共查询到19条相似文献，搜索用时 640 毫秒
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目前,长期预报的业务工作主要还是采用统计方法,传统的统计建模要求建模之前建模者必须事先确定或假设模式里的应变量和变量之间的函数关系f,而统计建模工作的实质是根据数据或资料去确定该函数f里的参数或系数。 相似文献
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运用改进系统建模法对南海气象数据的建模研究 总被引：2，自引：0，他引：2
在系统建模理论的基础上,运用改进的动态数据建模方法,对南海气象数据中的温度进行建模并验证了模型的适用性.根据模型推导出格林函数、逆函数和自协方差函数等,并讨论了南海气象数据中温度模型的稳定性、可逆性和合理性.对系统的频率特性和谱函数进行分析讨论,并给出建模过程中的一些图像.根据模型的适用性检验发现,对所研究的气象数据而言,ARMA(4, 3)模型是最合适的,具有平稳可逆性.所有的建模和分析过程在MATLAB上实现.实验结果表明这种建模方案简便易行,能够快速准确地确定系统的合理模型. 相似文献
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在天气预报中,采用多维时间序列分析,考虑了因子数值的前后承继关系还注意了因子间的相互联系,其物理意义是无疑的。但是,建立多维自迴归数学模型在一般气象台却难以实现,因为无论是 BOX 的统计建模理论,还是吴贤铭的系统建模思想,都必须求助于大型电子计算机方 相似文献
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一种局地非线性气候动力统计模型及其预报试验 总被引：1，自引：5，他引：1
根据反演建模理论，在引入一次样条函数的基础上，设计了一种局地非线性气候动力统计模型及其一整套反演方案。其实质是用逐段线性化的研究局地气候演化的非线性特征。作为初步试验，利用云南省18个测站1956年1月－1990年12月逐月温度距平和逐月雨量距平率的时间序列，反演得到一组近似描述云南省局地气候系统的非线性动力统计方程，应用反演获得的此非线性动力统计方程进行了云南省18个测站1991年1月－1994年12月逐月温度距平和逐月雨量距平率的预报试验。试验结果表明，温度距平和雨量距平率的拟合准确率分别约为78％和64％；温度距平和雨量距平率的外推预报准确率分别为75％和63％。表明此模型具有一定的拟合和预报能力，同时具有良好的稳定性。 相似文献
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<正>10年时间尺度的气候预测,由于能够提供给政策制定者和有关部门与单位近期的气候变化预测,作为经济规划和社会生活安排等的参考,因此越来越受到重视。10年气候预测是气候科学中一个新的领域,一般预测方法采用:一是统计预测方法,根据前期气候变化特征,利用统计关系,计算预测未来10年的气候变化;二是动力模式预测方法,利用全球或区域气候模式,在一定初边条件和外强迫作用下,预测未来10年的气候变化;三是动力加统计 相似文献
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在进行多元回归分析时,样本协方差L_(ij)这个统计量要经常地、大量地用到。就是在进行其它的多元统计分析时,也要经常用到这个统计量。而在做统计分析时,还要经常出现样本容量的不断变化,或增加,或减少,或者还要合并几个样本。在1983年第2期的《山东气象》上我们曾对1952年至1977年的26组数据进行过降水预报方程计算,利用样本协方差递推公式一个一个增加 相似文献
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统计预报近年来在国内外有了很大的发展。它已成为目前气象台站日常应用的主要预报方法之一。为此,我们特约中国科学院大气所周嘉斌同志介绍适合于气象台站应用的几种统计预报方法连续刊登。为使行文通俗简明,作者将所有较为复杂的理论推导全部略去。读者如有兴趣作进一步了解和研究,可参阅参考文献或有关书刊。 相似文献
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Summary First, the Group Method of Data Handling (GMDH) algorithm, a self-organizing method for constructing higher order regression, is applied to build a model for long-term forecasting. Then, the Group Method of Phase Space Component (GMPSC) model is set up based on chaos theory and GMDH. Several case studies show that both GMDH and GMPSC provide an efficient and potentially useful tool for non-linear time series modeling.Supported by the NKPFR Climate Dynamics and Climate Prediction Theory. 相似文献
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气象观测环境的变化对气温序列的影响分析 总被引：15，自引：2，他引：15
本文利用安徽省1971~2000年共30 a逐日平均气温、最高气温、最低气温的气候整编资料,选取气象观测环境完全符合相关规定(A类)和不完全符合相关规定(B类)两类代表站,分别建立了气温序列和两者的气温差值序列,并对气温序列的气候平均值和气温差值序列的气候趋势进行了分析。结果表明:气象观测环境的变化将影响气温序列。与A类台站相比,B类台站平均气温、最高气温和最低气温的气候平均值表现出一致偏高的特征,最低气温偏高最多;B类台站与A类台站平均气温、最高气温和最低气温的差值均有显著增大的趋势,平均气温差值的增大最为显著。 相似文献
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首先介绍了极轨气象卫星资料地理定位误差的来源,回顾了地理定位误差的研究状况.随后重点分析了3种可行的定位误差评估与订正的数学方法,并结合极轨卫星资料定位误差的订正实例,对不同订正方法进行了比较和讨论.最后展望了地理定位误差订正方法的研究方向. 相似文献
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Yu. A. Izrael S. M. Semenov O. A. Anisimov Yu. A. Anokhin A. A. Velichko B. A. Revich I. A. Shiklomanov 《Russian Meteorology and Hydrology》2007,32(9):551-556
Basic results of IPCC Working Group II, derived in the process of the work at the Fourth Assessment Report, are considered in brief. The results are given in conformity with the Summary for Policymakers adopted at the Plenary Meeting of Working Group II in Brussels on April 6, 2007. The authors’ comments on some results connected with the key vulnerable elements of natural and socioeconomic systems are given in the conclusion. 相似文献
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A uniform, international reference system of precipitation indices would greatly facilitate assessment of changes in global precipitation patterns, intensities and extremes. However, national/regional differences in precipitation monitoring standards, data quality control procedures, and product development practices complicate efforts to develop such a system. This report represents the results of Working Group B's concerted effort to examine in detail the problems associated with the development of the needed indicators and the Group's recommendations to address the identified issues. The Group concluded that a successful strategy must define a minimum set of indices/indicators based on higher quality data that would represent a global base set. The Group identified a set of indices for this purpose. This base data set should be complemented where possible by countries/regions having the data sets and processing resources to do more. 相似文献
