Article
Geosciences, Multidisciplinary
Thomas Richter, Veronique Dansereau, Christian Lessig, Piotr Minakowski
Summary: The ability of numerical sea ice models to accurately reproduce localized deformation features associated with fracture processes is crucial for accurately describing ice dynamics and dynamically coupled physical processes in the Arctic and Antarctic. Equally important is the ability of these models to minimize numerical diffusion caused by the advection of these features, ensuring that the associated strong gradients persist over time without the need for unphysical energy injection for re-localization.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
Article
Physics, Mathematical
Yaning Xie, Shuwang Li, Wenjun Ying
Summary: This paper presents a novel fourth-order Cartesian grid based boundary integral method for solving heterogeneous interface problems in two and three dimensional space. The method reinterprets the involved integrals as solutions to simple interface problems in an extended regular region and preserves the structure of the coefficient matrix. The proposed kernel-free boundary integral method eliminates the need for determining or computing analytical expressions of Green's functions.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2023)
Article
Mathematics, Applied
Yaning Xie, Shuwang Li, Wenjun Ying
Summary: In this paper, a fourth-order Cartesian grid-based boundary integral method (BIM) is proposed for solving a multiple acoustic scattering problem on closely packed obstacles. The method does not require complex computations for nearly singular, singular or hyper-singular boundary integrals, but instead reinterprets them as solutions to equivalent simple interface problems. Extensive numerical experiments show that the method is formally high-order accurate, fast convergent and insensitive to complexity of scatterers.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2022)
Article
Computer Science, Interdisciplinary Applications
J. Antoon van Hooft, Stephane Popinet
Summary: This article presents a numerical solver for the incompressible Navier-Stokes equations. The solver combines fourth-order-accurate discrete approximations and an adaptive tree grid to achieve high accuracy and efficiency. The solver employs a novel compact-upwind advection scheme and a 4th-order accurate projection algorithm to satisfy the incompressibility constraint. The paper also introduces a new refinement indicator tailored to this solver and demonstrates the consistency and convergence rate of the adaptive solver through tests and examples.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Aastha Gupta, Aditya Kaushik
Summary: The paper introduces a higher-order parameter uniform numerical approximation method for a fourth-order singularly perturbed boundary value problem on a non-uniform grid. By utilizing a positive monitor function and properties of the discrete operator, optimal convergence is achieved without any logarithmic terms present. Numerical results for two model problems are presented, showing agreement with theoretical estimates.
JOURNAL OF APPLIED MATHEMATICS AND COMPUTING
(2022)
Article
Computer Science, Interdisciplinary Applications
Sana Keita, Abdelaziz Beljadid, Yves Bourgault
Summary: In this study, a class of fourth-order parabolic equations is approximated by a novel second-order fully discrete mixed finite element method, which can be written as a system of second-order equations by introducing an auxiliary variable. The use of second-order backward differentiation formula for the time derivative and a special technique for the approximation of nonlinear terms enhances the efficiency of the numerical scheme. The numerical tests demonstrate the effectiveness and robustness of the proposed scheme with the spatial and temporal discretization analysis showing good convergence rates and accuracy.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Computer Science, Interdisciplinary Applications
Majid Haghi, Mohammad Ilati, Mehdi Dehghan
Summary: In this paper, a high-order compact scheme is proposed for solving two-dimensional nonlinear time-fractional fourth-order reaction-diffusion equations. The unique solvability of the numerical method is proved in detail, and the convergence of the proposed algorithm is proved using the energy method. Numerical examples are given to verify the theoretical analysis and efficiency of the developed scheme.
ENGINEERING WITH COMPUTERS
(2023)
Article
Computer Science, Interdisciplinary Applications
Hao Chen, Omid Nikan, Wenlin Qiu, Zakieh Avazzadeh
Summary: This paper introduces a time two-grid finite difference (TTGFD) method for solving the 1D fourth-order Sobolev-type equation. The method consists of three stages, in which an approximate solution is obtained on a fine grid using the Lagrangian interpolation formula. Compared to the standard finite difference scheme, the TTGFD method reduces computational cost while maintaining optimal accuracy.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2023)
Article
Mathematics, Applied
Shiyv Wang, Xueqin Lv, Songyan He
Summary: Based on the reproducing kernel theory, this paper solves the nonlinear fourth order boundary value problem and verifies the effectiveness and accuracy of the approximate solution method through examples.
