臭氧对夏季大气环流影响的数值模拟

利用球带ｐ－σ坐标系模式，模拟了臭氧对夏季大气环流的作用，结果表明，臭氧作用引入模式后，大气高压环流特征得到显著改善，臭氧使高层大气的加热率增大；对低层大气，虽然臭氧的加热作用很小，但可通过改变其他加热场分量的分布和量值，从而改变总加热率，使低层大气环流同样发生变化。     

极区大气臭氧变化对中国气候影响的数值模拟

首先利用TOMS资料分析了南北极区大气臭氧总量的季节变化特征。结果表明 ,南北极区的臭氧减少都是春季下降最快 ,然后通过数值试验得到 ,极区大气臭氧减少将造成高低层温度差值分布大致相反 ,由于臭氧减少也将使我国的大气环流形势和降水分布特征发生改变。在我国的不同区域 ,各气象要素的变化也具有不同特征。     

大气CO2浓度升高及气候变化对作物冠层光合影响的数值模拟

利用美国Licor-6200光合作用测定仪,对黄淮海地区代表性冬小麦品种鲁麦23号叶片光合作用速率进行了较为全面的测定,分别确定了冬小麦叶片光-光合作用响应曲线和CO2-光合作用响应曲线,在此基础上,建立了叶片光合作用模式,并进而建立了一个具有瞬时时间尺度,空间积分为叶片尺度的冬小麦冠层模式,利用模式分别分析了大气中CO2浓度升高和温度变化对冠层光合作用的不同影响,并在此基础上进一步进行了综合数值分析.单因子分析表明晴天状况下,冠层光合速率随CO2浓度升高而上升,当CO2浓度由330×10-6上升至660×10-6时,冠层光合日总量可增加19.7 %;冠层光合速率随辐射增加而增大,辐射量增加10.0 %,冠层光合日总量可增加6.7 %;冠层光合速率随温度升高而下降,温度升高1 ℃,冠层光合日总量减少2.9 %.多因子综合数值分析表明在辐射量较大的气候背景下,冠层光合日总量对温度和CO2变化响应更加敏感.本文的实测数据为研究气候变化对中国农业影响提供了最基本的可靠模型参数,冠层光合模型为未来改进作物模型提供了理论基础.     

夹卷对郊外大气边界层内臭氧影响的数值模拟研究

夹卷是大气边界层与自由大气进行能量和物质交换的重要途径,对边界层动力结构及边界层内温度、水汽和各种污染物浓度有重要影响。利用化学-地表-大气-土壤(CLASS)模式定量评估了夹卷过程对远郊地区大气边界层内臭氧（O₃）浓度的影响并与大气化学反应贡献进行了对比,结合地面O₃、NO_x及边界层高度、位温和比湿等观测资料和再分析资料对CLASS模拟结果进行了定量评估。结果表明:CLASS模式能较为真实地模拟夹卷和大气光化学反应对远郊地区大气边界层臭氧浓度的影响,且当自由大气层内臭氧浓度达到一定值时,两者对边界层内臭氧峰值影响相当。数值试验结果进一步揭示,夹卷对控制氮氧化物（NO_X）和可挥发性有机物(VOC_S)排放源控制效果有重要影响,且当夹卷区内O₃跳跃值增大到一定时,可完全抵消源排放减排控制的效果。本研究旨在表明,为有效控制近地层臭氧浓度,在制定人为污染源减排措施时必须考虑自由大气层臭氧的夹卷贡献。      

南半球臭氧变化气候效应的数值模拟

采用一个陆气耦合的９层谱模式模拟了南半球臭氧减少所产生的气候效应。数值试验结果表明,南半球臭氧的减少不仅对南半球温度场的 大气环流有影响,而且对北半球的温度场结构和大气环汉也有一定的影响。其气候效应具有全球性。南半球臭氧减少总体上可以使平流层中层以上大气降温、平流层低层增温、对流层顶附近降温。此外,在北半球冬半年期间,南半球臭氧的减少可使南北半球的副热带西风急流都减弱,极锋急流都增强;在北半球夏半     

