共查询到16条相似文献，搜索用时 312 毫秒
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积云对二氧化硫和硫酸盐气溶胶作用的研究 总被引：1，自引：1，他引：0
利用一个冰雹云模式与云化学模式耦合而成的二维积云化学模式,研究对流云的输送、微物理转化、云内化学过程、湿清除对SO2及硫酸盐气溶胶的作用。云化学模式的结果表明,由于SO2在向上输送的过程中可溶解于云水和雨水中,从而阻止了SO2向上部的转移,因此对气相SO2来说,云的输送是一个相当无效的过程,而液相清除起主要作用。硫酸盐气溶胶的收支分析表明,降水清除了1.67 mol的SO2-4,占气溶胶总量的64%,其中液态降水清除了0.72 mol,固态降水清除了0.95 mol,说明了冰相过程在硫沉降中的重要性。 相似文献
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深对流云输送对于对流层O3、NOx在分析的作用 总被引：4，自引：0，他引：4
利用一个冰雹云模式与云化学输送模块耦合而成的三维对流云化学／输送模式, 研究对流云对重要的大气污染物臭氧 （Ｏ３）、氮氧化物 （ＮＯｘ, 包括ＮＯ 和ＮＯ２） 的输送作用。模式较好地体现了一个单体积云的发展过程及其特征。云化学／输送模式的结果表明, 云内强烈的垂直输送能在３０ ｍ ｉｎ 左右, 把低层低体积分数的Ｏ３和高体积分数的ＮＯ２快速、有效地输送到对流层的上部, 造成化学物种的再分布。而在云顶附近, 由于对流穿透了对流层的顶部,造成了上层高体积分数Ｏ３的向下侵入,说明云的对流活动除了能把边界层内的污染物向上输送, 其夹卷作用还可以造成平流层和对流层化学物质的交换。 相似文献
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云对云中大气臭氧影响因子的分析 总被引：3，自引：0，他引：3
应用一个较详细的气相光化学和液相化学耦合的箱体模式, 研究了云层对云中大气臭氧的影响过程。这一过程可分解为三个因子来考虑： 因子Ａ （云的辐射效应）, 由于云的存在改变太阳光辐射通量, 使得对流层光化学反应减弱或增强, 从而降低或增加臭氧浓度; 因子Ｂ（云的吸收效应）, 云层中液态水对大气臭氧及其前体物 （ＮＯｘ、ＮＭＨＣ、自由基等） 的直接吸收作用; 因子Ｃ（云的液相化学效应）, 吸收进入云中的物质发生液相化学反应从而改变大气臭氧浓度。数值研究结果表明： 上述三因子对云中臭氧浓度影响的程度差别很大, 并且与云层的物理结构有密切关系。讨论了云的吸收及液相化学效应影响臭氧浓度的主要原因 相似文献
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利用一个三维的冰雹云模式与化学组分输送模块耦合，得到云输送引起大气光化学组分的再分布，然后用一个包含详细气相化学反应机制的箱模式研究了云输送引起的气相体积分数的变化及其对大气化学系统产生的影响。结果表明，云输送后O3体积分数大于无云个例，但其后两天内两者的变化趋势相差不大；HNO3、NO2、NO3、PAN等的体积分数均明显高于无云个例，分别增长了87％、70％、62％和49％，其中NO2体积分数的增加主要由于云输送造成，而NO3、HNO3、PAN主要是输送对化学扰动的结果。两天内OH和HO2自由基体积分数比无云个例平均增长了13％和11％。 相似文献
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在UWyo单组分气溶胶的绝热气块分档云模式基础上,发展了多种化学组分气溶胶的绝热气块分档云模式。利用2006年春季华北地区地面气溶胶分级采样的离子成分分析数据和同时段高空气溶胶、云微物理飞机观测资料,研究了气溶胶混合状态对暖云微物理特征的影响。模拟结果表明,华北地区气溶胶内部混合比外部混合有利于增加云凝结核数浓度、降低气块水汽最大饱和比、增加云滴数浓度。气溶胶的混合状态不同,形成的云滴谱的特征差异较大,主要体现在云滴谱的平均尺度和峰值的突出程度;云滴谱相对离散度在0.3附近变化,且随着云滴数浓度的增加,云滴谱相对离散度呈现减小的趋势。气溶胶混合状态能够影响暖云微物理特征,从而影响大气辐射和降水过程,在天气和气候变化的研究中应予以关注。 相似文献
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《中国气象科学研究院年报》2011,(1):39-45
2011年,云降水物理与人工影响天气研究主要在暖云数值模式研制及模拟、云物理过程对降水影响、冰雹物理过程、效果检验、南方冻雨的微物理过程以及华北气溶胶特征等方面取得如下研究成果。 相似文献
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A one-dimensional cumulus cloud chemistry model(1CCCM)is developed to simulate cloudphysical processes and chemical processes during the evolution of a convective cloud.The cloudphysical submodel includes a detailed microphysical parameterized scheme of 20 processes.Thechemistry submodel is composed of three parts:gas phase chemistry,aqueous phase chemistry andscavenging of soluble gases.The gas phase reaction mechanism contains 85 reactions among 45species including 13 organics.The aqueous phase reaction mechanism contains 54 reactions among40 species and 12 ion equilibria.Mass of 19 gases is transported between the gas phase and theaqueous phase.With this model,studies may be made to analyze the interactions among processesduring lifetime of a cumulus cloud. 相似文献
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A one-dimensional cumulus cloud chemistry model(ICCCM) is developed to simulate cloud physical processes and chemical processes during the evolution of a convective cloud.The cloud physical submodel includes a detailed microphysical parameterized scheme of 20 processes.The chemistry submodel is composed of three parts:gas phase chemistry,aqueous phase chemistry and scavenging of soluble gases.The gas phase reaction mechanism contains 85 reactions among 45 species including 13 organics.The aqueous phase reaction mechanism contains 54 reactions among 40 species and 12 ion equilibria.Mass of 19 gases is transported between the gas phase and the aqueous phase.With this model,studies may be made to analyze the interactions among processes during lifetime of a cumulus cloud. 相似文献
