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Chinese Physics B 2024年第2期33卷 96-107页

作者：郭亚楠曹小群宋君强冷洪泽 College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China College of Computer National University of Defense TechnologyChangsha 410073China Naval Aviation University Huludao 125001China

Efficiently solving partial differential equations(PDEs)is a long-standing challenge in mathematics and physics *** recent years,the rapid development of artificial intelligence technology has brought deep learning-based methods to the forefront of research on numerical methods for partial differential *** them,physics-informed neural networks(PINNs)are a new class of deep learning methods that show great potential in solving PDEs and predicting complex physical *** the field of nonlinear science,solitary waves and rogue waves have been important research *** this paper,we propose an improved PINN that enhances the physical constraints of the neural network model by adding gradient information *** addition,we employ meta-learning optimization to speed up the training *** apply the improved PINNs to the numerical simulation and prediction of solitary and rogue *** evaluate the accuracy of the prediction results by error *** experimental results show that the improved PINNs can make more accurate predictions in less time than that of the original PINNs.

关键词： physics-informed neural networks gradient-enhanced loss function meta-learned optimization nonlinear science

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中法海洋卫星散射计风场资料融合与检验

大气科学 2024年第3期48卷 1233-1246页

作者：冷洪泽曹航胡瑞生曹小群陈祥国赵军国防科技大学气象海洋学院长沙410073

单一的海面风场资料存在观测点稀少、分布不均匀或难以覆盖全球等问题,利用多源风场资料进行融合,实现快速标准网格化,一方面可有效覆盖海面,另一方面可提升风场业务化精度。为了促进以我国自主可控散射计风场资料为主的多源海面风场融... 详细信息

单一的海面风场资料存在观测点稀少、分布不均匀或难以覆盖全球等问题,利用多源风场资料进行融合,实现快速标准网格化,一方面可有效覆盖海面,另一方面可提升风场业务化精度。为了促进以我国自主可控散射计风场资料为主的多源海面风场融合效果提升,本文收集了四种海面风场资料:浮标、船舶报、ASCAT散射计反演风场以及国产中法海洋卫星散射计(CSCAT)反演风场资料,并进行了相关的融合试验与验证。首先对比验证CSCAT散射计风场资料质量,再利用时空加权插值法和最优插值法,以CSCAT散射计资料为核心,辅以其他风场资料进行日平均全球风场融合与3 h区域风场融合,最后对融合风场进行了质量检验。试验结果表明:CSCAT散射计风场资料在数据准确度及数据稳定性上略逊于ASCAT散射计;散射计风与船舶报两种资料融合后的全球风场可以满足一定的业务化精度需求;最优插值法更适合应用于太平洋海域,时空加权插值法更适合应用于印度洋海域,在大西洋海域两种方法融合效果相近;时空加权与最优插值集成方法下的3 h区域融合风场质量较全球日平均风场更高。本融合方法实现简便、运算快捷、融合数据可靠,特别是在观测极端稀疏区域,可为需求部门快速获取高分辨率海面标准网格化风场提供一定参考。

关键词：海面风场散射计时空加权最优插值质量评价

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面向空战仿真的智能对手建模研究进展与展望

火力与指挥控制 2024年第5期49卷 1-8,17页

作者：郭亚楠曹小群杨术周晓光海军航空大学辽宁葫芦岛125001 国防科技大学气象海洋学院长沙410073

智能对手建模是空战仿真领域的重要课题,对于加快空战模拟训练的转型升级,提高训练效益、节约训练成本、降低训练风险等方面具有重要意义。总结了近年来国外智能对手建模技术研究进展;论述了智能对手能力需求与关键技术,分别对智能对手... 详细信息

智能对手建模是空战仿真领域的重要课题,对于加快空战模拟训练的转型升级,提高训练效益、节约训练成本、降低训练风险等方面具有重要意义。总结了近年来国外智能对手建模技术研究进展;论述了智能对手能力需求与关键技术,分别对智能对手对抗空间表示与建模、态势评估与推理、智能对手自主决策与优化、多智能对手行动协同与控制进行分析。对未来空战智能对手建模技术的发展方向进行了总结和展望,以期为相关研究人员提供参考与启发。

关键词：空战模拟训练对手建模人工智能

Assimilation of All-Sky Radiance from the FY-3 MWHS-2 with the Yinhe 4D-Var System

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Journal of Meteorological Research 2022年第5期36卷 750-766页

作者： Shuo MA Weimin ZHANG xiaoqun cao Yanlai ZHAO Bainian LIU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073

