A Comparison of Trace Gas Trends in Urban Areas Collected via Whole Air
Sampling during the COVID-19 Pandemic
Abstract
COVID-19’s impact on society and our daily habits has been
unprecedented. With a decrease in vehicular traffic and industrial
production, a decrease in local emissions was expected to occur. In
order to capture any trends in ambient trace gas concentrations,
approximately one thousand whole air samples were collected in intervals
across the United States from April to July 2020 as part of the NASA
Student Airborne Research Program (SARP). These samples were then
analyzed by the UCI Rowland-Blake Lab using multi-column gas
chromatography for over one hundred unique trace gases, including
methane, non-methane hydrocarbons, and halocarbons, as described in
Colman et al. (2001) and Barletta et al. (2002). Initial samples
collected in April coincided with the peak of stay-at-home/social
distancing orders in most states while samples collected later in the
spring and early summer reflect the easing of these measures and initial
state reopenings. Overall trends in emissions over time in select
metropolitan areas will be discussed and compared to trends observed
across the entire United States.