scholarly journals Study of MODIS derived AOD at three different locations in the Indo Gangetic Plain: Kanpur, Gandhi College and Nainital

2012 ◽  
Vol 30 (10) ◽  
pp. 1479-1493 ◽  
Author(s):  
P. Choudhry ◽  
A. Misra ◽  
S. N. Tripathi
Keyword(s):  
Indian Subcontinent ◽  
Rural Site ◽  
Urban Site ◽  
Gangetic Plain ◽  
Large Variability ◽  
Entire Area ◽  
Aerosol Model ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
A Site ◽  
Indo Gangetic Plain

Abstract. Moderate resolution imaging spectroradiometer (MODIS) sensors, onboard Terra and Aqua, have been observing the Earth since start of 2000 and mid 2002, respectively. The present study provides a comparison of Collection 5 (C005), aerosol optical depth (AOD) retrieved by MODIS, with AERONET-observed AOD over Kanpur (an urban site), Gandhi College (a rural site) and Nainital (a relatively clean site) in the Indo Gangetic Plain (IGP). The results show that at Kanpur, MODIS retrievals are well within the prelaunch uncertainty ± 0.05 ±0.15 τ, and a good correlation (R2 > 0.7 for both Terra and Aqua). Nainital also shows good retrieval (R2 > 0.8 for Terra and R2 > 0.68 for Aqua), as more than 66% of total collocations are within the prelaunch uncertainty. However, it is seen that there is significant overestimation in this case, especially in the months of winter. Gandhi College poses a challenge to MODIS retrieval, as here <57% of MODIS-retrieved AOD values lay within the prelaunch uncertainty and the correlation is very poor (R2 ~ 0.5 for Aqua and R2 ~ 0.4 for Terra); also there is persistent underestimation in this case. Small value of slope shows that assumed model results in underestimation, and large intercept values for the linear regression fit show that errors due to surface reflectance are high here. Our comparison shows that MODIS retrieval works well over Kanpur, and Nainital with winter as an exception. However, MODIS retrieval is poor for Gandhi College which is a rural area. The aerosol properties at Kanpur are currently used as representative of the entire subcontinent in the MODIS C005 algorithm, which is not an accurate assumption. The large variability in land use and climate over India makes it a site too complex for a single aerosol model to be used over the entire area. Therefore further study with as many sites as possible over the Indian subcontinent would help provide more realistic modeling for the Indian subcontinent.

scholarly journals Wet Deposition of Total Dissolved Nitrogen in Indo-Gangetic Plain (India)

2021 ◽  
Author(s):  
Manisha Mishra ◽  
Umesh Chandra Kulshrestha
Keyword(s):  
Wet Deposition ◽  
Animal Husbandry ◽  
Rural Site ◽  
Urban Site ◽  
Organic N ◽  
Major Influence ◽  
Limited Information ◽  
Monsoon Period ◽  
Gangetic Plain ◽  
Indo Gangetic Plain

Abstract Very limited information on the magnitude and environmental impacts of both inorganic as well as organic forms of Nitrogen (N) wet deposition is available in India. Molar concentrations of inorganic (NH4+ and NO3−) and organic N in rainwater were monitored at three different land-use sites in Indo-Gangetic Plain (IGP) during the monsoon period (June-September) of 2017. It has been observed that dissolved organic N (DON) contributed significantly to the total dissolved N (TDN) ranging from 5–60%. Dissolved inorganic N (DIN = NH4+ + NO3−) concentration was recorded as high as 221.0 µmol L− 1 at urban site to as low as 65.9 µmol L− 1 at the rural site. A similar pattern was also observed for DON. NH4+ contribution to TDN had the order: urban megacity (65%) > urban (70%) > rural (75%). Agriculture and animal husbandry are the primary sources of NH4+ emissions in the rural site. However, NO3− has shown a contrasting trend at these sites (25%, 15% and 8%, respectively). Wet deposition fluxes of atmospheric TDN was observed to be higher at urban sites. This can attributed to a variety of local sources such as vehicular emission, microbial emissions, biomass burning, human excreta due to higher population density, and transportation from surrounding areas, as observed from concentration weighted trajectories (CWT) model and cluster analysis. Upwind region of IGP has experienced major influence of air mass transported from agriculturally rich northwest part of India. However, both the downwind sites have experienced by-and-large the influence of south-westerly air-masses originated over the Arabian Sea. Study has found that the DON contributes significantly to TDN and need to be included for budget assessment in South Asia.

scholarly journals Spatio-Temporal Variation of Atmospheric Gaseous and Particulate Reactive Nitrogen over Northern India

2021 ◽  
Vol Special Issue (1) ◽  
pp. 53-67
Author(s):  
Manisha Mishra ◽  
Umesh C Kulshrestha
Keyword(s):  
Source Parameters ◽  
Ambient Air ◽  
Water Soluble ◽  
Rural Site ◽  
Urban Site ◽  
Local Source ◽  
Reactive Nitrogen ◽  
Gangetic Plain ◽  
Reactive N ◽  
Spatio Temporal

