西安是关中盆地经济发展的核心城市,特殊的地形和工业发展导致冬季细颗粒物(PM2.5)污染严重,制定科学合理的治理措施迫切需要明确PM2.5的来源.本文基于空气质量模式CAMx(Comprehensive Air Quality Model with extensions)、颗粒物源解...西安是关中盆地经济发展的核心城市,特殊的地形和工业发展导致冬季细颗粒物(PM2.5)污染严重,制定科学合理的治理措施迫切需要明确PM2.5的来源.本文基于空气质量模式CAMx(Comprehensive Air Quality Model with extensions)、颗粒物源解析模块PSAT(Particulate Source Apportionment Technology)及融入多种来源数据后建立的排放清单来量化西安地区本地及区域传输贡献.在本文研究的重污染过程中,模式的模拟精度合理,模拟与观测值相关系数为0.78,FAC2达到95%.PSAT模块在本次重污染过程中对西安PM2.5的来源解析结果显示:在城区,西安本地为最大的排放源区,日均贡献率均大于60%,其次为咸阳8%,省外的传输为6%;在郊区,西安本地的贡献减少,传输贡献增加,其中阎良区传输贡献达到83%.对西安城区的一次细颗粒物面源排放量减少50%模拟后,城区和郊区来自周边区域渭南或咸阳的贡献率有6%~8%的增长.该研究结果表明需要从本地排放管控和区域联防两方面来改善西安地区的空气质量.展开更多
The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepa...The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepare the emission files for five different source combination cases (Base case, Biogenic, Area + Biogenic, Mobile + Biogenic, Low-level Point + Biogenic). These emission files are used to perform photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx), and the results are analyzed with Visual Environment for Rich Data Interpretation (VERDI) tool. The daily maximum ozone concentrations and individual contributions of the source categories were analyzed over a 15-day study period between June 1-15, 2012, at three locations (University of Houston-Sugarland, Bayland Park and Conroe). Biogenic sources contributed an average of 49.7% ± 12.8%, 43.1% ± 12.0%, and 39.9% ± 9.28% at Sugarland, Bayland Park and Conroe sites respectively, indicating the significance of isoprene emissions from the vegetation in northeast Houston. On peak ozone days, contribution of Mobile + Biogenic source category averages about 80.1% ± 12.6%, 79.9% ± 6.50%, and 75.9% ± 10.9% at Sugarland, Bayland Park and Conroe sites respectively, indicating the dominance of mobile source NOX emissions and the necessity for regulatory focus on mobile source emissions control.展开更多
目前各个国家开发使用的空气质量模型各不相同,但使用较普遍的是CAMx(Comprehensive Air Quality Model Extensions)模型和CMAQ(Community Multiscale Air Quality Modeling System)模型。通过介绍第三代空气质量模型中的CAMx模型...目前各个国家开发使用的空气质量模型各不相同,但使用较普遍的是CAMx(Comprehensive Air Quality Model Extensions)模型和CMAQ(Community Multiscale Air Quality Modeling System)模型。通过介绍第三代空气质量模型中的CAMx模型及其扩展和探测工具,分析CAMx模型在不同污染物中的应用及研究者对该模型性能的验证,以期为模型选用者提供更多的参考。通过对比,认为该模型能够较好地同时模拟多种污染物以及进行多尺度的大气污染预报,同时还兼具了颗粒物源识别技术(PSAT)和臭氧源识别技术(OSAT),能够很好地追踪示踪物质,快速、准确地模拟出示踪物质对目标区域的污染物贡献。展开更多
Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-...Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment area for ozone (O3). A summer episode of May 28 to July 2, 2006 is simulated using Comprehensive Air Quality Model with extensions (CAMx). During this period O3 concentration in HGB often exceeds the National Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that some specific volatile organic compounds are very reactive in atmosphere. The objective of this study is to analyze the influence of volatile organic compounds present in point source emissions on the air quality of HGB area. For this purpose ozone sensitivity for HGB area is analyzed by the ratio of hydrogen peroxides (H2O2) to nitric acid (HNO3). HGB area is found NOx limited but reactive VOCs are found to be influential too. From (1-4 June, 2006) maximum O3 concentration was found on weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde (FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation was found correlated to higher ozone production. Criteria pollutant Sulfur dioxide (SO2) was found to influence the ALD2 and ETHA concentrations, and thus indirectly influenced O3 production.展开更多
In this paper,the spatial,temporal distribution,transformation and source simulation of NO_3~- were analyzed systematically based on the monitoring data,literature review and numerical simulation(CMAQ4.7.1).Analysis r...In this paper,the spatial,temporal distribution,transformation and source simulation of NO_3~- were analyzed systematically based on the monitoring data,literature review and numerical simulation(CMAQ4.7.1).Analysis results showed that annual average concentration of NO_3~- in Beijing was between 6.69 and 12.48 μg/m~3 with an increasing trend in recent years;concentration of NO_3~- in Beijing in 2013 was higher in winter and autumn than that in spring and summer and diurnal variation of NO_3~- showed bimodal distribution and spatial distribution of NO_3~- showed significant north-south gradient distribution;annual average NOR in Beijing was between 0.12 and 0.17 while it was between 0.17 and 0.20 during heavy air pollution days in 2013;the average ratio of NO_3~-/SO_4~(2-) was between 0.97 and 1.06 while it was between 1.00 and 1.07 during heavy air pollution days in 2013;the emission sources of Beijing was being changed from fixed source to both fixed and moving sources in feature development;simulated local,external transportation,background and boundary condition were 40%,44%and 16%respectively to the annual average concentration of NO_3~- in Beijing in 2013 while they were 31%,57%and 12%respectively in heavy air pollution days,which indicated that external source played an important role to the concentration of NO_3~- in Beijing.展开更多
文摘西安是关中盆地经济发展的核心城市,特殊的地形和工业发展导致冬季细颗粒物(PM2.5)污染严重,制定科学合理的治理措施迫切需要明确PM2.5的来源.本文基于空气质量模式CAMx(Comprehensive Air Quality Model with extensions)、颗粒物源解析模块PSAT(Particulate Source Apportionment Technology)及融入多种来源数据后建立的排放清单来量化西安地区本地及区域传输贡献.在本文研究的重污染过程中,模式的模拟精度合理,模拟与观测值相关系数为0.78,FAC2达到95%.PSAT模块在本次重污染过程中对西安PM2.5的来源解析结果显示:在城区,西安本地为最大的排放源区,日均贡献率均大于60%,其次为咸阳8%,省外的传输为6%;在郊区,西安本地的贡献减少,传输贡献增加,其中阎良区传输贡献达到83%.对西安城区的一次细颗粒物面源排放量减少50%模拟后,城区和郊区来自周边区域渭南或咸阳的贡献率有6%~8%的增长.该研究结果表明需要从本地排放管控和区域联防两方面来改善西安地区的空气质量.
