Global and regional variations in aerosol loading during COVID-19 imposed lockdown

Sanap, S. D.

doi:10.1016/j.atmosenv.2020.118132

Cited by 38 publications

(35 citation statements)

References 33 publications

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“…Overall, the monthly deviation of AOD (at different wavelengths) during the lockdown period ranges between ~ 25-50% for Kyanjin_Gompa and ~ 20-60% for Pokhara, with a maximum decrement of AOD in the month of March. This result is consistent with the global study of AOD during the lockdown period by Sanap [23]. However, comparatively less deviation in AOD was observed in the month of April and May.…”

Section: Diurnal Variation Of Mean Aodsupporting

confidence: 91%

“…Raza et al [22] reported that AOD was reduced in Pakistan during the lockdown period in 2020 in comparison to the previous years. From the worldwide study of AOD during the pandemic period, Sanap [23] recorded a decrease in AOD from mid-March to April 2020; however, a drastic reduction in AOD was observed in May. Furthermore, despite many impacts of lockdown on people's social life and the national economy, several ndings [e.g., Shrestha et al [24], Gautam et al [25], Baral & Thapa [26] observed that lockdown had temporarily better environmental conditions in Nepal.…”

Section: Introductionmentioning

confidence: 99%

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Influence of COVID-19 Lockdown on Aerosol Optical Depth over Pokhara and Kyanjin Gompa in Nepal

Silwal

Gautam

Karki

et al. 2021

Preprint

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The outbreak of the COVID-19 pandemic and the subsequent global economic shutdown provided an opportunity to conduct a real-time experiment assessing the influence of global emission reductions in the Aerosol Optical Depth (AOD) level, an indicator of air pollution over Nepal. Nepal's government imposed a lockdown on the country for approximately three months (from 24 March onwards) in 2020. The purpose of this study is to examine the temporal fluctuation in Aerosol Optical Depth (AOD) caused by the COVID-19 shutdown by comparing its value during the same time period of the past year over two sites: Pokhara and Kyanjin Gompa. We comparatively analyzed the variation of diurnal mean and monthly average AOD of two selected sites, from the month of January to May 2020 and January to May 2018. By examining the time-series graph of daily average AOD prior to and during the lockdown period, our study showed an apparent fluctuation in AOD throughout the studied areas. The major findings of the research revealed that after the lockdown, a significant variation in monthly averaged AOD was observed, ranging from 20–60% deviation over Pokhara and 25–50% deviation in Kyanjin Gompa at different wavelengths. This confirms previous studies on aerosols and other particulate matter during COVID-19 lockdown, as well as theoretical assumptions. In addition, we performed the heatmap correlation analysis among AOD, Total precipitable water (Tpw), Angstrom exponent (α), Turbidity coefficient (β), and Visibility (V) during the studied period with possible explanations. We believe this research work serves as a crucial reference for our government to implement appropriate policies for pollution control over the studied areas in the future.

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Section: Diurnal Variation Of Mean Aodsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Influence of COVID-19 Lockdown on Aerosol Optical Depth over Pokhara and Kyanjin Gompa in Nepal

Silwal

Gautam

Karki

et al. 2021

Preprint

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“…The lockdown measures had a pronounced effect on social life and on industry and commerce. This led to a reduction in motorized traffic and thus supposedly [14] also to measurable reductions in traffic-related air pollutants, namely NO2. We observed a relatively quick change in the behavior as the measures were announced on Friday and went into force on Monday.…”

Section: Methodsmentioning

confidence: 99%

COVID-19 and air pollution in Vienna—a time series approach

Moshammer

Poteser

Hutter

2021

Wien Klin Wochenschr

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SummaryWe performed a time series analysis in Vienna, Austria, investigating the temporal association between daily air pollution (nitrogen dioxide, NO2 and particulate matter smaller than 10 µm, PM10) concentration and risk of coronavirus disease 2019 (COVID-19) infection and death. Data covering about 2 months (March–April 2020) were retrieved from public databases. Infection risk was defined as the ratio between infected and infectious. In a separate sensitivity analysis different models were applied to estimate the number of infectious people per day. The impact of air pollution was assessed through a linear regression on the natural logarithm of infection risk. Risk of COVID-19 mortality was estimated by Poisson regression. Both pollutants were positively correlated with the risk of infection with the coefficient for NO2 being 0.032 and for PM10 0.014. That association was significant for the irritant gas (p = 0.012) but not for particles (p = 0.22). Pollutants did not affect COVID-19-related mortality. The study findings might have wider implications on an interaction between air pollution and infectious agents.

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“…The data obtained provided by the daily fire mask compounds derived from MODIS radiances show the presence of active fires in rural areas of the countries of Colombia and Venezuela. Sanap (2021) estimated global and regional variations in aerosol loading imposed by the lockdown. Their results show that, in northern Colombia where our study area is located, forest fire emissions contributed significantly to the high aerosol and associated negative aerosol radiative forcing anomalies during the April lockdown.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Effects of Lockdown due to the COVID-19 Pandemic on Air Quality at Latin America’s Largest Open-pit Coal Mine

Arregocés

Rojano

Restrepo

2021

Aerosol Air Qual. Res.

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Particulate Matter is the main pollutant produced in open-pit mining operations. Its emission into the atmosphere is strongly associated with adverse health effects in the surrounding communities. The objective of the study is to evaluate the impact of lockdown due to the COVID-19 pandemic on the particulate matter (PM) levels in the Northern, Central, and Southern Zones of the largest open-pit coal mine in Latin America. We analyzed and compared daily data on PM10 and PM2.5 before and during the emergency shutdown from the week of March 6 through April 13, 2020, while comparing daily values from the combined product of the Terra-Aqua/MODIS satellites to elucidate the effects of the closure. Unlike other sites monitored globally, we observed an increase in the average PM 10 concentrations in the Northern Zone (13-38%) and Southern Zone (4-7%) of the coal mine. Additionally, PM2.5 concentrations increased in the Southern Zone by up to 43% throughout the lockdown when compared to daily records prior to the commencement of mandatory isolation. PM10 concentrations in the Central Zone decreased (26-31%) in the course the lockdown. Further, higher aerosol optic depth (AOD) values (≥0.4) were evident over the Central and Southern study areas during the lockdown, as well as significant AOD loads upwind and downwind of the coal production pits. Wetter (up to 3.5%), warmer (up to 0.3 K), reduced planetary boundary layer height (up to 0.11 km), wind field variability, and biomass burning in rural areas determine the spatial-temporal behavior of PM. The reduction of emissions from PMmining activities was almost compensated by changes in meteorology and external sources. These results provide a baseline for regulators to establish future mitigation plans.

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Global and regional variations in aerosol loading during COVID-19 imposed lockdown

Cited by 38 publications

References 33 publications

Influence of COVID-19 Lockdown on Aerosol Optical Depth over Pokhara and Kyanjin Gompa in Nepal

Influence of COVID-19 Lockdown on Aerosol Optical Depth over Pokhara and Kyanjin Gompa in Nepal

COVID-19 and air pollution in Vienna—a time series approach

Effects of Lockdown due to the COVID-19 Pandemic on Air Quality at Latin America’s Largest Open-pit Coal Mine

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