Article
Mathematics, Applied
Shaohong Du, Yongping Cheng, Mingjun Li
Summary: In this paper, the development of error estimates for high-order spline finite element approximation to a class of fourth-order parabolic equations is investigated. L-2 estimates for semi-discrete scheme are derived by constructing two auxiliary problems and utilizing the structure of solutions of the second-order ordinary differential equation and the similarity theory of matrices. H-2 energy estimates for spline-element central difference approximation are established under a condition of stability and are optimal in terms of the regularity of the exact solution. Numerical examples are presented to validate the theory.
APPLIED NUMERICAL MATHEMATICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Zhifang Du, Jiequan Li
Summary: This paper presents a method using the volume fraction of fluid (VOF) approach to track the dynamics of free boundaries. It applies a two-stage fourth order accurate time discretization method to solve the VOF equation, aiming to provide a compact diffuse-interface algorithm for simulating multi-material problems with sharp interfaces. The numerical results demonstrate high resolution and high fidelity for interface capturing.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Mathematics, Applied
Jing Guo, Qing Pan, Da Xu, Wenlin Qiu
Summary: This paper considers the nonlinear fourth-order time-fractional equation using the combination of the Sinc-Galerkin method and the double exponential transformation. The proposed scheme is validated through three numerical experiments, demonstrating its feasibility and high efficiency in achieving the expected convergence order for problems with singular points.
JOURNAL OF APPLIED MATHEMATICS AND COMPUTING
(2022)
Article
Meteorology & Atmospheric Sciences
C. Mehlmann, S. Danilov, M. Losch, J. F. Lemieux, N. Hutter, T. Richter, P. Blain, E. C. Hunke, P. Korn
Summary: This study compares numerical solutions of sea ice models with different velocity staggering, finding that the CD-grid approach has a higher effective resolution and is more efficient in simulating the number and length of LKFs than traditional methods.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2021)
Article
Engineering, Multidisciplinary
Rachel Gordon, Eli Turkel, Dan Gordon
Summary: A compact fourth-order scheme was developed for the three-dimensional elastic wave equation in frequency space, using the first-order velocity-stress formulation. The numerical implementation for homogeneous media showed significant improvements over the second-order scheme in both acoustic and elastic cases, with results comparing favorably to analytic solutions.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Mathematics, Applied
Amin Abrishami Moghadam, Ali R. Soheili, Amir Saboor Bagherzadeh
Summary: This paper presents a new method for solving fourth-order boundary value problems using Lidstone interpolating functions. The method constructs piecewise Lidstone interpolating functions to improve accuracy. The paper discusses the method and the entire process in detail, obtaining a large system of algebraic equations. Error estimations are conducted and comparisons with other methods are presented.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Geosciences, Multidisciplinary
Yu-heng Tseng, Jo-Hsu Huang, Han-Ching Chen
Summary: This study investigates the differences between Central Pacific (CP) and Eastern Pacific (EP) types of El Nino-Southern Oscillation events in terms of their forming locations and mechanisms. The results show that the forecast model has overall higher skills in predicting CP indices compared to EP indices. Including extratropical precursors from the North Pacific greatly enhances the predictability of CP indices, revealing the impact of North Pacific Oscillation (NPO)/Victoria Mode (VM) evolution on the ocean-atmosphere interaction. In contrast, the predictability of EP indices can be moderately enhanced by including extratropical precursors from the south.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Kuan-Mei Hsiung, Yi-Chun Kuo, Yen-Ting Lin, Yu-Heng Tseng, Yu-San Han
Summary: The larvae of Japanese eel travel a long distance through the North Equatorial Current and the Kuroshio, and the spawning behavior of mature eels results in monthly arrival waves in eastern Taiwan. Recent research has shown that the total length of glass eels can indicate their larval duration and age. Analyzing the monthly mean lengths of eels in eastern Taiwan from 2010 to 2021, it was found that the early recruits had significantly larger total lengths than the late recruits. The recruitment lag between Taiwan and Japan was about 1-1.5 months, with higher abundance of early recruits in Taiwan and late recruits in Japan. The study suggests that the main streams of the North Equatorial Current and the Kuroshio, as well as their monthly velocity changes, could influence the distribution patterns of Japanese glass eels in Taiwan and Japan.
