Introduction to Reduced Anthropogenic

This study investigates the impact of reduced anthropogenic emissions during the lockdown period on the concentration, composition, and characteristics of non-refractory particular matter ≤ 2.

Under the influence of Coronavirus Disease 2019 (COVID‐19), China conducted a nationwide lockdown (LD) which significantly reduced anthropogenic emissions.

Instead, the simulations with reduced anthropogenic aerosol load show more a mere locally increased temperature.

However, these reduced anthropogenic activities negatively affected the livelihood and social well-being of the local communities.

Thus, the restrictions during lockdown, which reduced anthropogenic activities, such as land use conversion and biomass burning, and related events, such as peatland and forest fires, significantly influenced the level of atmospheric CH4 above the peatlands in Indonesia.

The ongoing COVID-19 pandemic necessitated a complete lockdown from 24 March to 31 May 2020 as imposed by the Government of India to prevent the spread of the virus that resulted into halting most of the economic activities during that period The stringent anthropogenic activities during the lockdown phase resulted in a notable drop in the air pollution level The prevailing global scenario during the pandemic has provided an opportunity of assessing the air quality in the absence of normal anthropogenic activities In the present article, the impacts of reduced anthropogenic activities on the black carbon concentration and associated atmospheric parameters have been studied over a tropical urban location, Kolkata (22 57 degrees N, 88 37 degrees E) in eastern India Investigations have been made on the impacts on the parameters like atmospheric electric field, wind speed, temperature, relative humidity, dew point temperature, rain accumulation and soil moisture during this unusual time in comparison to the same time span of the previous year 2019 when the usual human activities were pursued.

Suspensions of commercial and social activities due to COVID-19 reduced anthropogenic emissions, mainly from industry and transportation, which decreased the level of air pollutants other than O3.

Air pollution control and cleaner energy production have reduced anthropogenic emissions of sulfur and selenium, which has led to lower atmospheric deposition fluxes of these elements.

The restrictions on human activities during the lockdown have reduced anthropogenic emissions and subsequently improved air quality and human health in one of the most polluted cities in the world.

Our study suggested for the first time that, during MAM and JJA 2020, the reduced anthropogenic emissions related to the COVID-19 restrictions lowered the amount of this short-lived climate forcer/pollutant at remote locations above the PBL over northern Italy.

Stringent national lockdown policies imposed by China to prevent the spread of the virus reduced anthropogenic emissions and improved air quality.

The present study addresses the impacts of reduced anthropogenic activities during the lockdown period of COVID-19 pandemic on the aerosol concentration, treated as heat absorbing agent, and on the related atmospheric processes, using ground-based and spaceborne measurements over a highly polluted Indian metropolis, Kolkata The investigation reveals that reduced aerosol concentrations during the pre-monsoon of 2020, when the lockdown was implemented, decreased atmospheric instability as indicated by low values of the convective available potential energy (CAPE) This hindered the abundance of aerosols above the atmospheric boundary layer Also, micro rain radar (MRR) observations showed a significant reduction of convective precipitation occurrences over Kolkata during this period The back trajectory analysis has revealed the absence of continental component toward the wind clusters associated with rain occurrences during pre-monsoon 2020 This resulted in increased occurrences of stratiform rain events during the pre-monsoon of 2020 compared to the same period of previous years IEEE.

The decrease in lipid peroxidation and the increase in ascorbic acid in the population of Arctic districts may be explained by reduced anthropogenic stress and protein-lipid type nutrition, distinct from the population of other districts.

Since the methodology used in the model is based on reduced anthropogenic emissions, compared to a reference run, the choice of the percentage in the reductions has been tested by using three different values (5 %, 15 %, and 50 %).

This provided a unique opportunity to evaluate the effects of reduced anthropogenic activity on groundwater quality.

The results show that the water quality in AYRS has improved slightly due to the reasonably reduced anthropogenic industrial impact.

The impacts of VOC emissions on O3 sensitivity are limited in North America and Europe because reduced anthropogenic VOC emissions are offset by higher biogenic VOC emissions.

The occurrence of higher ground-level O 3 concentrations on weekends rather than on weekdays, despite reduced anthropogenic activity in urban areas, is known as the O 3 weekend effect (OWE).

In this study, we have analyzed the change in the air quality levels stemming from the reduced anthropogenic activities in one of the most polluted cities in the world, the Delhi Metropolitan Region (DMR).

Our study indicates that the reduced anthropogenic emissions caused by the unprecedented COVID-19 restrictions had a favourable effect on the hydrological cycle over South Asia, which has been facing water scarcity during the past decades.

It is assumed that the increased concentration of birds of prey in the frontier zone is associated with better feeding conditions and reduced anthropogenic load, compared to other more developed and transformed areas in agricultural and technogenic terms.

During the COVID-19 pandemic, the lockdown reduced anthropogenic emissions of NO2 in Paris.

Furthermore, reduced anthropogenic aerosols resulted in reduction of availed cloud condensation nuclei (CCN) leading to larger cloud droplet size and hence increased precipitation during pre-monsoon, 2020.

3%)] was recorded as an immediate consequence of the reduced anthropogenic activities.

Reduced mobility and less anthropogenic activity under special case circumstances over various parts of the world have pronounced effects on air quality The objective of this study is to investigate the impact of reduced anthropogenic activity on air quality in the mega city of Shanghai, China Observations from the highly sophisticated multi-axis differential optical absorption spectroscope (MAX-DOAS) instrument were used for nitrogen dioxide (NO2) and formaldehyde (HCHO) column densities In situ measurements for NO2, ozone (O3), particulate matter (PM2 5) and the air quality index (AQI) were also used The concentration of trace gases in the atmosphere reduces significantly during annual Spring Festival holidays, whereby mobility is reduced and anthropogenic activities come to a halt The COVID-19 lockdown during 2020 resulted in a considerable drop in vertical column densities (VCDs) of HCHO and NO2 during lockdown Level-1, which refers to strict lockdown, i e , strict measures taken to reduce mobility (43% for NO2;24% for HCHO), and lockdown Level-2, which refers to relaxed lockdown, i e , when the mobility restrictions were relaxed somehow (20% for NO2;22% for HCHO), compared with pre-lockdown days, as measured by the MAX-DOAS instrument However, for 2019, a reduction in VCDs was found only during Level-1 (24% for NO2;6 62% for HCHO), when the Spring Festival happened The weekly cycle for NO2 and HCHO depicts no significant effect of weekends on the lockdown After the start of the Spring Festival, the VCDs of NO2 and HCHO showed a decline for 2019 as well as 2020 Backward trajectories calculated using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated more air masses coming from the sea after the Spring Festival for 2019 and 2020, implying that a low pollutant load was carried by them No impact of anthropogenic activity was found on O3 concentration The results indicate that the ratio of HCHO to NO2 (RFN) fell in the volatile organic compound (VOC)-limited regime.

In the simulations reduced anthropogenic aerosol emissions in February generate anomalous surface warming and warm-moist air advection which promotes low-level cloud formation over China.

The emergence of the novel corona virus and the resulting lockdowns over various parts of the world have substantially impacted air quality due to reduced anthropogenic activity.

We estimated the economic benefit of reduced anthropogenic emissions using two valuation approaches: (1) the median externality value coefficient approach, applied for satellite data, and (2) the public health burden approach, applied for in-situ data.

The COVID-19 pandemic resulted in reduced anthropogenic carbon dioxide (CO 2 ) emissions during 2020 in large parts of the world.