scholarly journals Observationally-constrained carbonaceous aerosol source estimates for the Pearl River Delta area of China

2015 ◽  
Vol 15 (22) ◽  
pp. 33583-33629 ◽  
Author(s):  
N. Li ◽  
T.-M. Fu ◽  
J. J. Cao ◽  
J. Y. Zheng ◽  
Q. Y. He ◽  
...  
Keyword(s):  
Pearl River Delta ◽  
River Delta ◽  
Carbonaceous Aerosol ◽  
Pearl River ◽  
Aerosol Formation ◽  
Top Down ◽  
Secondary Sources ◽  
The Pearl River Delta ◽  
Emission Estimate ◽  
The Pearl River

Abstract. We simulated elemental carbon (EC) and organic carbon (OC) aerosols over the Pearl River Delta (PRD) area of China and compared the results to seasonal surface measurements, with the aim of quantifying carbonaceous aerosol sources from a "top-down" perspective. Our regional model was driven by current-best estimates of PRD EC (39.5 Gg C yr−1) and OC (32.8 Gg C yr−1) emissions and included updated secondary organic aerosol formation pathways. The simulated annual mean EC and OC concentrations were 4.0 and 7.7 μg C m−3, respectively, lower than the observed annual mean EC and OC concentrations (4.5 and 13.1 μg C m−3, respectively). We used multiple regression to match the simulated EC against seasonal mean observations. The resulting top-down estimate for EC emission in the PRD area was 52.9 ± 8.0 Gg C yr−1. We estimated the OC emission in the PRD area to be 60.2 ± 10.3 Gg C yr−1, based on the top-down EC emission estimate and the primary OC / EC ratios derived from bottom-up statistics. Using these top-down emission estimates, the simulated average annual mean EC and OC concentrations were improved to 4.4 and 9.5 μg C m−3, respectively, closer to the observations. Secondary sources accounted for 42 % of annual mean surface OC in our top-down simulations, with biogenic VOCs being the most important precursors.

scholarly journals Dramatic increase of reactive VOC emission from ships at berth after implementing the fuel switch policy in the Pearl River Delta Emission Control Area

2019 ◽  
Author(s):  
Zhenfeng Wu ◽  
Yanli Zhang ◽  
Junjie He ◽  
Hongzhan Chen ◽  
Xueliang Huang ◽  
...  
Keyword(s):  
South China ◽  
Pearl River Delta ◽  
Carbon Number ◽  
Emission Control ◽  
River Delta ◽  
Pearl River ◽  
Aerosol Formation ◽  
Ship Emissions ◽  
The Pearl River Delta ◽  
The Pearl River

Abstract. Limiting the fuel sulfur content (FSC) is a widely adopted approach to reduce ship emissions of sulfur dioxide (SO2) and particulate matters (PM) particularly in emission control areas (ECA), but its impact on the emission of volatile organic compounds (VOCs) is still not well understood. In this study, emissions from ships at berth in Guangzhou, south China, were characterized before and after implementing the fuel switch policy with a FSC limit of 0.5 % in the Pearl River Delta ECA in south China. After implementing the fuel switch policy, the emission factors (EFs) of SO2 and PM2.5 for coastal vessels dropped by 78 % and 56 % on average, respectively; the EFs of non-methane hydrocarbons (NMHCs), however, reached 1807 ± 1746 mg/kg, about 15 times that of 118 ± 56.1 mg/kg before implementing the new policy. This dramatic increase in the emission of NMHCs might be largely due to the replacement of high-sulfur residual fuel oil with low-sulfur diesel or heavy oils, which are typically more rich in short-chain hydrocarbons. Moreover, reactive alkenes overtook alkanes to become the dominant group among NMHCs and low carbon number NMHCs, such as ethylene, propene and isobutane, became the dominant species after the new policy. As a result of the largely elevated EFs of reactive alkenes and aromatics after the new policy, for per kilogram of fuel burned, emitted NMHCs had nearly 29 times larger ozone formation potentials (OFPs) and about 2 times higher secondary organic aerosol formation potentials (SOAFPs). Unlike coastal vessels, river vessels in the region used diesel fuels all along and were not affected by the fuel switch policy, but their EFs of NMHCs were even 90 % larger than that of coastal vessels after implementing the new policy, with about 120 % larger fuel-based OFPs and 70–140 % larger SOAFPs. The results from this study suggest that while the fuel switch policy could effectively reduce SO2 and PM emissions and thus help combat PM2.5 pollution, it would also lead to greater emissions of reactive VOCs, that may threatens ozone pollution control in the harbor cities. This change for coastal or ocean-going vessels, along with the large amounts of reactive VOCs from river vessels, raises regulatory concerns for ship emissions of reactive VOCs.

