共查询到15条相似文献，搜索用时 109 毫秒
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地面臭氧的变化规律和计算方法的初步研究Ⅰ.紫外波段 总被引：5，自引：1，他引：4
通过对广州鼎湖山近地面O3、NOx、太阳辐射、气象参数等项目的观测和理论分析,研究了地面O3与NOx等微量气体及太阳辐射的变化规律,详细讨论了紫外波段、不同天气条件地面O3与NOx,光化学反应、气溶胶、光化辐射等之间复杂的关系.用光能量传输与守恒的观点来考虑大气中与紫外辐射有关的主要过程,并以此来研究大气光化学过程中所遵循的能量规律,建立了一个简单、实用、省时的统计模式,用于计算地面O3浓度.结果表明,不同情况下计算值与观测值均吻合较好. 相似文献
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地面臭氧的变化规律和计算方法的初步研究Ⅱ.可见光波段 总被引：7，自引：0，他引：7
通过对广州鼎湖山近地面O3、NOx、太阳辐射,气象参数等项目的观测和理论分析,研究了地面O3与NOx等微量气体及太阳可见光辐射的变化规律,详细讨论了可见光波段、不同天气条件地面O3与NOx、光化学反应、气溶胶、可见光辐射等之间复杂的关系.提出以光能量传输与守恒的观点来考虑大气中与可见光辐射有关的主要过程,并以此来研究大气光化学过程中所遵循的能量规律,建立了一个简单、实用、省时的统计模式,用于计算地面O3浓度.结果表明:不同情况下,计算值与观测值吻合得均比较一致. 相似文献
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海盐气溶胶影响酸碱气体及无机盐气溶胶的敏感性试验 总被引：1，自引：0，他引：1
利用热力学平衡模式ISORROPIA及与之耦合的气相化学模式,通过两类敏感性试验,探讨了海盐气溶胶、相对湿度、温度对3种无机盐（硫酸盐、硝酸盐、铵盐,包括液态和固态）和3种酸碱气体（氨气、气态硝酸、氯化氢）浓度的影响,以及不同海盐气溶胶浓度对热力学平衡的影响。试验结果表明,海盐浓度相对较低、相对湿度达到0．4～0．5以上、温度在-10～15℃之间时对各物种的平衡浓度影响比较显著。温度升高抑制硝酸盐、铵盐的生成,同时引起气态硝酸、氨气和氯化氢浓度的增加。而湿度升高时对硝酸盐、铵盐的生成有促进作用,反而造成气态硝酸、氨气和氯化氢浓度的降低。海盐气溶胶、相对湿度及温度的变化对硫酸盐气溶胶没有影响。在热力学平衡中如果考虑海盐气溶胶（主要成分NaGl）的作用会使得硝酸盐气溶胶、氨气浓度增加,而硝酸气体、铵盐气溶胶浓度减小,其中硝酸盐和气态硝酸的改变最为明显。由于海盐气溶胶和硫酸、硝酸的反应,产生了氯化氢气体,造成海盐气溶胶的氯亏损现象。 相似文献
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准两年振荡对大气中微量气体分布的影响 总被引：6，自引：5，他引：6
NCAR的包含化学、辐射、动力相互作用的两维模式（SOCRATES）移植回国后进行了初步的模拟试验,用以研究某些对环境问题重要的微量气体的化学、辐射、动力传输过程。在不考虑极地平流层云和气溶胶表面非均相化学等情况下,模式积分多年,计算结果稳定,模拟的风场、温度场显示出正常的季节变化,模拟的微量气体分布与卫星实测资料对照,结果也比较一致。为了探讨热带平流层风场的准两年周期振荡（QBO）对平流层微量气体分布的影响,我们做了QBO强迫的数值试验,即在模式中加入QBO强迫,并与不考虑QBO强迫的模拟结果对比。结果表明,QBO与其相关的次级环流所引起动力输送的变化,使平流层微量气体分布发生变化。 相似文献
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北京地区气溶胶PM2.5粒子浓度的相关因子及其估算模型 总被引：20，自引：0，他引：20
文中运用统计分析和气象统计预报的方法 ,使用北京白石桥小区的污染物观测资料和同期北京地区的气象观测资料 ,对影响大气污染的气象因子进行了综合分析 ,并分别建立了气溶胶PM 2 .5粒子浓度与气体污染物、气象要素场的两类统计相关拟合模型。发现气溶胶PM2 .5粒子浓度与气体污染物浓度存在不同程度的相关性 ,且与气象条件亦存在显著的相关关系 ,此类时空变化及其量化估算模型具有一定实际应用价值。通过确定气象要素场和气溶胶浓度的关系可进一步研究不同地区的污染物输送和污染源扩散影响的问题。 相似文献
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为了研究气溶胶粒子浓度垂直分布及其与温度廓线及云水的关系,选取河北地区2013—2014年的9次气溶胶飞机探测资料(高度大于4000 m)进行分析,用指数函数a×exp(b×x)对气溶胶粒子浓度的垂直分布进行拟合、分类,对于出现强逆温的情况将气溶胶粒子浓度与温度廓线作相关性分析。结果表明:当气溶胶本底浓度较低时,云的出现对气溶胶的垂直分布影响较小;当气溶胶本底浓度较高时,气溶胶垂直分布的极大值并未出现在云底,而是存在于距离云底下方1000—1500 m高度处。逆温层对气溶胶粒子浓度的垂直分布有重要作用,粒子在逆温层下累积,出现浓度的极大值。在逆温强度较弱的情况下,数浓度最大值一般出现在近地面附近,但若受到强的平流作用,在该平流层高度处的气溶胶粒子浓度可能会出现超过近地面气溶胶粒子浓度的情况。气溶胶浓度的垂直分布可以分为缓慢递减型、快速递减型、温度相关型三种类型。在出现强逆温的情况下,气溶胶浓度的垂直分布为温度相关型,可以直接通过大气温度廓线和气溶胶本底浓度判断气溶胶浓度的分布。 相似文献
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The trace gases （O3, HCl, CH4, H2O, NO, NO2） in the stratosphere play an important role, not only in the photochemical processes in which the ozone layer destroyed, but also in the radiative processes. In this paper, we review the works on the distribution and variation of the trace gases in the stratosphere and their impact on climate, which have been carried out at the University of Science and Technology of China in the recent 20 years. The Halogen Occultation Experiment （HALOE） data were used to analyse the distribution and variation of the mixing ratio of these trace gases and the temperature trends in the stratosphere in the most recent decade. And the reanalyzed National