Co-occurrence patterns of gaseous air pollutant pairs at different minimum concentrations in the united states

The unequal spatial distribution of ambient nitrogen dioxide (NO2), an air pollutant related to traffic, leads to higher exposure for minority and low socioeconomic status communities. We exploit the unprecedented drop in urban activity during the COVID-19 pandemic and use high-resolution, remotely sensed NO2 observations to investigate disparities in NO2 levels across different demographic subgroups in the United States. We show that, prior to the pandemic, satellite-observed NO2 levels in the least White census tracts of the United States were nearly triple the NO2 levels in the most White tracts. During the pandemic, the largest lockdown-related NO2 reductions occurred in urban neighborhoods that have 2.0 times more non-White residents and 2.1 times more Hispanic residents than neighborhoods with the smallest reductions. NO2 reductions were likely driven by the greater density of highways and interstates in these racially and ethnically diverse areas. Although the largest reductions occurred in marginalized areas, the effect of lockdowns on racial, ethnic, and socioeconomic NO2 disparities was mixed and, for many cities, nonsignificant. For example, the least White tracts still experienced ∼1.5 times higher NO2 levels during the lockdowns than the most White tracts experienced prior to the pandemic. Future policies aimed at eliminating pollution disparities will need to look beyond reducing emissions from only passenger traffic and also consider other collocated sources of emissions such as heavy-duty vehicles.

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Hazardous air pollutant exposure as a contributing factor to COVID-19 mortality in the United States

Environmental Research Letters ◽

10.1088/1748-9326/abaf86 ◽

2020 ◽

Vol 15 (9) ◽

pp. 0940a9 ◽

Cited By ~ 2

Author(s):

Michael Petroni ◽

Dustin Hill ◽

Lylla Younes ◽

Liesl Barkman ◽

Sarah Howard ◽

...

Keyword(s):

United States ◽

The United States ◽

Air Pollutant ◽

Hazardous Air Pollutant

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Assessment of the effect of air pollution controls on trends in shortwave radiation over the United States from 1995 through 2010 from multiple observation networks

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-23719-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 23719-23755 ◽

Cited By ~ 1

Author(s):

C.-M. Gan ◽

J. Pleim ◽

R. Mathur ◽

C. Hogrefe ◽

C. N. Long ◽

...

Keyword(s):

United States ◽

Cloud Cover ◽

Surface Concentration ◽

The United States ◽

Air Pollutant ◽

Shortwave Radiation ◽

Clear Sky ◽

Western Us ◽

The Us ◽

Increasing Trends

Abstract. Long term datasets of all-sky and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction and aerosol optical depth (AOD) are analyzed together with surface concentration from several networks (e.g. SURFRAD, CASTNET, IMPROVE and ARM) in the United States (US). Seven states with varying climatology are selected to better understand the effects of aerosols and clouds on SW radiation. This analysis aims to assess the effects of reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) over the past 16 yr across the US on trends in SW radiation. The SO2 and NOx emission data show decreasing trends from 1995 to 2010 which indirectly validates the effects of the Clean Air Act (CAA) in the US. Meanwhile, the total column AOD and surface total PM2.5 observations also show decreasing trends in the eastern US but slightly increasing trends in the western US. Moreover, measured surface concentrations of several other pollutants (i.e. SO2, SO4 and NOx) have the same behavior as the AOD and total PM2.5. First, all-sky downwelling SW radiation is assessed together with the cloud cover. Results of this analysis show strong increasing trends in all-sky downwelling SW radiation with decreasing trends in cloud cover. However, since observations of both all-sky direct and diffuse SW radiation are increasing, there may be other factors contributing to the radiation trends in addition to the decreasing trends in overall cloud cover. To investigate the role of direct radiative effects of aerosols, clear-sky downwelling radiation is analyzed so that cloud effects are eliminated. However, similar increasing trends in clear-sky direct and diffuse SW radiation are observed. While significantly decreasing trends in AOD and surface concentration along with increasing SW radiation (both all-sky and clear-sky) in the eastern US during 1995–2010 imply the occurrence of direct aerosol mediated "brightening", the increasing trends of both all-sky and clear sky diffuse SW radiation contradicts this conclusion since diffuse radiation would be expected to decrease as aerosols direct effects decrease. After investigating several confounding factors, the increasing trend in diffuse SW may be due to more high-level cirrus from increasing air traffic over the US. In contrast to the eastern US, radiation observations in the western US do not show any indication of "brightening" which is consistent with the observations (e.g. AOD, PM2.5 and surface concentration) that show the aerosol loading increasing slightly. This outcome is not unexpected because the CAA controls were mainly aimed at reducing air pollutants emission in the eastern US and air pollutant level in the western US are much lower.

