两层原始方程海流数值模式和模拟

设计了一个两层原始方程海流数值模式，利用１月和７月多年平均的海平面气压场和由该气压诊断出的海面风场，对此模式的性能进行了检验，结果表明，模拟得出的海洋表层及次表层流与实况较为一致，文中还将模拟结果和ＩＡＰ ＯＧＣＭ以及ＯＳＵ ＯＧＣＭ的相庆结果作了初步比较和分析。     

34层线性球面原始方程谱模式与模式大气对地形强迫的响应

本文建立了一个34层包括牛顿冷却、Rayleigh摩擦和非绝热加热线性原始方程谱模式。用此模式对地形强迫为下边界条件进行时间积分。结果表明,此模式计算稳定,有较好的精度及计算时间节省的特点模式的积分结果还表明,此模式对球面大气准定常行星波的形成和传播有较好的描写能力。     

一个全球变网格多层原始方程差分模式的设计

文章设计了一个以均匀网格差分模式为基础的全球变网格多层原始方程差分模式。还证明了如果前者满足了一定条件,从而具有质量与能量守恒性质以及与连续情况一致的动能、位能和表面位能之间的转换关系,则变网格模式也同样具有。而且,把前者改变为后者增加的运算量很小,也非常方便。     

半拉格朗日方法在全球原始方程模式中的实现

简单介绍了半拉格朗日平流方案的基本概念,并详细总结了基估全球原始方程模式,特别是在ＩＦＳ的具体实现过程,拉格朗日平流的观点是着流体质点看流体运动,基贩关键是流体轨迹的计算。轨迹中点和起始点水平坐标的示得可以利用球面三角,直接在球极坐标中进行,并采用一些较高的近似。为了充分获得半拉格朗日方案析益处,在起始点的内插能工巧匠春阶数至少应在四阶以上,为避免昂贵的三维三次内插,可以采用三维“准三次”内插 。     

物理守恒律保真格式构造与数值预报斜压原始方程传统谱模式改进研究

文中构造并证明了一般二次和三次物理守恒律时间差分保真格式两个构造定理,以往一些主要时间离散守恒格式构造方案可作为两个定理特例给出。它们不仅可为解决更加广泛类别的时间离散保真格式构造基本问题提供适用数学基础,而且也为结合已有瞬时空间离散守恒格式,解决更加广泛类别的时-空离散意义下保真格式构造基本问题提供适用的数学基础。此外,文中两个定理还可解决两大类问题的线性和非线性计算不稳定性问题。斜压原始方程传统半隐式全球谱-垂直有限差分模式目前是世界上许多国家的业务预报和大气环流模式。本工作利用文中新构定理,构造并且实现了斜压原始方程全球谱-垂直有限差分模式半隐式高阶全能量守恒方案。以往该项基本问题无论在理论还是实践上长期以来一直都未能得到解决。     

全球大气多层原始方程距平谱模式的研制

距平滤波模式（ＡＦＭ）是具有独特优点的长期天气预报模式，本文推广进而设计了一类全球大气多层原始方程距平谱模式，并利用该模式对热带海温距平产生的大气响应进行了试验性模拟，结果表明多层原始方程距平模式不同于ＡＦＭ，更有别于ＧＣＭ，在短期气候异常的动力学过程研究或预报方面显示出广泛的应用价值。     

对多层原始方程模式的合理性分析

本文分理论基础和数值分析两部份。在第一部份中,利用绝热无耗散多层原始方程模式从理论上证明:如在初始时刻t_0时运动是对称的(包括地形是对称的),则在t>t_0的任一时刻,运动将保持是对称的。还在考虑对称地形情况下用模式进行时间数值积分,证明了理沦结果的正确性,因而,理论结果可以作为分析模式合理性的基础。 但是,如考虑实际地形,则由于其对称部份和反对称部份数量相当,运动的对称性会大大降低,受影响的地区主要是北半球高山地区和南半球与之对称的低地。而且,这种影响是从低层逐渐传播到高层的。     

南海热带气旋数值预报模式与全球谱模式的嵌套试验

分析了各嵌套变量的作用和效果，发现采用部分变量嵌套就能取得一定效果，各变量的作用也不完全相同。这样，可以选取作用大，质量好，易处理的变量进行嵌套。并相应地提出了一个边界嵌套处理方案，应用于南海带热带气旋数值预报有限区模式（ＴＬ１０）与全球谐模式（Ｔ６３）的嵌套过程，通过数值预报试验，表明采用该嵌套处理方案能够取得良好的效果。     

A regional spectral nested multilevel primitive equation model

By means of vertical normal modes a regional nested multilevel primitive equation model can be reduced to sev-eral sets of shallow water equations characterized by various equivalent depths. Therefore, time integration of the model in spectral form can be performed in the manner similar to those used in the spectral nested shallow water equation model case.     

