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您的检索式:作者名="Guixiong Liang"
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| 1 | WRF/CHEM modeling of impacts of weather conditions modified by urban expansion on secondary organic aerosol formation over Pearl River Delta显示文摘In this paper,the online Weather Research and Forecasting and Chemistry (WRF/CHEM) model,coupled with urban canopy (UCM) and biogenic-emission models,is used to explore impacts of urban expansion on secondary organic aerosols (SOA) formation. Two scenarios of urban maps are used in WRF/CHEM to represent early 1990s (pre-urbanization) and current urban distribution in the Pearl River Delta (PRD). Month-long simulation results using the above land-use scenarios for March 2001 show:(1) urbanization can increase monthly averaged temperatures by about 0.63 ?C,decrease monthly averaged 10-m wind speeds by 38%,increase monthly averaged boundary-layer depths by 80 m,and decrease monthly aver-aged water mixing ratio by 0.2 g/kg. (2) Changes in meteorological conditions can result in detectable concentration changes of NOx,VOC,O3 and NO3 radicals. Urbanization decreases surface NOx and VOC concentrations by a maximum of 4 ppbv and 1.5 ppbv,respectively. Surface O3 and NO3 radical concen-trations over major cities increase by about 2-4 ppbv and 4-12 pptv,respectively; areas with increasing O3 and NO3 radical concentrations generally coincide with the areas of temperature increase and wind speed reduction where NOx and VOC decrease. (3) Urbanization can induce 9% increase of SOA in Foshan,Zhongshan and west Guangzhou and 3% decrease in Shenzhen and Dongguan. Over PRD major cities,SOA from Aitken mode reduces by 30% but with more than 70% SOA from accumulate mode. Urbanization has stronger influence on SOA formation from Aitken mode. (4) Over the PRD,55-65% SOA comes from aromatics precursors. Urbanization has strongest influence on aromatics precursors to produce SOA (14% increase),while there is less influence on alkane precursors. Alkene precursors have negative contribution to SOA formation under urbanization situation. | Xuemei Wang Zhiyong Wu Guixiong Liang | 2009 | Particuology2009,7,5: | 25 |
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