Decadal trends of air pollutants in 9 US cities, and an alternative method to calculate modified combustion efficiency

The COVID-19 pandemic led to lower on-road emissions as a significant portion of the workforce began working from home. In part I of the seminar, I examine the concentrations of NO2, CO, O3, and PM2.5 from 9 U.S. cities in 2020 using roadside monitoring data to determine how they changed during the pandemic, and other notable features of decadal trends in these pollutants. In part II of the seminar, I discuss calculating the modified combustion efficiency, MCE = 1/(1 + ΔCO/ΔCO2), using in situ data measured from airborne platforms. I specifically examine fire plumes where the CO to CO2 enhancement ratio does not accurately represent the emission ratio of these two gases.