The global impacts of COVID-19 lockdowns on urban air pollution

Elementa Science of the Anthropocene, Journal Year: 2021, Volume and Issue: 9(1)

Published: Jan. 1, 2021

The coronavirus-19 (COVID-19) pandemic led to government interventions limit the spread of disease which are unprecedented in recent history; for example, stay at home orders sudden decreases atmospheric emissions from transportation sector. In this review article, current understanding influence emission reductions on pollutant concentrations and air quality is summarized nitrogen dioxide (NO2), particulate matter (PM2.5), ozone (O3), ammonia, sulfur dioxide, black carbon, volatile organic compounds, carbon monoxide (CO). first 7 months following onset pandemic, more than 200 papers were accepted by peer-reviewed journals utilizing observations ground-based satellite instruments. Only about one-third literature incorporates a specific method meteorological correction or normalization comparing data lockdown period with prior reference despite importance doing so interpretation results. We use stringency index (SI) as an indicator severity measures show how key pollutants change SI increases. observed decrease NO2 increasing general agreement inventories that account lockdown. Other compounds such O3, PM2.5, CO also broadly covered. Due chemistry O3 PM2.5 concentrations, their responses may not be linear respect primary pollutants. At most sites, we found increased, whereas decreased slightly, SI. Changes other understudied. highlight future research needs emerging sets preview state atmosphere world targeted permanent emissions. Finally, emphasize need effects meteorology, trends, when determining concentrations.

Language: Английский

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Global Changes in Secondary Atmospheric Pollutants During the 2020 COVID‐19 Pandemic

Journal of Geophysical Research Atmospheres, Journal Year: 2021, Volume and Issue: 126(8)

Published: April 15, 2021

Abstract We use the global Community Earth System Model to investigate response of secondary pollutants (ozone O 3 , organic aerosols SOA) in different parts world modified emissions primary during COVID‐19 pandemic. quantify respective effects reductions NOx and volatile carbon (VOC) emissions, which, most cases, affect oxidants opposite ways. Using model simulations, we show that level has been reduced by typically 40% China February 2020 similar amounts many areas Europe North America mid‐March mid‐April 2020, good agreement with space surface observations. that, relative a situation which emission are ignored despite calculated increase hydroxyl peroxy radicals, ozone concentration increased only few NOx‐saturated regions (northern China, northern Europe, US) winter months pandemic when titration this molecule was reduced. In other regions, where is NOx‐controlled, decreased. SOA concentrations decrease concurrent reduction VOC emissions. The also shows atmospheric meteorological anomalies produced substantial variations chemical species for example, large fraction associated anomalies, while Plain, enhanced resulted primarily from pollutants.

Language: Английский

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Changes in global air pollutant emissions during the COVID-19 pandemic: a dataset for atmospheric modeling

Earth system science data, Journal Year: 2021, Volume and Issue: 13(8), P. 4191 - 4206

Published: Aug. 26, 2021

Abstract. In order to fight the spread of global COVID-19 pandemic, most world's countries have taken control measures such as lockdowns during a few weeks months. These had significant impacts on economic and personal activities in many countries. Several studies using satellite surface observations reported important changes spatial temporal distributions atmospheric pollutants greenhouse gases. Global regional chemistry-transport model are being performed analyze impact these distribution compounds. modeling aim at evaluating scale. provide input for simulations, dataset providing adjustment factors (AFs) that can easily be applied current emission inventories has been developed. This provides, January–August 2020 period, gridded AFs 0.1×0.1 latitude–longitude degree resolution daily or monthly basis transportation (road, air ship traffic), power generation, industry residential sectors. The quantification is based activity data collected from different databases previously published studies. A range provided each grid point sensitivity developed this study CAMS inventory (CAMS-GLOB-ANT_v4.2_R1.1), emissions main discussed regions world first 6 months 2020. Maximum decreases total found February eastern China, with an average reduction 20 %–30 % NOx, NMVOCs (non-methane volatile organic compounds) SO2 relative reference emissions. other regions, maximum occur April, reductions CO Europe North America larger (30 %–50 %) South America. India African NOx NMVOC reduced by 15 %. For species, generally less than %, except America, where large BC (black carbon) estimated. As paper, vary highly across sectors due differences duration before partial complete recovery. (average ± standard deviation) called CONFORM (COvid-19 adjustmeNt Factors fOR eMissions) (https://doi.org/10.25326/88; Doumbia et al., 2020). It distributed Emissions Compounds Compilation Ancillary Data (ECCAD) database (https://eccad.aeris-data.fr/, last access: 23 August 2021).

