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Three-dimensional inversion of metallic minerals electromagnetic data using efficient multigrid solver 认领 引用
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作者 Yong-fei WANG Rong-wen GUO +2 位作者 Zhuo LIU Ding-hui YANG Deng-kang WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2026年第3期943-955,共13页
A three-dimensional(3D)electromagnetic(EM)inversion algorithm based on the nonlinear conjugate gradient(NLCG)method and a two-color plane Gauss-Seidel(GS)multigrid(MG)forward solver is developed to improve inversion e... A three-dimensional(3D)electromagnetic(EM)inversion algorithm based on the nonlinear conjugate gradient(NLCG)method and a two-color plane Gauss-Seidel(GS)multigrid(MG)forward solver is developed to improve inversion efficiency.The results indicate that the computational efficiency of each inversion can be improved by approximately a factor of three by using the proposed MG solver.First,the accuracy of the MG solver is validated through a test on a synthetic model.Next,the numerical performance of the inversion algorithm is evaluated using this model.Finally,the inversion algorithm is applied to a field EM data collected at the Beiya gold polymetallic ore district.A 3D resistivity model is obtained,and the formation process of the metal ore is analyzed. 展开更多
关键词 metallic minerals electromagnetic data gradient inversion method multigrid solver
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L^2-ERROR OF EXTRAPOLATION CASCADIC MULTIGRID (EXCMG) 认领 引用 被引量：9
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作者 陈传淼 胡宏伶 +1 位作者 谢资清 李郴良 《Acta Mathematica Scientia》 SCIE 2009年第3期539-551,共13页
Based on an asymptotic expansion of finite element, an extrapolation cascadic multigrid method （EXCMG） is proposed, in which the new extrapolation and quadratic interpolation are used to provide a better initial val... Based on an asymptotic expansion of finite element, an extrapolation cascadic multigrid method （EXCMG） is proposed, in which the new extrapolation and quadratic interpolation are used to provide a better initial value on refined grid. In the case of multiple grids, both superconvergence error in H^1-norm and the optimal error in l2-norm are analyzed. The numerical experiment shows the advantage of EXCMG in comparison with CMG. 展开更多
关键词 cascadic multigrid finite element new extrapolation quadratic interpolation L^2-error
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3-D direct current resistivity forward modeling by adaptive multigrid finite element method 认领 引用 被引量：16
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作者 汤井田 王飞燕 +1 位作者 任政勇 郭荣文 《Journal of Central South University》 SCIE EI CAS 2010年第3期587-592,共6页
Based on the fact that 3-D model discretization by artificial could not always be successfully implemented especially for large-scaled problems when high accuracy and efficiency were required, a new adaptive multigrid... Based on the fact that 3-D model discretization by artificial could not always be successfully implemented especially for large-scaled problems when high accuracy and efficiency were required, a new adaptive multigrid finite element method was proposed. In this algorithm, a-posteriori error estimator was employed to generate adaptively refined mesh on a given initial mesh. On these iterative meshes, V-cycle based multigrid method was adopted to fast solve each linear equation with each initial iterative term interpolated from last mesh. With this error estimator, the unknowns were nearly optimally distributed on the final mesh which guaranteed the accuracy. The numerical results show that the multigrid solver is faster and more stable compared with ICCG solver. Meanwhile, the numerical results obtained from the final model discretization approximate the analytical solutions with maximal relative errors less than 1%, which remarkably validates this algorithm. 展开更多
关键词 adaptive multigrid a-posteriori error estimator unstructured mesh V-cycle finite element method
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A Multigrid Block LU-SGS Algorithm for Euler Equations on Unstructured Grids 认领 引用 被引量：9
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作者 Ruo Li Xin Wang Weibo Zhao 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE EI 2008年第1期92-112,共21页
