我国对流层大气臭氧的数值模拟   总被引：7，自引：2，他引：7  

何东阳  黄美元 《大气科学》1993,17(6):741-749

本文建立了一个用于对流层大气臭氧模拟的三维欧拉模式,针对影响臭氧光化学转化的各种因素及我国城市光化学污染的特点,模式中简化了光化学项的计算。根据实际观测资料,提出了模拟云雾对臭氧影响的参数化方法,并确定了云雾作用系数,通过模式的数值模拟,得出了我国对流层大气臭氧,特别是近地面层大气臭氧的分布状况、我国城市光化学污染的分布特征以及它们的季节变化规律.  相似文献   

Photooxidation of dimethyl sulfide and dimethyl disulfide. II: Mechanism evaluation     

Fangdon Yin  Daniel Grosjean  Richard C. Flagan  John H. Seinfeld 《Journal of Atmospheric Chemistry》1990,11(4):365-399

The mechanisms for atmospheric photooxidation of CH₃SCH₃ and CH₃SSCH₃ developed in Part I are evaluated by a series of outdoor smog chamber experiments. Measured product yields, including SO₂, H₂SO₄, CH₃SO₃H and HCHO, are reported. The predictions of the mechanisms developed in Part I are found to be in substantial agreement with the measured concentrations from the smog chamber. By comparison of mechanism predictions and observations, critical uncertainties in the mechanism are identified.  相似文献   

Nitric acid forming potential of five prototype hydrocarbons     

Gerassimos Mineshos  Nikolaos Roumelis  Efthalia Evmorfopoulou  Sotirios Glavas 《Journal of Atmospheric Chemistry》1991,13(4):343-357

The nitric acid formed from trans-2-butene, propene, ethene, toluene, and n-butane in single hydrocarbon/NO₂/purified air systems was examined in smog chamber experiments. The effect of hydrocarbon and NO₂ concentrations on the maximum HNO₃ yield, defined as percentages of initial NO₂ converted to HNO₃, was studied in two sets of experiments. In every hydrocarbon system, we found no effect of hydrocarbon concentration variation on the nitric acid formed. Out of initially added 100 ppb NO₂, in the hydrocarbon-rich systems, ethene formed most HNO₃ (45%), followed by propene, toluene, and n-butane (24%), and trans-2-butene (13%). When the initial NO₂ concentration was varied with a constant hydrocarbon concentration, the amount of HNO₃ formed was found to linearly increase with the added NO₂ down to |HC|/|NO₂| ratios, which depended on the nature of the hydrocarbon studied. The initial rate of HNO₃ formation in hydrocarbon excess experiments varied between 50, 35, 23, 16, and 8 ppb/hr for butene, propene, toluene, ethene, and butane systems, respectively.  相似文献   

Preliminary calculations concerning the maintenance of the zonal mean ozone distribution in the Northern Hemisphere     

D. M. Cunnold  F. N. Alyea  R. G. Prinn 《Pure and Applied Geophysics》1980,118(1):329-354

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Impact of coupled perturbations of atmospheric trace gases on Earth's climate and ozone     

Maria Pia Nicoli  Guido Visconti 《Pure and Applied Geophysics》1982,120(4):626-641

We have studied the effects on the ozone concentration and surface temperature, of perturbations in the atmospheric content of nitrous oxide, methane, carbon dioxide and chlorofluorocarbons (CFC). The sensitivity study has been carried out with a radiative-convective-photochemical model. The doubling of carbon dioxide concentration has the effect of warming the troposphere and cooling the stratosphere. As a result of this cooling, the change of ozone columnar density produced by 10 ppb of chlorine amount to 9.3% as compared to –10.9% obtained without temperature feedback. Perturbation in nitrous oxide correspond to an increase in NO _x of the stratosphere with consequent ozone reduction while doubling the methane concentration correspond to a slight increase in columnar density. The effect of the increased methane concentration in the stratosphere contributes to reduce the effect of CFC due to the enhanced formation of HCl. The perturbation of these two minor constituents appreciably increase the greenhouse effect to 2.30 from 1.67°, obtained when carbon dioxide alone is considered.  相似文献   

