气候变化领域集成服务门户(CCPortal): High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak

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DOI	10.1016/j.atmosenv.2020.117947
	High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak
	Chatterjee A.; Mukherjee S.; Dutta M.; Ghosh A.; Ghosh S.K.; Roy A.
发表日期	2021
ISSN	1352-2310
卷号	244
英文摘要	The present study has been conducted to investigate the relative changes of carbonaceous aerosols (CA) over a high altitude Himalayan atmosphere with and without (very low) anthropogenic emissions. Measurements of atmospheric organic (OC) and elemental carbon (EC) were conducted during the lockdown period (April 2020) due to global COVID 19 outbreak and compared with the normal period (April 2019). The interesting, unexpected and surprising observation is that OC, EC and the total CA (TCA) during the lockdown (OC: 12.1 ± 5.5 μg m−3; EC: 2.2 ± 1.1 μg m−3; TCA: 21.5 ± 10 μg m−3) were higher than the normal period (OC: 7.04 ± 2.2 μg m−3; EC: 1.9 ± 0.7 μg m−3; TCA: 13.2 ± 4.1 μg m−3). The higher values for OC/EC ratio too was observed during the lockdown (5.7 ± 0.9) compared to the normal period (4.2 ± 1.1). Much higher surface O3 during the lockdown (due to very low NO) could better promote the formation of secondary OC (SOC) through the photochemical oxidation of biogenic volatile organic compounds (BVOCs) emitted from Himalayan coniferous forest cover. SOC during the lockdown (7.6 ± 3.5 μg m−3) was double of that in normal period (3.8 ± 1.4 μg m−3). Regression analysis between SOC and O3 showed that with the same amount of increase in O3, the SOC formation increased to a larger extent when anthropogenic emissions were very low and biogenic emissions dominate (lockdown) compared to when anthropogenic emissions were high (normal). Concentration weighted trajectory (CWT) analysis showed that the anthropogenic activities over Nepal and forest fire over north-east India were the major long-distant sources of the CA over Darjeeling during the normal period. On the other hand, during lockdown, the major source regions of CA over Darjeeling were regional/local. The findings of the study indicate the immense importance of Himalayan biosphere as a major source of organic carbon. © 2020 Elsevier Ltd
关键词	Biogenic VOC Carbonaceous aerosols Eastern himalaya Secondary organic carbon
语种	英语
scopus关键词	Aerosols; Deforestation; Regression analysis; Volatile organic compounds; Anthropogenic activity; Anthropogenic emissions; Biogenic emission; Biogenic volatile organic compounds; Carbonaceous aerosol; Coniferous forests; North- East India; Photochemical oxidation; Organic carbon; beta pinene; biofuel; carbon; fossil fuel; limonene; monoterpene; nitrogen oxide; nitrous oxide; organic carbon; ozone; pinene; volatile organic compound; aerosol; anthropogenic effect; biosphere; coniferous forest; elemental carbon; forest fire; organic carbon; oxidation; trajectory; aerosol; air sampling; Article; atmosphere; biomass; biosphere; carbonaceous aerosol; circadian rhythm; climate; combustion; coronavirus disease 2019; forest; forest fire; geographic distribution; human; India; isolation; lockdown; measurement; meteorology; photooxidation; priority journal; quarantine; regression analysis; urban area; Darjeeling; Himalayas; India; Nepal; West Bengal
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248809
作者单位	Environmental Sciences Section, Bose Institute, P 1/12 CIT Scheme VIIM, Kolkata, 700054, India
推荐引用方式 GB/T 7714	Chatterjee A.,Mukherjee S.,Dutta M.,et al. High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak[J],2021,244.
APA	Chatterjee A.,Mukherjee S.,Dutta M.,Ghosh A.,Ghosh S.K.,&Roy A..(2021).High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak.ATMOSPHERIC ENVIRONMENT,244.
MLA	Chatterjee A.,et al."High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak".ATMOSPHERIC ENVIRONMENT 244(2021).