We propose an efficient and robust algorithm to solve the steady Euler equa- tions on unstructured grids.The new algorithm is a Newton-iteration method in which each iteration step is a linear multigrid method using b... We propose an efficient and robust algorithm to solve the steady Euler equa- tions on unstructured grids.The new algorithm is a Newton-iteration method in which each iteration step is a linear multigrid method using block lower-upper symmetric Gauss-Seidel(LU-SGS)iteration as its smoother To regularize the Jacobian matrix of Newton-iteration,we adopted a local residual dependent regularization as the replace- ment of the standard time-stepping relaxation technique based on the local CFL number The proposed method can be extended to high order approximations and three spatial dimensions in a nature way.The solver was tested on a sequence of benchmark prob- lems on both quasi-uniform and local adaptive meshes.The numerical results illustrated the efficiency and robustness of our algorithm. 展开更多
关键词 Multigrid block LU-SGS Euler equations aerodynamics airfoil
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A theoretical study of the multigrid three-dimensional variational data assimilation scheme using a simple bilinear interpolation algorithm 认领 引用 被引量：6
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作者 LI Wei XIE Yuanfu HAN Guijun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第3期80-87,共8页
In order to solve the so-called ＂bull-eye＂ problem caused by using a simple bilinear interpolation as an observational mapping operator in the cost function in the multigrid three-dimensional variational （3DVAR） d... In order to solve the so-called ＂bull-eye＂ problem caused by using a simple bilinear interpolation as an observational mapping operator in the cost function in the multigrid three-dimensional variational （3DVAR） data assimilation scheme, a smoothing term, equivalent to a penalty term, is introduced into the cost function to serve as a means of troubleshooting. A theoretical analysis is first performed to figure out what on earth results in the issue of ＂bull-eye＂, and then the meaning of such smoothing term is elucidated and the uniqueness of solution of the multigrid 3DVAR with the smoothing term added is discussed through the theoretical deduction for one-dimensional （1D） case, and two idealized data assimilation experiments （one- and two-dimensional （2D） cases）. By exploring the relationship between the smoothing term and the recursive filter theoretically and practically, it is revealed why satisfied analysis results can be achieved by using such proposed solution for the issue of the multigrid 3DVAR. 展开更多
关键词 multigrid three-dimensional variational data assimilation bilinear interpolation
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基于5阶精度格式WCNS-E-5的p-multigrid方法研究 认领 引用 被引量：3
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作者 王新光 毛枚良 +1 位作者 邓小刚 涂国华 《空气动力学学报》 EI CSCD 北大核心 2012年第1期1-6,共6页
p-multigrid方法的基本思想是:在保证收敛结果为高阶精度的同时,利用低阶精度格式耗散大的特点,来改善高精度有限差分格式在迭代计算时收敛速度慢的弱点。本文基于5阶精度WCNS-E-5差分格式,引入1阶精度迎风格式和3阶精度加权格式,构造了... p-multigrid方法的基本思想是:在保证收敛结果为高阶精度的同时,利用低阶精度格式耗散大的特点,来改善高精度有限差分格式在迭代计算时收敛速度慢的弱点。本文基于5阶精度WCNS-E-5差分格式,引入1阶精度迎风格式和3阶精度加权格式,构造了p-multigrid方法,在迭代过程中采用了V循环、W循环、S循环、Pre_V和FMG循环等不同方式来应用这三种格式,并通过典型算例考察了这些循环方式对收敛速度的影响,初步数值试验表明,采用恰当的循环方式,本文所设计的p-multigrid方法能够加快收敛速度,并保证了最终收敛结果与5阶精度WCNS-E-5差分格式的一致性。 展开更多
关键词 高精度格式 加速收敛方法 p-multigrid方法
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A Preconditioned Multigrid Method for Efficient Simulation of Three-dimensional Compressible and Incompressible Flows 认领 引用 被引量：15
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作者 Han Zhonghua He Fei Song Wenping Qiao Zhide 《Chinese Journal of Aeronautics》 SCIE EI CAS 2007年第4期289-296,共8页
To develop an efficient and robust aerodynamic analysis method for numerical optimization designs of wing and complex configuration, a combination of matrix preconditioning and multigrid method is presented and invest... To develop an efficient and robust aerodynamic analysis method for numerical optimization designs of wing and complex configuration, a combination of matrix preconditioning and multigrid method is presented and investigated. The time derivatives of three-dimensional Navier-Stokes equations are preconditioned by Choi-Merkle preconditioning matrix that is originally designed for two-dimensional low Mach number viscous flows. An extension to three-dimensional viscous flow is