The photo-oxidations of propyl acetates in synthetic air-HONO-NO x mixtures: Product formation studies and proposed kinetic mechanisms     

J. Alistair Kerr  David W. Stocker 《Journal of Atmospheric Chemistry》1986,4(2):263-276

The formation of products following the hydroxyl radical initiated photo-oxidations of n-and isopropyl acetates has been studied. Mixtures of synthetic air containing a few ppm of nitrous acid, nitric oxide, nitrogen dioxide and one of the propyl acetates were irradiated with sunlamps in a Teflon bag smog chamber. The decay of reactants and the formation of products was monitored by chemiluminescent analysis or by gas chromatography. The major primary products from the photo-oxidation of n-propyl acetate are acetaldehyde and propionaldehyde while from isopropyl acetate they are acetone and methyl nitrate. It was not possible to analyse for formaldehyde, an expected primary product in these systems. The nature and distribution of products indicate that a significant fraction of primary products arise from decomposition reactions of the alkoxy-type radicals generated following the initial attack of hydroxyl radicals on the esters. The derived reaction stoichiometries (molecules of NO oxidised per molecule of ester reacted) are also consistent with the proposed mechanisms.  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   

北京城市重烟尘雾与水雾过程的边界层结构   总被引：7，自引：2，他引：7  

周小刚  王强 《气象科技》2004,32(6):404-409

分析1999年11月1日至12月20日北京城市雾综合性观测试验中5次雾过程的实测资料，对如何区分重烟尘雾与水雾过程给出了判定方法，并对重烟尘雾与水雾过程的边界层结构特征作了探讨。主要结论为：从能见度、相对湿度、长波辐射平衡3个方面可以区分重烟尘雾过程和水雾过程；由于重烟尘雾和水雾的物理化学性质差异很大，对城市大气边界层结构产生的影响也不同，因此造成它们在相对湿度逆温层、风速分布、水汽变化等方面也有很大差异。  相似文献   

Ozone Weekend Effect Analysis in Three European Urban Areas     

José Carlos M. Pires 《洁净——土壤、空气、水》2012,40(8):790-797

This paper aims to apply statistical procedures to analyse the ozone weekend effect (OWE) in three European urban areas: Lisbon, Oporto and London. Seasonal variations of surface ozone (O₃) and total oxidant species (O_x) concentrations are presented. The studied period was from January 2007 to December 2009. The O₃ annual average profile in London was significantly different from the ones achieved for Lisbon and Oporto, due to the high emissions of nitrogen oxides and low temperatures (associated with low solar radiations). The influence of nitrogen oxides in atmospheric chemistry of London was analysed by linear correlations between O₃ concentrations and NO₂/NO ratio. High values during almost all period showed that O₃ concentrations are mainly influenced by NO? NO₂? O₃ chemical reaction. On the other hand, the linear correlations between O₃ and NO₂ concentrations only presented positive values in Lisbon and Oporto. This behaviour is associated with photo‐dissociation of NO₂, producing O₃ during the spring and summer periods. Additionally, cluster analysis was applied to group the days of week according the correspondent O₃ behaviour. The weekend and some weekdays (immediately after or before) were grouped in the same cluster, showing that OWE occurs in all urban areas selected in this study. These findings suggest that the applied statistical procedures should be used to analyse the OWE and that the causes for the different O₃ behaviours during the week may be influenced by meteorological variables.  相似文献   

基于MODIS数据的城市光化学污染预警系统及预警等级研究   总被引：2，自引：2，他引：0  

夏丽华  王芳  王德辉 《地理科学》2006,26(6):712-716

通过分析MODIS遥感数据反演的大气气溶胶光学厚度(AOD)与大气环境污染的关系,结果表明当空气清洁没有污染时,AOD小于0.3,当空气轻度污染时,AOD在0.3~1.0之间,当空气污染严重时,AOD大于1.0。在分析AOD与地面大气污染的关系的基础上,结合地面空气污染监测数据的空气污染指数,将城市光化学污染的预警等级分为无、微弱、较弱、较强和强五级,并对城市光化学污染预警系统进行了框架分析,为进一步建设城市光化学污染预警系统提供基础。  相似文献