Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China

Isobel J. Simpson, Tao Wang, Hai Guo, Y. H. Kwok, Frank Flocke, Elliot L Atlas, Simone Meinardi, F. Sherwood Rowland, Donald R. Blake

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Mixing ratios of seven C1-C5 alkyl nitrates (RONO2) were measured during a 16-month study (August 2001-December 2002) at Tai O, a coastal site 30 km west of central Hong Kong in the Pearl River Delta, the fastest-growing industrial region in the world. The C 3-C4 (rather than C1-C2) RONO 2 were most abundant throughout the study, showing the importance of photochemical (rather than marine) RONO2 production in the sampled air. A lack of methyl nitrate (MeONO2) enhancement during summer, when the prevailing winds are from the ocean, indicates that the South China Sea is not a region of strong RONO2 emissions. By contrast, MeONO 2 levels during pollution episodes (up to 25 parts per trillion by volume (pptv)) were the highest that our group has recorded during urban photochemical RONO2 production, as opposed to marine emissions or biomass burning. The highest summed RONO2 level of the study (204 pptv) was measured in the afternoon of 7 November 2002, during an intense pollution episode that captured the highest ozone (O3) level ever recorded in Hong Kong (203 ppbv). During pollution episodes, the average ratio of O3 to summed RONO2 was roughly 1000:1 in freshly polluted air (ethyne/CO∼3-5 pptv/ppbv) and 500:1 in very freshly polluted air (ethyne/CO∼6-8 pptv/ppbv). Ozone and RONO2 share a common photochemical source, and their good correlation in pollution plumes shows that RONO2 can be used as a tracer of photochemical O3 production. Even MeONO2 showed similar diurnal variations as the C2-C5 RONO2, indicating a strong photochemical source despite its very slow photochemical production from methane oxidation. The decomposition of longer-chain alkoxy radicals also does not explain the high MeONO2 levels, and rough calculations show that methoxy radical reaction with NO2 appears to be a viable alternate pathway for MeONO2 production in polluted atmospheres, though further measurements and modeling are required to confirm this mechanism.

Original languageEnglish (US)
Pages (from-to)1619-1632
Number of pages14
JournalAtmospheric Environment
Volume40
Issue number9
DOIs
StatePublished - Mar 2006

Fingerprint

Nitrates
Rivers
nitrate
Pollution
pollution
river
air
Ozone
ozone
Air
biomass burning
mixing ratio
diurnal variation
plume
methane
tracer
decomposition
Methane
Biomass
oxidation

Keywords

  • Alkyl nitrates
  • China
  • Ozone
  • Photochemistry
  • Urban pollution

ASJC Scopus subject areas

  • Atmospheric Science
  • Environmental Science(all)
  • Pollution

Cite this

Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China. / Simpson, Isobel J.; Wang, Tao; Guo, Hai; Kwok, Y. H.; Flocke, Frank; Atlas, Elliot L; Meinardi, Simone; Rowland, F. Sherwood; Blake, Donald R.

In: Atmospheric Environment, Vol. 40, No. 9, 03.2006, p. 1619-1632.

Research output: Contribution to journalArticle

Simpson, IJ, Wang, T, Guo, H, Kwok, YH, Flocke, F, Atlas, EL, Meinardi, S, Rowland, FS & Blake, DR 2006, 'Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China', Atmospheric Environment, vol. 40, no. 9, pp. 1619-1632. https://doi.org/10.1016/j.atmosenv.2005.10.062
Simpson, Isobel J. ; Wang, Tao ; Guo, Hai ; Kwok, Y. H. ; Flocke, Frank ; Atlas, Elliot L ; Meinardi, Simone ; Rowland, F. Sherwood ; Blake, Donald R. / Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China. In: Atmospheric Environment. 2006 ; Vol. 40, No. 9. pp. 1619-1632.
@article{6c130c6f5c63456693366ea891b021ac,
title = "Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China",
abstract = "Mixing ratios of seven C1-C5 alkyl nitrates (RONO2) were measured during a 16-month study (August 2001-December 2002) at Tai O, a coastal site 30 km west of central Hong Kong in the Pearl River Delta, the fastest-growing industrial region in the world. The C 3-C4 (rather than C1-C2) RONO 2 were most abundant throughout the study, showing the importance of photochemical (rather than marine) RONO2 production in the sampled air. A lack of methyl nitrate (MeONO2) enhancement during summer, when the prevailing winds are from the ocean, indicates that the South China Sea is not a region of strong RONO2 emissions. By contrast, MeONO 2 levels during pollution episodes (up to 25 parts per trillion by volume (pptv)) were the highest that our group has recorded during urban photochemical RONO2 production, as opposed to marine emissions or biomass burning. The highest summed RONO2 level of the study (204 pptv) was measured in the afternoon of 7 November 2002, during an intense pollution episode that captured the highest ozone (O3) level ever recorded in Hong Kong (203 ppbv). During pollution episodes, the average ratio of O3 to summed RONO2 was roughly 1000:1 in freshly polluted air (ethyne/CO∼3-5 pptv/ppbv) and 500:1 in very freshly polluted air (ethyne/CO∼6-8 pptv/ppbv). Ozone and RONO2 share a common photochemical source, and their good correlation in pollution plumes shows that RONO2 can be used as a tracer of photochemical O3 production. Even MeONO2 showed similar diurnal variations as the C2-C5 RONO2, indicating a strong photochemical source despite its very slow photochemical production from methane oxidation. The decomposition of longer-chain alkoxy radicals also does not explain the high MeONO2 levels, and rough calculations show that methoxy radical reaction with NO2 appears to be a viable alternate pathway for MeONO2 production in polluted atmospheres, though further measurements and modeling are required to confirm this mechanism.",
keywords = "Alkyl nitrates, China, Ozone, Photochemistry, Urban pollution",
author = "Simpson, {Isobel J.} and Tao Wang and Hai Guo and Kwok, {Y. H.} and Frank Flocke and Atlas, {Elliot L} and Simone Meinardi and Rowland, {F. Sherwood} and Blake, {Donald R.}",
year = "2006",
month = "3",
doi = "10.1016/j.atmosenv.2005.10.062",
language = "English (US)",
volume = "40",
pages = "1619--1632",
journal = "Atmospheric Environment",
issn = "1352-2310",
publisher = "Pergamon Press Ltd.",
number = "9",