implemented, and a method improving the convergence for transonic flow is proposed. The space discretizaition is performed by employing a finite-volume cell-centered scheme and using a central difference. The time marching is based on an explicit Rtmge-Kutta scheme proposed by Jameson. An efficient FAS multigrid method is used to accelerate the convergence to steady-state solutions. Viscous flows over ONERA M6 wing and M100 wing are numerically simulated with Mach numbers ranging from 0.010 to 0.839. The inviscid flow over the DLR-F4 wing-body configuration is also calculated to preliminarily examine the performance of the presented method for complex configuration. The computed results are compared with the experimental data and good agreement is achieved. It is shown that the presented method is efficient and robust for both compressible and incompressible flows and is very attractive for aerodynamic optimization designs of wing and complex configuration. 展开更多
关键词 Navier-Stokes equations preconditioning method multigrid method numerical simulation
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System of Multigrid Nonlinear Least-squares Four-dimensional Variational Data Assimilation for Numerical Weather Prediction(SNAP):System Formulation and Preliminary Evaluation 认领 引用 被引量：1
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作者 Hongqin ZHANG Xiangjun TIAN +1 位作者 Wei CHENG Lipeng JIANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第11期1267-1284,共18页
A new forecasting system-the System of Multigrid Nonlinear Least-squares Four-dimensional Variational(NLS-4DVar)Data Assimilation for Numerical Weather Prediction(SNAP)-was established by building upon the multigrid N... A new forecasting system-the System of Multigrid Nonlinear Least-squares Four-dimensional Variational(NLS-4DVar)Data Assimilation for Numerical Weather Prediction(SNAP)-was established by building upon the multigrid NLS-4DVar data assimilation scheme,the operational Gridpoint Statistical Interpolation(GSI)−based data-processing and observation operators,and the widely used Weather Research and Forecasting numerical model.Drawing upon lessons learned from the superiority of the operational GSI analysis system,for its various observation operators and the ability to assimilate multiple-source observations,SNAP adopts GSI-based data-processing and observation operator modules to compute the observation innovations.The multigrid NLS-4DVar assimilation framework is used for the analysis,which can adequately correct errors from large to small scales and accelerate iteration solutions.The analysis variables are model state variables,rather than the control variables adopted in the conventional 4DVar system.Currently,we have achieved the assimilation of conventional observations,and we will continue to improve the assimilation of radar and satellite observations in the future.SNAP was evaluated by case evaluation experiments and one-week cycling assimilation experiments.In the case evaluation experiments,two six-hour time windows were established for assimilation experiments and precipitation forecasts were verified against hourly precipitation observations from more than 2400 national observation sites.This showed that SNAP can absorb observations and improve the initial field,thereby improving the precipitation forecast.In the one-week cycling assimilation experiments,six-hourly assimilation cycles were run in one week.SNAP produced slightly lower forecast RMSEs than the GSI 4DEnVar(Four-dimensional Ensemble Variational)as a whole and the threat scores of precipitation forecasts initialized from the analysis of SNAP were higher than those obtained from the analysis of GSI 4DEnVar. 展开更多
关键词 data assimilation numerical weather prediction NLS-4DVar multigrid GSI
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Standard and Economical Cascadic Multigrid Methods for the Mortar Finite Element Methods 认领 引用 被引量：3
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作者 Xuejun Xu Wenbin Chen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第2期180-201,共22页
In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full ell... In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full elliptic regularity, so they can be used to tackle more general elliptic problems. Numerical experiments are reported to suonort our theorv. 展开更多
关键词 Cascadic multigrid mortar finite elements.