文摘The goal of this study is to analyze the relative contribution of different emission source categories to ozone in the Houston-Galveston-Brazoria (HGB) area of Texas. Emission Processing System (EPS3) is used to prepare the emission files for five different source combination cases (Base case, Biogenic, Area + Biogenic, Mobile + Biogenic, Low-level Point + Biogenic). These emission files are used to perform photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx), and the results are analyzed with Visual Environment for Rich Data Interpretation (VERDI) tool. The daily maximum ozone concentrations and individual contributions of the source categories were analyzed over a 15-day study period between June 1-15, 2012, at three locations (University of Houston-Sugarland, Bayland Park and Conroe). Biogenic sources contributed an average of 49.7% ± 12.8%, 43.1% ± 12.0%, and 39.9% ± 9.28% at Sugarland, Bayland Park and Conroe sites respectively, indicating the significance of isoprene emissions from the vegetation in northeast Houston. On peak ozone days, contribution of Mobile + Biogenic source category averages about 80.1% ± 12.6%, 79.9% ± 6.50%, and 75.9% ± 10.9% at Sugarland, Bayland Park and Conroe sites respectively, indicating the dominance of mobile source NOX emissions and the necessity for regulatory focus on mobile source emissions control.
文摘目前各个国家开发使用的空气质量模型各不相同,但使用较普遍的是CAMx(Comprehensive Air Quality Model Extensions)模型和CMAQ(Community Multiscale Air Quality Modeling System)模型。通过介绍第三代空气质量模型中的CAMx模型及其扩展和探测工具,分析CAMx模型在不同污染物中的应用及研究者对该模型性能的验证,以期为模型选用者提供更多的参考。通过对比,认为该模型能够较好地同时模拟多种污染物以及进行多尺度的大气污染预报,同时还兼具了颗粒物源识别技术(PSAT)和臭氧源识别技术(OSAT),能够很好地追踪示踪物质,快速、准确地模拟出示踪物质对目标区域的污染物贡献。
文摘Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment area for ozone (O3). A summer episode of May 28 to July 2, 2006 is simulated using Comprehensive Air Quality Model with extensions (CAMx). During this period O3 concentration in HGB often exceeds the National Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that some specific volatile organic compounds are very reactive in atmosphere. The objective of this study is to analyze the influence of volatile organic compounds present in point source emissions on the air quality of HGB area. For this purpose ozone sensitivity for HGB area is analyzed by the ratio of hydrogen peroxides (H2O2) to nitric acid (HNO3). HGB area is found NOx limited but reactive VOCs are found to be influential too. From (1-4 June, 2006) maximum O3 concentration was found on weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde (FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation was found correlated to higher ozone production. Criteria pollutant Sulfur dioxide (SO2) was found to influence the ALD2 and ETHA concentrations, and thus indirectly influenced O3 production.
基金Supported by National Key Technology R & D Program (2014BAC23B02,2014BAC06B05) the Commonweal Project in Ministry of Environment Protection (201409005,201309071)
文摘In this paper,the spatial,temporal distribution,transformation and source simulation of NO_3~- were analyzed systematically based on the monitoring data,literature review and numerical simulation(CMAQ4.7.1).Analysis results showed that annual average concentration of NO_3~- in Beijing was between 6.69 and 12.48 μg/m~3 with an increasing trend in recent years;concentration of NO_3~- in Beijing in 2013 was higher in winter and autumn than that in spring and summer and diurnal variation of NO_3~- showed bimodal distribution and spatial distribution of NO_3~- showed significant north-south gradient distribution;annual average NOR in Beijing was between 0.12 and 0.17 while it was between 0.17 and 0.20 during heavy air pollution days in 2013;the average ratio of NO_3~-/SO_4~(2-) was between 0.97 and 1.06 while it was between 1.00 and 1.07 during heavy air pollution days in 2013;the emission sources of Beijing was being changed from fixed source to both fixed and moving sources in feature development;simulated local,external transportation,background and boundary condition were 40%,44%and 16%respectively to the annual average concentration of NO_3~- in Beijing in 2013 while they were 31%,57%and 12%respectively in heavy air pollution days,which indicated that external source played an important role to the concentration of NO_3~- in Beijing.