以数值预报产品为基础的大到暴雪预报系统

利用Ｔ６３数值预报产品,根据灰色系统原理,研制出河南省暴雨２４小时预报系统,并于１９９６年冬季（１９９６年１１月～次年３月）实时业务工作中逐日试报,取得了较为满意的结果,该方法简单明了,便于使用。     

蓄电池直流屏智能控制系统的设计

简介蓄电池直流屏的用途和工作原理，说明在直流屏中的应用ＳＴＤ工控机的可行性，并详细论述智能系统的工作原理，给出系统软硬件的原理图，说明系统的使用情况和应用前景，并讨论了几点存在的问题。     

713雷达数字化终端技术分析

对雷达的探测原理和工作过程进行了简单介绍，重点对７１３雷达的数字化终端ＣＴＣ－８７系统的组成及组成系统的各分机模块，如：视频积分器，天线控制器，雷达定标器，计算机接口的组成和原理进行了深入分析。     

酒店气象专用电视频道技术方案

阐述了酒店气象专用电视频道的工作原理，同时还推荐了本系统软硬件具体的配置，最后对专用系统软件的工作流程及其使用方法进行了详细的说明。     

多普勒天气雷达常见故障维修技巧

通过对CINRAD／CD型天气雷达的发射系统，接收系统，伺服系统及馈线系统工作原理的介绍，指出了各子系统易出现的故障现象原因，处理情况及日常维护注意事项。     

虚拟仪器在天气雷达接收机测试中的应用

目前天气雷达测试和日常维护主要依赖于传统台式仪器,其功能单一、不便携带等局限性极大制约雷达故障诊断和修复,给气象服务带来严重影响。通过对接收机原理和性能参数进行分析,介绍了虚拟仪器的硬件结构和软件特点,并以中频带宽测试为例,详细介绍了虚拟仪器测试系统的设计思路、工作原理和操作方法。由于采用便携式PXI模块化仪器为硬件基础,以软件编程为核心,虚拟仪器体积小、重量轻、便于携带,克服了传统仪器的不足,具有良好的环境适应能力和功能扩展优势,特别适用于雷达台站进行现场测试。     

火情监测系统—极轨卫星遥感应用（TVGA）

利用ＴＶＧＡ卡的１０２４×７６８×２５６模式研制了火情监测系统，介绍了系统的组成、功能和工作流程，并讨论了系统的卫星遥感应用原理和在计算机上实现方法．     

ZQZ-CⅡ型自动气象站故障分析与排除方法

本文从ZQZ-CⅡ型自动气象站的系统构成和工作原理出发，介绍了ZQZ-CⅡ型自动气象站的部分故障分析排除方法。     

语音技术在气象报文传输中的应用

本文主要介绍了电话语音卡的基本工作原理在电话语音传报系统中的应用，为保证报务员用电话按键输入报文所建立的语音工作流程和解决的技术难题。     

黑龙江省林火气象等级预警遥感监测系统

介绍黑龙江省林大气象等级监测顸警系统的功能、原理以及系统軟、硬件组成，对业务化工作应用情况进行了描述。同时，阐述了极轨气象卫星林火监測资料处理方法,并就具体的林火监测实例进行分析,总結了卫星遥感技术在森林防火工作中的应用。     

Tropical Forests Under the Climates of the Last 30,000 Years

Vegetational history can help us to predict future environments by providing data for testing AGCMs, for indicating the vegetational response to rapid warming and changing CO₂ concentrations, and for mathematical modelling of vegetation. Most of the data are palynological, and there are well over 100 pollen diagrams from tropical regions. Maps are presented showing summarized pollen diagrams from the lowlands of South-East Asia and the West Pacific, Tropical Latin America and Tropical Africa. In all these regions there is some evidence suggesting that at the LGM lowland forests were somewhat restricted in area and included montane elements. This is consistent with cooler and drier climate at the LGM. From the montane and lowland areas of these three regions, the pollen evidence is summarized in altitudinal diagrams. These suggest considerable depression of altitudinal zones at the LGM, suggesting temperatures c. 5–10°C cooler than now. These results conflict with earlier oxygen isotope data from marine foraminifera, but do not conflict with more recent oxygen isotope measurements from tropical corals. It is also suggested that altitudinal movements may be partly controlled by CO₂ concentration and ultraviolet light.     

