Regional Air Quality Modelling in Canada – Applications for Policy and Real-Time Prediction     

Venkatesh  S.  Gong  W.  Kallaur  A.  Makar  P. A.  Moran  M. D.  Pabla  B.  Ro  C.  Vet  R.  Burrows  W. R.  Montpetit  R. 《Natural Hazards》2000,21(2-3):101-129

Acid rain and photochemical smog are two regionalair-quality issues that have received considerableattention in the last two decades due to their harmfuleffects. Health impacts of particulate matter (PM) inthe atmosphere is another issue of concern.Sulphur dioxide emission controls were introducedin both Canada and the U.S.A. to reduceacid-deposition-related damage. While these emissionreductions have already resulted in reduced sulphatedeposition, based on results from modelling studiesmuch of southeastern Canada is still expected toexperience damaging levels of acid deposition evenafter all currently legislated emission controls arefully implemented. Moreover, there has not been acorresponding reduction in the acidity ofprecipitation. This may be attributable to aconcurrent reduction in base-cation concentration inprecipitation.Models were also developed to understand theformation, transport and diffusion of troposphericozone. The models have been used to provide policyguidance for emission control options to reduceground-level ozone to acceptable limits. In thesummer of 1997 a Canadian pilot project was initiatedto provide real-time forecasts of ground-level ozonein the southeastern part of the province of NewBrunswick in eastern Canada.With the emergence of fine Particulate Matter(PM_2.5) as a health concern, efforts are underwayin Canada to develop a unified' regional air-qualitymodel that will address the combined impacts ofvarious pollutants in the atmosphere. In this effortthe atmosphere is viewed as a single entity where theimpacts of multiple pollutants are considered at thesame time.  相似文献   

基于多元线性回归算法的雾霾预测模型的研究     

李悦  谈进忠  陈鹏  赵信一 《沙漠与绿洲气象(新疆气象)》2019,13(2):102-107

对乌鲁木齐市环境监测站2013—2015年冬季逐日AQI、PM_2.5、PM₁₀、SO_2、NO_2、CO、O_3数据进行相关分析,并利用MATLAB编程工具进行多元回归统计分析,建立了多元回归统计预测模型。对2015年1—3月乌鲁木齐雾霾天气进行预测试验,发现预测值与实际值有较好的拟合效果和预报效果。实验证明,在大气层结稳定的冬季将当天的大气污染物浓度作为因子,用多元线性回归算法建立预测模型对次日雾霾天气进行预测是一种有效的雾霾统计预报手段,本文试图用MATLAB编程工具建立动态多元回归预测模型,编写了自动预测系统软件,测试取得了较好的预测效果。  相似文献   

Diurnal cycling of carbon monoxide (CO) in the upper ocean near Bermuda     

A. James Kettle   《Ocean Modelling》2005,8(4):337-367

A coupled photochemical–physical model for the upper ocean carbon monoxide concentration is presented. The coupled model uses a spectral optical model and a number of different mixing parameterizations. It is run using the meteorological forcing conditions measured during a 9-day investigation near Bermuda in the Sargasso Sea in March 1993 in the declining phase of the spring bloom. The baseline runs of the model are successful in simulating measurements made during the campaign, and form the basis of an optimization routine to find better estimates of the production and destruction constants of the photochemical tracer. The optimized values derived in this inverse procedure depend on the mixing parameterization and the assumed dark production rate of carbon monoxide.  相似文献   

基于HJ1A数据的沈阳市雾霾时空变化模拟研究     

卫亚星  王莉雯 《测绘与空间地理信息》2017,40(5)

基于HJ1A-CCD数据,采用6S大气辐射传输模型,反演出研究区气溶胶光学厚度。采用偏最小二乘法,基于气溶胶空间分布的估算结果,模拟出研究区PM_(2.5)的空间分布。基于GIS和改进的高斯大气扩散模型,进行了研究区PM_(2.5)的扩散模拟。根据我国PM_(2.5)检测网的空气质量新标准,对沈阳市的雾霾进行等级了划分。  相似文献   

