the Guadalquivir valley, southern Spain.

The Guadalquivir Valley is one of three major O hotspots in Spain. An airborne and surface measurement campaign was carried out from July 9th to 11th, 2019 to quantify the local/regional O contributions using experimental approaches. Air quality and meteorology data from surface measurements, a microlight aircraft, a helium balloon, and remote sensing data (TROPOMI-NO2-ESA) were used to obtain the 3D distribution of O and various tracer pollutants.

Changes in air quality during the lockdown in Barcelona (Spain) one month into the SARS-CoV-2 epidemic.

Lockdown measures came into force in Spain from March 14th, two weeks after the start of the SARS-CoV-2 epidemic, to reduce the epidemic curve. Our study aims to describe changes in air pollution levels during the lockdown measures in the city of Barcelona (NE Spain), by studying the time evolution of atmospheric pollutants recorded at the urban background and traffic air quality monitoring stations. After two weeks of lockdown, urban air pollution markedly decreased but with substantial differences among pollutants.