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Jianhong WANG Meiqi LI X.San LIANG Xing WANG Feng XUE Mo PENG Chunsheng MIAO 《大气科学进展》2018,35(7):826-838
The asymmetrical structure of typhoon-induced ocean eddies(TIOEs) in the East China Sea(including the Yellow Sea)and the accompanying air–sea interaction are studied using reanalysis products. Thirteen TIOEs are analyzed and divided into three groups with the k-prototype method: Group A with typhoons passing through the central Yellow Sea; Group B with typhoons re-entering the sea from the western Yellow Sea after landing on continental China; and Group C with typhoons occurring across the eastern Yellow Sea near to the Korean Peninsula. The study region is divided into three zones(Zones Ⅰ, Ⅱ and Ⅲ) according to water depth and the Kuroshio position. The TIOEs in Group A are the strongest and could reverse part of the Kuroshio stream, while TIOEs in the other two groups are easily deformed by topography. The strong currents of the TIOEs impact on the latent heat flux distribution and upward transport, which facilitates the typhoon development. The strong divergence within the TIOEs favors an upwelling-induced cooling. A typical TIOE analysis shows that the intensity of the upwelling of TIOEs is proportional to the water depth, but its magnitude is weaker than the upwelling induced by the topography. In Zones Ⅰ and Ⅱ, the vertical dimensions of TIOEs and their strong currents are much less than the water depths.In shallow water Zone Ⅲ, a reversed circulation appears in the lower layer. The strong currents can lead to a greater, faster,and deeper energy transfer downwards than at the center of TIOEs. 相似文献
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The paper investigates topics, emphases, frames and absences in the Summary for Policymakers parts of the three Working Group reports in the IPCC 5th Assessment Report and the Summary for Policymakers of the Synthesis Report. It explores similarities and differences by using various tools of lexical and discourse analysis, combining quantitative and qualitative methods. The main results are these: First, each Working Group’s Summary reflects not only the Working Group’s distinctive mandate but also a distinctive intellectual framing. Second, although there are some significant differences in the emphases given to different themes from the Working Groups, the Synthesis Summary covers the main topics of the three other Summaries, and constitutes a relatively integrated summary of the complete Assessment Report. Third, we find though that the Synthesis Summary centrally follows up the risk framing and language which are prominent in Working Group II but semi-absent in the other Working Groups, as part of constructing a policy-relevant statement from the three distinctive reports. In addition, the Synthesis Summary makes use of linguistic devices which contribute to ‘amplify’ the strength of statements, as part of transferring messages effectively from the scientific context to a policy-maker audience. Fourth, we find that the style and tone of the IPCC Summaries conduce also to important absences and imbalances in emphasis: main victims of climate change (particular groups of vulnerable people) remain virtually invisible in the Summaries, unlike the impacts in nature and ecological systems or the aggregate economic impacts, and correspondingly the challenges, options and opportunities for action remain relatively underdeveloped in the analysis. 相似文献
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IPCC于2022年4月正式发布了第六次评估报告(AR6)第三工作组(WGⅢ)报告《气候变化2022:减缓气候变化》,该报告以已发布的第一和第二工作组报告作为基础,评估了各领域减缓气候变化的进展。报告的第九章建筑章节系统全面地评估了全球建筑领域的温室气体排放现状、趋势和驱动因素,综述并评估了建筑减缓气候变化的措施、潜力、成本和政策。报告主要结论认为,全球建筑领域有可能在2050年实现温室气体净零排放,但如果政策措施执行不力,将有可能在建筑领域形成长达几十年的高碳锁定效应。报告的主要结论将成为全球建筑领域应对气候变化行动的重要参考,对于我国建筑领域实现碳达峰、碳中和目标也有非常重要的借鉴意义。 相似文献