A fuel-based method for updating mobile source emissions during the Covid-19 pandemic

Bibliographic Data

ID15548679
AuthorsColin Harkins (0000-0001-5692-3427, National Oceanic and Atmospheric Administration), Brian McDonald (0000-0003-1601-5445, corresponding author), Brian C McDonald (0000-0001-8600-5096, National Oceanic and Atmospheric Administration, corresponding author), Daven K Henze (0000-0001-6431-4963, University of Colorado Boulder), Christine Wiedinmyer (0000-0001-9738-6592, Cooperative Institute for Research in Environmental Sciences)
Year2021
Volume16
Issue6
Pages065018-065018
Publication date2021-05-28
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/ac0660
OpenAlexW3170721647
LanguageEN
Citations received4
References cited41

The COVID-19 pandemic and ensuing lockdown of many US States resulted in rapid changes to motor vehicle traffic and their associated emissions. This presents a challenge for air quality modelling and forecasting during this period, in that transportation emission inventories need to be updated in near real-time. Here, we update the previously developed fuel-based inventory of vehicle emissions (FIVE) to account for changes due to COVID-19 lockdowns. We first construct a 2020 business-as-usual (BAU) case inventory and adjust the emissions for a COVID-19 case using monthly fuel sales information. We evaluate cellular phone-based mobility data products (Google COVID-19 Community Mobility, Apple COVID-19 Mobility Trends) in comparison to embedded traffic monitoring sites in four US cities. We find that mobility datasets tend to overestimate traffic reductions in April 2020 (i.e. lockdown period), while fuel sales adjustments are more similar to changes observed by traffic monitors; for example, mobility-based methods for scaling emissions result in an approximately two-times greater estimate of on-road nitrogen oxide (NO x ) reductions in April 2020 than we find using a fuel-based method. Overall, FIVE estimates a 20%–25% reduction in mobile source NO x emissions in April 2020 versus BAU, and a smaller 6%–7% drop by July. Reductions in April showed considerable spatial heterogeneity, ranging from 6% to 39% at the state level. Similar decreases are found for carbon monoxide (CO) and volatile organic compounds. Decreases to mobile source NO x emissions are expected to lower total US anthropogenic emissions by 9%–12% and 3%–4% in April and July, respectively, with larger relative impacts in urban areas. Changes to diurnal and day-of-week patterns of light- and heavy-duty vehicular traffic are evaluated and found to be relatively minor. Beyond the applicability to modelling air quality in 2020, this work also represents a methodology for quickly updating US transportation inventories and for calibrating mobility-based estimates of emissions

Air pollution · Air quality index · Coronavirus disease 2019 (COVID-19 · Fuel efficiency · Geography · Meteorology · Mobile phone · Nitrogen oxides · Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 · Telecommunications · Waste management · Air Quality and Health Impacts · Air Quality Monitoring and Forecasting · Chemistry · Computer Science · COVID-19 impact on air quality · Engineering · Environmental Science · Automotive Engineering

Tools

Open DOIOpen Access