Evaluation of WRF-Chem-simulated meteorology and aerosols over northern India during the severe pollution episode of 2016

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(4), С. 2239 - 2266

Опубликована: Фев. 22, 2024

Abstract. We use a state-of-the-art regional chemistry transport model (WRF-Chem v4.2.1) to simulate particulate air pollution over northern India during September–November 2016. This period includes severe episode marked by exceedingly high levels of hourly PM2.5 (particulate matter having an aerodynamic diameter ≤ 2.5 µm) 30 October 7 November, particularly the wider Indo-Gangetic Plain (IGP). provide comprehensive evaluation simulated seasonal meteorology (nudged ERA5 reanalysis products) and aerosol (PM2.5 its black carbon (BC) component) using range ground-based, satellite products, with focus on November 2016 haze episode. find daily diurnal features in surface temperature show best agreement followed relative humidity, largest discrepancies being overestimate night-time wind speeds (up 1.5 m s−1) confirmed both ground radiosonde observations. Upper-air comparisons observations excellent skill reproducing vertical gradient (r>0.9). evaluate modelled at 20 observation sites across IGP including eight Delhi compare optical depth (AOD) data from four AERONET sites. also our results MERRA-2 fields MODIS AOD. that captures many observed distributions but tends September (by factor 2) due too much dust, underestimate peak experiences some highest mean concentrations within study region, dominant components nitrate (∼25 %), dust secondary organic aerosols (∼20 %) ammonium (∼10 %). Modelled BC spatially correlate well products whole domain. High AOD 550nm is predicted (r≥0.8) ground-based (r≥0.7), except September. Overall, realistically spatial variations ambient India. However, underestimations pollutant likely come combination underestimated emissions, dispersion, missing or poorly represented processes. Nevertheless, we sufficiently accurate be useful tool for exploring sources processes control episodes.

Язык: Английский

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The impact of different fertiliser management options and cultivars on nitrogen use efficiency and yield for rice cropping in the Indo-Gangetic Plain: Two seasons of methane, nitrous oxide and ammonia emissions

Agriculture Ecosystems & Environment, Год журнала: 2023, Номер 355, С. 108593 - 108593

Опубликована: Май 20, 2023

This study presents detailed crop and gas flux data from two years of rice production at the experimental farm ICAR-Indian Agricultural Research Institute, New Delhi, India. In comparing 4 nitrogen (N) fertiliser regimes across cultivars (CRD 310, IR-64, MTU 1010, P-44), we have added to growing evidence environmental costs in region. The shows that cultivar can impact yields both grain, total biomass produced given circumstances, with CRD 310 showing consistently high use efficiency (NUE) for compared other tested varieties, but not necessarily highest grain yield, which was P-44 this experiment. While NUE did vary depending on treatments (ranging 41% 73%), translate directly into reduction emissions ammonia (NH3) nitrous oxide (N2O). Emissions were relatively similar different regardless NUE. Conversely, agronomic practices reduced N losses associated higher yield. terms application, outstanding very methane (CH4) as a result incorporating farmyard manure (FYM) paddies, dominated overall effect global warming potential. nitrification urease inhibiting substances decreased N2O overall, NH3 unaffected (or slightly higher). Overall, greatest greenhouse (GHG) came reducing irrigation water fields, resulting N2O, significantly less CH4 emissions, net GHG emission continuous flooding. genetic differences generated more variation yield than management (excluding controls), whereas agronomy larger genetics concerning gaseous losses. suggests mixed approach needs be applied when attempting reduce pollution potential swapping synergies need considered. Finding right balance cultivar, technique type could while getting it wrong considerably poorer pollution.

Язык: Английский

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Role of atmospheric aerosols in severe winter fog over the Indo-Gangetic Plain of India: a case study

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(11), С. 6635 - 6662

Опубликована: Июнь 6, 2024

Abstract. Winter fog and severe aerosol loading in the boundary layer over northern India, particularly Indo-Gangetic Plain (IGP), disrupt daily lives of millions people region. To better understand role aerosol–radiation (AR) feedback on occurrence, spatial extent, persistence winter fog, as well associated aqueous chemistry IGP, several model simulations have been performed using Weather Research Forecasting coupled with Chemistry (WRF-Chem). While WRF-Chem was able to represent formation for 23–24 December 2017 event central IGP comparison station satellite observations, underestimated PM2.5 concentrations compared Central Pollution Control Board (CPCB) India monitoring network. evaluating composition events we found that quite different from measurements obtained during Fog Experiment (WiFEX) Delhi, secondary aerosols, chloride fraction, being strongly underpredicted (∼ 66.6 %). Missing emission sources (e.g., industry residential burning cow dung trash) processes need be investigated improve model–observation agreement. By investigating a weakens turbulence, lowers height, increases relative humidity (RH) within layer. Factors affecting include loss aerosols through deposition cloud droplets internal mixing absorbing scattering aerosols. Aqueous-phase concentrations, which subsequently affect by both increased mass sizes. With interaction aqueous-phase chemistry, began 1–2 h earlier caused longer duration than when these were not included simulation. The increase RH experiments important it promoted growth size water uptake, increasing content IGP. results this study suggest play an air quality intensity lifetime yet other feedbacks, such aerosol–cloud interactions, quantified.

