脱硝技术与天然气应用情景下京津冀地区空气质量模拟评估     

李健  安俊岭  陈勇  屈玉 《气候与环境研究》2013,18(4):472-482

针对京津冀地区主要大气污染物NOx（氮氧化物）和PM2.5（大气中粒径小于或等于2.5μm的颗粒物）,应用柴油车尾气净化技术及中小锅炉烟气脱硝技术,并根据2015年和2030年我国能源规划,设计3种技术应用情景,采用WRF-CAMx耦合模式,对京津冀地区大气中NOx和PM2.5进行了应用情景模拟。结果表明,单独应用柴油车尾气净化技术后（方案1）,北京、天津地区大气中的NOx浓度降低幅度达20%,河北地区降低5%;PM2.5的浓度降低幅度约10%;应用柴油车尾气净化技术和2015年能源规划情景（方案2）,京津冀地区大气中NOx和PM2.5浓度的降低幅度均超过20%;应用柴油车尾气净化技术和2030年能源规划情景（方案3）,该地区NOx浓度降低幅度与之相当,PM2.5浓度降低幅度超过30%。可见脱硝技术和清洁能源利用的有效性依赖于其应用比例。二次气粒转化的化学过程形成的硝酸盐、硫酸盐和铵盐对该地区空气中PM2.5浓度的贡献很大,冬、春、秋季硝酸盐最大贡献高达60%,夏、秋季硫酸盐最大贡献超过70%,铵盐四季最大贡献约25%。这说明PM2.5的主要前体物NOx、SO2、NH3、VOCs (Volatile Organic Compounds)、CO等均大幅度削减才能有效降低该地区空气中PM2.5浓度。  相似文献   

Algorithm Studies on How to Obtain a Conditional Nonlinear Optimal Perturbation (CNOP)     

SUN Guodong  MU Mu  ZHANG Yale 《大气科学进展》2010,27(6):1311-1321

The conditional nonlinear optimal perturbation (CNOP), which is a nonlinear generalization of the linear singular vector (LSV), is applied in important problems of atmospheric and oceanic sciences, including ENSO predictability, targeted observations, and ensemble forecast. In this study, we investigate the computational cost of obtaining the CNOP by several methods. Differences and similarities, in terms of the computational error and cost in obtaining the CNOP, are compared among the sequential quadratic programming (SQP) algorithm, the limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm, and the spectral projected gradients (SPG2) algorithm. A theoretical grassland ecosystem model and the classical Lorenz model are used as examples. Numerical results demonstrate that the computational error is acceptable with all three algorithms. The computational cost to obtain the CNOP is reduced by using the SQP algorithm. The experimental results also reveal that the L-BFGS algorithm is the most effective algorithm among the three optimization algorithms for obtaining the CNOP. The numerical results suggest a new approach and algorithm for obtaining the CNOP for a large-scale optimization problem.  相似文献   

What Kind of Initial Errors Cause the Severest Prediction Uncertainty of El Nino in Zebiak-Cane Model     

XU Huiand DUAN Wansuo State Laboratory of Numerical Modeling for Atmospheric Sciences  Geophysical Fluid Dynamics 《大气科学进展》2008,(4)

With the Zebiak-Cane(ZC)model,the initial error that has the largest effect on ENSO prediction is explored by conditional nonlinear optimal perturbation(CNOP).The results demonstrate that CNOP-type errors cause the largest prediction error of ENSO in the ZC model.By analyzing the behavior of CNOP- type errors,we find that for the normal states and the relatively weak El Nino events in the ZC model,the predictions tend to yield false alarms due to the uncertainties caused by CNOP.For the relatively strong El Nino events,the ZC model largely underestimates their intensities.Also,our results suggest that the error growth of El Nino in the ZC model depends on the phases of both the annual cycle and ENSO.The condition during northern spring and summer is most favorable for the error growth.The ENSO prediction bestriding these two seasons may be the most diffcult.A linear singular vector(LSV)approach is also used to estimate the error growth of ENSO,but it underestimates the prediction uncertainties of ENSO in the ZC model.This result indicates that the different initial errors cause different amplitudes of prediction errors though they have same magnitudes.CNOP yields the severest prediction uncertainty.That is to say,the prediction skill of ENSO is closely related to the types of initial error.This finding illustrates a theoretical basis of data assimilation.It is expected that a data assimilation method can filter the initial errors related to CNOP and improve the ENSO forecast skill.  相似文献   

