一个SO2气相化学模式及其敏感性分析

气相化学过程是硫沉降过程中的重要过程。气相化学反应既是ＳＯ２气体的氧化去除过程,也为液相化学过程提供初值条件。首先建立了一个适合于研究硫沉降过程的气相化学数值模式,模式包括了５２个方程、３１个物种。然后利用这个气相化学模式探讨了ＳＯ２的气相氧化过程对大气温度、湿度、太阳光强等条件的敏感性并给出了ＳＯ２气相氧化率的日变化。     

一种新的线性回归模型及其应用示例

回归分析是统计分析中常用的方法之一。传统的回归模型不具备全域分析能力,而变量场之间的关系多采用SVD（Singular Value Decomposition）进行分析,与传统的回归分析有所脱节。更为广义的线性回归模型是传统线性回归模型的延拓,在标量情况下,该模型可转化为传统线性回归模型。该模型的基本特征包含乘法不可互易性、等价于传统线性回归（因子项为标量时）、可分析性、延拓性、降维特征及容错性等。该模型解决了传统的线性回归模型不具备全域分析能力及模型表达能力受限于模型维数的现实问题。本文采用了NCEP（National Centers for Environmental Prediction）降水、高度场、风场月平均资料及国家气候中心西太平洋副热带高压指数资料,利用该模型和传统回归方案进行对比分析,分析结果表明,该模型具有一定的实用参考价值。     

The Tropospheric Gas-Phase Degradation of NH3 and Its Impact on the Formation of N2O and NOx

The gas-phase degradation of NH3 in the atmosphere still has many uncertainties. One of them is the possible isomerisation of NH2O to NHOH, as indicated by kinetic studies. Since NH2O is formed during the gas-phase oxidation of ammonia in the troposphere, this reaction can potentially influence the subsequent production of N2O and NOx. So far, the isomerisation has never been implemented into current chemical schemes describing the atmospheric gas-phase degradation of NH3 and its atmospheric relevance has never been assessed. The N2O yield from NH3 degradation is calculated to be in the range of 10–43 %. It depends on the NO2 and O3 concentrations, but is independent of the NH3 concentration. Compared with the results from recent literature, the N2O yield derived from the new mechanism is 20–80% lower, implying a smaller global N2O source strength of 0.4 Tg yr- 1. The production of NH2SO2 seems to be less important for the atmospheric degradation of NH3. NH3 oxidation is a sink for NOx at NOx mixing ratios of more than about 1 ppb and a source at lower NOx burdens.     

Chemical Mechanism Development: Laboratory Studies and Model Applications

Within the German Tropospheric Research Programme (TFS) numerous kinetic and mechanistic studies on the tropospheric reaction/degradation of the following reactants were carried out: oxygenated VOC, aromatic VOC, biogenic VOC, short-lived intermediates, such as alkoxy and alkylperoxy radicals.At the conception of the projects these selected groups were classes of VOC or intermediates for which the atmospheric oxidation mechanisms were either poorly characterised or totally unknown. The motivation for these studies was the attainment of significant improvements in our understanding of the atmospheric chemical oxidation processes of these compounds, particularly with respect to their involvement in photooxidant formation in the troposphere. In the present paper the types of experimental investigations performed and the results obtained within the various projects are briefly summarised. The major achievements are highlighted and discussed in terms of their contribution to improving our understanding of the chemical processes controlling photosmog formation in the troposphere.     

全球二维大气化学模式和大气化学成分的数值模拟

建立了一个全球二维纬向平均化学模式,模式包括了从90°S到90°N,从地面到20 km高度的大气.模式中应用的流场来自根据加热率计算得到的剩余环流.模式化学部分包括34种大气成分、104个化学反应和光化学反应.其中,甲烷、一氧化碳和氮氧化物排放分为季节性和非季节性排放源,并将其参数化为时间和纬度的函数再应用到模式中去.按1990年的甲烷、一氧化碳和氮氧化物的的排放水平模拟得到了多种大气组成的分布,模拟结果与观测有较好的一致性.由于模式考虑了一氧化碳的季节变化,模拟得到的OH自由基分布更为合理.模式的建立为今后进一步研究大气微量成分的全球循环过程及其长期变化提供了有效的手段.     

