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一、引言1982年邓聚龙教授创建了灰色系统理论。几年来,在工农业生产与气象预报服务中都取得了一批可喜的成果。所谓灰色系统,即只能掌握或只能获取其部分信息的系统。人们将信息完全清楚的系统称为白色系统;信息基本不清楚的系统称黑色系统。灰色系统理论将预测问题作为一个未来系统进 相似文献
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基于混沌吸引子的复杂农业系统预测模型研究 总被引：1，自引：0，他引：1
农业生产是自然再生产和经济再生产有机结合的过程，农业系统是高度耦合了自然生态、社会经济系统等的复杂大系统，具有非线性和耗散性特征。复杂农业系统要素非线性作用所表现的系统行为形成农业系统的整个演化轨迹。从长期演化来看，由于系统内部自组织作用、系统协同和外部随机扰动的作用使得农业系统出现混沌现象，故复杂系统具有长期不可预测性。本文根据复杂农业系统的预测规范，重构复杂农业系统相空间，建立了基于“混沌吸引子”的非线性混沌动力学预测模型，并以成都的相关数据进行分析验证。 相似文献
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典型块结构非线性系统包括基本的输入非线性系统、输出非线性系统、输入输出非线性系统、反馈非线性系统等.输入非线性系统包括输入非线性方程误差类系统和输入非线性输出误差类系统.以输入非线性方程误差自回归系统,即输入非线性受控自回归自回归(IN-CARAR)系统为例,分别基于过参数化模型,基于关键项分离原理,基于数据滤波技术以及基于辨识模型分解技术,研究和提出了IN-CARAR系统的随机梯度辨识方法、多新息随机梯度辨识方法、递推最小二乘辨识方法、多新息最小二乘辨识方法.这些方法可以推广到其他输入非线性方程误差系统、输入非线性输出误差类系统、输出非线性方程误差类系统、输出非线性输出类系统、反馈非线性系统等.同时,给出了几个典型辨识算法的计算步骤、流程图和计算量. 相似文献
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热带气旋外围环流中次天气尺度系统及其与天气尺度系统相互作用的诊断分析 总被引：1，自引：0，他引：1
本文应用带通滤波的方法,分离出热带气旋外围环流中的天气尺度和次天气尺度系统。发现热带气旋外围强降水与低层次天气尺度系统的辐合关系相当密切。文中还计算了两种尺度系统间的动能和涡度转换。得出:在650hPa以上基本上是天气尺度系统向次天气尺度系统提供动能,在650hPa以下基本上是次天气尺度系统向天气尺度系统提供动能,整层积分的结果是天气尺度系统向次天气尺度系统提供动能。在900hPa和400hPa之间的涡度转换为次天气尺度系统向天气尺度系统转换,即涡度转换的结果是使得次天气尺度系统气旋性减弱,天气尺度系统气旋性增强。900hPa以下和400hPa以上则相反。整层积分的结果是次天气尺度系统向天气尺度系统提供正涡度。 相似文献
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设计了数值分析预报产品的拼合图制作系统。该系统是在原地面传输网络上的格点资料绘图系统基础上制作的 ,对原系统进行了一系列改进。该系统属于MICAPS系统的二次开发内容之一 相似文献
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长江中下游地区梅雨期线状中尺度对流系统分析Ⅰ：组织类型特征 总被引：17，自引：4，他引：13
利用2010年6—7月长江流域雷达拼图和观测资料,统计分析了长江中下游地区梅雨期中尺度对流系统的类型和活动特征。结果表明,长江中下游地区梅雨期线状中尺度对流系统发生个数比非线状中尺度对流系统发生个数略多,存在8类典型的线状中尺度对流系统:尾随层状降水中尺度对流系统(TS)、准静止后向建立中尺度对流系统(BB)、邻接层状单向发展中尺度对流系统(TL/AS)、前导层状降水中尺度对流系统(LS)、平行层状降水中尺度对流系统(PS)、断裂线状中尺度对流系统(BL)、镶嵌线状中尺度对流系统(EL)、长带层状降水中尺度对流系统(LL)。其中,有6类和已有的研究结果类似,EL中尺度对流系统和LL中尺度对流系统是长江流域梅雨期新统计的两类线状中尺度对流系统。TS、LS、PS和BL等4类中尺度对流系统是移动性的,TL/AS、BB、EL和LL类中尺度对流系统为移动缓慢相对静止的。线状中尺度对流系统平均持续时间大多数在7h以上,TL/AS和TS类持续时间较长。线状中尺度对流系统多形成在长江两岸附近,重庆北部至鄂西沿江地带、江汉平原地区、皖南和赣北地区、大别山地区是中尺度对流系统的多发地;中尺度对流系统移动路径分为东、东偏北、东偏南、南等4种,这与环境场的引导气流有关。长江中下游地区中尺度对流系统发展阶段日变化呈现多峰型特征,在成熟阶段的下午至夜间发生强降水的概率明显大于凌晨至上午。 相似文献
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为适应省级中尺度数值预报业务的需要,设计实现了天津市中尺度数值预报业务系统。该系统由高性能计算机系统、中尺度数值预报模式以及业务运行流程组成的,其设计与实现涉及到高性能计算机系统的建设、中尺度数值预报模式的业务数据流转以及系统运行监控流程的设计等多个方面。高性能计算机系统的建设包括系统选型、功能设计和安装调试等部分,中尺度数值预报模式的业务数据流转以及系统运行监控流程的设计是整个系统业务化的关键。天津市中尺度数值预报业务系统通过工程建设和技术开发完成了奥运期间的气象预报服务任务,已投入业务化运行。 相似文献
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一、前言日本南极地区观测队为使昭和基地的地面、高空气象观测自动化,在气象楼的屋顶上设置了综合自动化气象观测装置(以下简称 AMOS)。AMOS 分为地面气象观测系统和高空气象观测系统(以下简称地面系统、高空系统),通过电路控制装置组成一个能互相交换资料的系统。地面系统进行地面气象自动观测,高空系统进行无线电探空的自动观测、资料分析、地面和高空的数据统计处理等。二、装置概要地面系统和高空系统都备有正副中央处理机(CPU)各2台,地面系统另备有输入输出信号控制部分和标准计时器各2台,高空系统备有输入输出 相似文献
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我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格. 相似文献
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Comparing the theoretical versions of the Beaufort scale, the T-Scale and the Fujita scale 总被引：1，自引：0，他引：1
G. Terence Meaden S. Kochev L. Kolendowicz A. Kosa-Kiss Izolda Marcinoniene Michalis Sioutas Heino Tooming John Tyrrell 《Atmospheric Research》2007,83(2-4):446-449
