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Construction and numerical tests of the multi-conservation difference scheme

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Chinese Science Bulletin 2003年第10期48卷 1016-1020页

作者： wang bin & ji {3. lasg, {3., Chinese Academy of Sciences, beijing 100029, china lasg Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A difference scheme with four conservation properties for solving the spherical barotropic shallow water equations is constructed, based on a proper formulae of the equations and a skillful correction on the spatial difference parts of the semi-discrete equations with which the number of the conservation properties of these equations is increased from three to four. Numerical tests are included, and good results are achieved in this study.

关键词：多态守恒差分图解法动力系统正压浅水波方程大气系统数字模型

A new method for constructing total energy conservation algorithms

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Progress in Natural Science:Materials International 2003年第1期13卷 59-62页

作者： ZHAO Ying , ji zhongzhen, YANG Hongwei and wang {3. (1. lasg, {3., Chinese Academy of Sciences, beijing 100029, china 2. institute of Science, PLA University of Science and Technology, Nanjing 211101, china) Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China PLA Univ Sci & Technol Inst Sci Nanjing 211101 Peoples R China

Abstract Based on a basic rule for the research on numerical methods which requires that the properties of the original problemshould be preserved as much as possible under discretization, a new method for constructing total energy conservation algorithms is pre-sented. By this method, all kinds of implicit schemes with energy conservation laws including many classical conservation schemes can beconstructed from a kind of special function. Also, the concrete criterion for judging total energy conservation schemes is given. Numericaltests show that these new schemes are effective.

关键词： total energy conservation difference scheme quasi-antisymmetric operator norm-preserving operator.

Three-dimensional variational data assimilation implemented in numerical modeling for Wuhan torrential rain in July 1998

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Progress in Natural Science:Materials International 2002年第6期 47-50页

作者： ZHANG Xin , wang bin, ji {3. and lin wantao({3., institute of atmospheric physics, Chinese Academy of Sciences, beijing 100029, china) lasg Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

On July 20-21, 1998, a torrential rain with 24-hour rainfall of 286mm occurred in Wuhan, Hubei Province of china. In this study, a three-dimensional variational data assimilation system developed at the Fifth-Generation Pennsylvania State University/National Center for atmospheric Research Mesoscale Model ( MM5 ) along with conventional rawinsonde sounding and surface observation is used for modeling the heavy rain. It successfully incorporates observational data of temperature, humidity and wind, and provides an optimal analysis being in favor of the formation of heavy rain. The 24-hour rainfall predicted by the new scheme is 109 mm rather tban 2.5 mm forecasted by control experiment. Furthermore, the forecasted accuracy of location and time-variation of hourly rainfall reproduced by this model is also improved.

关键词： variational data assimilation torrential rain numerical modeling.

A new method for judging the computational stability of the difference schemes of nonlinear evolution equations

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Chinese Science Bulletin 2000年第15期45卷 1358-1361页

作者： lin wantao Jl zhongzhen wang {3. YANG Xiaozhong State Key Laboratory of Numerical Modeling for atmospheric Science and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China North china Electric Power University Beijing 102206China

For the non-conservative difference schemes of nonlinear evolution equations with aperiodic boundary conditions, taken one-dimensional nonlinear advection equation as an example, a new method for judging the computational stability is given. It is proved to be practical and effective through several numerical examples. The stability criteria obtained by this method are really the necessary conditions of computational stability.

关键词： nonlinear evolution equation difference scheme computational stability heuristic analysis.

Construction of Explicit Quasi-complete Square Conservative Difference Schemes of Forced Dissipative Nonlinear Evolution Equations

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Advances in atmospheric Sciences 2001年第4期18卷 604-612页

作者：林万涛季仲贞王斌 State Key Lab. Numer. Modeling A. Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China institute of Physical Ocean Qingdao Ocean University Qingdao 266003 China

Based on the forced dissipetive nonlinear evolution equations for describing the motion of atmosphere and ocean, the computational stability of the explicit difference schemes of the forced dissipotive nonlinear {3. and oceanic equations is analyzed and the computationally stable explicit complete square conservative difference schemes are constructed. The theoretical analysis and numerical experiment prove that the explicit complete square conservative difference schemes are computationally stable and deserve to be disseminated.

关键词： Forced dissipative nonlinear evolution equation Explicit quasi-complete square conservative difference scheme Computational stability

Computational Stability of the Explicit Difference Schemes of the Forced Dissipative Nonlinear Evolution Equations

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Advances in atmospheric Sciences 2001年第3期18卷 413-417页

作者：林万涛季仲贞王斌 lasg Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

The computational stability of the explicit difference schemes of the forced dissipative nonlinear evolution equations is analyzed and the computational quasi-stability criterion of explicit difference schemes of the forced dissipative nonlinear atmospheric equations is obtained on account of the concept of computational quasi-stability, Therefore, it provides the new train of thought and theoretical basis for designing computational stable difference scheme of the forced dissipative nonlinear atmospheric equations. Key words Computational quasi-stability - Computational stability - Forced dissipative nonlinear evolution equation - Explicit difference scheme This work was supported by the National Outstanding Youth Scientist Foundation of china (Grant No. 49825109), the Key Innovation Project of Chinese Academy of Sciences (KZCX1-10-07), the National Natural Science Foundation of china (Grant Nos, 49905007 and 49975020) and the Outstanding State Key Laboratory Project (Grant No. 40023.01).

关键词： Computational quasi-stability Computational stability Forced dissipative nonlinear evolution equation Explicit difference scheme

Performance of a Parallel Finite Difference atmospheric General Circulation Model

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Advances in atmospheric Sciences 2001年第6期18卷 1175-1184页

作者：张昕王斌季仲贞 lasg Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

A new version of the institute of atmospheric physics (IAP) 9-Layer (9L) atmospheric general circulation model (AGCM) suitable for Massively Parallel Processor (MPP) has been developed. This paper presents the principles of the parallel code design and examines its performance on a variety of state-of-the-art parallel computers in china. Domain decomposition strategy is used to achieve parallelism that is implemented by Message Passing Interface (MPI). Only the one dimensional domain decomposition algorithm is shown to scale favorably as the number of processors is increased.

关键词： IAP 9L AGCM domain decomposition parallel speedup and efficiency

Initialization and Simulation of a Typhoon Using 4-Dimensional Variational Data Assimilation——Research on Typhoon Herb (1996)

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Advances in atmospheric Sciences 2003年第4期20卷 612-622页

作者：张晓艳王斌季仲贞肖庆农张昕 lasg Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 Mesoscale and Microscale Meterorology National Center for Atmospheric ResearchBoulderColoradoUSA

The MM5 and its four dimensional variational data assimilation (4D-Var) system are used in this paper. Based on the National Centers for Environmental Prediction/National Center for atmospheric Research (NCEP/NCAR) reanalysis data, the authors generate an optimal initial condition for a typhoon by using the bogus data assimilation (BDA) scheme. BDA is able to recover many of the structural features of typhoons including a warm-core vertex, the correct center position, and the strong circulation. As a result of BDA using a bogus surface low, dramatic improvement is achieved in the 72 h prediction of typhoon Herb. Through several cases, the initialization by BDA effectively generates the harmonious inner structure of the typhoon, but which is lacking in the original analysis field. Therefore the intensity forecast is improved greatly. Some improvements are made in the track forecast, but more work still needs to be done.

关键词： variational data assimilation bogus scheme BDA Typhoon Herb numerical simulation