Centers of Environmental Prediction （NCEP）/NCAR data were also used to give the temperature trends and compared with the results from HALOE data. Numerical simulations were also carried out to study the impact of ozone depletion on the global climate. In this review, the distributions of the trace gases, especially those over the Qinghai-Xizang Plateau, are discussed, and the variations and trends for the trace gases in various levels in the stratosphere have been given for the most recent decade. The temperature variation and the cooling trend obtained from HALOE data in the middle and lower stratosphere for the last 13 years are significant, which agree well with the results from NCEP/NCAR data. While the temperature trend in the upper stratosphere in this period do not seem to have much cooling. The numerical simulations show that either the Antarctic ozone hole or the ozone valley over Qinghai-Xizang Plateau affect not only the temperature and circulation in the stratosphere, but also the temperature, pressure and wind fields in the troposphere, then lead to the global climate change. 相似文献
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There are many indicators that human activity may change climate conditions all around the globe through emissions of greenhouse
gases. In addition, aerosol particles are emitted from various natural and anthropogenic sources. One important source of
aerosols arises from biomass burning, particularly in low latitudes where shifting cultivation and land degradation lead to
enhanced aerosol burden. In this study the counteracting effects of greenhouse gases and aerosols on African climate are compared
using climate model experiments with fully interactive aerosols from different sources. The consideration of aerosol emissions
induces a remarkable decrease in short-wave solar irradiation near the surface, especially in winter and autumn in tropical
West Africa and the Congo Basin where biomass burning is mainly prevailing. This directly leads to a modification of the surface
energy budget with reduced sensible heat fluxes. As a consequence, temperature decreases, compensating the strong warming
signal due to enhanced trace gas concentrations. While precipitation in tropical Africa is less sensitive to the greenhouse
warming, it tends to decrease, if the effect of aerosols from biomass burning is taken into account. This is partly due to
the local impact of enhanced aerosol burden and partly to modifications of the large-scale monsoon circulation in the lower
troposphere, usually lagging behind the season with maximum aerosol emissions. In the model equilibrium experiments, the greenhouse
gas impact on temperature stands out from internal variability at various time scales from daily to decadaland the same holds
for precipitation under the additional aerosol forcing. Greenhouse gases and aerosols exhibit an opposite effect on daily
temperature extremes, resulting in an compensation of the individual responses under the combined forcing. In terms of precipitation,
daily extreme events tend to be reduced under aerosol forcing, particularly over the tropical Atlantic and the Congo basin.