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Life-Cycle Greenhouse Gas and Criteria Air Pollutant Emissions of Electric Vehicles in the United States

SAE International Journal of Alternative Powertrains ◽

10.4271/2013-01-1283 ◽

2013 ◽

Vol 2 (2) ◽

pp. 325-336 ◽

Cited By ~ 2

Author(s):

Hao Cai ◽

Michael Wang ◽

Amgad Elgowainy ◽

Jeongwoo Han

Keyword(s):

United States ◽

Life Cycle ◽

Greenhouse Gas ◽

Electric Vehicles ◽

The United States ◽

Air Pollutant ◽

Pollutant Emissions

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Assessment of the effect of air pollution controls on trends in shortwave radiation over the United States from 1995 through 2010 from multiple observation networks

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-1701-2014 ◽

2014 ◽

Vol 14 (3) ◽

pp. 1701-1715 ◽

Cited By ~ 31

Author(s):

C.-M. Gan ◽

J. Pleim ◽

R. Mathur ◽

C. Hogrefe ◽

C. N. Long ◽

...

Keyword(s):

United States ◽

Cloud Cover ◽

The United States ◽

Air Pollutant ◽

Pollutant Emissions ◽

Clear Sky ◽

Western Us ◽

The Us ◽

Clean Air ◽

Increasing Trends

Abstract. Long-term data sets of all-sky and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction, and aerosol optical depth (AOD) were analyzed together with surface concentrations from several networks (e.g., Surface Radiation Budget Network (SURFRAD), Clean Air Status and Trend Network (CASTNET), Interagency Monitoring of Protection Visual Environments (IMPROVE) and Atmospheric Radiation Measurement (ARM)) in the United States (US). Seven states with varying climatology were selected to better understand the effects of aerosols and clouds on SW radiation. This analysis aims to assess the effects of reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) over the past 16 yr across the US, based on trends in SW radiation. The SO2 and NOx emission data show decreasing trends from 1995 to 2010, which indirectly validates the effects of the Clean Air Act (CAA) in the US. Meanwhile, the total column AOD and surface total PM2.5 observations also show decreasing trends in the eastern US but slightly increasing trends in the western US. Moreover, measured surface concentrations of several other pollutants (i.e., SO2, SO4 and NOx) have similar behavior to AOD and total PM2.5. Analysis of the observed data shows strong increasing trends in all-sky downwelling SW radiation with decreasing trends in cloud cover. However, since observations of both all-sky direct and diffuse SW radiation show increasing trends, there may be other factors contributing to the radiation trends in addition to the decreasing trends in overall cloud cover. To investigate the role of direct radiative effects of aerosols, clear-sky downwelling radiation is analyzed so that cloud effects are eliminated. However, similar increasing trends in clear-sky total and diffuse SW radiation are observed. While significantly decreasing trends in AOD and surface PM2.5 concentrations along with increasing SW radiation (both all-sky and clear-sky) in the eastern US during 1995–2010 imply the occurrence of direct aerosol mediated "brightening", the increasing trends of both all-sky and clear-sky diffuse SW radiation contradicts this conclusion since diffuse radiation would be expected to decrease as aerosols direct effects decrease and cloud cover decreases. After investigating several confounding factors, the increasing trend in clear-sky diffuse SW may be due to more high-level cirrus from increasing air traffic over the US. The clear-sky radiation observations in the western US also show indications of "brightening" even though the AOD, PM2.5 and surface concentration do not vary drastically. This outcome was not unexpected because the CAA controls were mainly aimed at reducing air pollutant emissions in the eastern US and air pollutant levels in the western US were much lower at the onset. This suggests other factors affect the "brightening" especially in the western US.