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Abstract The Acid Deposition and Oxidant Model (ADOM) is an Eulerian long‐range transport and deposition model. One of the most highly parametrized and least well established parts of the model is the scavenging module that describes cloud formation, pollutant scavenging, aqueous‐phase chemistry and wet deposition. As a means of gaining insight into the scavenging module, results from simulations with the module are compared with the results from simulations for equivalent conditions with a three‐dimensional dynamic cloud chemistry model. Comparisons of results for a variety of initial conditions show that wet deposition of sulphate, nitrate and ammonium ions tend to be underpredicted by the scavenging module and that the pH of the rain is overpredicted. Although the differences are for the most part not large, they are sensitive to cloud top height. The amount of hydrogen peroxide deposited at the surface is significantly smaller in the ADOM module than in the cloud chemistry model. For the particular conditions that are considered, oxidation is limited by the hydrogen peroxide concentration for the cloud chemistry model, but by the sulphur dioxide concentration for the ADOM module. 相似文献
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用一组化学模式和二维时变积云模式及扩散模式相结合，研究了云和降水发展各阶段污染物浓度对云水和降水的降化影响及SO2冲刷过程的影响（侧重灵敏度试验的讨论）。 相似文献
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R. N. Colvile R. Sander T. W. Choularton K. N. Bower D. W. F. Inglis W. Wobrock D. Schell I. B. Svenningsson A. Wiedensohler H. -C. Hansson A. Hallberg J. A. Ogren K. J. Noone M. C. Facchini S. Fuzzi G. Orsi B. G. Arends W. Winiwarter T. Schneider A. Berner 《Journal of Atmospheric Chemistry》1994,19(1-2):189-229
The airflow, cloud microphysics and gas- and aqueous-phase chemistry on Kleiner Feldberg have been modelled for the case study of the evening of 1 November 1990, in order to calculate parameters that are not easily measured in the cloud and thus to aid the interpretation of the GCE experimental data-set. An airflow model has been used to produce the updraught over complex terrain for the cloud model, with some care required to ensure realistic modelling of the strong stable stratification of the atmosphere. An extensive set of measurements has been made self-consistent and used to calculate gas and aerosol input parameters for the model. A typical run of the cloud model has calculated a peak supersaturation of 0.55% which occurs about 20 s after entering cloud where the updraught is 0.6 m s–1. This figure has been used to calculate the efficiency with which aerosol particles were scavenged; it is higher than that calculated by other methods, and produces a cloud with slightly too many droplets. A broad cloud droplet size spectrum has been produced by varying the model inputs to simulate turbulent mixing and fluctuations in cloud parameters in space and time, and the ability of mixing processes near cloud-base to produce a lower peak supersaturation is discussed. The scavenging of soluble gases by cloud droplets has been observed and departures from Henry's Law in bulk cloud-water samples seen to be caused by variation of pH across the droplet spectrum and the inability of diffusion to adjust initial distributions of highly soluble substances across the spectrum in the time available. Aqueous-phase chemistry has been found to play a minor role in the cloud as modelled, but circumstances in which these processes would be more important are identified. 相似文献