初始方程三层模式的改进试验

本文针对三层初始方程模式在业务使用中存在的问题,进行了一些改进试验。内容包括提高空间差分精度、缩小网格距离和改进初值风的计算等三个方面。对系统移速偏慢的问题,改进是明显的。对系统发展预报偏弱的问题,也有改进。试验表明,地转参数在低纬的取值,可能是一个敏感的因子。     

Initialization and data assimilation experiments with a primitive equation model

The process of combining models of the ocean circulation with large data sets is known in meteorology as model initialization and data assimilation. This process is new to oceanographers, who only now are on the verge of having available world-wide synoptic maps of dynamic variables. In this paper we carry out a series of idealized initialization/assimilation experiments with a primitive equation (PE) model, which constitute a first step in developing a realistic process model and data assimilation techniques for the Gulf Stream system. The PE model is used in a spin-down mode and initialized with an analytic jet profile with geostrophically balanced fields.Two major questions are addressed in the present study. The first concerns the initialization process of a PE model during which internal/inertial gravity wave noise is produced. We ask: are the initialization shocks equally crucial for ocean models as they have been for their atmospheric counterparts? The results of an extensive series of balanced versus unbalanced initializations indicate that, for a PE model with a rigid lid, a brutally unbalanced initialization is required to produce strong internal gravity wave shocks. A geostrophically balanced initialization is sufficient to ensure smooth jet evolutions, with no apparent gravity waves, over long time durations in the spin-down mode. No sophisticated initialization procedures seem, therefore, to be required.The second question addressed is: which component of the flow is the most important in data assimilation to drive the model response towards a baseline reference ocean? We specifically compare the knowledge of the depth-integrated flow only, corresponding to measurements of the total transport, with the knowledge of the density field only, or equivalently the velocity shear. The knowledge of the interior density field is much more effective in decreasing the root-mean-square (r.m.s.) errors relative to the reference ocean. If the baroclinic structure is known, coarse horizontal resolutions of data insertion can be reached before significantly worsening the model estimates. If only the depth-averaged flow is known, a decrease in the horizontal resolution of data assimilation has an immediate effect: the r.m.s. errors sharply increase and the assimilation run diverges from the reference ocean. In the assimilation of the barotropic flow alone, even with dense resolution, the errors in the deep layers always show an increasing trend. The relative effectiveness of baroclinic versus barotropic data insertion can be rationalized in the context of geostrophic adjustment theory.     

A Global Spectral Model and Test of Its Performance

A brief introduction is given of a global spectral model, its dynamical framework and diabatic physical processes involved. A number of real forecasts are shown to illustrate the forecasting capability of the model for various weather processes. It can even manage to predict some of those typical weather processes in summer which used to be difficult to forecasters.     

Analysis—Prediction experiments over Indian region using primitive equation barotropic model

The impact of initial guess and grid resolutions on the analysis and prediction has been investigated over the In-dian region. For this purpose, an univariate objective analysis scheme and a primitive equation barotropic model have been used. The impact of initial guess and the resolutions on analysis and prediction is discussed.     

采用隐式立方样条计算平流过程的数值模式及理想实验

本文介绍了一种用隐式立方样条求解平流方程的数值方法,并从理论上对其无条件稳定性进行了证明,在此基础上建立了一个在地形坐标系下的两维原始方程模式,模式在行星边界层参数化中引入了湍流动能方程,在模式顶部引入了吸收层.数值实验表明:模式有较好的计算稳定性,对较高的模式水平分辨率和复杂地形均有较强的适应能力;对复杂地形和下垫面非均匀热源条件下中尺度系统的模拟能获得合理的结果,并具有较高的精确度.     

The water-bearing numerical model and its operational forecasting experiments part I: the water-bearing numerical model

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A regional spectral nested shallow water equation model

A method to expand meteorological elements in terms of finite double Fourier series in a limited-region and a spectral nested shallow water equation model based upon the method with conformal map projection in rectangular coordinates, have been proposed, and computational stability and efficiency of time integration have been discussed.     

The water-bearing numerical model and its operational forecasting experiments part ii: The operational forecasting experiments

The water-bearing numerical model is undergone all round examinations during the operational forecasting ex-periments from 1994 to 1996. A lot of difficult problems arising from the model’s water-bearing are successfully re-solved in these experiments through developing and using a series of technical measures. The operational forecasting running of the water-bearing numerical model is realized stably and reliably, and satisfactory forecasts are obtained.