SCIENTIFIC REPORTS
(2022)
Article
Environmental Sciences
Wen-Cheng Liu, Hong-Ming Liu, Chih-Chieh Young, Wei-Che Huang
Summary: Tidal estuaries play a crucial role in contaminant transport, and salinity levels serve as natural tracers. Numerical modeling results are consistent with measurements, and the impacts of freshwater discharge and wind stress on river plume are analyzed.
Article
Environmental Sciences
Wei-Ting Chao, Chih-Chieh Young
Summary: This paper proposes a hybrid model combining parametric cyclone and neural network for accurate and long lead-time storm surge prediction. The model is applied in the northeastern coastal region of Taiwan and has shown excellent performance in reducing complexity and retaining important typhoon indicators, leading to improved accuracy in surge prediction.
Article
Biochemistry & Molecular Biology
Pang-Shuo Huang, Yu-Heng Tseng, Chin-Feng Tsai, Jien-Jiun Chen, Shao-Chi Yang, Fu-Chun Chiu, Zheng-Wei Chen, Juey-Jen Hwang, Eric Y. Chuang, Yi-Chih Wang, Chia-Ti Tsai
Summary: The use of artificial intelligence (AI) with electrocardiograms (ECGs) can identify significant coronary artery disease (CAD) and determine the site of the coronary obstruction. This technology can be easily implemented in health check-ups to identify high-risk patients for future coronary events.
Article
Meteorology & Atmospheric Sciences
Xiaofan Li, Zeng-Zhen Hu, Yu-heng Tseng, Yunyun Liu, Ping Liang
Summary: This study examines the evolution and impact of the 2020/2021 La Nina event and compares it with historical events. It found that the La Nina event during this period was weaker than expected and showed some differences compared to other events, indicating that the in-phase amplification of time scale variations is an important factor determining the intensity of La Nina events.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Meteorology & Atmospheric Sciences
Liang Shi, Ruiqiang Ding, Shujuan Hu, Jianping Li, Yuheng Tseng, Xumin Li
Summary: This study focuses on the influence of the North Pacific Victoria mode (VM) on the persistence of the sea surface temperature anomalies (SSTAs) of El Nino-Southern Oscillation (ENSO). The study finds that VM events can enhance the persistence of ENSO SSTAs and reduce the intensity of the spring persistence barrier (SPB) of ENSO SSTAs. The findings suggest that the development or decay of SSTAs is slower in strong VM cases and faster in weak VM cases.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Multidisciplinary Sciences
Ruiqiang Ding, Yu-Heng Tseng, Emanuele Di Lorenzo, Liang Shi, Jianping Li, Jin-Yi Yu, Chunzai Wang, Cheng Sun, Jing-Jia Luo, Kyung-Ja Ha, Zeng-Zhen Hu, Feifei Li
Summary: The authors find that persistent two-way teleconnections between the North Pacific Oscillation and the tropical Pacific are a key source of multi-year El Nino events. These teleconnections lead to the prolonged El Nino phenomena, resulting in severe floods and droughts worldwide with significant socioeconomic impacts. Model experiments and future projections suggest that with enhanced NPO variability under future anthropogenic forcing, more frequent multi-year El Nino events should be expected. Therefore, properly accounting for the effects of the NPO on the evolution of El Nino events may improve multi-year El Nino prediction and projection.
NATURE COMMUNICATIONS
(2022)
Article
Environmental Sciences
Wen-Cheng Liu, Hong-Ming Liu, Chih-Chieh Young
Summary: The impact of environmental factors on suspended sediment plumes in the continental shelf out of the Danshuei River estuary was investigated using a numerical model. The results showed that tides, salinity, river discharge, and wind stress all played significant roles in the dynamics of the sediment plumes. This study is important for understanding the movement of suspended sediment in the study area.
