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DOI	10.5194/acp-19-5615-2019
	Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons
	Brooks J.; Allan J.D.; Williams P.I.; Liu D.; Fox C.; Haywood J.; Langridge J.M.; Highwood E.J.; Kompalli S.K.; O'Sullivan D.; Babu S.S.; Satheesh S.K.; Turner A.G.; Coe H.
发表日期	2019
ISSN	16807316
起始页码	5615
结束页码	5634
卷号	19 期号:8
英文摘要	The vertical distribution in the physical and chemical properties of submicron aerosol has been characterised across northern India for the first time using airborne in situ measurements. This study focusses primarily on the Indo-Gangetic Plain, a low-lying area in the north of India which commonly experiences high aerosol mass concentrations prior to the monsoon season. Data presented are from the UK Facility for Airborne Atmospheric Measurements BAe-146 research aircraft that performed flights in the region during the 2016 pre-monsoon (11 and 12 June) and monsoon (30 June to 11 July) seasons. Inside the Indo-Gangetic Plain boundary layer, organic matter dominated the submicron aerosol mass (43 %) followed by sulfate (29 %), ammonium (14 %), nitrate (7 %) and black carbon (7 %). However, outside the Indo-Gangetic Plain, sulfate was the dominant species, contributing 44% to the total submicron aerosol mass in the boundary layer, followed by organic matter (30 %), ammonium (14 %), nitrate (6 %) and black carbon (6 %). Chlorine mass concentrations were negligible throughout the campaign. Black carbon mass concentrations were higher inside the Indo-Gangetic Plain (2 μgm-3) compared to outside (1 μgm-3). Nitrate appeared to be controlled by thermodynamic processes, with increased mass concentration in conditions of lower temperature and higher relative humidity. Increased mass and number concentrations were observed inside the Indo-Gangetic Plain and the aerosol was more absorbing in this region, whereas outside the Indo-Gangetic Plain the aerosol was larger in size and more scattered in nature, suggesting greater dust presence, especially in north-western India. The aerosol composition remained largely similar as the monsoon season progressed, but the total aerosol mass concentrations decreased by 50% as the rainfall arrived; the pre-monsoon average total mass concentration was 30 μgm-3 compared to a monsoon average total mass concentration of 10-20 μgm-3. However, this mass concentration decrease was less noteworthy (20 %-30 %) over the Indo-Gangetic Plain, likely due to the strength of emission sources in this region. Decreases occurred in coarse mode aerosol, with the fine mode fraction increasing with monsoon arrival. In the aerosol vertical profile, inside the Indo-Gangetic Plain during the pre-monsoon, organic aerosol and absorbing aerosol species dominated in the lower atmosphere (< 1:5 km), with sulfate, dust and other scattering aerosol species enhanced in an elevated aerosol layer above 1.5 km with maximum aerosol height 6 km. The elevated concentration of dust at altitudes < 1:5 km isa clear indication of dust transport from the Great Indian Desert, also called the Thar Desert, in north-western India. As the monsoon progressed into this region, the elevated aerosol layer diminished, the aerosol maximum height reduced to-2 km. The dust and sulfate-dominated aerosol layer aloft was removed upon monsoon arrival, highlighted by an increase in fine mode fraction throughout the profile. © Author(s) 2019.
语种	英语
scopus关键词	aerosol; atmospheric chemistry; boundary layer; chemical composition; concentration (composition); in situ measurement; monsoon; organic matter; spatial distribution; Gangetic Plain; India
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144454
作者单位	Centre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, United Kingdom; National Centre for Atmospheric Science, Manchester, United Kingdom; Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Observation Based Research, Met Office, Exeter, United Kingdom; College of Engineering, Mathematics and Physical Sciences, Exeter, United Kingdom; Department of Meteorology, University of Reading, Reading, United Kingdom; Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvanathapuram, Kerala, India; Centre for Atmospheric and Oceanic Sciences of Science, Bengaluru, India
推荐引用方式 GB/T 7714	Brooks J.,Allan J.D.,Williams P.I.,et al. Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons[J],2019,19(8).
APA	Brooks J..,Allan J.D..,Williams P.I..,Liu D..,Fox C..,...&Coe H..(2019).Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons.Atmospheric Chemistry and Physics,19(8).
MLA	Brooks J.,et al."Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons".Atmospheric Chemistry and Physics 19.8(2019).