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Variational Bayesian Tensor Quantile Regression

Acta Mathematica Sinica,English Series 2025年第2期41卷 733-756页

作者： Yunzhi Jin Yanqing Zhang Yunnan Key Laboratory of Statistical Modeling and Data Analysis Yunnan UniversityKunming 650091P.R.China Yunnan Key Laboratory of Statistical Modeling and Data Analysis Southwest United Graduate SchoolYunnan UniversityKunming 650091P.R.China

Quantile regression is widely used in variable relationship research for statistical *** quantile regression model is based on vector-valued covariates and can be efficiently estimated via traditional estimation ***,many modern applications involve tensor data with the intrinsic tensor *** quantile regression can not deal with tensor regression issues *** this end,we consider a tensor quantile regression with tensor-valued covariates and develop a novel variational Bayesian estimation approach to make estimation and prediction based on the asymmetric Laplace model and the CANDECOMP/PARAFAC decomposition of tensor *** incorporate the sparsity of tensor coefficients,we consider the multiway shrinkage priors for marginal factor vectors of tensor *** key idea of the proposed method is to efficiently combine the prior structural information of tensor and utilize the matricization of tensor decomposition to simplify the complexity of tensor coefficient *** coordinate ascent algorithm is employed to optimize variational lower *** studies and a real example show the numerical performances of the proposed method.

关键词： Asymmetric Laplace model CANDECOMP PARAFAC decomposition matricization tensor quantile regression variational Bayesian

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CENTRAL LIMIT THEOREM FOR TEMPORAL AVERAGE OF BACKWARD EULER-MARUYAMA METHOD

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Journal of Computational Mathematics 2025年第3期43卷 588-614页

作者： Diancong Jin School of Mathematics and Statistics Hubei Key Laboratory of Engineering Modeling and Scientific ComputingHuazhong University of Science and TechnologyWuhan 430074China

This work focuses on the temporal average of the backward Euler-Maruyama(BEM)method,which is used to approximate the ergodic limit of stochastic ordinary differential equations(SODEs).We give the central limit theorem(CLT)of the temporal average of the BEM method,which characterizes its asymptotics in *** the deviation order is smaller than the optimal strong order,we directly derive the CLT of the temporal average through that of original equations and the uniform strong order of the BEM *** the case that the deviation order equals to the optimal strong order,the CLT is established via the Poisson equation associated with the generator of original *** experiments are performed to illustrate the theoretical *** main contribution of this work is to generalize the existing CLT of the temporal average of numerical methods to that for SODEs with super-linearly growing drift coefficients.

关键词： Central limit theorem Temporal average Ergodicity Backward Euler-Maruyama method

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Empirical relationship between significant wave period and wave energy period in the coastal waters of China

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Acta Oceanologica Sinica 2025年第1期44卷 50-58页

作者： Yuhuan Xue Chuanjiang Huang Gang Wang Dejun Dai Fangli Qiao First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Qingdao Marine Science and Technology CenterQingdao 266237China Key Laboratory of Marine Science and Numerical Modeling Ministry of Natural ResourcesQingdao 266061China

Significant wave period is an important parameter in coastal and offshore engineering *** spectral wave models do not directly calculate this parameter,which means that it needs to be estimated from the spectral periods using empirical *** wave energy period is one of the wave periods directly output by many wave models and is often used in studies of wave *** study investigated the relationship between significant wave period and wave energy period using wave data measured at three stations in the coastal waters of *** observations recorded at these stations in the South China Sea,the East China Sea,and the Bohai Sea covered a wide range of surface wave *** indicated that the ratio of significant wave period to wave energy period is closely related to the Goda peakedness parameter of the wave ***,we proposed an empirical formula in which significant wave period is a function of wave energy period and the Goda peakedness *** results showed that the performance of this formula is substantially better than that of fitting formulas that use constant coefficients.