Compared with traditional microwave humidity sounding capabilities at 183 GHz,new channels at 118 GHz have been mounted on the second generation of the Microwave Humidity Sounder(MWHS-2)onboard the Chinese FY-3C and FY-3D polar orbit meteorological satellites,which helps to perform moisture *** this study,as the allsky approach can manage non-linear and non-Gaussian behavior in cloud-and precipitation-affected satellite radiances,the MWHS-2 radiances in all-sky conditions were first assimilated in the Yinhe four-dimensional variational data assimilation(YH4DVAR)*** data quality from MWHS-2 was evaluated based on observation minus background *** is found that the MWHS-2 data of both FY-3C and FY-3D are of good quality in *** months of MWHS-2 radiances in all-sky conditions were then assimilated in the YH4DVAR *** on the forecast scores and observation fits,we conclude that the all-sky assimilation of the MWHS-2 at 118-and 183-GHz channels on FY-3C/D is beneficial to the analysis and forecast fields of the temperature and humidity,and the impact on the forecast skill scores is neutral to ***,we compared the impacts of assimilating the 118-GHz channels and the equivalent Advanced Microwave Sounding Unit-A(AMSUA)channels on global forecast accuracy in the absence of other satellite ***,the impact of the 118-GHz channels on the forecast accuracy is not as large as that for the equivalent AMSUA ***,all-sky radiance assimilation of MWHS-2 in the YH4DVAR system has indeed benefited from the 118-GHz channels.

关键词： Microwave Humidity Sounder-2 data assimilation Yinhe four-dimensional variational data assimilation all-sky radiance Fengyun-3

Assimilation of HY-2A Scatterometer Ambiguous Winds Based on Feature Thinning

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Journal of Meteorological Research 2017年第4期31卷 720-730页

作者： Boheng DUAN Weimin ZHANG xiaoqun cao Yi YU Haijin DAI Academy of Ocean Science and Engineering National University of Defense TechnologyChangsha 410073

This paper focuses on the data assimilation methods for sea surface winds, based on the level-2B HY-2A satellite microwave scatterometer wind products. We propose a new feature thinning method, which is herein used to screen scatterometer winds while maintaining the key structure of the wind field in the process of data thinning for highresolution satellite observations. We also accomplish feeding the ambiguous wind solutions directly into the data assimilation system, thus making better use of the retrieved information while simplifying the assimilation process of the scatterometer products. A numerical simulation experiment involving Typhoon Danas shows that our method gives better results than the traditional approach. This method may be a valuable alternative for operational satellite data assimilation.

关键词： data assimilation HY-2A scatterometer feature thinning ambiguous winds

Assimilation of HY-2A scatterometer sea surface wind data in a 3DVAR data assimilation system-A case study of Typhoon Bolaven

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Frontiers of Earth Science 2015年第2期9卷 192-201页

作者： Yi YU Weimin ZHANG Zhongyuan WU Xiaofeng YANG xiaoqun cao Mengbin ZHU National University of Defense Technology Changsha 410073 China State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing 100101 China

The scatterometer （SCAT） on-board China＇s HY-2A satellite has the capability to provide high resolution wind vector information over the global ocean surface. These wind vector data produced by the HY-2A scatterometer （HY-2A SCAT） are available to the data assimilation system with real-time information of high accuracy. In this paper, two experiments are designed to investigate the impact of HY-2A SCAT data in the three- dimensional variational assimilation system for the Weather Research and Forecast model （WRF 3DVAR）. The powerful Typhoon Bolaven, which struck South Korea in August 2012, is selected for this case study. The results clearly demonstrate that HY-2A SCAT data can effectively complement the scarce observations over the ocean surface and improve the prediction of the wind and pressure fields of a typhoon. The case study of Typhoon Bolaven exhibits the significant and positive impact of HY- 2A SCAT data on the numerical prediction of the tropical cyclone track.

关键词： HY-2A scatterometer data assimilation seasurface wind 3DVAR

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大数据时代:数值天气预报的机遇与挑战

网络安全与数据治理 2024年第1期43卷 28-32页

作者：郭亚楠曹小群周梦鸽彭柯澄国防科技大学气象海洋学院湖南长沙410073 海军航空大学辽宁葫芦岛125001

随着地球观测系统及数值模拟方法的不断发展,数值天气预报研究进入以数据驱动为核心的新范式,大气科学也迈入了大数据时代,大数据技术赋能数值天气预报发展成为大气科学研究的热点方向。从气象海洋大数据的内涵、分类及其特征出发,概括... 详细信息

随着地球观测系统及数值模拟方法的不断发展,数值天气预报研究进入以数据驱动为核心的新范式,大气科学也迈入了大数据时代,大数据技术赋能数值天气预报发展成为大气科学研究的热点方向。从气象海洋大数据的内涵、分类及其特征出发,概括和梳理了气象海洋大数据在数值天气预报的应用,从技术方面,对资料同化、物理过程参数化、数值预报产品订正,以及机理与数据融合的模式开发等问题进行分析,并对相关应用进行了深入探讨和展望,从而为气象海洋大数据与数值天气预报的融合发展提供重要参考依据。

关键词：气象海洋大数据数值天气预报

Application of a novel constrained wavelet threshold denoising method in ensemble-based background-error variance

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Science China(Technological Sciences) 2018年第6期61卷 809-818页

作者： HUANG QunBo LIU BaiNian ZHANG WeiMin ZHU MengBin SUN JingZhe cao xiaoqun XING Xiang LENG HongZe ZHAO YanLai Academy of Ocean Science and Engineering National University of Defense Technology Changsha 410073 China College of Computer National University of Defense Technology Changsha 410073 China Weather Center of Chinese People's Liberation Army Air Force Beijing 100843 China