近地层臭氧对我国树木生产力和作物产量的影响:进展与展望

大气污染严重威胁了我国陆地生态系统的固碳能力,但随着减污降碳协同治理的快速推进,减缓大气污染将有利于提升陆地碳汇,并切实推动碳达峰碳中和目标的实现。为了更好地理解大气污染与生态系统固碳的关系,本文以主要空气污染物臭氧（O₃）为例,基于田间控制实验的整合分析、剂量响应关系及机理模型三种评估方法综述了近地层O₃污染对植被碳固定影响的最新进展。尽管不同作物种类以及品种、不同功能型木本植物对O₃的响应有着显著的差异,且各种方法的评估结果也不尽相同,但目前O₃浓度造成我国粮食作物减产、森林生产力降低已是不争的事实。持续升高的O₃浓度将严重威胁我国陆地生态系统的固碳能力。利用我国作物和树木的O₃剂量响应方程进行评估的结果表明,在CO₂减排和O₃污染协同治理下,预计2060年我国树木生物量和作物产量将比当前显著提高,增加陆地生态系统碳汇,助力碳中和目标。最后,对如何提高O₃污染环境下植物固碳能力也进行了展望。     

大气臭氧垂直分布变化的模拟研究

利用包括垂直平流、扩散和化学过程的一维平流层—对流层的大气化学模式，通过增加NOx的地面源，发现由于NOx地面源的增强，引起对流层下部臭氧浓度增加，夏季臭氧浓度的增加远大于冬季；通过扩散系数和垂直风速的敏感性试验比较，看出由平流层向对流层输送臭氧的过程中，平流过程的影响可能更重要。     

地形对近地层风场日变化影响的数值模拟

利用修改的Mass模式和辽宁地区的地形资料，模拟了地形加热作用对辽宁地区近地层风场日变化的影响。结果表明，渤海和黄海北部海域对辽宁地区近地层风场的影响起着非常重要的作用。由于海陆加热的不同，加热冷却速度的不同以及山地地形等可产生不同的流场日变化。     

近地层O3和CO2浓度变化对冬小麦影响的数值模拟：Ⅱ模拟结果和分析

针对CO2和O3浓度变化对冬小麦影响,改进了农田生态系统碳氮生物化学模型(DNDC),并利用模型模拟了O3和CO2浓度变化对冬小麦生长发育和产量的影响,检验了模型的模拟效果.通过对原DNDC模型适用性的调整,使之适用于固城站,为进一步改进作物模型打下了可靠的基础.通过试验资料验证表明,模型较好地反映了O3和CO2浓度变化对冬小麦生长发育和产量形成的影响.通过敏感性分析得出,模型对温度变化反映灵敏;在CO2浓度倍增情况下,O3浓度变化对冬小麦的复合影响分析看出,一定浓度范围内,CO2可缓解O3对作物影响的负效应,O3对CO2带来的正效应有削弱作用.     

大气CO2浓度升高及气候变化对作物冠层光合影响的数值模拟

利用美国Licor-6200光合作用测定仪,对黄淮海地区代表性冬小麦品种鲁麦23号叶片光合作用速率进行了较为全面的测定,分别确定了冬小麦叶片光—光合作用响应曲线和CO₂—光合作用响应曲线,在此基础上,建立了叶片光合作用模式,并进而建立了一个具有瞬时时间尺度,空间积分为叶片尺度的冬小麦冠层模式,利用模式分别分析了大气中CO₂浓度升高和温度变化对冠层光合作用的不同影响,并在此基础上进一步进行了综合数值分析。单因子分析表明:晴天状况下,冠层光合速率随CO₂浓度升高而上升,当CO₂浓度由330×10^-6上升至660×10^-6时,冠层光合日总量可增加19.7%;冠层光合速率随辐射增加而增大,辐射量增加10.0%,冠层光合日总量可增加6.7%;冠层光合速率随温度升高而下降,温度升高1℃,冠层光合日总量减少2.9%。多因子综合数值分析表明:在辐射量较大的气候背景下,冠层光合日总量对温度和CO₂变化响应更加敏感。本文的实测数据为研究气候变化对中国农业影响提供了最基本的可靠模型参数,冠层光合模型为未来改进作物模型提供了理论基础。     

