Multiple sites ground-based evaluation of carbonaceous aerosol mass concentrations retrieved from the CAMS and MERRA-2 over the 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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Regional and local variations in atmospheric aerosols using ground-based sun photometry during Distributed Regional Aerosol Gridded Observation Networks (DRAGON) in 2012

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-14795-2016 ◽

2016 ◽

Vol 16 (22) ◽

pp. 14795-14803 ◽

Cited By ~ 5

Author(s):

Itaru Sano ◽

Sonoyo Mukai ◽

Makiko Nakata ◽

Brent N. Holben

Keyword(s):

Atmospheric Aerosols ◽

Urban Areas ◽

Regional Scale ◽

Reanalysis Data ◽

Aerosol Dynamics ◽

Aerosol Mass ◽

Combined Use ◽

Environmental Prediction ◽

Almost All ◽

Observation Networks

Abstract. Aerosol mass concentrations are affected by local emissions as well as long-range transboundary (LRT) aerosols. This work investigates regional and local variations of aerosols based on Distributed Regional Aerosol Gridded Observation Networks (DRAGON). We constructed DRAGON-Japan and DRAGON-Osaka in spring of 2012. The former network covers almost all of Japan in order to obtain aerosol information in regional scale over Japanese islands. It was determined from the DRAGON-Japan campaign that the values of aerosol optical thickness (AOT) decrease from west to east during an aerosol episode. In fact, the highest AOT was recorded at Fukue Island at the western end of the network, and the value was much higher than that of urban areas. The latter network (DRAGON-Osaka) was set as a dense instrument network in the megalopolis of Osaka, with a population of 12 million, to better understand local aerosol dynamics in urban areas. AOT was further measured with a mobile sun photometer attached to a car. This transect information showed that aerosol concentrations rapidly changed in time and space together when most of the Osaka area was covered with moderate LRT aerosols. The combined use of the dense instrument network (DRAGON-Osaka) and high-frequency measurements provides the motion of aerosol advection, which coincides with the wind vector around the layer between 700 and 850 hPa as provided by the reanalysis data of the National Centers for Environmental Prediction (NCEP).

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Development of a Regression Model for Estimating Daily Radiative Forcing Due to Atmospheric Aerosols from Moderate Resolution Imaging Spectrometers (MODIS) Data in the Indo Gangetic Plain (IGP)

Atmosphere ◽

10.3390/atmos9100405 ◽

2018 ◽

Vol 9 (10) ◽

pp. 405 ◽

Cited By ~ 1

Author(s):

Shreemat Shrestha ◽

Murray Peel ◽

Graham Moore

Keyword(s):

Regression Model ◽

Water Vapour ◽

Atmospheric Aerosols ◽

Radiative Forcing ◽

Crop Production ◽

Atmospheric Water ◽

Gangetic Plain ◽

Atmospheric Water Vapour ◽

Station Data ◽

Indo Gangetic Plain

The assessment of direct radiative forcing due to atmospheric aerosols (ADRF) in the Indo Gangetic Plain (IGP), which is a food basket of south Asia, is important for measuring the effect of atmospheric aerosols on the terrestrial ecosystem and for assessing the effect of aerosols on crop production in the region. Existing comprehensive analytical models to estimate ADRF require a large number of input parameters and high processing time. In this context, here, we develop a simple model to estimate daily ADRF at any location on the surface of the IGP through multiple regressions of AErosol RObotic NETwork (AERONET) aerosol optical depth (AOD) and atmospheric water vapour using data from 2002 to 2015 at 10 stations in the IGP. The goodness of fit of the model is indicated by an adjusted R2 value of 0.834. The Jackknife method of deleting one group (station data) was employed to cross validate and study the stability of the regression model. It was found to be robust with an adjusted R2 fluctuating between 0.813 and 0.842. In order to use the year-round ADRF model for locations beyond the AERONET stations in the IGP, AOD, and atmospheric water vapour products from MODIS Aqua and Terra were compared against AERONET station data and they were found to be similar. Using MODIS Aqua and Terra products as input, the year-round ADRF regression was evaluated at the IGP AERONET stations and found to perform well with Pearson correlation coefficients of 0.66 and 0.65, respectively. Using ADRF regression model with MODIS inputs allows for the estimation of ADRF across the IGP for assessing the aerosol impact on ecosystem and crop production.