一个植被模式的检验和它在陆气相互作用中的应用

简要介绍了一个植被模式（Simplified Simple Biosphere Model）的发展过程及其在气候研究中的作用。许多观测资料被用来检验和标定这个模式。文中着重介绍了俄罗斯土壤湿度资料和非洲的HAPEX-Sahel观测资料如何帮助我们改进模式和对陆面过程的机制的认识,对观测误差的影响也作了讨论。在地气相互作用中,着重讨论了东亚地气作用的特征。在文中介绍的两个东亚地区的试验中,尽管地面的异常被假设在东亚的两个不同的地区,但都对夏季风传输途径上的降水有很大影响。最后用一个区域模式对陆面模式在预测试验中的应用作了简介。初步的结果显示,这将是一个有很大发展潜力的新领域。     

华北地区农业干旱预测模型及其应用研究

对华北地区冬小麦进行了水分胁迫实验,确定了冬小麦光合作用速率对水分胁迫的响应曲线,提出了农业干旱指数和农业干旱预警指数两个基本概念,在此基础上建立了具有明确生物学机理的华北农业干旱预测数值模式。对北京、石家庄、郑州和济南1998年至2000年432旬的农业干旱模拟结果表明：农业干旱预警定性准确率为90.7%,定量准确率在87.5%左右;此外,模拟表明模式也可以对区域农业干旱进行准确有效的预测。利用1961~2000年气象资料对北京等地区历年农业干旱进行数值分析,结果表明：不同于大气干旱,在自然气象条件下,北京等地区作物生长期内几乎每年都存在农业干旱现象,特别是冬小麦灌浆至成熟期每年均存在一次较为严重的农业干旱胁迫过程,但农业干旱胁迫程度年际间存在一定波动,功率谱分析表明其具有3~6年的周期变化规律。对平均气候状况下华北地区农业干旱进行了时空动态分析,结果发现在自然条件下,华北大部分地区冬小麦4月下旬至5月下旬,即大约在冬小麦开花、灌浆至成熟期,农业干旱胁迫指数存在一种自然的逐渐加强的动态过程,这与华北地区的农业生产实践是基本一致的。     

一种可变采样率数据采集方法与应用

为了既能完整采集观测要素数据信息,又能降低功耗,根据观测要素的波动周期特征,用可变采样率方法进行数据采集,由预设定时器控制设备工作,降低了对设备电源的功率要求,解决了受供电能力制约的问题。实际应用表明,这为农业气象自动站的节能设计提供一个有效方法。     

Kinetics of the reactions of Cl atoms with 2-buten-1-ol, 2-methyl-2-propen-1-ol, and 3-methyl-2-buten-1-ol as a function of temperature

The reactions of three structurally similar unsaturated alcohols, 2-buten-1-ol (crotyl alcohol), 2-methyl-2-propen-1-ol (MPO221) and 3-methyl-2-buten-1-ol (MBO321) with Cl atoms, have been investigated for the first time, using a 400 l Teflon reaction chamber coupled with gas chromatograph-coupled with flame-ionization detection (GC-FID). The experiments were performed at atmospheric pressure and at temperatures between 255 and 298 K, in air or nitrogen as the bath gas. The obtained kinetic data were used to derive the Arrhenius expressions , , (in units of cm³ molecule⁻¹ s⁻¹). Finally, atmospheric lifetimes of those unsaturated alcohols with respect to OH, NO₃, O₃ and Cl have been calculated.     

气象灾害的灾体模型及其初步应用

基于灾度相关模型,提出了面向气象灾害的四维灾体模型。模型以受灾人数、受灾面积和直接经济损失形成的灾度平面作为损失的基本规模,在灾度平面垂直方向,以死亡失踪人数为要素形成第四维,最终形成四维灾体。将模型初步应用于我国气象灾害损失年景评价分析之中,结果显示,2003、2006和2010年为气象灾害损失明显偏重年景;验证分析表明,灾体模型将死亡失踪人数作为特殊的一维来考虑,凸显了其在整个气象灾害损失评价中的重要地位,另外增加受灾面积指标,使得评价结果更趋完整。     

高寒草甸生态系统陆地生物圈模式研究及应用

改进了适合于高寒草甸生态系统的陆地生物圈模式，分析了模式中温度变化与水分运动分层的物理原因，说明了气候状况对地表面能量交换的影响，给出了净辐射和蒸散量新的计算方法，提出了有限差分计算中具有二阶精度的Euler隐式格式，介绍了中国科学院海北高寒草甸生态站的气候概况和野外观测情况。最后利用本模式对高寒草甸生态站地区的土壤－－植被－－大气间水热交换过程进行了数值模拟，模拟值与实测值吻合较好。     

Formulation and Evaluation of IMS, an Interactive Three-Dimensional Tropospheric Chemical Transport Model 2. Model Chemistry and Comparison of Modelled CH4, CO, and O3 with Surface Measurements