The present study reports spatio-temporal distribution pattern of major gaseous (NH3 and NO2) and particulate water soluble total nitrogen (pWSTN) in the ambient air to explore the seasonal variation, major interactions and dominating sources. Considering the major hotspot of atmospheric reactive nitrogen (N) emission, three sites in Indo-Gangetic plain (IGP) were selected based on different local source parameters. Results have shown that gas phase reactive N contribute up to 90% of total analyzed reactive N, where NH3 imparted highest at all the three sites. Prayagraj, a fast growing urban site, has shown highest concentrations of NH3 (72.0 μg m−3), followed by Madhupur rural site (57.7 μg m−3) and Delhi, an urban megacity site (35.8 μg m−3). As compared to previous studies conducted at different sites of IGP, NH3 concentrations were reported to be the highest at the former two sites. However, unlike NH3, NO2 levels were recorded lower at Madhupur (3.1 μg m−3) and Prayagraj (9.4 μg m−3) sites as compared to Delhi (13.4 μg m−3). Similarly, pWSTN concentrations were in the order of Madhupur (6.6 μg m−3) < Prayagraj (10.0 μg m−3) < Delhi (10.1 μg m−3). A strong correlation of NO2 with pWSTN at urban sites has shown the crucial role of NO2 in the formation of nitrogenous aerosols. Significant spatial variation can be attributed to varying local emission sources ranging from microbial emission from improper sewage treatment and open waste dumping at Prayagraj, agricultural activities at Madhupur and vehicular exhausts at Delhi site.

Evaluation of emission strength efficacy in simulating black carbon burden with CHIMERE: estimating wintertime radiative effect over Indo-Gangetic Plain

2020 ◽  
Author(s):  
Sanhita Ghosh ◽  
Shubha Verma ◽  
Jayanarayanan Kuttippurath
Keyword(s):  
Black Carbon ◽  
Transport Model ◽  
Indian Subcontinent ◽  
Chemical Transport ◽  
Climate Impacts ◽  
Eastern Coast ◽  
Spatial And Temporal Patterns ◽  
Gangetic Plain ◽  
Bc Aerosols ◽  
Indo Gangetic Plain

&lt;p&gt;Black carbon (BC) aerosols over the Indian subcontinent have been represented inadequately so-far in chemical transport models restricting the accurate assessment of BC-induced climate impacts. The divergence between simulated and measured BC concentration has specifically been reported to be large over the Indo-Gangetic Plain (IGP) during winter when a large BC burden is observed. In this study, we evaluate the BC transport simulations over the IGP in a high resolution (0.1&amp;#186; &amp;#215; 0.1&amp;#186; ) chemical transport model, CHIMERE. We examine the model efficiency to simulate the observed BC distribution executing five sets of simulation experiments: &lt;em&gt;Constrained &lt;/em&gt;and&lt;em&gt; bottomup&lt;/em&gt; (&lt;em&gt;Smog, Pku, Edgar, Cmip&lt;/em&gt;) implementing respectively, the recently estimated India-based constrained BC emission and the latest bottom-up BC emissions (India-based: Smog-India, and global: Coupled Model Intercomparison Project phase 6 (CMIP6), Emission Database for Global Atmospheric Research-V4 (EDGAR-V4) and Peking University BC Inventory (PKU)). The mean BC emission flux over most of the IGP from the five emission datasets is considerably high (450&amp;#8211;1000 kg km&lt;sup&gt;-2&lt;/sup&gt; y&lt;sup&gt;-1&lt;/sup&gt;) with a relatively low divergence obtained for the eastern and upper-mideastern IGP. Evaluation of BC transport simulations shows that the spatial and temporal gradient in the simulated BC concentration from the &lt;em&gt;Constrained &lt;/em&gt;was equivalent to that from the &lt;em&gt;bottomup&lt;/em&gt; and also to that from observations. This indicates that the spatial and temporal patterns of BC concentration are consistently simulated by the model processes. However, the efficacy to simulate BC distribution is commendable for the estimates from &lt;em&gt;Constrained&lt;/em&gt; for which the lowest normalised mean bias (NMB, &lt; 20%) is obtained in comparison to that from the &lt;em&gt;bottomup&lt;/em&gt; (37&amp;#8211;52%). 75&amp;#8211;100% of the observed all-day (daytime) mean BC concentration is simulated most of the times (&gt;80% of the number of stations data) for &lt;em&gt;Constrained&lt;/em&gt;, whereas, this being less frequent (&lt;50%) for the &lt;em&gt;Pku, Smog, Edgar&lt;/em&gt; and poor for &lt;em&gt;Cmip&lt;/em&gt;. The BC-AOD (0.04&amp;#8211;0.08) estimated from the &lt;em&gt;Constrained&lt;/em&gt; is 20&amp;#8211;50% higher than the &lt;em&gt;Pku&lt;/em&gt; and &lt;em&gt;Smog&lt;/em&gt;. Three main hotspot locations comprising of a large value of BC load are identified over the eastern, mideastern, and northern IGP. Assessment of the effect of BC burden on the wintertime radiative perturbation over the IGP shows that the presence of BC aerosols in the atmosphere enhances atmospheric heating by 2&amp;#8211;3 times more compared to that considering atmosphere without BC. Also, a net warming at the top of the atmosphere (TOA) by 10&amp;#8211;17 W m&lt;sup&gt;-&lt;/sup&gt;&lt;sup&gt;2&lt;/sup&gt; is noticed from the &lt;em&gt;Constrained&lt;/em&gt;, with the largest value estimated in and around megacities (Kolkata and Delhi) that extends to the eastern coast. This value is higher by 10&amp;#8211;20% than that from &lt;em&gt;Cmip&lt;/em&gt; over the IGP and by 2&amp;#8211;10% than that from &lt;em&gt;Smog&lt;/em&gt; over Delhi and eastern part of the IGP.&lt;/p&gt;

