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...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
In this study, three Danish sites having the longest (1990-2004) time-series of ozone measurements were analysed on inter-annual, monthly and diurnal cycle variability as well as elevated and lowered ozone concentrati...In this study, three Danish sites having the longest (1990-2004) time-series of ozone measurements were analysed on inter-annual, monthly and diurnal cycle variability as well as elevated and lowered ozone concentration events were identified. The atmospheric trajectory (HYSPLIT) and dispersion (HIRLAM + CAMx) models were employed to study dominating atmospheric transport patterns associated with elevated events and to evaluate spatio-temporal variability of ozone specific episode and typical seasonal patterns for Denmark. It was found that generally inter-annual variability has a positive trend, and events with low ozone concentration (≤10 μg/m3) continued to diminish. On a monthly scale, the highest and lowest mean concentrations are observed in May and November-December, respectively. The elevated concentrations (≥120 μg/m3) are observed during March-September. On a diurnal cycle, it is observed mostly during 13-16 of local time, and more frequent (ten-fold) compared with nighttime-early morning hours. For ozone elevated events, several sectors (or pathways of atmospheric transport) were identified depending on the sites’ positions, showing the largest (39%) number of such events associated with the north-western sector, and lowest (13% each)—southwestern and northern sectors. For each site, less than 60 events showed very high concentrations (≥180 μg/m3). Among 12 episodes, one longest elevated episode (19-21 Jun 2000) simultaneously registered at all sites and characterized by dominating transport from the south-southwestern sector, low wind speed, clear-sky, and multiple inversions was studied using modelling tools. For this episode, both measurements and modeling (trajectory and dispersion) results showed a relatively good agreement.展开更多
The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of ...The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of 2007 were examined in a modeling study.The modeling system consisted of the Weather Research and Forecasting （WRF） model and the photochemical dispersion model,CAMx.The factor separation technique （FST） was used to quantify the effect of individual emission source types and the synergistic interactions among two or more types.Additionally,the effectiveness of emission reduction scenarios was explored.The industry,power plant,and transportation emission source types were found to be the most important in terms of their individual effects on O3DM.The key contributor to high surface O3 was power plant emissions,with a peak individual effect of 40 ppbv in the southwestern BTH area.The individual effect from the biogenic emission category was quite low.The synergistic effects from the combinations of each pair of anthropogenic emission types suppressed O3 formation,while the synergistic effects for combinations of three were favorable for O3 formation when the industrial and power plant emission source types coexisted.The quadruple synergistic effects were positive only with the combination of power plant,transportation,residential,and biogenic sources,while the quintuple synergistic effect showed only minor impacts on O3DM concentrations.A 30％ reduction in industrial and transportation sources produced the most effective impacts on O3 concentrations,with a maximum decrease of 20 ppbv.These results suggested that the synergistic impacts among emission source types should be considered when formulating emission control strategies for O3 reduction.展开更多
关中地区是我国大气污染的重点监测区域,为探究偏东风输送对关中地区冬季PM_(2.5)重污染的影响,重点分析了2018年1月12—18日在偏东风输送影响下关中地区ρ(PM_(2.5))日均值的变化过程;利用WRF和CAMx模式对PM_(2.5)重污染过程进行模拟...关中地区是我国大气污染的重点监测区域,为探究偏东风输送对关中地区冬季PM_(2.5)重污染的影响,重点分析了2018年1月12—18日在偏东风输送影响下关中地区ρ(PM_(2.5))日均值的变化过程;利用WRF和CAMx模式对PM_(2.5)重污染过程进行模拟并讨论其消长原因.结果表明:①冬季关中地区在高压脊和西南槽的控制下,偏东风将污染物输送至关中地区,加之关中地区地形阻滞,致使关中地区的ρ(PM_(2.5))上升.②研究期间,关中地区ρ(PM_(2.5))日均值范围为103~240μg m 3,偏东风输送是导致此次重污染过程的重要原因.重污染的发生还与气象要素的变化有关,其中ρ(PM_(2.5))日均值与气温、相对湿度均呈滞后相关性.在ρ(PM_(2.5))日均值相等的情况下,相对湿度越大,能见度越低;随着ρ(PM_(2.5))日均值和相对湿度的升高,能见度下降的速率逐渐变慢.③根据WRF-CAMx的模拟结果,此次重污染过程中关中地区PM_(2.5)污染输送关系不均衡,宝鸡市和咸阳市均以本地贡献为主,其本地贡献率超过45.00%,而渭南市接收关中地区其他城市及关中地区以外区域污染输送占比为69.82%;位于盆地中东部的咸阳市、西安市和渭南市的ρ(PM_(2.5))月均值均大于关中地区ρ(PM_(2.5))平均值;渭南市、西安市、运城市以及关中地区以外城市是此次关中地区跨市PM_(2.5)污染输送的主要来源.研究显示,偏东风输送是关中地区此次大气重污染过程的重要原因.展开更多