关键词： surface waves significant wave period wave energy period wave spectral parameter wave spectra

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Accelerated warming of High Mountain Asia predicted at multiple years ahead

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Science Bulletin 2025年第3期70卷 419-428页

作者： Shuai Hu Tianjun Zhou Bo Wu Key Laboratory of Earth System Numerical Modeling and Application Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of the Chinese Academy of Sciences Beijing 100049China

High-Mountain Asia(HMA)is an important source of freshwater since it holds the largest reservoir of frozen water outside the polar *** feeds ten great rivers,ultimately supporting more than 2 billion ***,the threat of accelerated glacier melt,which is a consequence of unprecedented global warming since the early 1950s,threatens water resources in the surrounding *** predictions of the near-term temperature change and synergistic mass loss of glaciers are essential but challenging to implement because of the impacts of internal climate ***,based on large ensembles of state-of-the-art decadal climate prediction experiments,we provide evidence that the internally generated surface air temperature variations in HMA can be predicted multiple years in advance,and the model initialization has robust added value to the decadal prediction ***-time decadal forecasts suggest that the HMA will experience accelerated warming in 2025-2032,where the surface warming will increase by 0.98°C(0.67 to 1.33°C;5%to 95%range)relative to the reference period 1991-2020,which is equivalent to 1.75 times the observed warming during *** decadal predictability originates from extratropical Pacific decadal variability modes,which modulate the convective heating in the tropical Pacific and influence HMA via the eastward-propagating atmospheric Kelvin *** warming in the coming decade will likely increase the shrinkage of the glacier volume over the HMA by 1.4%.This change poses unprecedented challenges,including potential water scarcity,ecosystem disruption,and increased risk of natural disasters,to HMA and surrounding regions.

关键词： Decadal prediction High Mountain Asia Surface air temperature Pacific decadal variabilities Glacier

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Targeted sounding observations from geostationary satellite and impacts on high impact weather forecasts

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Science China Earth Sciences 2025年第4期68卷 963-976页

作者： Wei HAN Ruoying YIN Jun LI Yongzhu LIU Jincheng WANG Yonghui LI Xiaohao QIN Zhiqing ZHANG Xueshun SHEN CMA Earth System Modeling and Prediction Centre(CEMC) Beijing100081China National Satellite Meteorological Center Beijing100081China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China State Key Laboratory of Severe Weather(LaSW) Beijing100081China University of Chinese Academy of Sciences Beijing101408China

In monitoring and predicting high-impact weather(HIW)events,targeted atmospheric temperature and moisture sounding observations in sensitive areas are more valuable than conventional *** conditional nonlinear optimal perturbation(CNOP)method and the linear singular vector(SV)method can be employed to identify these weather-sensitive areas for targeted *** observations can be conducted by using hyperspectral infrared sounders onboard geostationary weather *** Geostationary Interferometric Infrared Sounder(GIIRS)onboard China's Fengyun(FY)-4geostationary satellite series can provide atmospheric sounding observations with a temporal resolution of up to 15 min over areas prone to active weather *** offers unprecedented opportunities for targeted observations,enabling flexible measurement modes that focus on weather-sensitive ***-temporal-resolution measurements not only reveal the threedimensional(3D)thermodynamic structure of the atmosphere,but also track moisture characteristics to capture the 3D dynamic ***,high-temporal-resolution measurements of clear radiances can enhance atmospheric sounding retrievals(used for HIW situation awareness)and data assimilation(used to improve numerical weather prediction).The four-dimensional variational(4D-Var)system facilitates the utilization of the high-temporal-resolution GIIRS targeted *** this study,we explore the applications of FY-4A and FY-4B GIIRS targeted observations and focus on data assimilation based on the 4DVar system for improving HIW *** typhoon cases are selected for impact ***,we compare CNOP and SV methods for identifying sensitive areas,and use the 4D-Var assimilation system of the Global Assimilation Forecasting System of the China Meteorological Administration(CMA-GFS)for real-time data *** results indicate hightemporal-resolution observations positively impact typhoon forecasts,with high

关键词： Targeted observations GIIRS Data assimilation High temporal resolution THORPEX

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Development of a Four-Dimensional Diagnostic Analysis Model for Assessing Ensemble Forecast Uncertainty

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Journal of Meteorological Research 2025年第2期39卷 288-302页

作者： Fei PENG Yuejian ZHU Jing CHEN Xiaoli LI Jian TANG CMA Earth System Modeling and Prediction Centre China Meteorological Administration （CMA） State Key Laboratory of Severe Weather Science and Technology China Meteorological Administration Key Laboratory of Earth System Modeling and Prediction China Meteorological Administration National Meteorological Centre China Meteorological Administration