Article
Geosciences, Multidisciplinary
Ming-Huei Chang, Yu-Hsin Cheng, Yu-Yu Yeh, Je-Yuan Hsu, Sen Jan, Yu-heng Tseng, Chung-Hsiung Sui, Yiing Jang Yang, Po-Hsiung Lin
Summary: We conducted Lagrangian diurnal warm layer (DWL) observations and used satellite products in the strong Kuroshio east of Taiwan, where the winds and advection effect are significantly modified by the boundary terrain. The synoptic easterly wind bifurcates into southward-blowing and northward-blowing branches when it encounters Taiwan's coast. These branches create areas with enhanced and weakened apparent wind speed compared to the northeastward flowing Kuroshio. The DWL can reach 5m due to shear instability-induced mixing, and sea surface temperature (SST) enhancement occurs around and north of the wind bifurcation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Yi-Chun Kuo, Yang Yu, Yu-Heng Tseng
Summary: This study investigated the long-term interannual changes in summer circulation and hydrology in the East China Sea. The results showed that the sea surface temperature in summer was mainly influenced by horizontal advection and heat flux. Baroclinic circulation played a crucial role in subsurface mixing, with atmospheric wind and Kuroshio modes dominating interannual variations in ocean circulation.
Editorial Material
Environmental Sciences
Chih-Chieh Young
Article
Environmental Sciences
Wen-Cheng Liu, Wei-Che Huang, Chih-Chieh Young
Summary: Large-scale particle image velocimetry (LSPIV) is a cost-effective, rapid, and secure monitoring tool for streamflow measurements. However, surveys of ground control points (GCPs) may impact camera parameters and introduce uncertainty to the measurements. In this study, an uncertainty analysis was conducted for image-based streamflow measurements, focusing on the effects of GCPs. The results showed that the uncertainty could be reduced by averaging the coordinates of control points and using smaller standard errors in GCP measurements.
Article
Multidisciplinary Sciences
Ruiqiang Ding, Hyacinth C. Nnamchi, Jin-Yi Yu, Tim Li, Cheng Sun, Jianping Li, Yu-Heng Tseng, Xichen Li, Fei Xie, Juan Feng, Kai Ji, Xumin Li
Summary: The connection between the North Tropical Atlantic (NTA) sea surface temperature (SST) anomalies and El Nino-Southern Oscillation (ENSO) events varies considerably over multidecadal timescales and is mainly controlled by the multidecadal variability of the North Atlantic Oscillation (NAO). During the positive phase of the NAO, the NTA impact on ENSO is amplified due to strengthening of precipitation over the equatorial Atlantic and enhancement of the persistence of NTA SST anomalies.
NATURE COMMUNICATIONS
(2023)
Article
Meteorology & Atmospheric Sciences
Francois Counillon, Noel Keenlyside, Shuo Wang, Marion Devilliers, Alok Gupta, Shunya Koseki, Mao-Lin Shen
Summary: A supermodel is created by connecting different models interactively to compensate for their systematic errors and achieve superior performance. This approach differs from non-interactive multi-model ensembles as it combines model outputs in real-time. The development of supermodels with Earth system models is technically challenging due to the combination of models with different state spaces. In this study, a supermodel framework for Earth system models is formulated and data assimilation is used to synchronize models. Monthly assimilation of pseudo sea surface temperature observations is performed to handle discrepancies in grid and resolution. The comparison between two supermodel approaches and non-interactive ensembles shows that both versions achieve synchronization in the ocean and atmosphere. The time variability of the supermodel multi-model mean sea surface temperature is reduced compared to observations, especially in areas where synchronization is not achieved. The trained supermodel still needs to be tested.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Computer Science, Interdisciplinary Applications
Jeffrey Wade, Christa Kelleher, Barret L. Kurylyk
Summary: This study developed a physically-based water temperature model coupled with the National Water Model (NWM) to assess the potential for water temperature prediction to be incorporated into the NWM at the continental scale. By evaluating different model configurations of increasing complexity, the study successfully simulated hourly water temperatures in the forested headwaters of H.J. Andrews Experimental Forest in Oregon, USA, providing a basis for integrating water temperature simulation with predictions from the NWM.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Shaun SH. Kim, Lucy A. Marshall, Justin D. Hughes, Lynn Seo, Julien Lerat, Ashish Sharma, Jai Vaze
Summary: A major challenge in hydrologic modelling is producing reliable uncertainty estimates outside of calibration periods. This research addresses the challenge by improving model structures and error models to more reliably estimate uncertainty. The combination of the RBS model and SPUE produces statistically reliable predictions and shows better matching performance in tests.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Juan Pedro Carbonell-Rivera, Javier Estornell, Luis Angel Ruiz, Pablo Crespo-Peremarch, Jaime Almonacid-Caballer