Язык: Английский

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Evaluating the sensitivity of fine particulate matter (PM2.5) simulations to chemical mechanism in WRF-Chem over Delhi

Atmospheric Environment, Год журнала: 2024, Номер 323, С. 120410 - 120410

Опубликована: Фев. 17, 2024

Язык: Английский

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Decision Support System version 1.0 (DSS v1.0) for air quality management in Delhi, India

Geoscientific model development, Год журнала: 2024, Номер 17(7), С. 2617 - 2640

Опубликована: Апрель 10, 2024

Abstract. This paper discusses the newly developed Decision Support System version 1.0 (DSS v1.0) for air quality management activities in Delhi, India. In addition to standard forecasts, DSS provides contribution of its surrounding districts, and stubble-burning fires neighboring states Punjab Haryana PM2.5 load Delhi. also quantifies effects local neighborhood emission-source-level interventions on pollution The DSS-simulated Air Quality Index post-monsoon winter seasons 2021–2022 shows high accuracy (up 80 %) a very low false alarm ratio (∼ 20 from day 1 5 especially when ambient index (AQI) is > 300. During season (winter season), emissions rest National Capital Region (NCR)'s biomass-burning activities, all other remaining regions average contribute 34.4 % (33.4 %), 31 (40.2 7.3 (0.1 27.3 (26.4 respectively, peak events (stubble-burning periods or wintertime), however, main sources (farm Punjab–Haryana within Delhi) could reach 65 %–69 %. According DSS, (40 reduction anthropogenic across NCR districts would result 12 (24 Delhi seasonal mean basis. critical tool policymakers because it such information daily through single simulation with plethora emission scenarios.

Язык: Английский

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Acidity and Phase Behavior of Frozen Hydrochloric Acid during Thawing

The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(41), С. 17674 - 17685

Опубликована: Окт. 3, 2024

Язык: Английский

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Exploring the chemical composition and processes of submicron aerosols in Delhi using aerosol chemical speciation monitor driven factor analysis

Scientific Reports, Год журнала: 2025, Номер 15(1)

Опубликована: Апрель 24, 2025

Abstract Wintertime non-refractory submicron particulate matter (NR-PM 1 ) species were measured in Delhi with an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during February–March 2018. The average NR-PM mass concentration throughout the study was 58.0 ± 42.6 µg m −3 , where contribution of organic aerosol (OA) 69% total . In Delhi, chloride (10%) main inorganic contributor, followed by ammonium (8%), sulfate (7%), and nitrate (6%), contrasting prevalence most urban environments. Source apportionment analysis OA identified five major factors, including three primary contributors: hydrocarbon-like (HOA), biomass burning (BBOA), cooking-related (COA) two secondary oxygenated (OPOA), more-oxidized (MO-OOA). A 19% rise OPOA observed high episodes, suggesting potential role atmospheric chemical transformation OA. Traffic emissions significantly contribute to ambient OA, accounting for at least 41% mass. Furthermore, exhibited low oxidation levels regardless its source. f 44 : 43 revealed slower oxidization compared other locations worldwide. Further investigations, chamber experiments tailored atmosphere, are necessary elucidate oxidants genesis alongside emissions.

Язык: Английский

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Comprehensive multiphase chlorine chemistry in the box model CAABA/MECCA: implications for atmospheric oxidative capacity

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(23), С. 15165 - 15180

Опубликована: Дек. 13, 2023

Abstract. Tropospheric chlorine chemistry can strongly impact the atmospheric oxidation capacity and composition, especially in urban environments. To account for these reactions, gas- aqueous-phase Cl of community box model Chemistry As A Boxmodel Application/Module Efficiently Calculating Atmosphere (CAABA/MECCA) has been extended. In particular, an explicit mechanism ClNO2 formation following N2O5 uptake to aerosols developed. The updated applied two environments with different concentrations NOx (NO + NO2): New Delhi (India) Leicester (United Kingdom). shows a sharp build-up at sunrise through Cl2 photolysis both Besides photolysis, ClO+NO reaction ClONO are also prominent sources Leicester. High-NOx conditions tend suppress nighttime due titration O3 thus lead lower ClNO2, contrast Major loss is its on chloride, producing Cl2, which consequently leads photolysis. reactivities OH much higher Delhi; however, Cl/OH reactivity ratio up ≈ 9 times greater contribution significant even exceeds (by 2.9 times) that during morning hours Sensitivity simulations suggest additional consumption volatile organic compounds (VOCs) active enhances OH, HO2, RO2 near sunrise. simulation results have important implications future studies air quality.

Язык: Английский

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HONO chemistry and its impact on the atmospheric oxidizing capacity over the Indo-Gangetic Plain

The Science of The Total Environment, Год журнала: 2024, Номер 947, С. 174604 - 174604

Опубликована: Июль 7, 2024

Язык: Английский

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Evolution, composition, and chemical processes of submicron aerosols from Indian megacity: Factor analysis from Aerosol Chemical Speciation Monitor (ACSM)

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Ноя. 26, 2024

Wintertime non-refractory submicron particulate matter (NR-PM₁) species were measured in Delhi with an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during February–March 2018. The average NR-PM₁ mass concentration throughout the study was 58.0 ± 42.6 µg m^{− 3}, where contribution of organic aerosol (OA) 69% total NR-PM₁. In Delhi, chloride (10%) main inorganic contributor, followed by ammonium (8%), sulfate (7%), and nitrate (6%), contrasting prevalence most urban environments. Source apportionment analysis OA identified five major factors, including three primary contributors: hydrocarbon-like (HOA), biomass burning (BBOA), cooking-related (COA) two secondary oxygenated (OPOA), more-oxidized (MO-OOA). A 19% rise OPOA observed high episodes, suggesting potential role atmospheric chemical transformation OA. Traffic emissions significantly contribute to ambient OA, accounting for at least 41% mass. Furthermore, exhibited low oxidation levels regardless its source. f₄₄:f₄₃ revealed slower oxidization compared other locations worldwide. Further investigations, chamber experiments tailored atmosphere, are necessary elucidate oxidants genesis alongside emissions.

Язык: Английский

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