共查询到20条相似文献，搜索用时 125 毫秒
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几乎一切天气现象都与大气运动息息相关。大气运动遵循一定的流体力学和热力学规律,在数学上表示为所谓大气运动控制方程组。数值天气预报是采用数值方法求解这组控制方程,从而预报出未来的天气要素场。 相似文献
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大气动力学方程组的定性理论及其应用 总被引：9，自引：2，他引：7
基于完整的湿大气动力学方程组,利用无穷维动力系统的新理论和新方法,系统讨论了强迫耗散的非线性大气系统的定性理论及其应用。将完整的强迫耗散非线性湿大气动力学方程组化为Hilbert空间中一个等价的算子方程,研究了算子的性质及其物理意义,在此基础上得到湿大气系统全局吸引子的存在性定理,揭示出系统向外源的非线性适应特征,并把结果推广到有地形动力作用和非定常外源强迫的情形。同时探讨了大气方程组惯性流形的存在,大气多平衡态产生的根源以及强迫、耗散和非线性对系统解的渐近行为的影响。在理论结果的基础上,提出强迫耗散的非线性动力系统中存在三类时间边界层、方程组简化准则、分解算法的算子约束原则以及支撑吸引子基底的少数自由度的构造方法,探讨了理论在非线性发展方程差分格式的设计和计算稳定性分析、多平衡态的数值分析、数值模式延伸预报的改进、短期气候预测以及一类中尺度系统分析与预测中的应用,指出描述长期过程动力学模式的必备条件,给出初值与模式相协调的合理解释。最后,对今后的研究方向作了展望。 相似文献
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大气动力学研究始于20世纪初期，如运用流体力学发展了环流理论；1930年代，应用波动力学发现了Rossby波。50年代初实现了基于正压模式的数值天气预报，因此动力学在大气科学一直处于主导地位。但自1980年代起随着气候和全球变化研究的进展，热力学放到越来越重要的位置上，因为热力学因子对大气和地球系统的长期行为更为重要。 相似文献
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GRAPES模式中三维科氏力计算及其效果评估 总被引：1，自引：0，他引：1
作为一种连续可压缩流体,大气具有分层流体特性,其状态变化可由牛顿第二定律、热力学第一定律、连续方程和理想大气状态方程组成的偏微分方程组描述。为了更加精细地描述GRAPES全球模式的动力过程,使模式大气更接近真实大气,在全球非静力模式GRAPES中考虑三维科氏力作用,通过重新构建半隐式半拉格朗日求解大气动力方程组的亥姆霍兹方程系数,在不改变求解方案的前提下实现对GRAPES模式动力过程的更新。然后采用在静力平衡基础上建立的三维大气理想试验对新的动力过程进行数值试验,检验其计算效果和数值稳定性。结果显示,考虑三维科氏力的模式动力框架计算稳定,提高了三维标量和矢量场的计算精度,在水平1°×1°分辨率模式中,平衡流试验第15天计算结果标量场Π'的l1和l2误差分别为0.00023和0.0004,而三维矢量场 V 的l1和l2误差分别为0.002和0.003,均较原模式误差小一个数量级。在罗斯贝-豪威兹波、地形罗斯贝波和斜压波试验中,新框架均表现出很高的计算稳定性和良好的计算效果。 相似文献
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对T106分析／预报场可预报性的初步分析 总被引：3，自引：3，他引：3
本文围绕日常天气预报的需求和为区域数值天气预报模式定义天气背景场和初值场的需要，针对9210工程MICAPS系统中T106谱模式的客观分析场和预报场的可预报性进行了初步诊断，定量分析比较了T106、欧洲中心ECMWT、华盛顿KEBC和日本JAPAN数值模式对天气环流形势和预报的统计误差，并初步探讨了模式误差的自身预报问题。文中指出了T106模式的误差源主要来自于其客观分析场的固定误差，提出了以集成客观分析场作为客观分析，提供预报员预报参考或作为数值预报的背景初值场。 相似文献
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初论双三次数值模式 总被引：4，自引：1，他引：4
讨论在数学Rn空间里,存在孔斯双三次曲面拟合的可能数值模式(以下称双三次数值模式)。双三次数值模式特点是,在诊断上对天气系统中的由各个物理定律表述的(离散点)大气物理量场,可通过数学三次样条函数做双三次曲面拟合,则模式大气(包括天气系统)的各个物理量场均达到二阶可导,即是大气运动方程中的各个物理量场都存在各自的一、二阶空间微商,从而可以对模式大气与天气系统做时间积分。与有限差分模式和谱模式存在所谓的空间截断误差和波数截断误差相比较,双三次数值模式存在所谓的空间拟合误差,恰是现行有限差分模式空间截断误差的高阶小量。而双三次数值模式具有谱模式准确计算空间微商的优点,且双三次数值模式的数学构架能够较好地适应大气运动动力框架,是可与有限差分模式和谱模式相比较的另一数值分析新算法的气象数值模式。 相似文献
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中尺度数值天气预报模式——MM5V3 总被引：2，自引：0，他引：2
ＭＭ5是由美国国家大气科学研究中心 (ＮＣＡＲ)和宾夕法尼亚州州立大学共同研制开发的流体非静力中尺度数值天气预报模式 ,其完全可压缩 ,支持多网格嵌套 ,且其物理过程全面 ,有多种物理过程可供选择 ,具有四维资料同化功能 ,对从天气尺度、中尺度到积云尺度的天气系统均能进行模拟。ＭＭ5Ｖ3是ＭＭ5的第三版本 ,其性能更为稳定。ＭＭ5的分辨率是可调的 ,其最小分辨率可达到 1ｋｍ(这一分辨率对计算机的内存和运算速度要求很高 ) ,其模式输出涵盖了几乎所有常规气象场及诊断场。由于ＭＭ5Ｖ3地形资料和地表特征资料的分辨率很高 (0 .9ｋｍ)… 相似文献
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雷兆崇 《南京气象学院学报》1988,(3)
本文提出了一个可以用于大气定常波数值模拟的线性化初始方程三维谱模式。在模式中物理场的水平结构采用了球谐函数展开,而其垂直结构则采用了勒让德多项式展开。模式中包含了Newton冷却、Rayleigh摩擦及▽~4水平扩散等耗散作用。文中给出了模式参数选择、数值求解的详细方案以及该模式大气的扰动流函数场对于北半球大尺度地形和1979年1月平均非绝热加热场的响应的实际计算结果。 相似文献
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THE MODELING IMPROVEMENT OF HURRICANE ANDREW BY THE TECHNIQUE OF IRREVERSIBLE THERMODYNAMIC OPERATORS* 
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下载免费PDF全文 Although incorporating the horizontal diffusion into the atmospheric governing equations is a part of the dynamics of a model,it is based on the computational consideration originally,which is to overcome the nonlinear aliasing or computational instability and smooth the physical fields at the same time.The generally used forms of the fourth-order diffusion,either linear or nonlinear,however,can not properly describe the real physical diffusion processes and thus affect the accuracy of forecasting and modeling.In this paper,based on the nature of the physical diffusion.the scheme of horizontal diffusion of the MM5 Version 3 is improved according to the second law of thermodynamics which controls the irreversable evolutionary direction of a many-body system and the potential ability of the improvement of the new scheme in modeling accuracy is revealed by introducing the technique suggested in this paper,via a theoretical case and the computational case of the hurricane Andrew that landed on Florida in 1992. 相似文献