Sources of excess urban carbonaceous aerosol in the Pearl River Delta Region, China

2011 ◽  
Vol 45 (5) ◽  
pp. 1175-1182 ◽  
Author(s):  
Mei Zheng ◽  
Fu Wang ◽  
G.S.W. Hagler ◽  
Ximei Hou ◽  
Michael Bergin ◽  
...  
Keyword(s):  
Pearl River Delta ◽  
River Delta ◽  
Carbonaceous Aerosol ◽  
Pearl River ◽  
Pearl River Delta Region ◽  
Delta Region ◽  
The Pearl River Delta ◽  
The Pearl River

scholarly journals Dramatic increase in reactive volatile organic compound (VOC) emissions from ships at berth after implementing the fuel switch policy in the Pearl River Delta Emission Control Area

2020 ◽  
Vol 20 (4) ◽  
pp. 1887-1900 ◽  
Author(s):  
Zhenfeng Wu ◽  
Yanli Zhang ◽  
Junjie He ◽  
Hongzhan Chen ◽  
Xueliang Huang ◽  
...  
Keyword(s):  
Pearl River Delta ◽  
Emission Control ◽  
River Delta ◽  
Pearl River ◽  
Aerosol Formation ◽  
Ship Emissions ◽  
Formation Potential ◽  
The Pearl River Delta ◽  
Volatile Organic ◽  
The Pearl River

Abstract. Limiting fuel sulfur content (FSC) is a widely adopted approach for reducing ship emissions of sulfur dioxide (SO2) and particulate matter (PM), particularly in emission control areas (ECAs), but its impact on the emissions of volatile organic compounds (VOCs) is still not well understood. In this study, emissions from ships at berth in Guangzhou, southern China, were characterized before and after the implementation of the fuel switch policy (IFSP) with an FSC limit of 0.5 % in the Pearl River Delta ECA (ECA-PRD). After IFSP, the emission factors (EFs) of SO2 and PM2.5 for the coastal vessels decreased by 78 % and 56 % on average, respectively; however, the EFs of the VOCs were 1807±1746 mg kg−1, approximately 15 times that of 118±56.1 mg kg−1 before IFSP. This dramatic increase in the emissions of the VOCs might have been largely due to the replacement of high-sulfur residual fuel oil with low-sulfur diesel or heavy oils, which are typically richer in short-chain hydrocarbons. Moreover, reactive alkenes surpassed alkanes to become the dominant group among the VOCs, and low-carbon-number VOCs, such as ethylene, propene and isobutane, became the dominant species after IFSP. As a result of the largely elevated EFs of the reactive alkenes and aromatics after IFSP, the emitted VOCs per kilogram of fuel burned had nearly 29 times greater ozone formation potential (OFP) and approximately 2 times greater secondary organic aerosol formation potential (SOAFP) than those before IFSP. Unlike the coastal vessels, the river vessels in the region used diesel fuels consistently and were not affected by the fuel switch policy, but the EFs of their VOCs were 90 % greater than those of the coastal vessels after IFSP, with approximately 120 % greater fuel-based OFP and 70 %–140 % greater SOAFP. The results from this study suggest that while the fuel switch policy could effectively reduce SO2 and PM emissions, and thus help control PM2.5 pollution, it will also lead to greater emissions of reactive VOCs, which may threaten ozone pollution control in harbor cities. This change for coastal or ocean-going vessels, in addition to the large amounts of reactive VOCs from the river vessels, raises regulatory concerns for ship emissions of reactive VOCs.

scholarly journals Top-down estimates of benzene and toluene emissions in the Pearl River Delta and Hong Kong, China

2016 ◽  
Vol 16 (5) ◽  
pp. 3369-3382 ◽  
Author(s):  
Xuekun Fang ◽  
Min Shao ◽  
Andreas Stohl ◽  
Qiang Zhang ◽  
Junyu Zheng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Pearl River Delta ◽  
River Delta ◽  
Pollutant Emissions ◽  
Rural Site ◽  
Pearl River ◽  
Top Down ◽  
Bottom Up ◽  
The Pearl River Delta ◽  
The Pearl River

Abstract. Benzene (C6H6) and toluene (C7H8) are toxic to humans and the environment. They are also important precursors of ground-level ozone and secondary organic aerosols and contribute substantially to severe air pollution in urban areas in China. Discrepancies exist between different bottom-up inventories for benzene and toluene emissions in the Pearl River Delta (PRD) and Hong Kong (HK), which are emission hot spots in China. This study provides top-down estimates of benzene and toluene emissions in the PRD and HK using atmospheric measurement data from a rural site in the area, Heshan, an atmospheric transport model, and an inverse modeling method. The model simulations captured the measured mixing ratios during most pollution episodes. For the PRD and HK, the benzene emissions estimated in this study for 2010 were 44 (12–75) and 5 (2–7) Gg yr−1 for the PRD and HK, respectively, and the toluene emissions were 131 (44–218) and 6 (2–9) Gg yr−1, respectively. Temporal and spatial differences between the inversion estimate and four different bottom-up emission estimates are discussed, and it is proposed that more observations at different sites are urgently needed to better constrain benzene and toluene (and other air pollutant) emissions in the PRD and HK in the future.

EVOLUTION OF SEDIMENTARY FACIES AND PALEOENVIRONMENT DURING THE LATE QUATERNARY IN WANQINGSHA AREA OF THE PEARL RIVER DELTA

2010 ◽  
Vol 29 (6) ◽  
pp. 35-42
Author(s):  
Jianhua WANG ◽  
Linglong CAO ◽  
Xiaojing WANG ◽  
Xiaoqiang YANG ◽  
Jie YANG ◽  
...  
Keyword(s):  
Pearl River Delta ◽  
Late Quaternary ◽  
Sedimentary Facies ◽  
River Delta ◽  
Pearl River ◽  
The Pearl River Delta ◽  
The Pearl River
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