大气低频振荡的数值模拟

本文利用IAP_GCM积分结果中10年候平均资料，研究了模式大气中的低频振荡现象。结果表明，该模式能相当逼真地模拟出低频振荡的地理分布、垂直结构和传播过程的主要特征，因而低频振荡是大气本身所固有的一种现象。而流场与大气加热场之间在低频域内的相关分析则证实了大气加热对低频振荡的产生起重要的作用，其中最重要的因子是水汽潜热的释放。     

Numerical Simulation Study on the Impacts of Tropospheric and CO_2 Concentration Changes on Winter Wheat. Part I: Model Description

Ozone is well documented as the air pollutant most damaging to agricultural crops and other plants. It is reported that tropospheric O3 concentration increases rapidly in recent 20 years. Evaluating and predicting impacts of ozone concentration changes on crops are drawing great attention in the scientific community. In China, main study method about this filed is controlled experiments, for example, Open Top Chambers. But numerical simulation study about impacts of ozone on crops with crop model was developed slowly, what is more, the study about combined impacts of ozone and carbon dioxide has not been reported. The improved agroecosystem model is presented to evaluate simultaneously impacts of tropospheric O3 and CO2 concentration changes on crops in the paper by integrating algorithms about impacts of ozone on photosynthesis with an existing agroecosystem biogeochemical model (named as DNDC). The main physiological processes of crop growth (phenology, leaf area index, photosynthesis, respiration, assimilated allocation and so on) in the former DNDC are kept. The algorithms about impacts of ozone on photosynthesis and winter wheat leaf are added in the modified DNDC model in order to reveal impacts of ozone and carbon dioxide on growth, development, and yield formation of winter wheat by coupling the simulation about impacts of carbon dioxide on photosynthesis of winter wheat which exists in the former DNDC. In the paper, firstly assimilate allocation algorithms and some genetic parameters (such as daily thermal time of every development stage) were modified in order that DNDC can be applicable in North China. Secondly impacts of ozone on crops were simulated with two different methods- one was impacts of ozone on light use efficiency, and the other was direct effects of ozone on leaves photosynthesis. The latter simulated results are closer to experiment measurements through comparing their simulating results. At last the method of direct impacts of ozone on leaf growth is adopted and the coefficients about impacts of ozone on leaf growth and death are ascertained. Effects of climate changes, increasing ozone, and carbon dioxide concentration on agroecosystem are tried to be simulated numerically in the study which is considered to be advanced and credible.     

Numerical Simulation Study on the Impacts of Tropospheric O3 and CO2 Concentration Changes on Winter Wheat.Part I: Model Description