2005 is the bicentenary of the Beaufort Scale and its wind-speed codes: the marine version in 1805 and the land version later. In the 1920s when anemometers had come into general use, the Beaufort Scale was quantified by a formula based on experiment. In the early 1970s two tornado wind-speed scales were proposed: (1) an International T-Scale based on the Beaufort Scale; and (2) Fujita's damage scale developed for North America. The International Beaufort Scale and the T-Scale share a common root in having an integral theoretical relationship with an established scientific basis, whereas Fujita's Scale introduces criteria that make its intensities non-integral with Beaufort. Forces on the T-Scale, where T stands for Tornado force, span the range 0 to 10 which is highly useful world wide. The shorter range of Fujita's Scale (0 to 5) is acceptable for American use but less convenient elsewhere. To illustrate the simplicity of the decimal T-Scale, mean hurricane wind speed of Beaufort 12 is T2 on the T-Scale but F1.121 on the F-Scale; while a tornado wind speed of T9 (= B26) becomes F4.761. However, the three wind scales can be uni-fied by either making F-Scale numbers exactly half the magnitude of T-Scale numbers [i.e. F′half = T / 2 = (B / 4) − 4] or by doubling the numbers of this revised version to give integral equivalence with the T-Scale. The result is a decimal formula F′double = T = (B / 2) − 4 named the TF-Scale where TF stands for Tornado Force. This harmonious 10-digit scale has all the criteria needed for world-wide practical effectiveness. 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：11，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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The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998–2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features. 相似文献
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流场配置及地形对西南低涡形成的动力作用 总被引：10，自引：8，他引：10
本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用. 相似文献
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由中国历史气候记录对季风导致唐朝灭亡说的质疑 总被引：1，自引：0，他引：1
张德二 《气候变化研究进展》2008,4(2):126-130
2007年1月4日杂志发表了Yancheva等10人的题为"Influence of the intertropical convergence zone on the East-Asian monsoon"(热带辐合带对东亚季风的影响)的论文[1],这是德国波兹坦地学研究中心气候动力与沉积学科的主管豪格(G.H.Haug)率领的科研小组的一项成果,认为是季风的变化引起的长期干旱导致了唐朝的灭亡. 相似文献
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Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over
the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature
(SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds.
Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early)
onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in
these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly
correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with
respect to its mean date in most of El Ni?o cases.
The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by
the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America
during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region.
The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple
regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation
coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill
to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully
predicted, and there were no predictions of categories opposed to those observed.
Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002 相似文献
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Chunguang CUI Wen ZHOU Hao YANG Xiaokang WANG Yi DENG Xiaofang WANG Guirong XU Jingyu WANG 《大气科学进展》2023,40(4):711-724
Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230... 相似文献