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Uniform Convergence of Multigrid V-Cycle on Adaptively Refined Finite Element Meshes for Elliptic Problems with Discontinuous Coefficients 认领 引用 被引量：1
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作者 Haijun Wu Weiying Zheng 《Communications in Mathematical Research》 CSCD 2023年第3期437-475,共39页
The multigrid V-cycle methods for adaptive finite element discretizations of two-dimensional elliptic problems with discontinuous coefficients are considered.Under the conditions that the coefficient is quasi-monotone... The multigrid V-cycle methods for adaptive finite element discretizations of two-dimensional elliptic problems with discontinuous coefficients are considered.Under the conditions that the coefficient is quasi-monotone up to a constant and the meshes are locally refined by using the newest vertex bisection algorithm,some uniform convergence results are proved for the standard multigrid V-cycle algorithm with Gauss-Seidel relaxations performed only on new nodes and their immediate neighbours.The multigrid V-cycle algorithm uses O(N)operations per iteration and is optimal. 展开更多
关键词 Multigrid adaptive finite elements elliptic problems discontinuous coefficients uniform convergence
A New Multigrid 3D-VAR Optimization Method for Bottom Friction Using HF Radar Current Observation 认领 引用
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作者 ZHANG Xiaoshuang WU Xinrong +7 位作者 LI Wei WANG Bin ZHU Xiande LIU Kexiu SHAO Caixia SUN Chunjian CHAO Guofang ZHANG Tiecheng 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1247-1255,共9页
This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient.In this method,the shallow water wa... This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient.In this method,the shallow water wave equation is introduced into the cost function of the multigrid three-dimensional variation data assimilation method as the weak constraint term,the surface current and the bottom friction coefficient are defined as the analytical variables,and the high spatiotemporal resolution surface radial flow observed by the high-frequency ground wave radar is used to optimize the surface current and bottom friction coefficient.This method can effectively consider the spatiotemporal correlation of radar data and extract multiscale information from surface radial flow data from long waves to short waves.Introducing the shallow water wave equation into the cost function as a weak constraint condition can adjust both the momentum and mass fields simultaneously to obtain more reasonable analysis information.The optimized bottom friction coefficient is introduced into the regional ocean numerical model to carry out numerical experiments.The test results show that the bottom friction coefficient obtained by this method can effectively improve the accuracy of the numerical simulation of sea surface height in the offshore area and reduce the simulation error. 展开更多
关键词 multigrid 3D-VAR optimization radial current velocity bottom friction
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Sound speed profiles in high spatiotemporal resolution using multigrid three-dimensional variational method:a coastal experiment off northern Shandong Peninsula 认领 引用
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作者 Guangchao HOU Jingsheng ZHAI +4 位作者 Qi SHAO Yanling ZHAO Wei LI Guijun HAN Kangzhuang LIANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期57-71,共15页
It is essential to ac quire sound speed profiles(SSPs)in high-precision spatiotemporal resolution for undersea acoustic activities.However,conventional observation methods cannot obtain high-resolution SSPs.Besides,S ... It is essential to ac quire sound speed profiles(SSPs)in high-precision spatiotemporal resolution for undersea acoustic activities.However,conventional observation methods cannot obtain high-resolution SSPs.Besides,S SPs are complex and changeable in time and space,especially in coastal areas.We proposed a new space-time multigrid three-dimensional variational method with weak constraint term(referred to as STC-MG3DVar)to construct high-precision spatiotemporal resolution SSPs in coastal areas,in which sound velocity is defined as the analytical variable,and the Chen-Millero sound velocity empirical formula is introduced as a weak constraint term into the cost function of the STC-MG3DVar.The spatiotemporal correlation of sound velocity observations is taken into account in the STC-MG3DVar method,and the multi-scale information of sound velocity observations from long waves to short waves can be successively extracted.The weak constraint term can optimize sound velocity by the physical relationship between sound velocity and temperature-salinity to obtain more reasonable and accurate SSPs.To verify the accuracy of the STC-MG3DVar,SSPs observations and CTD observations(temperature observations,salinity observations)are obtained from field experiments in the northern coastal area of the Shandong Peninsula.The average root mean square error(RMSE)of the STC-MG3DVar-constructed SSPs is 0.132 m/s,and the STC-MG3DVar method can improve the SSPs construction accuracy over the space-time multigrid 3DVar without weak constraint term(ST-MG3DVar)by 10.14%and over the spatial multigrid 3DVar with weak constraint term(SC-MG3DVar)by 44.19%.With the advantage of the constraint term and the spatiotemporal correlation information,the proposed STC-MG3DVar method works better than the ST-MG3DVar and the SCMG3DVar in constructing high-precision spatiotemporal re solution SSPs. 展开更多