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Perspectives for Mitigation of CO2 Emission due to Development of Electromobility in Several Countries

Energies ◽

10.3390/en13164127 ◽

2020 ◽

Vol 13 (16) ◽

pp. 4127 ◽

Cited By ~ 4

Author(s):

Karol Tucki ◽

Olga Orynycz ◽

Mateusz Mitoraj-Wojtanek

Keyword(s):

United States ◽

European Union ◽

Power Plants ◽

The United States ◽

Primary Energy ◽

Air Pollutant ◽

Pollutant Emissions ◽

The European Union ◽

Growth Data ◽

Electric Cars

The creep trend method is used for the analysis of the development of electric car production in three regions: The United States, the European Union and Japan. Based on vehicle registration and population growth data for each year the creep trend method using historical data for the years 2007–2017 is applied for forecasting development up to 2030. Moreover, the original method for calculating the primary energy factor (PEF) was applied to the analysis of power engineering systems in the regions investigated. The assessment of the effects of electromobility development on air quality has been performed, reduction values for pollutant and greenhouse gas emissions have been determined, which was the main objective of this manuscript. Mitigation of air pollutant emissions, i.e., carbon dioxide (CO2), carbon monoxide (CO) and nitrogen oxides (NOx) was estimated and compared to the eventual expected increase of emissions from power plants due to an increase of the demand for electricity. It can be concluded that electricity powered cars along with appropriate choices of energetic resources as well as electricity distribution management will play the important role to achieve the sustainable energy economy. Based on the emission reduction projections resulting from the projected increase in the number of electric cars, (corrected) emissions will be avoided in 2030 in the amount of over 14,908,000 thousand tonnes CO2 in European Union, 3,786,000 thousand tonnes CO2 in United States and 111,683 thousand tonnes CO2 in Japan.

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Improving NOAA NAQFC PM2.5 Predictions with a Bias Correction Approach

Weather and Forecasting ◽

10.1175/waf-d-16-0118.1 ◽

2017 ◽

Vol 32 (2) ◽

pp. 407-421 ◽

Cited By ~ 20

Author(s):

Jianping Huang ◽

Jeffery McQueen ◽

James Wilczak ◽

Irina Djalalova ◽

Ivanka Stajner ◽

...

Keyword(s):

United States ◽

Air Quality ◽

Bias Correction ◽

The United States ◽

Correction Method ◽

Ensemble Member ◽

Air Pollutant ◽

Wildfire Smoke ◽

Skill Scores ◽

Forecast Guidance

Abstract Particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) is a critical air pollutant with important impacts on human health. It is essential to provide accurate air quality forecasts to alert people to avoid or reduce exposure to high ambient levels of PM2.5. The NOAA National Air Quality Forecasting Capability (NAQFC) provides numerical forecast guidance of surface PM2.5 for the United States. However, the NAQFC forecast guidance for PM2.5 has exhibited substantial seasonal biases, with overpredictions in winter and underpredictions in summer. To reduce these biases, an analog ensemble bias correction approach is being integrated into the NAQFC to improve experimental PM2.5 predictions over the contiguous United States. Bias correction configurations with varying lengths of training periods (i.e., the time period over which searches for weather or air quality scenario analogs are made) and differing ensemble member size are evaluated for July, August, September, and November 2015. The analog bias correction approach yields substantial improvement in hourly time series and diurnal variation patterns of PM2.5 predictions as well as forecast skill scores. However, two prominent issues appear when the analog ensemble bias correction is applied to the NAQFC for operational forecast guidance. First, day-to-day variability is reduced after using bias correction. Second, the analog bias correction method can be limited in improving PM2.5 predictions for extreme events such as Fourth of July Independence Day firework emissions and wildfire smoke events. The use of additional predictors and longer training periods for analog searches is recommended for future studies.

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