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Atmospheric aerosols properties over Indo-Gangetic Plain: A trend analysis using ground – truth AERONET data for the year 2009 - 2017

Advances in Space Research ◽

10.1016/j.asr.2021.12.052 ◽

2022 ◽

Author(s):

Akhilesh Kumar ◽

Vineet Pratap ◽

Sarvan Kumar ◽

A.K. Singh

Keyword(s):

Trend Analysis ◽

Atmospheric Aerosols ◽

Ground Truth ◽

Gangetic Plain ◽

Indo Gangetic Plain

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Vertical and horizontal distribution of sub-micron aerosol chemical composition and physical characteristics across Northern India, during the pre-monsoon and monsoon seasons

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acp-2018-1109 ◽

2018 ◽

pp. 1-31

Author(s):

James Brooks ◽

James D. Allan ◽

Paul I. Williams ◽

Dantong Liu ◽

Cathryn Fox ◽

...

Keyword(s):

Black Carbon ◽

Total Mass ◽

Mass Concentration ◽

Monsoon Season ◽

Aerosol Layer ◽

Gangetic Plain ◽

Submicron Aerosol ◽

Aerosol Mass ◽

Indo Gangetic Plain ◽

Mass Concentrations

Abstract. The vertical distribution in the physical and chemical properties of submicron aerosol has been characterised across northern India for the first time using airborne in-situ measurements. This study focusses primarily on the Indo-Gangetic Plain, a low-lying area in the north of India which commonly experiences high aerosol mass concentrations prior to the monsoon season. Data presented are from the UK Facility for Airborne Atmospheric Measurements BAe-146 research aircraft that performed flights in the region during the 2016 pre-monsoon (11th and 12th June) and monsoon (30th June to 11th July) seasons. Inside the Indo-Gangetic Plain boundary layer, organic matter dominated the submicron aerosol mass (43&thinsp;%) followed by sulphate (29&thinsp;%), ammonium (14&thinsp;%), nitrate (7&thinsp;%) and black carbon (7&thinsp;%). However, outside the Indo-Gangetic Plain, sulphate was the dominant species contributing 44&thinsp;% to the total submicron aerosol mass in the boundary layer, followed by organic matter (30&thinsp;%), ammonium (14&thinsp;%), nitrate (6&thinsp;%) and black carbon (6&thinsp;%). Chlorine mass concentrations were negligible throughout the campaign. Black carbon mass concentrations were higher inside the Indo-Gangetic Plain (2&thinsp;µg/m3 std) compared to outside (1&thinsp;µg/m3 std). Nitrate appeared to be controlled by thermodynamic processes, with increased mass concentration in conditions of lower temperature and higher relative humidity. Increased mass and number concentrations were observed inside the Indo-Gangetic Plain and the aerosol was more absorbing in this region, whereas outside the Indo-Gangetic Plain the aerosol was larger in size and more scattering in nature, suggesting greater dust presence especially in northwest India. The aerosol composition remained largely similar as the monsoon season progressed, but the total aerosol mass concentrations decreased by ~&thinsp;50&thinsp;% as the rainfall arrived; the pre-monsoon average total mass concentration was 30&thinsp;µg/m3 std compared to a monsoon average total mass concentration of 10&ndash;20&thinsp;µg/m3 std. However, this mass concentration decrease was less noteworthy (~&thinsp;20&ndash;30&thinsp;%) over the Indo-Gangetic Plain, likely due to the strength of emission sources in this region. Decreases occurred in coarse mode aerosol, with the fine mode fraction increasing with monsoon arrival. In the aerosol vertical profile, inside the Indo-Gangetic Plain during the pre-monsoon, organic aerosol and absorbing aerosol species dominated in the lower atmosphere (<&thinsp;1.5&thinsp;km) with sulphate, dust and other scattering aerosol species enhanced in an elevated aerosol layer above 1.5&thinsp;km with maximum aerosol height ~&thinsp;6&thinsp;km. As the monsoon progressed into this region, the elevated aerosol layer diminished, the aerosol maximum height reduced to ~&thinsp;2&thinsp;km and the total mass concentrations decreased by ~&thinsp;50&thinsp;%. The dust and sulphate-dominated aerosol layer aloft was removed upon monsoon arrival, highlighted by an increase in fine mode fraction throughout the profile.

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Variation in carbonaceous and ionic species at a rural receptor location in the eastern Indo-Gangetic Plain

10.5194/egusphere-egu21-7205 ◽

2021 ◽

Author(s):

Bijay Sharma ◽

Anurag J. Polana ◽

Jingying Mao ◽

Shiguo Jia ◽

Sayantan Sarkar

Keyword(s):

Organic Carbon ◽

Forest Fires ◽

Ionic Species ◽

Water Soluble ◽

Photochemical Oxidation ◽

Carbonaceous Aerosol ◽

Charge Ratio ◽

Gangetic Plain ◽

Post Monsoon ◽

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

Urban Climate ◽

10.1016/j.uclim.2021.100964 ◽

2021 ◽

Vol 39 ◽

pp. 100964

Author(s):

Dipanjali Majumdar ◽

Rita Mondal ◽

Arivalagan Periyasamy ◽

Nabasmita Barman ◽

Swarnadeepa Dey ◽

...