Evaluating whether an ensemble prediction system(EPS) can accurately represent forecast uncertainty is a key aspect of model development and ensemble forecast applications. In this study, a four-dimensional diagnostic analysis model for assessing ensemble forecast uncertainty is proposed, by analyzing the relationship between the ensemble spread and root-mean-square error(RMSE) of the ensemble mean in terms of their temporal evolution(one-dimensional) and spatial distribution(three-dimensional), together with use of the linear variance calibration(LVC) *** on this model and the daily operational forecast data of the China Meteorological Administration(CMA) global EPS(CMA-GEPS) in December 2022–November 2023, characteristics of the CMA-GEPS forecast uncertainty are diagnosed and analyzed, and compared against the state-of-the-art operational global EPS of ECMWF. Generally,there is a deficiency in CMA-GEPS, which underestimates the forecast uncertainty, especially in the tropics. However, at certain initialization times in some seasons and over some locations, the spread appears greater than the RMSE, indicating an overestimation of forecast uncertainty. Moreover, CMA-GEPS performs better in capturing the forecast uncertainty of lower-level variables than upper-level variables; and in comparison with the mass and thermal fields, the forecast uncertainty of the dynamic field is better represented. Diagnostic analysis using the LVC method reveals that the relevance between the ensemble variance and the ensemble mean error variance of CMA-GEPS increases with forecast lead time, and the problem of underestimated forecast uncertainty is continuously alleviated. In addition, ECMWF EPS behaves distinctly better than CMA-GEPS in representing the forecast uncertainty and its growth process, the reasons for which are discussed and elucidated from the perspective of shortcomings in the methods to generate the initial and model perturbations, the ensemble size, and the f

关键词： diagnostic analysis ensemble forecast ensemble variance-error variance relationship forecast uncertainty spread-error relationship

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Interactions between Initial and Lateral Boundary Perturbations in Convection-Permitting Ensemble Prediction

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Journal of Meteorological Research 2025年第1期39卷 116-131页

作者： Jingzhuo WANG Jing CHEN Fajing CHEN Yanan Ma CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing100081China State Key Laboratory of Severe Weather China Meteorological AdministrationBeijing100081China Key Laboratory of Earth System Modeling and Prediction China Meteorological AdministrationBeijing100081China Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing100081China

How to construct appropriate perturbations for convection-permitting ensemble prediction systems(CPEPSs)is a critical issue awaiting urgent *** two common perturbations,initial perturbations(IPs)and lateral boundary perturbations(BPs)interact with each other,affecting the model error growth,especially in mesoscale *** the China Meteorological Administration(CMA)-CPEPS,this study tries to elucidate how BPs interact with matched and mismatched IPs under varied large-scale weather conditions/*** groups of experiments were conducted for strong-forcing and weak-forcing weather regimes over southern China:three with single IPs,one with single BPs,and three with combined *** is found that the perturbation magnitudes were dominated by meso-α-scale components,and IPs under weak forcing exhibited more pronounced effects than under strong forcing;whereas BPs exerted more pronounced effects under strong forcing than weak forcing ***,it lasts longer for high-level variables when the perturbation energy from BPs is higher than that from IPs,compared to low-level ***,for precipitation and dynamic variables,IPs and BPs can mutually *** source of these perturbations,and their specific vertical levels,do not alter the extent of their ***,the weather regime and the scales of the perturbations influence the strength of their mutual *** particular,the weak-forcing regimes exhibit a more pronounced reinforcing effect,and meso-α-scale perturbations are more conducive to fostering interactions compared to meso-β-scale ***,it is the perturbation magnitude inherent in the initial perturbation itself that determines the interactions between IPs and BPs.