}

TY - JOUR

T1 - Long-term atmospheric measurements of C1-C5 alkyl nitrates in the Pearl River Delta region of southeast China

AU - Simpson, Isobel J.

AU - Wang, Tao

AU - Guo, Hai

AU - Kwok, Y. H.

AU - Flocke, Frank

AU - Atlas, Elliot L

AU - Meinardi, Simone

AU - Rowland, F. Sherwood

AU - Blake, Donald R.

PY - 2006/3

Y1 - 2006/3

N2 - Mixing ratios of seven C1-C5 alkyl nitrates (RONO2) were measured during a 16-month study (August 2001-December 2002) at Tai O, a coastal site 30 km west of central Hong Kong in the Pearl River Delta, the fastest-growing industrial region in the world. The C 3-C4 (rather than C1-C2) RONO 2 were most abundant throughout the study, showing the importance of photochemical (rather than marine) RONO2 production in the sampled air. A lack of methyl nitrate (MeONO2) enhancement during summer, when the prevailing winds are from the ocean, indicates that the South China Sea is not a region of strong RONO2 emissions. By contrast, MeONO 2 levels during pollution episodes (up to 25 parts per trillion by volume (pptv)) were the highest that our group has recorded during urban photochemical RONO2 production, as opposed to marine emissions or biomass burning. The highest summed RONO2 level of the study (204 pptv) was measured in the afternoon of 7 November 2002, during an intense pollution episode that captured the highest ozone (O3) level ever recorded in Hong Kong (203 ppbv). During pollution episodes, the average ratio of O3 to summed RONO2 was roughly 1000:1 in freshly polluted air (ethyne/CO∼3-5 pptv/ppbv) and 500:1 in very freshly polluted air (ethyne/CO∼6-8 pptv/ppbv). Ozone and RONO2 share a common photochemical source, and their good correlation in pollution plumes shows that RONO2 can be used as a tracer of photochemical O3 production. Even MeONO2 showed similar diurnal variations as the C2-C5 RONO2, indicating a strong photochemical source despite its very slow photochemical production from methane oxidation. The decomposition of longer-chain alkoxy radicals also does not explain the high MeONO2 levels, and rough calculations show that methoxy radical reaction with NO2 appears to be a viable alternate pathway for MeONO2 production in polluted atmospheres, though further measurements and modeling are required to confirm this mechanism.

AB - Mixing ratios of seven C1-C5 alkyl nitrates (RONO2) were measured during a 16-month study (August 2001-December 2002) at Tai O, a coastal site 30 km west of central Hong Kong in the Pearl River Delta, the fastest-growing industrial region in the world. The C 3-C4 (rather than C1-C2) RONO 2 were most abundant throughout the study, showing the importance of photochemical (rather than marine) RONO2 production in the sampled air. A lack of methyl nitrate (MeONO2) enhancement during summer, when the prevailing winds are from the ocean, indicates that the South China Sea is not a region of strong RONO2 emissions. By contrast, MeONO 2 levels during pollution episodes (up to 25 parts per trillion by volume (pptv)) were the highest that our group has recorded during urban photochemical RONO2 production, as opposed to marine emissions or biomass burning. The highest summed RONO2 level of the study (204 pptv) was measured in the afternoon of 7 November 2002, during an intense pollution episode that captured the highest ozone (O3) level ever recorded in Hong Kong (203 ppbv). During pollution episodes, the average ratio of O3 to summed RONO2 was roughly 1000:1 in freshly polluted air (ethyne/CO∼3-5 pptv/ppbv) and 500:1 in very freshly polluted air (ethyne/CO∼6-8 pptv/ppbv). Ozone and RONO2 share a common photochemical source, and their good correlation in pollution plumes shows that RONO2 can be used as a tracer of photochemical O3 production. Even MeONO2 showed similar diurnal variations as the C2-C5 RONO2, indicating a strong photochemical source despite its very slow photochemical production from methane oxidation. The decomposition of longer-chain alkoxy radicals also does not explain the high MeONO2 levels, and rough calculations show that methoxy radical reaction with NO2 appears to be a viable alternate pathway for MeONO2 production in polluted atmospheres, though further measurements and modeling are required to confirm this mechanism.

KW - Alkyl nitrates

KW - China

KW - Ozone

KW - Photochemistry

KW - Urban pollution

UR - http://www.scopus.com/inward/record.url?scp=32044448545&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=32044448545&partnerID=8YFLogxK

U2 - 10.1016/j.atmosenv.2005.10.062

DO - 10.1016/j.atmosenv.2005.10.062

M3 - Article

AN - SCOPUS:32044448545

VL - 40

SP - 1619

EP - 1632

JO - Atmospheric Environment

JF - Atmospheric Environment

SN - 1352-2310

IS - 9

ER -