Keyword(s):

Carbonaceous Aerosol ◽

Gangetic Plain ◽

Indo Gangetic Plain

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Evolution of Aerosol Size and Composition in the Indo-Gangetic Plain: Size-Resolved Analysis of High-Resolution Aerosol Mass Spectra

ACS Earth and Space Chemistry ◽

10.1021/acsearthspacechem.8b00207 ◽

2019 ◽

Vol 3 (5) ◽

pp. 823-832

Author(s):

Navaneeth M. Thamban ◽

Bhuvana Joshi ◽

S. N. Tripathi ◽

Donna Sueper ◽

Manjula R. Canagaratna ◽

...

Keyword(s):

High Resolution ◽

Mass Spectra ◽

Gangetic Plain ◽

Aerosol Mass ◽

Indo Gangetic Plain

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Supplementary material to "Organic molecular tracers in the atmospheric aerosols from Lumbini, Nepal, in the northern Indo-Gangetic Plain: Influence of biomass burning"

10.5194/acp-2016-1176-supplement ◽

2017 ◽

Author(s):

Xin Wan ◽

Shichang Kang ◽

Quanlian Li ◽

Dipesh Rupakheti ◽

Qianggong Zhang ◽

...

Keyword(s):

Biomass Burning ◽

Atmospheric Aerosols ◽

Gangetic Plain ◽

Supplementary Material ◽

Molecular Tracers ◽

Indo Gangetic Plain

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Change in global aerosol composition since preindustrial times

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-5585-2006 ◽

2006 ◽

Vol 6 (3) ◽

pp. 5585-5628 ◽

Cited By ~ 2

Author(s):

K. Tsigaridis ◽

M. Krol ◽

F. J. Dentener ◽

Y. Balkanski ◽

J. Lathière ◽

...

Keyword(s):

Chemical Composition ◽

Atmospheric Aerosols ◽

Transport Model ◽

Sea Salt ◽

Carbonaceous Aerosol ◽

Aerosol Formation ◽

Aerosol Composition ◽

Aerosol Mass ◽

Composition Changes ◽

Aerosol Chemical Composition

Abstract. To elucidate human induced changes of aerosol load and composition in the atmosphere, a coupled aerosol and gas-phase chemistry transport model of the troposphere and lower stratosphere has been used. This is the first 3-d modeling study that focuses on aerosol chemical composition change since preindustrial times considering the secondary organic aerosol formation together with all other main aerosol components including nitrate. In particular, we evaluate non-sea-salt sulfate (nss-SO4=), ammonium (NH4+), nitrate (NO3-), black carbon (BC), sea-salt, dust, primary and secondary organics (POA and SOA) with a focus on the importance of secondary organic aerosols. Our calculations show that the aerosol optical depth (AOD) has increased by about 21% since preindustrial times. This enhancement of AOD is attributed to a rise in the atmospheric load of BC, nss-SO4=, NO3-, POA and SOA by factors of 3.3, 2.6, 2.7, 2.3 and 1.2, respectively, whereas we assumed that the natural dust and sea-salt sources remained constant. The nowadays increase in carbonaceous aerosol loading is dampened by a 34–42% faster conversion of hydrophobic to hydrophilic carbonaceous aerosol leading to higher removal rates. These changes between the various aerosol components resulted in significant modifications of the aerosol chemical composition. The relative importance of the various aerosol components is critical for the aerosol climatic effect, since atmospheric aerosols behave differently when their chemical composition changes. According to this study, the aerosol composition changed significantly over the different continents and with height since preindustrial times. The presence of anthropogenically emitted primary particles in the atmosphere facilitates the condensation of the semi-volatile species that form SOA onto the aerosol phase, particularly in the boundary layer. The SOA burden that is dominated by the natural component has increased by 24% while its contribution to the AOD has increased by 11%. The increase in oxidant levels and preexisting aerosol mass since preindustrial times is the reason of the burden change, since emissions have not changed significantly. The computed aerosol composition changes translate into about 2.5 times more water associated with non sea-salt aerosol. Additionally, aerosols contain 2.7 times more inorganic components nowadays than during the preindustrial times. We find that the increase in emissions of inorganic aerosol precursors is much larger than the corresponding aerosol increase, reflecting a non-linear atmospheric response.

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