Impact of biogenic VOC emissions on a tropical cyclone-related ozone episode in the Pearl River Delta region, China

X. L. Wei, Yok Sheung Li, Ka Se Lam, A. Y. Wang, T. J. Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

58 Citations (Scopus)

Abstract

For quantitative estimate of biogenic volatile organic compound emissions (BVOCs) in South China and their impact on the regional atmospheric chemistry, a 3-day tropical cyclone-related ozone episode was modeled using chemical transport model CMAQ, which was driven by the mesoscale meteorological model MM5. Hourly biogenic emission inventories were constructed using the Sparse Matrix Operator Kernel Emissions (SMOKE) model. The simulation results show good agreement with observation data in air temperature, ozone and NOxlevels. The estimated biogenic emissions of isoprene, terpene, and other reactive VOCs (ORVOCs) during this tropical cyclone-related episode are 8500, 3400, and 11 300 ton day-1, respectively. The ratio of isoprene to the total BVOCs was 36.4%. Two test runs were carried out with one incorporated biogenic emissions and the other without. The simulations show that Guangdong province, particularly the Pearl River Delta (PRD) region, was the area most reactive to biogenic emissions in South China. More ozone was produced in all layers under 1500 m when biogenic emissions were included in comparison to that without BVOCs. The net formation of ozone from 9:00 to 15:00 h was the highest near the surface and could reach 38 ppb, which include 4 ppb attributed to biogenic impact. The enhanced ozone due to biogenic emissions first appeared in the PRD region and slowly spread to a greater area in South China. Process analysis indicated that the surface ozone budget was dominated by the vertical transport and dry deposition. The horizontal transport and gas-phase chemical production were relatively small in the surface layer. Presumably, ozone was produced in upper layers within the atmospheric boundary layer and convected down to surface where it is destroyed. When BVOCs was included, apart from the enhancement of gas-phase chemical production of ozone, both the surface deposition and vertical transport were also augmented.
Original languageEnglish
Pages (from-to)7851-7864
Number of pages14
JournalAtmospheric Environment
Volume41
Issue number36
DOIs
Publication statusPublished - 1 Nov 2007

Keywords

  • Air modeling
  • Biogenic emissions
  • Ozone episode
  • The Pearl River Delta region
  • Tropical cyclone

ASJC Scopus subject areas

  • Atmospheric Science
  • Environmental Science(all)
  • Pollution

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