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Although incorporating the horizontal diffusion into the atmospheric governing equations is apart of the dynamics of a model,it is based on the computational consideration originally,which isto overcome the nonlinear aliasing or computational instability and smooth the physical fields at thesame time.The generally used forms of the fourth-order diffusion,either linear or nonlinear,however,can not properly describe the real physical diffusion processes and thus affect theaccuracy of forecasting and modeling.In this paper,based on the nature of the physical diffusion.the scheme of horizontal diffusion of the MM5 Version 3 is improved according to the second law ofthermodynamics which controls the irreversable evolutionary direction of a many-body system andthe potential ability of the improvement of the new scheme in modeling accuracy is revealed byintroducing the technique suggested in this paper,via a theoretical case and the computational caseof the hurricane Andrew that landed on Florida in 1992. 相似文献
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The second law of thermodynamics has never been taken into account in the traditional hydrodynamics and numerical weather prediction models,which is a serious oversight in the history of mechanics.Introducing the thermodynamic irreversibility into the hydrodynamic systems,the theory and method proposed in this study would not only lead the outputs of a numerical weather prediction model to noticeable improvement,but lead the structure of hydrodynamics to deepgoing transformation. 相似文献
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The second law of thermodynamics has never been taken into account in the traditional hydrodynamics and numer-ical weather prediction models,which is a serious oversight in the history of mechanics.Introducing the thermodynamicirreversibility into the hydrodynamic systems,the theory and method proposed in this study would not only lead theoutputs of a numerical weather prediction model to noticeable improvement,but lead the structure of hydrodynamics todeepgoing transformation. 相似文献
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将计算流体力学(CFD)技术与中尺度数值天气模式预报结合,提出了一种实现米级分辨率的街区局地气象场的计算方法。介绍了该方法的基本原理、特点、实现条件和用途等,并用实例展示了其应用领域。 相似文献
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The paper is a contribution to present knowledge of the system: atmosphere-ice-ocean. A theoretical model for investigation of the dynamics and thermodynamics of an ice-cover regime is suggested.Based on this physical model, a series of numerical experiments has been performed to define the influence of changing external conditions on the ice cover regime (variations of albedo and heat flux from water to the lower ice surface). 相似文献
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It is generally believed by those undertaking research in the fundamental aspects of geophysical fluid dynamics and meteorology that their results contribute to the improvements to numerical weather prediction and in practical weather forecasting. However, the techniques whereby the appropriate research results are selected and incorporated into the numerical models are not widely known, particularly the methods for representing the phenomena whose horizontal scale is less than that of the grid boxes.(say, 50 km). Some accounts of numerical weather prediction imply that the representation of subgrid-scale phenomena is formally similar to classical physics. In fact, atmospheric motions on these scales are not like molecular motions in an ideal gas, but show considerable structure, approximating to combinations of various idealized states. Great skill and experience in this specialized activity has been applied to deciding on these states, finding physical criteria for defining them and then modelling the relevant phenomena occurring on this scale. In this paper, we focus on a restricted range of phenomena associated with stably stratified flows, notably mountain waves, convection and clouds, and boundary layer phenomena. This category provides many examples of structures which need to be considered in detail to reconstruct the large-scale picture accurately, as well as in local forecasting. 相似文献
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