Effect of Pandemic-induced Mobility Restrictions on Surface Ozone in Quito, Ecuador: Results from Measurements and Modeling

Abstract:

In this work we investigate the effect of COVID-19 mobility restrictions on surface ozone in Quito, Ecuador, a high altitude city in the Andes. Due to the rapid spread of the disease, the Ecuadorian government imposed a quarantine at the national level, in addition to curfew measures, as early as mid-March 2020. As a result, there was a significant drop in primary emissions such as nitrogen oxides and carbon monoxide, but ozone levels remained unchanged. We present ground station measurements and box model results of the impact on ozone chemistry in Quito due to the shift in ambient levels of precursors. We discuss main findings in regard to the potential of the local atmosphere to increase rates of ozone production under a shifted regime of primary precursors. Within this context, we also discuss the role that meteorology plays at this high altitude urban site with respect to influencing the ozone budget near the surface.