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In this study, three Danish sites having the longest (1990-2004) time-series of ozone measurements were analysed on inter-annual, monthly and diurnal cycle variability as well as elevated and lowered ozone concentration events were identified. The atmospheric trajectory (HYSPLIT) and dispersion (HIRLAM + CAMx) models were employed to study dominating atmospheric transport patterns associated with elevated events and to evaluate spatio-temporal variability of ozone specific episode and typical seasonal patterns for Denmark. It was found that generally inter-annual variability has a positive trend, and events with low ozone concentration (≤10 μg/m3) continued to diminish. On a monthly scale, the highest and lowest mean concentrations are observed in May and November-December, respectively. The elevated concentrations (≥120 μg/m3) are observed during March-September. On a diurnal cycle, it is observed mostly during 13-16 of local time, and more frequent (ten-fold) compared with nighttime-early morning hours. For ozone elevated events, several sectors (or pathways of atmospheric transport) were identified depending on the sites’ positions, showing the largest (39%) number of such events associated with the north-western sector, and lowest (13% each)—southwestern and northern sectors. For each site, less than 60 events showed very high concentrations (≥180 μg/m3). Among 12 episodes, one longest elevated episode (19-21 Jun 2000) simultaneously registered at all sites and characterized by dominating transport from the south-southwestern sector, low wind speed, clear-sky, and multiple inversions was studied using modelling tools. For this episode, both measurements and modeling (trajectory and dispersion) results showed a relatively good agreement.
基金jointly supported by a key project of the Chinese Academy of Sciences (Grant No. XDB05030301)the National Natural Science Foundation of China (Grant Nos. 40905055 and 41175105)the special fund of the State Key Joint Laboratory of Environment Simulation and Pollution Control (Grant No. 13K04ESPCP)
文摘The impacts of emissions from industry,power plant,transportation,residential,and biogenic sources on daily maximum surface ozone （O3DM） over the Beijing-Tianjin-Hebei （BTH） region in North China in the summer of 2007 were examined in a modeling study.The modeling system consisted of the Weather Research and Forecasting （WRF） model and the photochemical dispersion model,CAMx.The factor separation technique （FST） was used to quantify the effect of individual emission source types and the synergistic interactions among two or more types.Additionally,the effectiveness of emission reduction scenarios was explored.The industry,power plant,and transportation emission source types were found to be the most important in terms of their individual effects on O3DM.The key contributor to high surface O3 was power plant emissions,with a peak individual effect of 40 ppbv in the southwestern BTH area.The individual effect from the biogenic emission category was quite low.The synergistic effects from the combinations of each pair of anthropogenic emission types suppressed O3 formation,while the synergistic effects for combinations of three were favorable for O3 formation when the industrial and power plant emission source types coexisted.The quadruple synergistic effects were positive only with the combination of power plant,transportation,residential,and biogenic sources,while the quintuple synergistic effect showed only minor impacts on O3DM concentrations.A 30％ reduction in industrial and transportation sources produced the most effective impacts on O3 concentrations,with a maximum decrease of 20 ppbv.These results suggested that the synergistic impacts among emission source types should be considered when formulating emission control strategies for O3 reduction.
文摘关中地区是我国大气污染的重点监测区域,为探究偏东风输送对关中地区冬季PM_(2.5)重污染的影响,重点分析了2018年1月12—18日在偏东风输送影响下关中地区ρ(PM_(2.5))日均值的变化过程;利用WRF和CAMx模式对PM_(2.5)重污染过程进行模拟并讨论其消长原因.结果表明:①冬季关中地区在高压脊和西南槽的控制下,偏东风将污染物输送至关中地区,加之关中地区地形阻滞,致使关中地区的ρ(PM_(2.5))上升.②研究期间,关中地区ρ(PM_(2.5))日均值范围为103~240μg m 3,偏东风输送是导致此次重污染过程的重要原因.重污染的发生还与气象要素的变化有关,其中ρ(PM_(2.5))日均值与气温、相对湿度均呈滞后相关性.在ρ(PM_(2.5))日均值相等的情况下,相对湿度越大,能见度越低;随着ρ(PM_(2.5))日均值和相对湿度的升高,能见度下降的速率逐渐变慢.③根据WRF-CAMx的模拟结果,此次重污染过程中关中地区PM_(2.5)污染输送关系不均衡,宝鸡市和咸阳市均以本地贡献为主,其本地贡献率超过45.00%,而渭南市接收关中地区其他城市及关中地区以外区域污染输送占比为69.82%;位于盆地中东部的咸阳市、西安市和渭南市的ρ(PM_(2.5))月均值均大于关中地区ρ(PM_(2.5))平均值;渭南市、西安市、运城市以及关中地区以外城市是此次关中地区跨市PM_(2.5)污染输送的主要来源.研究显示,偏东风输送是关中地区此次大气重污染过程的重要原因.