In part two of this series of papers on the IMS model, we present the chemistry reaction mechanism usedand compare modelled CH₄, CO, and O₃ witha dataset of annual surface measurements. The modelled monthly and 24-hour mean tropospheric OH concentrationsrange between 5–22 × 10⁵ moleculescm^–3, indicating an annualaveraged OH concentration of about 10 × 10⁵ moleculescm^–3. This valueis close to the estimated 9.7 ± 0.6 × 10⁵ moleculescm^–3 calculated fromthe reaction of CH₃CCl₃ with OH radicals.Comparison with CH₄ generally shows good agreementbetween model and measurements, except for the site at Barrow where modelledwetland emission in the summer could be a factor 3 too high.For CO, the pronounced seasonality shown in the measurements is generally reproduced by the model; however, the modelled concentrations are lower thanthe measurements. This discrepancy may due to lower the CO emission,especially from biomass burning,used in the model compared with other studies.For O₃, good agreement between the model and measurements is seenat locations which are away from industrial regions. The maximum discrepancies between modelled results and measurementsat tropical and remote marine sites is about 5–10 ppbv,while the discrepancies canexceed 30 ppbv in the industrial regions.Comparisons in rural areas at European and American continental sites arehighly influenced by the local photochemicalproduction, which is difficult to model with a coarse global CTM.The very large variations of O₃ at these locations vary from about15–25 ppbv in Januaryto 55–65 ppbv in July–August. The observed annual O₃amplitude isabout 40 ppbv compared with about 20 ppbv in the model. An overall comparison of modelled O₃ with measurements shows thatthe O₃seasonal surface cycle is generally governed bythe relative importance of two key mechanisms that drivea springtime ozone maximum and asummertime ozone maximum.     

帕默尔旱度模式在绵阳干旱研究中的应用

本文引用帕默尔旱度模式建模思路和建模方法,对其中可能蒸散量计算方法进行修正,采用国际通用的彭曼-蒙蒂斯公式,利用绵阳1954~2007年的气象资料和部分年份的土壤湿度观测资料,建立绵阳的帕默尔旱度模式,并将实际旱情与计算的帕默尔干旱指数进行了对比验证,帕默尔旱度模式能较好地反映实际旱情。     

A Statistically-Based Low-Level Cloud Scheme and Its Tentative Application in a General Circulation Model

1. Introduction Clouds are active factors in the climate system, and have significant influences on the global hydrolog- ical and thermal budgets. More and more the climate model developers and researchers have realized the im- portance to appropriately describe the interactions be- tween cloud and radiation in the atmospheric general circulation model (AGCM). It is well known that cloud is one of the contributing factors to the uncertainties in the simulation of climate by AGCM. Especiall…     

夏季日峰降温电力负荷预测灰色模型及其应用

基于2017—2020年石家庄市逐15分钟电力负荷及同期气象资料,计算人体舒适度指标有效温度和温湿指数,考虑基准负荷存在周期性和增长性,提出采用灰色模型GM(1,1)并结合滤波法、相关分析等方法,建立日峰降温电力负荷与人体舒适度指标分段回归模型。结果表明:石家庄电力负荷具有明显的逐年增长趋势;剥离出的日降温负荷曲线呈“W”型分布;分别对模型进行一次、二次和分段函数拟合,对3种预测模型进行检验发现分段函数预测精度较高,平均相对误差在4.8%～5.2%,有效温度和温湿指数的分段函数误差在-10%～10%所占比例分别为88.1%和90.5%;考虑了温度、湿度和风速的有效温度较温湿指数的夏季日峰降温电力负荷预测模型预测准确率更高,回归模型分段点为26.2℃,对电网“迎峰度夏”时期电力调度具有参考价值。     

区域雷电灾害风险评估模型与应用

在分析国内雷电灾害风险区划发展现状进行的基础上,从区域雷电灾害事前风险评估的角度出发,采用灾害评估的承灾体、致灾体模式,引入雷电风险、地域风险和承灾体风险作为评估指标,针对每个指标选取与其发生紧密度较高的参数作为2级评价标准,对区域雷电灾害风险进行基于事前致灾因子的区域雷电灾害风险评估研究,并以福建省为例,应用该模型进行了计算。结果表明,基于承灾体、致灾体模式的区域雷电灾害风险评估模型能较好地反应出区域雷电灾害发生的损失程度,对于行政区域范围的雷电灾害风险度区域与政府决策支持具有积极的指导意义。