A revised method of presenting wavenumber–frequency power spectrum diagrams that reveals the asymmetric nature of tropical large-scale waves

The popular method of presenting wavenumber–frequency power spectrum diagrams for studying tropical large-scale waves in the literature is shown to give an incomplete presentation of these waves. The so-called “convectively coupled Kelvin (mixed Rossby-gravity) waves” are presented as existing only in the symmetric (anti-symmetric) component of the diagrams. This is obviously not consistent with the published composite/regression studies of “convectively coupled Kelvin waves,” which illustrate the asymmetric nature of these waves. The cause of this inconsistency is revealed in this note and a revised method of presenting the power spectrum diagrams is proposed. When this revised method is used, “convectively coupled Kelvin waves” do show anti-symmetric components, and “convectively coupled mixed Rossby-gravity waves (also known as Yanai waves)” do show a hint of symmetric components. These results bolster a published proposal that these waves should be called “chimeric Kelvin waves,” “chimeric mixed Rossby-gravity waves,” etc. This revised method of presenting power spectrum diagrams offers an additional means of comparing the GCM output with observations by calling attention to the capability of GCMs to correctly simulate the asymmetric characteristics of equatorial waves.     

Synchronicity in Climate and Vegetation Transitions Between Europe and North America During the Holocene

Interpreting the postglacial climate history of the European continent using pollen data has proven difficult due in part to human modification of the landscape. Separating climate from human-caused changes in the vegetation requires a strategy for determining times of change across the entire region. We quantified transitions in the vegetation across Europe during the past 12,000 years using a mixture model approach on two datasets: radiocarbon dates from pollen diagrams and zone boundaries from selected reference sites. Major transitions in the vegetation, as recorded in pollen diagrams, appear synchronous across the continent. These transitions were also synchronous with those identified in North America pollen diagrams and major environmental changes recorded in North Atlantic marine records and Greenland ice cores. This synchronicity suggests that the major vegetation transitions in Europe during the Holocene and late glacial were primarily caused by large-scale atmospheric circulation change. These climate changes may have caused some of the cultural, political and migration changes in European societies during the Holocene.     

能见度目标物图自动化制作系统设计与实现

针对目前国家气象观测站能见度目标物图是手工绘制的现状,开发了能见度目标物图自动化制作系统,实现了任意距离的能见度目标物图的自动化制作。具有观测站信息管理、目标物管理、绘图面板管理和图片输出等功能,图片大小、圆圈系数及生成半径可自行设置,还可以在一张图片上将1000和50000 m目标物图合成,满足现行最小能见度观测业务需要。该系统自动化程度高,操作简单,具有较强的可操作性和实用性。     

Influence Diagrams for Representing Uncertainty in Climate-Related Propositions

In order to respond to policy questions about the potential impacts of climate change it is usually necessary to assemble large quantities of evidence from a variety of sources. Influence diagrams provide a formal mechanism for structuring this evidence and representing its relationship with the climate-related question of interest. When populated with probabilistic measures of belief an influence diagram provides a graphical representation of uncertainty, which can help to synthesize complex and contentious arguments into a relatively simple, yet evidence-based, graphical output.Following unusually damaging floods in October–November 2000 the UK government commissioned research with a view to establishing the extent to which the floods were a manifestation of hydrological climate change. By way of example application, influence diagrams have been used to represent the evidential reasoning and uncertainties in responding to this question. Three alternative approaches to the mathematization of uncertainty in influence diagrams are demonstrated and compared. In situations of information scarcity and imprecise expert judgements, methods based on interval probabilities have proved to be attractive. Interval probabilities can, it is argued, represent ambiguity and ignorance in a more satisfactory manner than the conventional Bayesian alternative. The analysis provides a quantified commentary on the uncertainties in the conclusion that the events of October–November 2000 were extreme, but cannot in themselves be attributed to climate change.     

泰山顶部近地层风的方差与谱分析

风在速度与方向上的不稳定性可引发结构振动并可导致损坏。山顶风较少受局地作用影响, 流场较稳定，作为典型风况对山顶风湍流脉动情形进行的观测和分析，对于研究建筑结构风载振动情形有着重要意义。在不同风况下对泰山气象站近地层风的风速和风向进行了同时、逐秒测记，所得样本经检验符合正态分布。计算表明，风向样本方差显著大于风速样本方差。绘制了各风速、风向样本自、互谱密度曲线图。谱图显示诸样本具有红噪声序列特征，不同样本自、互谱密度曲线具有相近形状，而以风速自谱曲线吻合程度最好，谱密度曲线在周期为4秒及2秒处有峰值。此后的研究应结合记录仪器的改进增加采样频率，对周期为2秒以下谱曲线作进一步分析。     