关键词： interactions initial perturbations lateral boundary perturbations convection-permitting ensemble prediction

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Gap-filling products for three GRACE/GRACE-FO mascon solutions

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Geodesy and Geodynamics 2025年第2期16卷 223-229页

作者： Pu Xie Shuang Yi National Key Laboratory of Earth System Numerical Modeling and Application/College of Earth and Planetary Sciences University of Chinese Academy of SciencesChineseAcademyofSciencesBeijing101408China

The primary mission of the Gravity Recovery and Climate Experiment(GRACE)satellite and its successor,GRACE Follow-On(GRACE-FO),is to provide time-variable gravity fields,and its observations have been widely used in various ***,the nearly one-year gap between GRACE and GRACE-FO has affected our ability to obtain continuous time-variable gravity *** this study,we use the Singular Spectrum Analysis(SSA)method to fll the nearly one-year gap between the GRACE and GRACE-FO missions,as well as the gaps within the GRACE mission itself,to generate a continuous and complete mascon product from April 2002 to December *** products are evaluated at the basin scale in Greenland,Antarctica,and ten river basins worldwide,as well as across *** results show that our flled data can effectively recover seasonal and interannual signals and exhibit good consistency with previous *** products provided in this study will benefit GRACE applications related to oceans,glaciers,and terrestrial water storage.

关键词： Singular spectrum analysis GRACE GRACE-FO Mascon solutions Data gap flling

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High-order finite volume methods for solving compressible multicomponent flows

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Science China Mathematics 2025年第3期68卷 729-760页

作者： Feng Zheng Jianxian Qiu School of Mathematics and Statistics Fujian Key Laboratory of Mathematical Analysis and ApplicationFujian Normal UniversityFuzhou 350117China School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling&High-Performance Scientific Computing Xiamen UniversityXiamen 361005China

In this paper, we propose a high-order finite volume method for solving multicomponent fluid problems. Our method couples the quasi-conservative form with the reconstruction of conservative variables in a characteristic manner. The source term and numerical fluxes are carefully designed to maintain the pressure and velocity equilibrium for the interface-only problem and preserve the equilibrium of physical parameters in a single-component fluid. These ingredients enable our scheme to achieve both high-order accuracy in the smooth region and the high resolution in the discontinuity region of the solution. Extensive numerical tests are performed to verify the high resolution and accuracy of the scheme.

关键词： finite volume high-order multicomponent flows

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Interannual variability of surface Indonesian Throughflow and its relationships with Pacific and Indian Oceans derived from satellite observation

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Acta Oceanologica Sinica 2025年第1期44卷 1-16页

作者： Yingyi Yang Tengfei Xu Zexun Wei Dingqi Wang Zhongrui Cai Yunzhuo Zhang Yongshun Ma First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao 266061China CMA-NJU Joint Laboratory for Climate Prediction Studies School of Atmospheric SciencesNanjing UniversityNanjing 210023China Earth Ocean and Atmospheric Sciences ThrustThe Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Zhonghai Yuntian(Guangdong)Marine Technology Co. LTDGuangzhou 510275China

The Indonesian Throughflow(ITF)plays important roles in global ocean circulation and climate *** studies suggested the ITF interannual variability is driven by both the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)*** detailed processes of ENSO and/or IOD induced anomalies impacting on the ITF,however,are still not *** this study,this issue is investigated through causal relation,statistical,and dynamical analyses based on satellite *** results show that the driven mechanisms of ENSO on the ITF include two ***,the ENSO related wind field anomalies driven anomalous cyclonic ocean circulation in the western Pacific,and off equatorial upwelling Rossby waves propagating westward to arrive at the western boundary of the Pacific,both tend to induce negative sea surface height anomalies(SSHA)in the western Pacific,favoring ITF reduction since the develop of the El Niño through the following ***,the ENSO events modulate equatorial Indian Ocean zonal winds through Walker Circulation,which in turn trigger eastward propagating upwelling Kelvin waves and westward propagating downwelling Rossby *** Rossby waves are reflected into downwelling Kelvin waves,which then propagate eastward along the equator and the Sumatra-Java coast in the Indian *** a result,the wave dynamics tend to generate negative(positive)SSHA in the eastern Indian Ocean,and thus enhance(reduce)the ITF transport with time lag of 0-6 months(9-12 months),*** the IOD condition,the wave dynamics also tend to enhance the ITF in the positive IOD year,and reduce the ITF in the following year.

关键词： Indonesian Throughflow(ITF) interannual variability information flow Indian Ocean Dipole(IOD) El Niño-Southern Oscillation(ENSO)

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