Characterization and sources of fine carbonaceous aerosol in winter over a megacity on Indo-Gangetic plain

The Indo-Gangetic Plain (IGP) is one of the world&#8217;s most populated river basins housing more than 700 million people. Apart from being a major source region of aerosols, the IGP is affected by transported aerosols from the Thar Desert, forest-fires and open burning of crop waste from central India. Studies have been carried out to understand the aerosol chemical composition and optical properties in source regions of IGP but knowledge is severely lacking for receptor locations viz. eastern IGP (eIGP). To address this, the present study reports the seasonal variability of carbonaceous and ionic species in ambient PM2.5 from a rural receptor location (Mohanpur, West Bengal) along with insights on aerosol acidity, its neutralization and potential source regimes. A total of 88 PM2.5 samples collected during the summer, post-monsoon and winter seasons of 2018 were analyzed for SO42-, NO3-, Cl-, Na+, NH4+, K+, Ca2+, Mg2+, F-,PO43-, water-soluble organic carbon (WSOC), organic carbon (OC) and elemental carbon (EC) fractions. Sulfate, nitrate and ammonium (SNA) were the dominating ionic species throughout the seasons (67-86% out of the total ionic species measured). Significant positive Cl- depletion in summer (49&#177;20%) pointed towards influx of marine air while negative depletion in post-monsoon and winter suggested a biomass burning (BB) source, which was further supported by concentration-weighted trajectory analysis. Strong acidity was found to be highest during post-monsoon (141&#177;76 nmol m-3), followed by winter (117&#177;36 nmol m-3) and summer (40&#177;14 nmol m-3) with significant differences between summer and the other seasons. Neutralization factor (Nf) and equivalent charge ratio of cation to anion (RC/A) revealed that summertime aerosols were neutral in nature while those of post-monsoon and winter were comparatively acidic with NH4+ being the major neutralizing agent throughout the seasons. Correlations between WSOC and OC fractions (OC1, OC2, OC3 and OC4) suggested secondary formation of summertime WSOC (WSOC vs OC3: r=0.48, p<0.05) via photochemical oxidation of volatile organic carbons (VOCs) while that of post-monsoon (WSOC vs OC1, OC2, OC3: r=0.45-0.62, p<0.05) and winter (WSOC vs OC1, OC2, OC3: r=0.58-0.68, p<0.05), both primary and secondary pathways seem important. To elucidate the role of BB, we looked into the two components of EC i.e., char-EC (EC1-PC) and soot-EC (EC2+EC3). The percent contribution of char-EC to EC was 65&#177;17%, 90&#177;10% and 98&#177;1% during summer, post-monsoon and winter, respectively. Along with this, char-EC/soot-EC ratios of 2.3&#177;1.8, 17.6&#177;16.4 and 50.3&#177;18.6 during summer, post-monsoon and winter, respectively, and significant correlations of the same with the BB-tracer K+ (post-monsoon: r=0.78, p<0.001; winter: r=0.64, p<0.01) indicated the importance of BB emissions in constraining carbonaceous aerosol profiles during post-monsoon and winter.

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Carbon isotope-constrained seasonality of carbonaceous aerosol sources from an urban location (Kanpur) in the Indo-Gangetic Plain

Journal of Geophysical Research Atmospheres ◽

10.1002/2016jd025634 ◽

2017 ◽

Vol 122 (9) ◽

pp. 4903-4923 ◽

Cited By ~ 13

Author(s):

Srinivas Bikkina ◽

August Andersson ◽

Kirpa Ram ◽

M. M. Sarin ◽

Rebecca J. Sheesley ◽

...

Keyword(s):

Carbon Isotope ◽

Carbonaceous Aerosol ◽

Gangetic Plain ◽

Urban Location ◽

Aerosol Sources ◽

Indo Gangetic Plain

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Multiple sites ground-based evaluation of carbonaceous aerosol mass concentrations retrieved from the CAMS and MERRA-2 over the Indo-Gangetic Plain

Environmental Science: Atmospheres ◽

10.1039/d1ea00067e ◽

2021 ◽

Author(s):

Ashish Soni ◽

Anil Kumar Mandariya ◽

Pradhi Rajeev ◽

Saifi Izhar ◽

Gyanesh Kumar Singh ◽

...

Keyword(s):

Atmospheric Aerosols ◽

Recent Progress ◽

Reanalysis Data ◽

Carbonaceous Aerosol ◽

Earth System ◽

Gangetic Plain ◽

Aerosol Mass ◽

System Variables ◽

Aerosol Module ◽

Indo Gangetic Plain

Recent progress towards the availability of reanalysis data of Earth system variables with high spatial-temporal resolution provides valuable information for estimating the impacts of atmospheric aerosols. However, the aerosol module...