关键词 space-time multigrid 3DVar sound speed profiles temperature salinity spatiotemporal correlation multiscale
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Multigrid Methods for Time-Fractional Evolution Equations:A Numerical Study 认领 引用
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作者 Bangti Jin Zhi Zhou 《Communications on Applied Mathematics and Computation》 EI 2020年第2期163-177,共15页
In this work,we develop an efficient iterative scheme for a class of nonlocal evolution models involving a Caputo fractional derivative of orderα(0,1)in time.The fully discrete scheme is obtained using the standard G... In this work,we develop an efficient iterative scheme for a class of nonlocal evolution models involving a Caputo fractional derivative of orderα(0,1)in time.The fully discrete scheme is obtained using the standard Galerkin method with conforming piecewise linear finite elements in space and corrected high-order BDF convolution quadrature in time.At each time step,instead of solving the linear algebraic system exactly,we employ a multigrid iteration with a Gauss–Seidel smoother to approximate the solution efficiently.Illustrative numerical results for nonsmooth problem data are presented to demonstrate the approach. 展开更多
关键词 Subdifusion Convolution quadrature Multigrid Incomplete iterative scheme
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The V-cycle Multigrid Method for a Hermite-type Rectangular Element 认领 引用
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作者 ZHAO Yan-min SHI Dong-yang 《Chinese Quarterly Journal of Mathematics》 2010年第1期140-145,共6页
In this paper, a V-cycle multigrid method is presented for a Hermite rectangular element. By defining proper mesh-dependent inner product and transfer operator, we obtain its convergence property and the uniform conve... In this paper, a V-cycle multigrid method is presented for a Hermite rectangular element. By defining proper mesh-dependent inner product and transfer operator, we obtain its convergence property and the uniform convergence rate independent of mesh size and level are established. 展开更多
关键词 V-cycle Hermite-type multigrid method transfer operator
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A 3D hybrid grid generation technique and a multigrid/parallel algorithm based on anisotropic agglomeration approach 认领 引用 被引量：17
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作者 Zhang Laiping Zhao Zhong +1 位作者 Chang Xinghua He Xin 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第1期47-62,共16页
A hybrid grid generation technique and a multigrid/parallel algorithm are presented in this paper for turbulence flow simulations over three-dimensional （3D） complex geometries. The hybrid grid generation technique ... A hybrid grid generation technique and a multigrid/parallel algorithm are presented in this paper for turbulence flow simulations over three-dimensional （3D） complex geometries. The hybrid grid generation technique is based on an agglomeration method of anisotropic tetrahedrons. Firstly, the complex computational domain is covered by pure tetrahedral grids, in which anisotropic tetrahedrons are adopted to discrete the boundary layer and isotropic tetrahedrons in the outer field. Then, the anisotropic tetrahedrons in the boundary layer are agglomerated to generate prismatic grids. The agglomeration method can improve the grid quality in boundary layer and reduce the grid quantity to enhance the numerical accuracy and efficiency. In order to accelerate the convergence history, a multigrid/parallel algorithm is developed also based on anisotropic agglomeration approach. The numerical results demonstrate the excellent accelerating capability of this multigrid method. 展开更多
关键词 Anisotropic agglomeration approach Hybrid mesh generation Multigrid method Parallel computation Complex geometry
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A Cascadic Multigrid Algorithm for the Mortar Element Method for Semiliner Ellptic Problems 认领 引用
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作者 邹战勇 《嘉应学院学报》 2015年第11期5-10,共6页
In this paper a cascadic multigrid algorithm for the mortar finite element approximation of the semilinear elliptic problem is proposed,and corresponding theorems aregiven,which display the error estimate and the comp... In this paper a cascadic multigrid algorithm for the mortar finite element approximation of the semilinear elliptic problem is proposed,and corresponding theorems aregiven,which display the error estimate and the computational complexity of the method. 展开更多
关键词 Mortar finite element Cascadic multigrid method Senilinear elliptic problems
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An efficient multigrid-DEIM semi-reduced-order model for simulation of single-phase compressible flow in porous media 认领 引用 被引量：1
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作者 Jing-Fa Li Bo Yu +2 位作者 Dao-Bing Wang Shu-Yu Sun Dong-Liang Sun 《Petroleum Science》 SCIE EI CAS CSCD 2021年第3期923-938,共16页