These results suggest that the simulation of the multiple aerosol effects from anthropogenic sources represents an important
factor in tropical climate change, hence, requiring more attention in climate modelling attempts. 相似文献
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We examine the simulated future change of the North Atlantic winter climate influenced by anthropogenic greenhouses gases
and sulfate aerosol. Two simulations performed with the climate model ECHAM4/OPYC3 are investigated: a simulation forced by
greenhouse gases and a simulation forced by greenhouse gases and sulfate aerosol. Only the direct aerosol effect on the clear-sky
radiative fluxes is considered. The sulfate aerosol has a significant impact on temperature, radiative quantities, precipitation
and atmospheric dynamics. Generally, we find a similar, but weaker future climate response if sulfate aerosol is considered
additionally. Due to the induced negative top-of-the-atmosphere radiative forcing, the future warming is attenuated. We find
no significant future trends in North Atlantic Oscillation (NAO) index in both simulations. However, the aerosol seems to
have a balancing effect on the occurence of extreme NAO events. The simulated correlation patterns of the NAO index with temperature
and precipitation, respectively, agree well with observations up to the present. The extent of the regions influenced by the
NAO tends to be reduced under strong greenhouse gas forcing. If sulfate is included and the warming is smaller, this tendency
is reversed. Also, the future decrease in baroclinicity is smaller due to the aerosols’ cooling effect and the poleward shift
in track density is partly offset. Our findings imply that in simulations where aerosol cooling is neglected, the magnitude
of the future warming over the North Atlantic region is overestimated, and correlation patterns differ from those based on
the future simulation including aerosols. 相似文献
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This paper describes a simulation policy model of the combined greenhouse effects of trace gases. With this model, the Integrated Model for the Assessment of the Greenhouse Effect (IMAGE) scenarios for the future impact of the greenhouse effect can be made, based on different assumptions for technological and socio-economic developments. The contribution of each trace gas can be estimated separately.Basically the model, consisting of a number of coupled modules, gives policy makers a concise overview of the problem and enables them to evaluate the impact of different strategies. Because the model covers the complete cause-effect relationship it can be utilized to derive allowable emission rates for the different trace gases from set effect related targets. Regular demonstration sessions with the simulation model have proven the importance of such science based integrated models for policy development.Four different scenarios are worked out for the most important trace gases (CO2, CH4, N2O, CFC-11 and CFC-12). One of these scenarios can be regarded as a growth scenario unrestricted by environmental concerns. The others are based on different strategic policies. After the simulation of future trace gas concentrations global equilibrium temperature increases are computed. Finally the sea level rise, the most threatening effect of the greenhouse problem for the Netherlands, is estimated.Simulation results so far emphasize the importance of trace gases other than CO2. The Montreal Protocol on reduction of CFC is found to stabilize the relative contribution of these substances to the greenhouse effect. 相似文献