A more efficiem noise filtering technique is needed in ensemble data assimilation, to improve traditional spectral filtering methods that cannot reflect the local characteristics of spatial scales. In this paper, we present the design of a novel constrained wavelet threshold denoising method （CWTDNM） by introducing an improved threshold value and a new constraining parameter. The proposed method aims to filter noise swamped over different scales. We prepared an ideal experiment object based on the two-dimensional barotropic vorticity equation. A suitable wavelet basis function （i.e., Dbl 1） and the optimal number of decomposition levels （i.e., five） were first selected. The results show that, given the wavelet coefficients are constrained by the parameter, the CWTDNM can produce better filtering results with the smallest root mean square error （RMSE） compared to similar methods. In addition, the filtering accuracy of 10 ensemble sample variances using the CWTDNM is equivalent to that estimated directly from 80 ensemble samples, but with the runtime reduced to approximately one-seventh. Furthermore, a large peak signal-to-noise ratio, which implies a low RMSE, suggests that the proposed method suitably preserves most of the information after denoising.

关键词： two-dimensional wavelet threshold denoising background-error variance ensemble data assimilation (EDA)

Impact of intensity variability of the Asian summer monsoon anticyclone on the chemical distribution in the upper troposphere and lower stratosphere

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Atmospheric and Oceanic Science Letters 2022年第3期15卷 25-30页

作者： Kecheng Peng Jiali Luo Jiayi Mu xiaoqun cao Hongying Tian Lin Shang Yanan Guo College of Meteorology and Oceanography National University of Defense TechnologyChangshaChina Key Laboratory of Semi-Arid Climate Change and College of Atmospheric Sciences Lanzhou UniversityLanzhouChina College of Computer National University of Defense TechnologyChangshaChina Shandong Provincial Climate Center JinanChina Trainer Simulation Training Center of Naval Aeronautical University HuludaoChina

During the Asian summer monsoon(ASM)season,the process of stratosphere-troposphere exchange significantly affects the concentration and spatial distribution of chemical constituents in the upper troposphere and lower stratosphere(UTLS).However,the effect of the intensity of the Asian summer monsoon anticyclone(ASMA)on the horizontal distribution of chemical species within and around the ASMA,especially on the daily time scale,remains ***,the authors use the MERRA-2 reanalysis dataset and Aura Microwave Limb Sounder observations to study the impact of ASMA intensity on chemical distributions at 100 hPa during the ASM *** intraseasonal variation of ASMA is classified into a strong period(SP)and weak period(WP),which refer to the periods when the intensity of ASMA remains strong and weak,*** relatively low ozone(O_(3))region is found to be larger at 100 hPa during SPs,while its mixing ratio is lower than during WPs in *** June,analysis shows that the O_(3) horizontal distribution is mainly related to the intensity of AMSA,especially during SPs in June,while deep convections also impact the O_(3) horizontal distribution in July and *** results indicate that the intraseasonal variation of the ASMA intensity coupled to deep convection can significantly affect the chemical distribution in the UTLS region during the ASM season.

关键词： Asian summer monsoon anticyclone Intensity index Chemical distribution Deep convection

Solving nonlinear soliton equations using improved physics-informed neural networks with adaptive mechanisms

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Communications in Theoretical Physics 2023年第9期75卷 36-50页

作者： Yanan Guo xiaoqun cao Kecheng Peng Simulation and Training Center Naval Aviation UniversityHuludao 125001China College of Computer National University of Defense TechnologyChangsha 410073China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China

Partial differential equations(PDEs)are important tools for scientific research and are widely used in various ***,it is usually very difficult to obtain accurate analytical solutions of PDEs,and numerical methods to solve PDEs are often computationally intensive and very *** recent years,Physics Informed Neural Networks(PINNs)have been successfully applied to find numerical solutions of PDEs and have shown great *** the while,solitary waves have been of great interest to researchers in the field of nonlinear *** this paper,we perform numerical simulations of solitary wave solutions of several PDEs using improved *** improved PINNs not only incorporate constraints on the control equations to ensure the interpretability of the prediction results,which is important for physical field simulations,in addition,an adaptive activation function is *** introducing hyperparameters in the activation function to change the slope of the activation function to avoid the disappearance of the gradient,computing time is saved thereby speeding up *** this paper,the m Kd V equation,the improved Boussinesq equation,the Caudrey–Dodd–Gibbon–Sawada–Kotera equation and the p-g BKP equation are selected for study,and the errors of the simulation results are analyzed to assess the accuracy of the predicted solitary wave *** experimental results show that the improved PINNs are significantly better than the traditional PINNs with shorter training time but more accurate prediction *** improved PINNs improve the training speed by more than 1.5 times compared with the traditional PINNs,while maintaining the prediction error less than 10~(-2)in this order of magnitude.

关键词： physics-informed neural networks adaptive activation function partial differential equations solitary wave