Emission characteristic of ozone related trace gases at a semi-urban site in the Indo-Gangetic plain using inter-correlations

2008 ◽  
Vol 60 (3) ◽  
pp. 189-204 ◽  
Author(s):  
S. Lal ◽  
L. K. Sahu ◽  
S. Gupta ◽  
S. Srivastava ◽  
K. S. Modh ◽  
...  
Keyword(s):  
Trace Gases ◽  
Urban Site ◽  
Emission Characteristic ◽  
Gangetic Plain ◽  
Indo Gangetic Plain

scholarly journals Study on Mercury in PM10 at an Urban Site in the Central Indo-Gangetic Plain: Seasonal Variability and Influencing Factors

2020 ◽  
Vol 20 (12) ◽  
pp. 2729-2740 ◽  
Author(s):  
Junming Guo ◽  
Kirpa Ram ◽  
Lekhendra Tripathee ◽  
Shichang Kang ◽  
Jie Huang ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Seasonal Variability ◽  
Urban Site ◽  
Gangetic Plain ◽  
Indo Gangetic Plain

Investigations of aerosol black carbon from a semi-urban site in the Indo-Gangetic Plain region

2016 ◽  
Vol 125 ◽  
pp. 346-359 ◽  
Author(s):  
Hema Joshi ◽  
Manish Naja ◽  
K.P. Singh ◽  
Rajesh Kumar ◽  
P. Bhardwaj ◽  
...  
Keyword(s):  
Black Carbon ◽  
Urban Site ◽  
Gangetic Plain ◽  
Plain Region ◽  
Indo Gangetic Plain

scholarly journals Organic molecular tracers in the atmospheric aerosols from Lumbini, Nepal, in the northern Indo-Gangetic Plain: Influence of biomass burning

2017 ◽  
Author(s):  
Xin Wan ◽  
Shichang Kang ◽  
Quanlian Li ◽  
Dipesh Rupakheti ◽  
Qianggong Zhang ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Vanillic Acid ◽  
Monsoon Season ◽  
Syringic Acid ◽  
Rural Site ◽  
Aerosol Composition ◽  
Gangetic Plain ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Indo Gangetic Plain

Abstract. To better understand the characteristics of biomass burning in the northern Indo-Gangetic Plain (IGP), total suspended particles were collected in a rural site, Lumbini, Nepal during April 2013 to March 2014 and analyzed for the biomass burning tracers (i.e., levoglucosan, mannosan, vanillic acid, etc.). The annual average concentration of levoglucosan was 734 ± 1043 ng m−3 with the maximum seasonal mean concentration during post-monsoon season (2206 ± 1753 ng m−3), followed by winter (1161 ± 1347 ng m−3), pre-monsoon (771 ± 524 ng m−3) and minimum concentration during monsoon season (212 ± 279 ng m−3). The other biomass burning tracers (mannosan, galactosan, p-hydroxybenzoic acid, vanillic acid, syringic acid, and dehydroabietic acid) also showed the similar seasonal variations. There were good correlations among levoglucosan, organic carbon (OC) and elemental carbon (EC), indicating significant impact of biomass burning activities on carbonaceous aerosol loading throughout the year in Lumbini area. According to the characteristic ratios: levoglucosan / mannosan (Lev / Man) and syringic acid / vanillic acid (Syr / Van), we deduced that the high abundances of biomass burning products during non-monsoon seasons were mainly caused by the burning of crop residues and hardwood while the softwood had less contribution. Based on the diagnostic tracer ratio (i.e., Lev / OC), the OC derived from biomass burning constituted large fraction of total OC, especially during post-monsoon season. By analyzing the MODIS fire spot product and five-day air-mass back trajectories, we further demonstrated that organic aerosol composition was not only related to the local agricultural activities and residential biomass usage, but was also impacted by the regional emissions. During the post-monsoon season, the emissions from rice residue burning in western India and eastern Pakistan could impact particulate air pollution in Lumbini and surrounding regions in southern Nepal. Therefore, our finding is meaningful and has a great importance for adopting the appropriate mitigation measures, not only at the local level but also by involving different regions and nations, to reduce the biomass burning emissions in the broader IGP region nations.

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