Biogenic and anthropogenic sources of isoprene and monoterpenes and theirsecondary organic aerosol in Delhi, India

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F23%3A00567429" target="_blank" >RIV/61388955:_____/23:00567429 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0347419" target="_blank" >https://hdl.handle.net/11104/0347419</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/acp-23-61-2023" target="_blank" >10.5194/acp-23-61-2023</a>

Result language

angličtina

Original language name

Biogenic and anthropogenic sources of isoprene and monoterpenes and theirsecondary organic aerosol in Delhi, India

Original language description

Isoprene and monoterpene emissions to the atmosphere are generally dominated by biogenic sources. The oxidation of these compounds can lead to the production of secondary organic aerosol, however the impact of this chemistry in polluted urban settings has been poorly studied. Isoprene and monoterpenes can form secondary organic aerosol (SOA) heterogeneously via anthropogenic-biogenic interactions, resulting in the formation of organosulfate (OS) and nitrooxy-organosulfate (NOS) species. Delhi, India, is one of the most polluted cities in the world, but little is known about the emissions of biogenic volatile organic compounds (VOCs) or the sources of SOA. As part of the DELHI-FLUX project, gas-phase mixing ratios of isoprene and speciated monoterpenes were measured during pre- and post-monsoon measurement campaigns in central Delhi. Nocturnal mixing ratios of the VOCs were substantially higher during the post-monsoon (isoprene: (0.65 +/- 0.43) ppbv, limonene: (0.59 +/- 0.11) ppbv, alpha-pinene: (0.13 +/- 0.12) ppbv) than the pre-monsoon (isoprene: (0.13 +/- 0.18) ppbv, limonene: 0.011 +/- 0.025 (ppbv), alpha-pinene: 0.033 +/- 0.009) period. At night, isoprene and monoterpene concentrations correlated strongly with CO during the post-monsoon period. Filter samples of particulate matter less than 2.5 mu m in diameter (PM2.5) were collected and the OS and NOS content analysed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS2). Inorganic sulfate was shown to facilitate the formation of isoprene OS species across both campaigns. Sulfate contained within OS and NOS species was shown to contribute significantly to the sulfate signal measured via AMS. Strong nocturnal enhancements of NOS species were observed across both campaigns. The total concentration of OS and NOS species contributed an average of (2.0 +/- 0.9) % and (1.8 +/- 1.4) % to the total oxidized organic aerosol and up to a maximum of 4.2 % and 6.6 % across the pre- and post-monsoon periods, respectively. Overall, this study provides the first molecular-level measurements of SOA derived from isoprene and monoterpene in Delhi and demonstrates that both biogenic and anthropogenic sources of these compounds can be important in urban areas.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Atmospheric Chemistry and Physics

ISSN

1680-7316

e-ISSN

1680-7324

Volume of the periodical

23

Issue of the periodical within the volume

1

Country of publishing house

DE - GERMANY

Number of pages

23

Pages from-to

61-83

UT code for WoS article

000906754100001

EID of the result in the Scopus database

2-s2.0-85147288646