Construction and characterization of an atmospheric simulation smog chamber   总被引：11，自引：0，他引：11  

武山  吕子峰  郝吉明  赵喆  李俊华 《大气科学进展》2007,24(2):250-258

Currently, air pollution in Beijing has become a complex problem with two types of source pollutants： coal smoke and photochemical smog. Furthermore the maximum hourly mean concentration of O3 increases continuously, especially in the summer. In order to simulate the photochemical reaction, develop an air quality simulation model and further improve the air quality of Beijing, a precisely temperature-controlled, indoor, smog chamber facility was designed and constructed at Tsinghua University. Characterization experiments have been carried out to acquire the basic parameters of the smog chamber, such as the wall loss rates of NO2, NO, O3, C3H6 and particulate matter （PM）, the intensity of ultraviolet （UV） light in the chamber, the reactivity of the purified air and the reproducibility of the experimental results. The results indicate that the facility performs up to specifications, and can meet the demands required for simulating the photochemical reaction. The effect of high primary contaminated PM on the formation of ozone and secondary organic aerosol （SOA） is under investigation.  相似文献   

珠江三角洲典型灰霾天气过程和清洁过程近地层流场的EOF对比分析   总被引：4，自引：2，他引：2  

廖国莲  曾鹏  程鹏 《气象研究与应用》2008,29(4):23-25

利用广东省466个地面自动气象站资料、广州气象站常规气象资料及珠江三角洲4个主要城市的PM 10浓度等资料,通过矢量EOF方法,对选出的珠江三角洲典型灰霾天气过程(2004年1月4~10日)和清洁过程(2005年11月15~21日)的近地层流场进行对比分析。分析表明典型灰霾天气过程第二、三模态有非常明显的日变化特征,受局地中小尺度环流系统影响,污染物局限在当地,出现严重的灰霾天气;而清洁过程与强平流输送有关,主要受大尺度环流系统影响。  相似文献   

The Australian Air Quality Forecasting System: Exploring First Steps Towards Determining The Limits of Predictability For Short-Term Ozone Forecasting     

M.?E.?Cope  G.?D.?HessEmail author  S.?Lee  K.?J.?Tory  M.?Burgers  P.?Dewundege  M.?Johnson 《Boundary-Layer Meteorology》2005,116(2):363-384

