Unprecedented reduction in airborne aerosol particles and nitrogen dioxide level in response to COVID-19 pandemic lockdown over the Indo-Pak region

Arshad, Arfan; Hussain, Saddam; Saleem, Farhan; Shafeeque, Muhammad; Khan, Shahbaz Nasir; Waqas, Muhammad Sohail

doi:10.1002/essoar.10503543.1

Cited by 6 publications

(8 citation statements)

References 25 publications

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“…It has been discovered that the running mean of NO 2 value during January-March 2020 (BL) has a fluctuation trend that differs from the average time series of 2016 to 2019. During the SL period (April-June 2020), the time series of average NO 2 emissions over all three cities in Pakistan moves with a slight fluctuation when compared to the baseline period (2016-2019) [28]. It has been observed that for the cities of Lahore and Islamabad, the anomaly changes in NO 2 emissions from January to March 2020 (before the lockdown) show a positive trend, demonstrating the high emissions from industrial sources and transportation compared to previous years.…”

Section: (D) City Level Analysismentioning

confidence: 99%

Situation of Urban Mobility in Pakistan: Before, during, and after the COVID-19 Lockdown with Climatic Risk Perceptions

et al. 2021

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The coronavirus pandemic (COVID-19) has impacted the usual global movement patterns, atmospheric pollutants, and climatic parameters. The current study sought to assess the impact of the COVID-19 lockdown on urban mobility, atmospheric pollutants, and Pakistan’s climate. For the air pollution assessment, total column ozone (O3), sulphur dioxide (SO2), and tropospheric column nitrogen dioxide (NO2) data from the Ozone Monitoring Instrument (OMI), aerosol optical depth (AOD) data from the Multi-angle Imaging Spectroradiometer (MISR), and dust column mass density (PM2.5) data from the MERRA-2 satellite were used. Furthermore, these datasets are linked to climatic parameters (temperature, precipitation, wind speed). The Kruskal–Wallis H test (KWt) is used to compare medians among k groups (k > 2), and the Wilcoxon signed-rank sum test (WRST) is for analyzing the differences between the medians of two datasets. To make the analysis more effective, and to justify that the variations in air quality parameters are due to the COVID-19 pandemic, a Generalized Linear Model (GLM) was used. The findings revealed that the limitations on human mobility have lowered emissions, which has improved the air quality in Pakistan. The results of the study showed that the climatic parameters (precipitation, Tmax, Tmin, and Tmean) have a positive correlation and wind speed has a negative correlation with NO2 and AOD. This study found a significant decrease in air pollutants (NO2, SO2, O3, AOD) of 30–40% in Pakistan during the strict lockdown period. In this duration, the highest drop of about 28% in NO2 concentrations has been found in Karachi. Total column O3 did not show any reduction during the strict lockdown, but a minor decline was depicted as 0.38% in Lahore and 0.55% in Islamabad during the loosening lockdown. During strict lockdown, AOD was reduced up to 23% in Islamabad and 14.46% in Lahore. The results of KWt and WRST evident that all the mobility indices are significant (p < 0.05) in nature. The GLM justified that restraining human activities during the lockdown has decreased anthropogenic emissions and, as a result, improved air quality, particularly in metropolitan areas.

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Section: (D) City Level Analysismentioning

confidence: 99%

Situation of Urban Mobility in Pakistan: Before, during, and after the COVID-19 Lockdown with Climatic Risk Perceptions

et al. 2021

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“…The study reported a 14% reduction in PM2.5 and 30% reduction in NO2, a 25% reduction in CO and a 3% rise in O3 during the lockdown phase. Arshad et al (2020) attempted AOD and NO2 variations during COVID-19 lockdown phase using satellite datasets over major cities of India and Pakistan. The study reported a reduction of 32-42% in NO2 and ~45% reduction in AOD over the entire Indo-Pak region.…”

Section: Introductionmentioning

confidence: 99%

Transformation of Air Quality over a Coastal Tropical Station Chennai during COVID-19 Lockdown in India

Singh¹,

Tyagi

2021

Aerosol Air Qual. Res.

