Source contribution of black carbon aerosol during 2020-2022 at an urban site in Indo-Gangetic Plain

Arpit Malik; Shankar G Aggarwal; Yutaka Kondo; Baban Kumar; Prashant Patel; Puna Ram Sinha; Naga Oshima; Sho Ohata; Tatsuhiro Mori; Makoto Koike; Khem Singh; Daya Soni; Akinori Takami

doi:10.1016/j.scitotenv.2024.173039

Source contribution of black carbon aerosol during 2020-2022 at an urban site in Indo-Gangetic Plain

Sci Total Environ. 2024 May 11:934:173039. doi: 10.1016/j.scitotenv.2024.173039. Online ahead of print.

Authors

Arpit Malik¹, Shankar G Aggarwal², Yutaka Kondo³, Baban Kumar¹, Prashant Patel¹, Puna Ram Sinha⁴, Naga Oshima⁵, Sho Ohata⁶, Tatsuhiro Mori⁷, Makoto Koike⁸, Khem Singh⁹, Daya Soni¹, Akinori Takami¹⁰

Affiliations

¹ CSIR-National Physical Laboratory, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
² CSIR-National Physical Laboratory, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India. Electronic address: aggarwalsg@nplindia.org.
³ National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan.
⁴ Department of Earth and Space Sciences, Indian Institute of Space Science and Technology, Thiruvananthapuram 695547, India.
⁵ Meteorological Research Institute, Japan Meteorological Agency, 1-1 Nagamine, Tsukuba, Ibaraki 305-0052, Japan.
⁶ Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
⁷ Department of Applied Chemistry, Faculty of Science and Technology, Keio University 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
⁸ The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
⁹ CSIR-National Physical Laboratory, New Delhi 110012, India.
¹⁰ National Institute for Environmental Studies, 16-2 Onogawa Tsukuba, Ibaraki 305-8506, Japan.

PMID: 38735325
DOI: 10.1016/j.scitotenv.2024.173039

Abstract

The extensive emissions of black carbon (BC) from the Indo-Gangetic Plain (IGP) region of India have been well recognized. Particularly, biomass emissions from month-specific crop-residue burning (April, May, October, November) and heating activities (December-February) are considered substantial contributors to BC emissions in the IGP. However, their precise contribution to ambient BC aerosol has not been quantified yet and remains an issue of debate. Therefore, this study aims to fill this gap by quantifying the contribution of these month-specific biomass emissions to ambient BC at an urban site in IGP. This study presents the analysis of BC mass concentrations (M_BC) measured for 3 years (2020-2022) in Delhi using an optical photometer i.e., continuous soot monitoring system (COSMOS). A statistical analysis of monthly mean M_BC and factors affecting the M_BC (ventilation coefficients, air mass back trajectories, fire counts) is performed to derive month-wise contribution due to background concentration, conventional emission, regional transport, crop-residue burning, and heating activities. The yearly mean M_BC (5.3 ± 4.7, 5.6 ± 5.0, and 5.3 ± 3.5 μg m^-3 during 2020, 2021, and 2022, respectively) remained relatively consistent with repetitive monthly patterns in each year. The peak concentrations were observed from November to January and low concentrations from June to September. Anthropogenic activities contributed significantly to M_BC over Delhi with background concentration contributing only 30 % of observed M_BC. The percentage contribution of emissions from crop-residue burning varied from 15 % (May) to 37 % (November), while the contribution from heating activities ranged from 25 % (December) to 39 % (January). This source quantification study highlights the significant impact of month-specific biomass emissions in the IGP and can play a vital role in better management and control of these emissions in the region.

Keywords: Black carbon; Crop-residue burning; Emissions; Heating activity; Indo-Gangetic Plains.