Impact of the 2008 Global Recession on air quality over the United States: Implications for surface ozone levels from changes in NO_x emissions

Abstract

Satellite and ground observations detected large variability in nitrogen oxides (NOx) during the 2008 economic recession, but the impact of the recession on air quality has not been quantified. This study combines observed NOx trends and a regional chemical transport model to quantify the impact of the recession on surface ozone (O3) levels over the continental United States. The impact is quantified by simulating O3 concentrations under two emission scenarios: business‐as‐usual (BAU) and recession. In the BAU case, the emission projection from the Cross‐State Air Pollution Rule is used to estimate the “would‐be” NOx emission level in 2011. In the recession case, the actual NO2 trends observed from Air Quality System ground monitors and the Ozone Monitoring Instrument on the Aura satellite are used to obtain “realistic” changes in NOx emissions. The model prediction with the recession effect agrees better with ground O3 observations over time and space than the prediction with the BAU emission. The results show that the recession caused a 1–2 ppbv decrease in surface O3 concentration over the eastern United States, a slight increase (0.5–1 ppbv) over the Rocky Mountain region, and mixed changes in the Pacific West. The gain in air quality benefits during the recession, however, could be quickly offset by the much slower emission reduction rate during the post‐recession period.

Satellite‐Based Daily PM2.5 Estimates During Fire Seasons in Colorado

“…Lee et al, 2017; Pan et al, 2014; Tong et al, 2016). This modeling system used the Community Multiscale Air Quality (CMAQ) model version 4.6 (Byun & Schere, 2006) to predict surface O 3 and PM 2.5 concentrations.…”

“…Daily surface PM 2.5 concentrations at 12 km resolution were produced using an experimental version of the National Air Quality Forecast Capability (NAQFC) system operated by the National Oceanic and Atmospheric Administration (P. Lee et al, 2017;Pan et al, 2014;Tong et al, 2016). This modeling system used the Community Multiscale Air Quality (CMAQ) model version 4.6 (Byun & Schere, 2006) to predict surface O 3 and PM 2.5 concentrations.…”

Fine-Scale Columnar and Surface NOx Concentrations over South Korea: Comparison of Surface Monitors, TROPOMI, CMAQ and CAPSS Inventory

“…Since the late 1990s, several instruments on board various platforms have been used to monitor changes in anthropogenic NO x emissions. Indeed, measuring NO 2 vertical column density has been an effective way of monitoring changes in surface anthropogenic NO x emissions globally, including over North America [8][9][10][11], Europe [12][13][14] and Asia [15][16][17][18][19][20]. Recently, comparing satellite-observed NO 2 content with modeled constituents using regional chemistry transport models has become common for evaluating information on the amount of NO x emissions released from anthropogenic sources [15,[21][22][23][24][25].…”

Quantifying Uncertainties of Ground‐Level Ozone Within WRF‐Chem Simulations in the Mid‐Atlantic Region of the United States as a Response to Variability

“…Eulerian air quality modeling is a multifaceted problem that depends on economic forcing (Tong et al, 2016), meteorological conditions (Seaman, 2000), biogenic emissions (Bell & Ellis, 2004), and chemistry (Mar et al, 2016). Each of these processes is variable, which affects the practical predictability of O 3 .…”