Regime Diagrams for <Emphasis Type="Italic">K</Emphasis>-Theory Dispersion

In atmospheric dispersion, the “non-Gaussian” effects of gravitational settling, the vertical gradient in diffusivity and the surface deposition do not enter uniformly but rather break up parameter space into several discrete regimes. Here, we describe regime diagrams that are constructed for K-theory dispersion of effluent from a surface line source in unsheared inhomogeneous turbulence, using a previously derived Fourier–Hankel method. This K-theory formulation differs from the traditional one by keeping a non-zero diffusivity at the ground. This change allows for turbulent exchange between the canopy and the atmosphere and allows new natural length scales to emerge. The axes on the regime diagrams are non-dimensional distance defined as the ratio of downwind distance to the characteristic length scale for each effect. For each value of the ratio of settling speed to the K gradient, two to four regimes are found. Concentration formulae are given for each regime. The regime diagrams allow real dispersion problems to be categorized and the validity of end-state concentration formulae to be judged.     

基于溃变理论的沙尘大风天气预测研究

依据溃变理论和溃变V-3θ结构图的信息数字化,预测天气的转折性变化取得了应用的有效性突破。文中针对沙尘大风天气的预测分析,利用单站探空资料的特性层资料,通过V-3θ图直观反映大气层结的滚流方向、稳定度和水汽含量等信息,以此判断大风、沙尘天气的转折性变化。结果表明,沙尘大风发生前,V-3θ图中位温(θ)、露点温度的假相当位温(θsed)曲线非常靠近,θ曲线左倾明显,整层大气存在顺滚流,且对流层上层存在"超低温"现象;当θsed曲线数值增大,明显靠右,则表明沙尘大风天气将结束。溃变图方法显示了简捷、直观和应用有效的特征。     

MJO structure associated with the higher-order CEOF modes

The real-time multivariate Madden–Julian oscillation (RMM; MJO) index has been widely employed to monitor the amplitude, phase, and time evolution of MJO events, as the index is formulated from the leading two combined-empirical orthogonal function (CEOF) modes of daily anomalous OLR and 850- and 200-hPa zonal winds, and the modes describe the MJO dynamics well. These two CEOF modes, however, are known to dominate in power spectra at zonal wavenumber one and may underestimate the power and structure at wavenumbers 2–5 where many MJO events are also prominent. This study approximated a baseline for MJO by applying band-pass filters to daily anomalies on 30–100 day periods and at 1–5 eastward propagating waves, as slightly different bands led to the same conclusions. Following the procedures to develop the RMM index, the daily anomalous data were derived and subjected to the CEOF analysis with all modes archived for diagnosis. Different numbers of the leading modes were compared in explained variance, standard deviation (STD), and wavenumber power spectra to describe the overall MJO magnitude and structure, and on the Hovmöller diagrams to represent the evolution of three distinct MJO events. Results show that the two leading CEOF modes explain only a small portion of the power spectra at wavenumbers 2–5. This spectral leakage notably reduces the MJO amplitude, particularly of the OLR in the western Pacific. The CEOF modes 3–10 can withhold power sufficiently such that the anomalies reconstructed by the first 10 modes contribute most of the baseline variance; their structures agree well with the baseline by constituting nearly the same proportion in the region from the central Indian Ocean to the dateline and by providing more complete evolutions of the three MJO events on the Hovmöller diagrams. Meanwhile, these modes introduce a notable amount of power for the equatorial Rossby and Kelvin waves that are partially embedded in the evolution of MJO. The first 50 of the total 432 CEOF modes retain all variance of the baseline MJO, while those higher than 10 contain less information and more noise and can be discarded. Furthermore, this study indicated that the longitudinal STD of the reconstructed anomalies detects the MJO phases and magnitudes in the western Pacific with more physical meaning and in better agreement with the Hovmöller diagrams than the RMM-like amplitude. The results provide an integral figure of the MJO structure from the CEOF analysis and a more robust RMM framework for monitoring the MJO’s evolution in real time and for validating its numerical forecast and simulations.     

Objective forecasting of frost using locally‐observed meteorological parameters

Abstract

An objective scheme for forecasting frost is derived using scatter diagrams of meteorological parameters observed at 20 h local time at a station in the western Jezreel Valley of Zsrael. Verifîcation based on independent data was highly consistent with probabilities of frost versus no‐frost predicted by the suggested procedure.