Language: Английский

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Opportunistic experiments to constrain aerosol effective radiative forcing

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(1), P. 641 - 674

Published: Jan. 17, 2022

Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due human activities. The nonlinearity cloud-state changes aerosol perturbations make it challenging attribute causality in observed relationships forcing. Using correlations infer can when meteorological variability also drives both and cloud independently. Natural anthropogenic from well-defined sources provide "opportunistic experiments" (also known as natural experiments) investigate ACI cases where may more confidently inferred. These cover a wide range locations spatiotemporal scales, including point such volcanic eruptions or industrial sources, plumes biomass burning forest fires, tracks individual ships shipping corridors. We review different experimental conditions conduct synthesis available satellite datasets field campaigns place these opportunistic experiments on common footing, facilitating new insights clearer understanding key uncertainties Cloud albedo strongly sensitive background conditions. Strong liquid water path increases largely ruled out by averaging across experiments. Opportunistic have significantly improved process-level ACI, but remains unclear how reliably found scaled global level, thus demonstrating need for deeper investigation order improve assessments climate change.

Language: Английский

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Lightning declines over shipping lanes following regulation of fuel sulfur emissions

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(5), P. 2937 - 2946

Published: March 11, 2025

Abstract. Aerosol interactions with clouds represent a significant uncertainty in our understanding of the Earth system. Deep convective may respond to aerosol perturbations several ways that have proven difficult elucidate observations. Here, we leverage two busiest maritime shipping lanes world, which emit particles and their precursors into an otherwise relatively clean tropical marine boundary layer, make headway on influence deep clouds. The recent 7-fold change allowable fuel sulfur by International Maritime Organization allows us test sensitivity lightning changes ship plume number-size distributions. We find that, across range atmospheric thermodynamic conditions, previously documented enhancement over has fallen 40 %. is therefore at least partially aerosol-mediated, conclusion supported observations droplet number cloud base, show similar decline lane. These results fundamental implications for aerosol–cloud interactions, suggesting are impacted distribution remote environment.

Language: Английский

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Limited Regional Aerosol and Cloud Microphysical Changes Despite Unprecedented Decline in Nitrogen Oxide Pollution During the February 2020 COVID‐19 Shutdown in China

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 47(17)

Published: Aug. 25, 2020

Following the emergence of a novel coronavirus in Wuhan, China instituted shutdown measures starting late January and continuing into February 2020 to arrest spread disease. This resulted sharp economic contraction unparalleled recent Chinese history. Satellite retrievals show that nitrogen dioxide pollution declined by an unprecedented amount (~50% regionally) from its expected unperturbed value, but regional-scale column aerosol loadings cloud microphysical properties were not detectably affected. The disparate impact is tied differential impacts shutdown, which transportation, disproportionate source oxide emissions, underwent drastic declines (~90% reductions passenger traffic), whereas industry power generation, responsible for >90% particulate relatively less affected (~20% electricity thermal generation). A combination anomalously warm humid meteorological conditions complex chemical interactions further decreased concentrations likely enhanced secondary formation.

Language: Английский

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Google Earth Engine based spatio-temporal analysis of air pollutants before and during the first wave COVID-19 outbreak over Turkey via remote sensing

Journal of Cleaner Production, Journal Year: 2021, Volume and Issue: 319, P. 128599 - 128599

Published: Aug. 14, 2021

Language: Английский

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Quantitative estimation of meteorological impacts and the COVID-19 lockdown reductions on NO2 and PM2.5 over the Beijing area using Generalized Additive Models (GAM)

Journal of Environmental Management, Journal Year: 2021, Volume and Issue: 291, P. 112676 - 112676

Published: May 4, 2021

Language: Английский

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The Climate Response to Emissions Reductions Due to COVID‐19: Initial Results From CovidMIP

Geophysical Research Letters, Journal Year: 2021, Volume and Issue: 48(8)

Published: March 11, 2021

Abstract Many nations responded to the corona virus disease‐2019 (COVID‐19) pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO 2 , greenhouse gases ozone aerosol precursors. We present initial results from a coordinated Intercomparison, CovidMIP, Earth system model simulations which assess impact on climate these reductions. 12 models performed multiple initial‐condition ensembles produce over 300 spanning both condition structural uncertainty. find consensus amounts (particularly southern eastern Asia) associated increases surface shortwave radiation levels. However, any near‐surface temperature or rainfall 2020–2024 is extremely small not detectable this analysis. Regional analyses finer scale, closer attention extremes (especially linked changes atmospheric composition air quality) are required test COVID‐19‐related emission reductions near‐term climate.

Language: Английский

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Climate Impacts of COVID‐19 Induced Emission Changes

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 48(3)

Published: Dec. 30, 2020

Abstract The COVID‐19 pandemic led to dramatic changes in economic activity 2020. We use estimates of emission for 2020 two Earth System Models (ESMs) simulate the impacts changes. Ensembles nudged simulations are used separate small signals from meteorological variability. Reductions aerosol and precursor emissions, chiefly black carbon sulfate (SO 4 ), reductions total anthropogenic cooling through aerosol‐cloud interactions. average overall Effective Radiative Forcing (ERF) peaks at +0.29 ± 0.15 Wm −2 spring Changes cloud properties smaller than observed during Impacts these on regional land surface temperature range up +0.3 K. peak impact global is very (+0.03 K). However, largest contribution radiative forcing as a result affected larger ozone, CO 2 contrail effects.

Language: Английский

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