Ozone is well documented as the air pollutant most damaging to agricultural crops and other plants.It is reported that tropospheric O3 concentration increases rapidly in recent 20 years. Evaluating and predicting impacts of ozone concentration changes on crops are drawing great attention in the scientific community. In China, main study method about this filed is controlled experiments, for example, Open Top Chambers. But numerical simulation study about impacts of ozone on crops with crop model was developed slowly, what is more, the study about combined impacts of ozone and carbon dioxide has not been reported.The improved agroecosystem model is presented to evaluate simultaneously impacts of tropospheric O3 and CO2 concentration changes on crops in the paper by integrating algorithms about impacts of ozone on photosynthesis with an existing agroecosystem biogeochemical model (named as DNDC). The main physiological processes of crop growth (phenology, leaf area index, photosynthesis, respiration, assimilated allocation and so on) in the former DNDC are kept. The algorithms about impacts of ozone on photosynthesis and winter wheat leaf are added in the modified DNDC model in order to reveal impacts of ozone and carbon dioxide on growth, development, and yield formation of winter wheat by coupling the simulation about impacts of carbon dioxide on photosynthesis of winter wheat which exists in the former DNDC. In the paper, firstly assimilate allocation algorithms and some genetic parameters (such as daily thermal time of every development stage) were modified in order that DNDC can be applicable in North China. Secondly impacts of ozone on crops were simulated with two different methods-one was impacts of ozone on light use efficiency , and the other was direct effects of ozone on leaves photosynthesis. The latter simulated results are closer to experiment measurements through comparing their simulating results. At last the method of direct impacts of ozone on leaf growth is adopted and the coe cients about impacts of ozone on leaf growth and death are ascertained. Effects of climate changes, increasing ozone, and carbon dioxide concentration on agroecosystem are tried to be simulated numerically in the study which is considered to be advanced and credible.     

Numerical Simulation Study on the Impacts of Tropospheric O3 and CO2 Concentration Changes on Winter Wheat. Part II: Simulation Results and Analyses

With the rapid development of industrialization and urbanization, the enrichment of tropospheric ozone and carbon dioxide concentration at striking rates has caused effects on biosphere, especially on crops. It is generally accepted that the increase of CO2 concentration will have obverse effects on plant productivity while ozone is reported as the air pollutant most damaging to agricultural crops and other plants. The Model of Carbon and Nitrogen Biogeochemistry in Agroecosystems (DNDC) was adapted to evaluate simultaneously impacts of climate change on winter wheat. Growth development and yield formation of winter wheat under different O3 and CO2 concentration conditions are simulated with the improved DNDC model whose structure has been described in another paper. Through adjusting the DNDC model applicability, winter wheat growth and development in Gucheng Station were simulated well in 1993 and 1999, which is in favor of modifying the model further. The model was validated against experiment observation, including development stage data, leaf area index, each organ biomass, and total aboveground biomass. Sensitivity tests demonstrated that the simulated results in development stage and biomass were sensitive to temperature change. The main conclusions of the paper are the following: 1) The growth and yield of winter wheat under CO2 concentration of 500 ppmv, 700 ppmv and the current ozone concentration are simulated respectively by the model. The results are well fitted with the observed data of OTCs experiments. The results show that increase of CO2 concentration may improve the growth of winter wheat and elevate the yield. 2) The growth and yield of winter wheat under O3 concentration of 50 ppbv, 100 ppbv, 200 ppbv and the based concentration CO2 are simulated respectively by the model. The simulated curves of stem, leaf, and spike organs growth as well as leaf area index are well accounted with the observed data. The results reveal that ozone has negative e ects on the growth and yield of winter wheat. Ozone accelerates the process of leaf senescence and causes yield loss. Under very high ozone concentration, crops are damaged dramatically and even dead. 3) At last, by the model possible effects of air temperature change and combined effects of O3 and CO2 are estimated respectively. The results show that doubled CO2 concentration may alleviate negative effect of O3 on biomass and yield of winter wheat when ozone concentration is about 70-80 ppbv. The obverse effects of CO2 are less than the adverse effects of O3 when the concentration of ozone is up to 100 ppbv. Future work should determine whether it can be applied to other species by adjusting the values of related parameters, and whether the model can be adapted to predict ozone e ects on crops in farmland environment.     

我国对流层大气臭氧的数值模拟

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.     

当前对流层臭氧数值模式研究中的若干问题

对当前对流层臭氧(O3)数值模式研究中存在的若干问题以及需要重点研究的方向进行了评述,内容包括O3前体物的生态源及其模拟、对流层化学机制、大气化学研究中的气象模式以及大气化学模式与气象模式的相容性等.