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To prevent the spread of COVID-19, Government of India imposed strict lockdown in the country from 24 March-31 May 2020, which allows the environment to revive with reduced emissions. The present work analyses the PM2.5, NO2, O3, CO and SO2 along with meteorological parameters (humidity, temperature and wind speed) at a tropical coastal station Chennai for March-May 2019 and 2020 at five locations: Alandur Bus depot, Velachery, Manali, Teynampet and U.S. Embassy Chennai. Chennai is a megacity of southern India and the state capital of Tamil Nadu, one of the worst affected states due to COVID-19. Though overall PM2.5 values decreased for the lockdown (ranging from ~32-187%), weekly analysis shows the variation in reduction/increase. SO2 and O3 values were found increasing for two sites: Teynampet (~40% in SO2 and ~48% in O3) and Velachery (~42% in SO2 and ~5% in O3), but decreasing for Alandur (~30% in SO2 and ~50% in O3) and Manali (~247% in SO2). NOx and CO were reduced during the lockdown (~47-125%) for all the sites. The source regions examined by concentration weighted trajectory analysis were found to change for transporting pollution to the site. The analysis shows there are local scale variations in the air pollution for the city during COVID-19 lockdown.

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“…Rather than a strict lock-down, Pakistan implemented "smart lockdown" to cause minimal adverse impact on social and economic conditions while reducing the spread of infection successfully. New satellite imageries released by ESA and recently published studies also reported that the average tropospheric NO 2 over the Asian counties reduced 40 À 50% in 2020 during the quarantine period compared to the average of last year (Arshad et al 2020). The recent decline in tropospheric NO 2 is associated with less consumption of fossil fuels (Sharma et al 2020;Wang et al 2021) due to the sharp reduction in transport and industry, which ultimately resulted in less air pollution (Mahato et al 2020).…”

Section: Regional Changes In Tropospheric Nomentioning

confidence: 94%

Impacts of reduced deposition of atmospheric nitrogen on coastal marine eco-system during substantial shift in human activities in the twenty-first century

Mumtaz

Arshad

Mirchi

et al. 2021

Geomatics, Natural Hazards and Risk

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The novel infectious disease (COVID-19) took only a few weeks from its official inception in December 2019 to become a global pandemic in early 2020. Countries across the world went to lockdown, and various strict measures were implemented to reduce the further spread of the infection. Although, the strict lockdown measures were aimed at stopping the spread of COVID-19, however, Its positive implications were also observed for the environmental conditions across the global regions. The present study attempted to explore the eco-restoration of coastal marine system in response to reduced deposition of atmospheric nitrogen (NO 2 ) emission during the substantial shift in human activities across the global metropolitan cities. Remotely data of NO 2 emission were taken from Ozone Monitoring Instrument and the coastal water quality along the marine system was estimated from MODIS-Aqua Level-3 using Semi-Analytic Sediment Model (SASM). The changes in tropospheric NO 2 in 2020s were also compared with the long-term average changes over the baseline period 2015 À 2019. A significant reduction in anthropogenic mobility (85 À 90%) has been observed in almost all countries over ARTICLE HISTORY

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Unprecedented reduction in airborne aerosol particles and nitrogen dioxide level in response to COVID-19 pandemic lockdown over the Indo-Pak region

Cited by 6 publications

References 25 publications

Situation of Urban Mobility in Pakistan: Before, during, and after the COVID-19 Lockdown with Climatic Risk Perceptions

Situation of Urban Mobility in Pakistan: Before, during, and after the COVID-19 Lockdown with Climatic Risk Perceptions

Transformation of Air Quality over a Coastal Tropical Station Chennai during COVID-19 Lockdown in India

Impacts of reduced deposition of atmospheric nitrogen on coastal marine eco-system during substantial shift in human activities in the twenty-first century

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