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

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.

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

Atmospheric Environment ◽

10.1016/j.atmosenv.2015.04.007 ◽

2016 ◽

Vol 125 ◽

pp. 346-359 ◽

Cited By ~ 35

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

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Primary and secondary aerosols from an urban site (Kanpur) in the Indo-Gangetic Plain: Impact on CCN, CN concentrations and optical properties

Atmospheric Environment ◽

10.1016/j.atmosenv.2014.02.009 ◽

2014 ◽

Vol 89 ◽

pp. 655-663 ◽

Cited By ~ 23

Author(s):

Kirpa Ram ◽

S.N. Tripathi ◽

M.M. Sarin ◽

D. Bhattu

Keyword(s):

Optical Properties ◽

Urban Site ◽

Gangetic Plain ◽

Secondary Aerosols ◽

Indo Gangetic Plain

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Characteristics of surface ozone in Agra, a sub-urban site in Indo-Gangetic Plain

Journal of Earth System Science ◽

10.1007/s12040-018-0934-3 ◽

2018 ◽

Vol 127 (3) ◽

Cited By ~ 1

Author(s):

Nidhi Verma ◽

Aparna Satsangi ◽

Anita Lakhani ◽

K Maharaj Kumari

Keyword(s):

Surface Ozone ◽

Urban Site ◽

Gangetic Plain ◽

Indo Gangetic Plain

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

Annales Geophysicae ◽

10.5194/angeo-30-1479-2012 ◽

2012 ◽

Vol 30 (10) ◽

pp. 1479-1493 ◽

Cited By ~ 29

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.

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