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Aerosol chemical characterization and role of carbonaceous aerosol on radiative effect over Varanasi in central Indo-Gangetic Plain

Atmospheric Environment ◽

10.1016/j.atmosenv.2015.07.031 ◽

2016 ◽

Vol 125 ◽

pp. 437-449 ◽

Cited By ~ 28

Author(s):

S. Tiwari ◽

U.C. Dumka ◽

D.G. Kaskaoutis ◽

Kirpa Ram ◽

A.S. Panicker ◽

...

Keyword(s):

Chemical Characterization ◽

Carbonaceous Aerosol ◽

Radiative Effect ◽

Gangetic Plain ◽

Indo Gangetic Plain

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Seasonal and trend analysis of TWS for the Indo-Gangetic plain using GRACE data

Geocarto International ◽

10.1080/10106049.2019.1573856 ◽

2019 ◽

Vol 35 (12) ◽

pp. 1343-1359

Author(s):

Saurabh Srivastava ◽

Onkar Dikshit

Keyword(s):

Trend Analysis ◽

Gangetic Plain ◽

Grace Data ◽

Indo Gangetic Plain

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Severe air pollution and characteristics of light-absorbing particles in a typical rural area of the Indo-Gangetic Plain

Environmental Science and Pollution Research ◽

10.1007/s11356-020-07618-6 ◽

2020 ◽

Vol 27 (10) ◽

pp. 10617-10628 ◽

Cited By ~ 2

Author(s):

Pengfei Chen ◽

Shichang Kang ◽

Lekhendra Tripathee ◽

Arnico K. Panday ◽

Maheswar Rupakheti ◽

...

Keyword(s):

Air Pollution ◽

Rural Area ◽

Gangetic Plain ◽

Indo Gangetic Plain

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Impact of Integrated Agronomic Practices on Soil Fertility and Respiration on the Indo-Gangetic Plain of North India

Agronomy ◽

10.3390/agronomy11020402 ◽

2021 ◽

Vol 11 (2) ◽

pp. 402

Author(s):

Rama Kant Dubey ◽

Pradeep Kumar Dubey ◽

Rajan Chaurasia ◽

Ch Srinivasa Rao ◽

Purushothaman Chirakkuzhyil Abhilash

Keyword(s):

Soil Respiration ◽

Soil Quality ◽

Mycorrhizal Fungi ◽

Field Experiments ◽

Block Design ◽

North India ◽

Gangetic Plain ◽

Agronomic Practices ◽

Soil Sustainability ◽

Indo Gangetic Plain

Global agricultural production is accountable for the emission of ~30% of greenhouse gases. Therefore, the wide-scale adoptions of low-input, soil-friendly, and resource-conserving agronomic practices are imperative for the ‘planet healthy food production’ and also for reducing the carbon emissions from agricultural soil. In this context, the present study aimed to analyze the impacts of integrated agronomic interventions i.e., the application of arbuscular mycorrhizal fungi (AMF) + reduced tillage (RT), biochar + RT, and AMF + biochar + RT, on spatiotemporal variations in soil-quality and soil-sustainability indicators, including microbial and soil respiration, in the Indo-Gangetic Plain (IGP) of North India. For this, field experiments on the above-mentioned agronomic interventions were employed using three different staple crops (Zea mays, Vigna mungo, and Brassica juncea) growing in three different agro-climatic zones of IGP (Varanasi, Sultanpur, and Gorakhpur) in a randomized block design. Periodic data collection was done to analyze the changes in physiochemical, biological, and biochemical properties of the soil, and statistical analyses were done accordingly. Irrespective of the sites, the experimental results proved that the integrated application of AMF + biochar + RT in V. mungo resulted in the highest soil organic carbon (i.e., 135% increment over the control) and microbial biomass carbon (24%), whereas the same application (i.e., AMF + biochar + RT) in Z. mays had the maximum reduction in microbial (32%) and soil (44%) respiration. On the other hand, enhanced occurrence of glomalin activity (98%) was noted in Z. mays cropping for all the sites. Significant negative correlation between soil respiration and glomalin activity under AMF + biochar + RT (−0.85), AMF + RT (−0.82), and biochar + RT (−0.62) was an indication of glomalin’s role in the reduced rate of soil respiration. The research results proved that the combined application of AMF + biochar + RT was the best practice for enhancing soil quality while reducing respiration. Therefore, the development of suitable packages of integrated agronomic practices is essential for agricultural sustainability.

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