Date: Wednesday, November 17, 2021
Time: 03:30 pm
Location
Zoom
Sponsored / Hosted by
Saewung Kim, Gracie Wong

Department Seminar: Brian McDonald

Wednesday, November 17, 2021 | 03:30 pm | Zoom
Brian McDonald
Environmental Engineer
Event Details

Title: Tracking Petroleum Use from Fossil Fuels to Chemical Products

Abstract: The average US person consumes ~10 kilograms of products derived from oil and natural gas per day. In this talk, the emissions of greenhouse gases and ozone and aerosol precursors will be discussed for three key sectors: (1) upstream oil and natural gas production, (2) mobile sources, and (3) volatile chemical products. Domestic US production of oil and natural gas has grown rapidly over the last two decades. However, quantifying both the absolute emissions and trends of methane, non-methane volatile organic compounds (VOCs), and nitrogen oxides (NOx) has proved challenging. Here, we explore advancements in satellite remote sensing as a means to constrain and track emissions from oil and gas producing regions, where ground-based monitoring is often lacking. In urban areas, mobile sources remain a major to dominant source of NOx, which contributes to both ozone and aerosol formation. Furthermore, the COVID-19 pandemic has offered insights into how well current earth observing systems are able to track changes in emissions resulting from transportation. We estimate that at the low point of traffic activity, mobile source NOx emissions decreased across the US by ~20% relative to business-as-usual conditions, and have remained below normal during the reopening/recovery phase. This is corroborated by satellite retrievals of nitrogen dioxide (NO2). Lastly, volatile chemical products, or VCPs, now comprise half of the anthropogenic VOC emissions budget in US cities and have emerged as one of the largest anthropogenic sources of VOCs to the atmosphere. Recent field measurements in New York City and Boulder, CO have been able to identify new chemical tracers by which to constrain VCP emissions. Using these tracers, we quantify urban VOC emissions pre- and during the COVID-19 pandemic. Prior to the pandemic, VOC emissions had been shifting away from transportation fuels and towards every day consumer products, as a result of successful efforts to control motor vehicle emissions over many decades. Ambient measurements of VOCs found in consumer products indicate that these emissions have been affected by the COVID-19 pandemic. Lastly, we perform weather-chemistry modeling to assess how changes in NOx and VOC emissions affect ground-level ozone formation. Preliminary results suggest that the net effect of changes in anthropogenic emissions during the COVID-19 pandemic tend to lower ground-level ozone formation.

The Department of Earth System Science acknowledges our presence on the ancestral and unceded territory of the Acjachemen and Tongva peoples, who still hold strong cultural, spiritual and physical ties to this region.