title: Molecular Markers of Secondary Organic Aerosol in Mumbai, India.
abstract: Biogenic secondary organic aerosols (SOA) are generally considered to be more abundant in summer than in winter. Here, polar organic marker compounds in urban background aerosols from Mumbai were measured using gas chromatography-mass spectrometry. Surprisingly, we found that concentrations of biogenic SOA tracers at Mumbai were several times lower in summer (8-14 June 2006; wet season; n = 14) than in winter (13-18 February 2007; dry season; n = 10). Although samples from less than 10% of the season are extrapolated to the full season, such seasonality may be explained by the predominance of the southwest summer monsoon, which brings clean marine air masses to Mumbai. While heavy rains are an important contributor to aerosol removal during the monsoon season, meteorological data (relative humidity and T) suggest no heavy rains occurred during our sampling period. However, in winter, high levels of SOA and their day/night differences suggest significant contributions of continental aerosols through long-range transport together with local sources. The winter/summer pattern of SOA loadings was further supported by results from chemical transport models (NAQPMS and GEOS-Chem). Furthermore, our study suggests that monoterpene- and sesquiterpene-derived secondary organic carbon (SOC) were more significant than those of isoprene- and toluene-SOC at Mumbai.
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.|Institute of Low Temperature Science, Hokkaido University , Sapporo 060-0819, Japan.
authors.forename: Pingqing
authors.initials: P
authors.lastname: Fu
authors.affiliation: Institute of Low Temperature Science, Hokkaido University , Sapporo 060-0819, Japan.|CSIR-National Physical Laboratory, New Delhi 110012, India.
authors.forename: Shankar G
authors.initials: SG
authors.lastname: Aggarwal
authors.affiliation: SKLEG, Institute of Geochemistry, Chinese Academy of Sciences , Guiyang 550081, China.|Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.
authors.forename: Yele
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.
authors.forename: Zifa
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.
authors.forename: Huansheng
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, China.|School of Environmental Science and Engineering, Nanjing University of Information Science & Technology , Nanjing 210044, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liao
authors.affiliation: Institute for Climate and Global Change Research & School of Atmospheric Sciences, Nanjing University , Nanjing, 210093, China.
authors.forename: Aijun
authors.initials: A
authors.lastname: Ding
authors.affiliation: Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay , Mumbai, 400076, India.
authors.forename: G S
authors.initials: GS
authors.lastname: Umarji
authors.affiliation: Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay , Mumbai, 400076, India.
authors.forename: R S
authors.initials: RS
authors.lastname: Patil
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Institute of Low Temperature Science, Hokkaido University , Sapporo 060-0819, Japan.
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kawamura
mesh_terms: D000336:Aerosols; D000393:Air Pollutants; D002244:Carbon; D008401:Gas Chromatography-Mass Spectrometry; D007194:India; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D002244:Carbon