Summary: This study presents Class3Dp, a software for classifying vegetation species in colored point clouds. The software utilizes geometric, spectral, and neighborhood features along with machine learning methods to classify the point cloud, allowing for the recognition of species composition in an ecosystem.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhi Li, Daniel Caviedes-Voullieme, Ilhan Oezgen-Xian, Simin Jiang, Na Zheng
Summary: The optimal strategy for solving the Richards equation numerically depends on the specific problem, particularly when using GPUs. This study investigates the parallel performance of four numerical schemes on both CPUs and GPUs. The results show that the scaling of Richards solvers on GPUs is influenced by various factors. Compared to CPUs, parallel simulations on GPUs exhibit significant variation in scaling across different code sections, with poorly-scaled components potentially impacting overall performance. Nonetheless, using GPUs can greatly enhance computational speed, especially for large-scale problems.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Ludovic Cassan, Leo Pujol, Paul Lonca, Romain Guibert, Helene Roux, Olivier Mercier, Dominique Courret, Sylvain Richard, Pierre Horgue
Summary: Methods and algorithms for measuring stream surface velocities have been continuously developed over the past five years to adapt to specific flow typologies. The free software ANDROMEDE allows easy use and comparison of these methods with image processing capabilities designed for measurements in natural environments and with unmanned aerial vehicles. The validation of the integrated algorithms is presented on three case studies that represent the targeted applications: the study of currents for eco-hydraulics, the measurement of low water flows and the diagnosis of hydraulic structures. The field measurements are in very good agreement with the optical measurements and demonstrate the usefulness of the tool for rapid flow diagnosis for all the intended applications.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Mariia Kozlova, Robert J. Moss, Julian Scott Yeomans, Jef Caers
Summary: This paper introduces a framework for quantitative sensitivity analysis using the SimDec visualization method, and tests its effectiveness on decision-making problems. The framework captures critical information in the presence of heterogeneous effects, and enhances its practicality by introducing a formal definition and classification of heterogeneous effects.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Chad R. Palmer, Denis Valle, Edward V. Camp, Wendy-Lin Bartels, Martha C. Monroe
Summary: Simulation games have been used in natural resource management for education and communication purposes, but not for data collection. This research introduces a new design process which involves stakeholders and emphasizes usability, relevance, and credibility testing criteria. The result is a finalized simulation game for future research.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Tao Wang, Chenming Zhang, Ye Ma, Harald Hofmann, Congrui Li, Zicheng Zhao
Summary: This study used numerical modeling to investigate the formation process of iron curtains under different freshwater and seawater conditions. It was found that Fe(OH)3 accumulates on the freshwater side, while the precipitation is inhibited on the seaward side due to high H+ concentrations. These findings enhance our understanding of iron transformation and distribution in subterranean estuaries.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Grant Hutchings, James Gattiker, Braden Scherting, Rodman R. Linn
Summary: Computational models for understanding and predicting fire in wildland and managed lands are becoming increasingly impactful. This paper addresses the characterization and population of mid-story fuels, which are not easily observable through traditional survey or remote sensing. The authors present a methodology to populate the mid-story using a generative model for fuel placement, which can be calibrated based on limited observation datasets or expert guidance. The connection of terrestrial LiDAR as the observations used to calibrate the generative model is emphasized. Code for the methods in this paper is provided.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Saswata Nandi, Pratiman Patel, Sabyasachi Swain
Summary: IMDLIB is an open-source Python library that simplifies the retrieval and processing of gridded meteorological data from IMD, enhancing data accessibility and facilitating hydro-climatic research and analysis.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
Article
Computer Science, Interdisciplinary Applications
Pengfei Wu, Jintao Liu, Meiyan Feng, Hu Liu
Summary: In this paper, a new flow distance algorithm called D infinity-TLI is proposed, which accurately estimates flow distance and width function using a two-segment-distance strategy and triangulation with linear interpolation method. The evaluation results show that D infinity-TLI outperforms existing algorithms and has a low mean absolute relative error.
ENVIRONMENTAL MODELLING & SOFTWARE
(2024)