两种不同减排情景下21世纪气候变化的数值模拟   总被引：4，自引：1，他引：3  

辛晓歌  吴统文  王在志 《气象学报》2009,67(6):935-946

利用国家气候中心最新发展的气候系统模式BCC-CSM1.0模拟了相对于B1排放情景,两种不同减排情景(De90和De07,表示按照B1情景排放到2012年,之后线性递减,至2050年时CO_2排放水平分别达到1990和2007年排放水平一半的情景)对全球和中国区域气候变化的影响.结果表明:两种减排情景下模式模拟的全球平均地表气温在21世纪40年代以后明显低于Bl情景,比减排情景浓度低于B1的时间延迟了20年左右;尽管De90减排情景在2050年所达到的稳定排放水平低于De07情景,但De90情景下的全球增温在2070年以后才一致低于De07情景,这种滞后町能与耦合系统(主要足海洋)的惯性有关;至21世纪末,De90和De07情景下的全球增温幅度分别比B1情景降低了0.4和0.2℃;从全球分布来看,B1情景下21世纪后30年的增温幅度在北半球高纬度和极地地区最大,减排情景能够显著减少这些地区的增温幅度,减排程度越大,则减少越多;在中国区域,B1情景下21世纪末平均增温比全球平均高约1.2℃,减排情景De90和De07分别比B1情景降低了0.4和0.3℃,中国北方地区增温幅度高于南方及沿海地区,减排情景能够显著减小中国西部地区的增温幅度;B1情景下21世纪后30年伞球增温在冬季最高,De90和De07情景分别能够降低各个季节全球升温幅度的17%和10%左右.  相似文献   

全球气候模式对宁夏区域未来气候变化的情景模拟分析   总被引：13，自引：0，他引：13  

杨侃  许吟隆  陈晓光  陈楠 《气候与环境研究》2007,12(5):629-637

利用多个全球气候模式(GCM)的情景模拟结果分析只考虑温室气体效应的IS92a GG情景和同时考虑温室气体效应和硫化物气溶胶辐射效应的IS92aGS情景以及SRESA2、B2情景下宁夏区域21世纪地面气温和降水量的可能变化,并进行不确定性分析。气候基准时段(1961~1990年)模拟结果与观测资料的对比分析表明,GCM对宁夏气候具有一定的模拟能力;整体上讲,GCM对地面气温的模拟值偏低,对降水量的模拟值偏高,其中ECHAM4和HadCM3对宁夏基准时段地面气温和降水量的模拟结果与观测比较接近。各GCM模拟值的平均结果显示,4种温室气体排放情景下21世纪宁夏区域气温持续升高,至21世纪末宁夏升温幅度可达4~6℃,与全国平均的增温幅度大致相当;与升温趋势相应的是降水量的增加,但降水变化呈现出很大的波动性,至21世纪末宁夏的降水变化幅度可达10%~40%。各个GCM模拟的宁夏气候变化的总趋势是一致的,但各模式在不同情景下模拟结果的差异很大,存在较大的不确定性。  相似文献   

网络分析方法在GPS控制网优化设计中的应用     

贺同江  杨国东 《测绘与空间地理信息》2005,28(6):85-87

讨论了网络分析方法中的深度优先遍历算法在GPS控制网优化设计中资源配置问题中的应用,并在该算法的基础上,进行了一定的改进,提出了并行项目的解决建议,为网络的资源配置提出了一种新的解决方法。  相似文献   

