TY - JOUR
T1 - Measurement of Black Carbon in Delhi
T2 - Evidences of Regional Transport, Meteorology and Local Sources for Pollution Episodes
AU - Malik, Arpit
AU - Aggarwal, Shankar G.
AU - Ohata, Sho
AU - Mori, Tatsuhiro
AU - Kondo, Yutaka
AU - Sinha, Puna Ram
AU - Patel, Prashant
AU - Kumar, Baban
AU - Singh, Khem
AU - Soni, Daya
AU - Koike, Makoto
N1 - Funding Information:
AM is thankful to University Grant Commission (UGC) for providing the fellowship under UGC-SRF scheme (P90802). Authors from CSIR-NPL thank to the Director, CSIR-NPL for providing all support to carry out this work, and further extend their thanks to Heads (present and past) of ESBM, Division #3.0, and students of Gas Metrology group for their help and support. This work was also supported by the Environment Research and Technology Development Fund (JPMEERF20202003) of the Environmental Restoration and Conservation Agency of Japan, and the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan Society for the Promotion of Science KAKENHI Grants (JP20H00638), and the Arctic Challenge for Sustainability II (ArCS II) project (JPMXD1420318865).
Publisher Copyright:
© 2022 The Author(s).
PY - 2022/8
Y1 - 2022/8
N2 - Measurement of particulate matter (PM) constituent such as black carbon (BC) over urban sites is critically important owing to its adverse health and climate impacts. However, the impacts associated with BC are poorly understood primarily because of the scarcity and uncertainties of measurements of BC. Here, we present BC measurement at an urban site of Delhi using a characterized continuous soot monitoring system (COSMOS) for a year-long period, i.e., from September, 2019 to August, 2020. This measurement period covers events, i.e., period of crop residue burnings from nearby states, festive events, e.g., Diwali and New Year, and first COVID-19 lockdown period. Effects of these events combining with local emissions and meteorological conditions on BC mass concentration (MBC) are investigated to find the possible cause of severe pollution levels in Delhi. Mean MBC for the complete observation period was found to be 5.02 ± 4.40 µg m–3. MBC showed significant seasonal as well diurnal variations. Winter season (December to February) is observed to be the most polluted season owing to increased local emissions and non-favorable meteorological conditions. Regional emission from crop burning in nearby states during October and November is the main contributing factor for increased pollution in this post-monsoon season. Furthermore, analysis reveals that cracker burning during festivals can also be considered as contributing factor to high MBC for a short period in post-monsoon and winter seasons. Significant decrease in MBC due to COVID-19 lockdown is also observed. MBC in summer and monsoon are lower as compared to other seasons but are still higher than mean MBC levels in several other urban cities of different countries. Also, the BC data obtained from nearby sites and Modern-Era Retrospective analysis for Research and Applications-version 2 (MERRA-2)’s surface black carbon (SBC) are compared against the MBC to evaluate coherency among the different datasets, and discussed in detail.
AB - Measurement of particulate matter (PM) constituent such as black carbon (BC) over urban sites is critically important owing to its adverse health and climate impacts. However, the impacts associated with BC are poorly understood primarily because of the scarcity and uncertainties of measurements of BC. Here, we present BC measurement at an urban site of Delhi using a characterized continuous soot monitoring system (COSMOS) for a year-long period, i.e., from September, 2019 to August, 2020. This measurement period covers events, i.e., period of crop residue burnings from nearby states, festive events, e.g., Diwali and New Year, and first COVID-19 lockdown period. Effects of these events combining with local emissions and meteorological conditions on BC mass concentration (MBC) are investigated to find the possible cause of severe pollution levels in Delhi. Mean MBC for the complete observation period was found to be 5.02 ± 4.40 µg m–3. MBC showed significant seasonal as well diurnal variations. Winter season (December to February) is observed to be the most polluted season owing to increased local emissions and non-favorable meteorological conditions. Regional emission from crop burning in nearby states during October and November is the main contributing factor for increased pollution in this post-monsoon season. Furthermore, analysis reveals that cracker burning during festivals can also be considered as contributing factor to high MBC for a short period in post-monsoon and winter seasons. Significant decrease in MBC due to COVID-19 lockdown is also observed. MBC in summer and monsoon are lower as compared to other seasons but are still higher than mean MBC levels in several other urban cities of different countries. Also, the BC data obtained from nearby sites and Modern-Era Retrospective analysis for Research and Applications-version 2 (MERRA-2)’s surface black carbon (SBC) are compared against the MBC to evaluate coherency among the different datasets, and discussed in detail.
KW - Black carbon
KW - Delhi air pollution
KW - Local emissions and regional transport
KW - MERRA-2’s surface black carbon
KW - Meteorology
UR - http://www.scopus.com/inward/record.url?scp=85134894153&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85134894153&partnerID=8YFLogxK
U2 - 10.4209/aaqr.220128
DO - 10.4209/aaqr.220128
M3 - Article
AN - SCOPUS:85134894153
SN - 1680-8584
VL - 22
JO - Aerosol and Air Quality Research
JF - Aerosol and Air Quality Research
IS - 8
M1 - 220128
ER -