In this paper,an efcient multigrid-DEIM semi-reduced-order model is developed to accelerate the simulation of unsteady single-phase compressible fow in porous media.The cornerstone of the proposed model is that the fu... In this paper,an efcient multigrid-DEIM semi-reduced-order model is developed to accelerate the simulation of unsteady single-phase compressible fow in porous media.The cornerstone of the proposed model is that the full approximate storage multigrid method is used to accelerate the solution of fow equation in original full-order space,and the discrete empirical interpolation method(DEIM)is applied to speed up the solution of Peng-Robinson equation of state in reduced-order subspace.The multigrid-DEIM semi-reduced-order model combines the computation both in full-order space and in reducedorder subspace,which not only preserves good prediction accuracy of full-order model,but also gains dramatic computational acceleration by multigrid and DEIM.Numerical performances including accuracy and acceleration of the proposed model are carefully evaluated by comparing with that of the standard semi-implicit method.In addition,the selection of interpolation points for constructing the low-dimensional subspace for solving the Peng-Robinson equation of state is demonstrated and carried out in detail.Comparison results indicate that the multigrid-DEIM semi-reduced-order model can speed up the simulation substantially at the same time preserve good computational accuracy with negligible errors.The general acceleration is up to 50-60 times faster than that of standard semi-implicit method in two-dimensional simulations,but the average relative errors of numerical results between these two methods only have the order of magnitude 10−4-10−6%. 展开更多
关键词 Compressible fow Porous media Multigrid method Discrete empirical interpolation method Peng-Robinson equation of state
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Multigrid fictitious boundary method for incompressible viscous flows around moving airfoils 认领 引用
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作者 WAN De-Cheng 《Journal of Marine Science and Application》 2007年第2期51-58,共8页
In this paper, an efficient multigrid fictitious boundary method （MFBM） coupled with the FEM solver package FEATFLOW was used for the detailed simulation of incompressible viscous flows around one or more moving NAC... In this paper, an efficient multigrid fictitious boundary method （MFBM） coupled with the FEM solver package FEATFLOW was used for the detailed simulation of incompressible viscous flows around one or more moving NACA0012 airfoils. The calculations were carded on a fixed multigrid finite element mesh on which fluid equations were satisfied everywhere, and the airfoils were allowed to move freely through the mesh. The MFBM was employed to treat interactions between the fluid and the airfoils The motion of the airfoils was modeled by Newton-Euler equations. Numerical results of experiments verify that this method provides an efficient way to simulate incompressible viscous flows around moving airfoils. 展开更多
关键词 airfoils induced-motion fictitious boundary method FEM multigrid
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MULTIGRID TECHNIQUE APPLIED TO LINEAR TIME-DEPENDENT HYPERBOLIC SYSTEMS 认领 引用 被引量：1
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作者 Naren Deore Avijit Chatterjee 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2013年第3期243-247,共5页
A system of linear time-dependent hyperbolic partial differential equations in the form of the time-domain Maxwell′s equations is numerically solved using ageometric multigrid method.The multilevel method is an adapt... A system of linear time-dependent hyperbolic partial differential equations in the form of the time-domain Maxwell′s equations is numerically solved using ageometric multigrid method.The multilevel method is an adaptation of Ni′s cell-vertex based multigrid technique,originally proposed for accelerating steady state convergence of nonlinear time-dependent Euler equations of gas dynamics.We discuss issues pertaining to the application of the geometric multigrid method to a system of equations where the major issue is of accurately propagating linear waves over large distances leading to major constraints on the required grid resolution in terms of points-perwavelength. 展开更多
关键词 multigrid linear hyperbolic finite volume maxwell
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Application of multigrid NLS-4DVar in radar radial velocity data assimilation with WRF-ARW 认领 引用 被引量：1
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作者 ZHANG Lu TIAN Xiangjun ZHANG Hongqin 《Atmospheric and Oceanic Science Letters》 CSCD 2019年第6期409-416,共8页
The nonlinear least-squares four-dimensional variational assimilation(NLS-4DVar)method intro-duced here combines the merits of the ensemble Kalman lter and 4DVar assimilation methods.The multigrid NLS-4DVar method can... The nonlinear least-squares four-dimensional variational assimilation(NLS-4DVar)method intro-duced here combines the merits of the ensemble Kalman lter and 4DVar assimilation methods.The multigrid NLS-4DVar method can be implemented without adjoint models and also corrects small-to large-scale errors with greater accuracy.In this paper,the multigrid NLS-4DVar method is used in radar radial velocity data assimilations.Observing system simulation experiments were conducted to determine the capability and efficiency of multigrid NLS-4DVar for assimilating radar radial velocity with WRF-ARW(the Advanced Research Weather Research and Forecasting model).The results show signi cant improvement in 24-h cumulative precipitation prediction due to improved initial conditions after assimilating the radar radial velocity.Additionally,the multigrid NLS-4DVar method reduces computational cost. 展开更多
关键词 Heavy rainfall multigrid scheme NLS-4DVar method radar radial velocity data assimilation
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