一种复杂地理环境越野通行路径寻优算法     

赵成  张涵斐  高毅  吴超辉  黄征 《测绘科学技术学报》2017,(5):525-528,534

设计了基于障碍距离的优化算法,解决突发事件应急联动中复杂地理环境下最短路径的寻优求解问题。在详细分析地理空间高程、坡度、障碍物等空间信息的基础上,通过计算搜索空间、搜索方向和网络弧段权值构建网络拓扑关系网,并利用遗传算法对最优路径进行寻优求解。  相似文献   

Optimal international technology cooperation for the low-carbon transformation     

Anselm Schultes  Marian Leimbach  Gunnar Luderer  Robert C. Pietzcker  Lavinia Baumstark  Nico Bauer 《Climate Policy》2018,18(9):1165-1176

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The global impacts of US climate policy: a model simulation using GCAM-TU and MAGICC     

Han Chen  Lining Wang  Yong Luo  Yu Wang  Sheng Zhou 《Climate Policy》2018,18(7):852-862

To assess the potential impacts of the US withdrawal from the Paris Agreement, this study applied GCAM-TU (an updated version of the Global Change Assessment Model) to simulate global and regional emission pathways of energy-related CO₂, which show that US emissions in 2100 would reduce to ?2.4?Gt, ?0.7?Gt and ?0.2?Gt under scenarios of RCP2.6, RCP3.7 and RCP4.5, respectively. Two unfavourable policy scenarios were designed, assuming a temporary delay and a complete stop for US mitigation actions after 2015. Simulations by the Model for the Assessment of Greenhouse-gas Induced Climate Change (MAGICC) indicate that the temperature increase by 2100 would rise by 0.081°C–0.161°C compared to the three original RCPs (Representative Concentration Pathways) if US emissions were kept at their 2015 levels until 2100. The probability of staying below 2°C would decrease by 6–9% even if the US resumes mitigation efforts for achieving its Nationally Determined Contribution (NDC) target after 2025. It is estimated by GCAM-TU that, without US participation, increased reduction efforts are required for the rest of the world, including developing countries, in order to achieve the 2°C goal, resulting in 18% higher global cumulative mitigation costs from 2015 to 2100.

Key policy insights

• President Trump’s climate policies, including planned withdrawal from the Paris Agreement, cast a shadow on international climate actions, and would lower the likelihood of achieving the 2°C target.

• To meet the 2°C target without the US means increased reduction efforts and mitigation costs for the rest of the world, and considerable economic burdens for major developing areas.

• Active state-, city- and enterprise-level powers should be supported to keep the emission reduction gap from further widening even with reduced mitigation efforts from the US federal government.

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中国森林乔木林碳储量及其固碳潜力预测   总被引：5，自引：0，他引：5  

李奇  朱建华  冯源  肖文发 《气候变化研究进展》2018,14(3):287-294

加强对我国森林碳储量和固碳潜力的研究,是制定中国增汇减排政策的重要依据,对我国国际气候谈判和全面了解森林碳汇潜力具有重要作用。利用我国第七次和第八次森林资源清查中各优势树种的面积和蓄积量数据,采用IPCC材积源生物量法（volume-biomass method),估算了我国森林（乔木林）碳储量和碳密度及其分布,分析我国不同省份天然乔木林和人工乔木林碳储量龄组结构特征;建立分区域、分起源主要优势树种的单位面积蓄积-林龄Logistic生长方程,结合我国森林2020年和2030年面积蓄积增长目标,预测我国乔木林2010—2050年间碳汇潜力。结果表明：第八次清查期间中国乔木林总碳储量为6135.68 Tg,碳密度为37.28 Mg/hm ²;天然乔木林和人工乔木林的碳储量分别为5246.07 Tg和889.61 Tg,分别占总碳储量的85.50%和14.50%。到2050年,中国乔木林和新造林的总碳储量和平均碳密度将分别达到11125.76 Tg和52.52 Mg/hm ²,与2010年相比分别增加81%和41%。分析结果表明中国乔木林有很大的碳汇潜力,将在应对和减缓全球气候变化中发挥重要作用。  相似文献