Physical parameterisations of turbulent transfer processes in the atmospheric boundary layer, such as the stability parameterisations developed by Joost Businger, and recent advances in computing capabilities, have been important factors leading to the emergence of operational, numerical air quality forecasting systems. The present paper investigates the performance of the Australian Air Quality Forecasting System (AAQFS) in forecasting the peak 1 h ozone for the current or next day. These 24/36 h forecasts are generated for the Sydney and Melbourne regions and issued twice daily. Quantitative evidence is presented of the potential for the AAQFS to provide accurate numerical air quality forecasts. A second goal is to provide an initial benchmark for investigating the limits of predictability for air quality in the Sydney and Melbourne regions by looking at the dependence of the forecasts on the domain spatial scale (while maintaining the same model grid resolution), the starting time and length of the forecast (0000 UTC starts are 36-h forecasts and 1200 UTC starts are 24-h forecasts), and the sophistication of the photochemical mechanism (simple chemistry, Generic Reaction Set (GRS) and complex chemistry, Carbon Bond IV (CBIV)). The probability of detection by the forecast model is much better than persistence, showing considerable skill. The normalised bias, in general, decreases going from regional scale to sub-regional scale and becomes negative at the station scale. In Melbourne the gross error increases as the domain spatial scale decreases, but in Sydney there is a dip in the error at the sub-regional scale due to a sampling artifact. Better results are obtained at the smaller domain scales for 1200 UTC forecasts in Sydney. These are attributed to the shorter forecast period and secondarily to greater model spin-up effects at 0000 UTC. In Melbourne the results are ambiguous. Similar conclusions are derived from scatter plots of forecasts versus observations. Dividing the scatter plots into four sections by plotting vertical and horizontal lines (at 60 ppb) forms contingency tables for categorical forecasting. These plots show the increase in missed forecasts due to underprediction and the decrease in the number of extreme events detected as the spatial scale decreases. A comparison of the highly condensed GRS photochemical mechanism with the comprehensive CBIV mechanism indicates that, in general, GRS performs well for predicting ozone in urban situations provided that the background concentrations are appropriately specified. The potential to improve the forecasts at the smaller spatial scales, particularly for extreme events at high ozone concentrations, may require moving to a more complex mechanism as computer resources become available. This paper is dedicated to Joost Businger, who had strong ties with the atmospheric boundary-layer community in Australia over the past 40 years. It was while visiting CSIRO in Aspendale, Victoria, in 1965–1966 that Joost determined the stability dependence of the Monin-Obukhov surface-layer profiles. He immediately walked over to Arch Dyer’s office to show Arch his results. Arch carefully examined them, and then opened his desk drawer and pulled out his own plots of the stability dependence that he and Bruce Hicks had obtained. They showed the same curves, and thus the Businger-Dyer-Hicks stability functions were born. Arch and Bruce at the time were struggling with how to handle the internal politics; they needed Bill Swinbank’s approval, as Assistant Divisional Chief, before they could submit their results for publication. Bill had his own very strong ideas that conflicted with observations. Joost’s independent confirmation of their results provided a way forward (Bruce Hicks, personal communication, 2003). Joost has contributed significantly, either directly or indirectly, to experimental field programs both within Australia and overseas and to the development of parameterisations of turbulent transfer processes in the boundary layer.  相似文献   

区域对流层光化学过程研究   总被引：4，自引：0，他引：4  

纪飞  苏文颖  秦瑜 《气象学报》2001,59(2):246-255

将 MM5和 RADM耦合 ,建立了一个区域大气光化学模式。用此模式来研究区域大气光化学过程。分析了大气光化学过程中前体物、自由基以及主要产物的时空分布及其随时间的变化情况。得到了大气光化学过程各主要成分的分布及其演变特征。在此基础上 ,分析了水平平流、垂直扩散及沉降以及化学转化等物理、化学过程在大气光化学过程中的相对重要性 ,结果表明 ,水平平流和垂直扩散及沉降等物理过程对大气光化学过程中各种成分的浓度分布及其随时间的变化有重要的作用。  相似文献   

城市交通废气与低层大气臭氧形成和分布的数值模拟   总被引：5，自引：1，他引：5  

蒋维楣  徐振涛等 《气象科学》2001,21(4):409-416

建立了一个三维的边界层光化学模式，气象过程的模拟舍弃了静力近似的假定，模式由细网格、高分辨率并取湍流能量（E－ε）闭合的气象模式，提供较为细致的气流场和湍流场。文章中以汽车尾气和植物排放为光化学反应前体物的源，模拟了不同季节南京市的光化学过程以及臭氧随时间和空间的分布。结果表明，夏季南京市的地面臭氧浓度远远高于冬季，臭氧分布有所不同。并且在不少地方出现较高的O3浓度值，超过国家二级标准，气流对污染物浓度分布的影响在较高的高度上显得尤其明显。  相似文献   

冬季西宁市区上空阴霾的监测与分析     

兰措  张永新 《气象》1998,24(6):26-28

根据１９９３￣１９９７年各年冬季清晨晴朗少云条件下所获得的ＮＯＡＡ－１２卫星云图资料,对西宁市区上空近地面大气层的污染物－－阴霾做了初步分析。首先总结了阴霾在ＮＯＡＡ－１２卫星云科上所呈现的物理量特征;其次利用这些特征计算了阴霾的面积、经纬度和中心经纬度值;最后从气象学方面证明了冬季西宁市区上空具有形成阴霾的条件。  相似文献