检索结果-南通市图书馆

Spatiotemporal variations of parameters of internal solitary waves in the northern South China Sea

Journal of Oceanology and Limnology 2024年第2期42卷 421-438页

作者： Yu’ang LIU Yifei JIANG Xiaojiang ZHANG Zhiyuan WANG Yu CAO Huizan WANG College of meteorology and Oceanography National University of Defense TechnologyChangsha 410000China

The dynamic parameters for internal solitary waves(ISWs)derived from the extended Korteweg-de Vries(eKdV)equation play an important role in the understanding and prediction of *** spatiotemporal variations of the dynamic parameters of the ISWs in the northern South China Sea(SCS)were studied based on the reanalysis of long-term temperature and salinity *** results for spectrum analysis show that there are definite geographical differences for the periodic variation of the parameters:in shallow water,all parameters vary with a wave period of one year,while in deep water wave components of the parameters at other frequencies *** wavelet analysis,the wavelet power spectral densities in deep water exhibited an inter-annual variation *** example,the wave component of the dispersion coefficient with a wave period of about half a year reached its power peak once every two *** on previous work,this inter-annual variation pattern was deduced to be caused by dynamic *** further work on the regulatory mechanisms,empirical orthogonal function(EOF)decomposition was *** was found that the modes of the dispersion coefficient have different geographical distributions,explaining the reason why the wave components in different frequencies appeared in different *** numerical simulation results confirm that the variations in the parameters of the ISWs derived from the eKdV equation could affect the waveforms significantly because of changes in the polarity of the ***,the periodic variations of the dynamic parameters are related to the geographical location because of dynamic processes operating.

关键词： internal solitary waves(ISWs) dynamic parameters eKdV equation spatiotemporal variation polarity empirical orthogonal function(EOF)decomposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improved Simulation of Summer Heavy Rainfall over Beijing and Henan by the YHGSM with Updated Subgrid Orographic Parameters

引用

Journal of Meteorological Research 2024年第3期38卷 504-529页

作者： Yingjie WANG Jianping WU Kaijun REN College of Computer Science and Technology National University of Defense TechnologyChangsha410600China College of meteorology and Oceanography National University of Defense TechnologyChangsha410600China

In numerical weather prediction(NWP),the parameterization of orographic drag plays an important role in representing subgrid orographic *** subgrid orographic parameters are the key input to the parameterization of orographic ***,the subgrid orographic parameters in most NWP models were produced based on elevation datasets generated many years ago,with a coarse resolution and low *** this paper,using the latest high-quality elevation data and considering the applicable scale range of the subgrid orographic parameters,we construct the orographic parameters,including the subgrid orographic standard deviation,anisotropy,orientation,and slope,that are required as input to the orographic gravity wave drag(OGWD)***,we introduce the newly constructed orographic parameters into the Yin-He Global Spectral Model(YHGSM),optimize the description of the orographic effect in the model,and improve the simulation of two typical heavy rainfall events in Beijing and Henan.

关键词： subgrid orographic parameters orographic drag heavy rainfall Yin-He Global Spectral Model(YHGSM) parameterization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MetaPINNs:Predicting soliton and rogue wave of nonlinear PDEs via the improved physics-informed neural networks based on meta-learned optimization

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changes of tropical cyclone size in three oceanic basins of the northern hemisphere from 2001 to 2021

引用

Frontiers of Earth Science 2024年第2期18卷 312-323页

作者： Banglin ZHANG Jeremy Cheuk-Hin LEUNG Shengyuan LIU Jianjun XU Guangzhou Institute of Tropical and Marine meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction CMAGuangzhou 510640China College of Atmospheric Science Lanzhou UniversityLanzhou 730020China College of Ocean and meteorology Guangdong Ocean UniversityZhanjiang 524088China CMA-GDOU Joint Laboratory for Marine meteorology&South China Sea Institute of Marine meteorology Guangdong Ocean UniversityZhanjiang 524088China

In this study the changes of tropical cyclone(TC)size from 2001 to 2021 are analyzed based on linear and quadratic curve fittings of the national Hurricane Center(NHC)/Joint Typhoon Warning Center(JTWC)best track data,based on the radius of maximum wind(RMW)and the average radius of 34-kt wind(AR34),in three oceanic basins of the North Atlantic(NATL),the Western North Pacific(WPAC)and the Eastern North Pacific(EPAC).The computations are done separately for two categories of tropical cyclones:tropical storms(TS)and hurricanes(HT).Size changes of landfalling and non-landfalling TCs are also *** show that there is a great inter-basin variability among the changes in TC *** conclusions include:1)overall,the inner cores of TSs have become larger in all three basins,with the increasing tendencies being significant in the NATL and WAPC,while those of HTs mostly get smaller or remain similar;2)meanwhile,comparatively large inter-basin differences are observed for the TC outer core sizes,and the sizes of landfalling TCs;3)particularly,a significant decrease in landfalling HT outer core size is observed over the EPAC;4)in contrast,significant increases in landfalling TS inner core size are found over the NATL and *** presented analysis results could benefit future research about TC forecasts,storm surge studies,and the cyclone climate and its changes.

关键词： tropical cyclone storm size frequency intensity duration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Diagnostic Study of an Extreme Explosive Cyclone over the Kuroshio/Kuroshio Extension Region

引用

Journal of Ocean University of China 2024年第3期23卷 605-617页

作者： ZHANG Shuqin LIAO Qinghua LIU Chunlei GAO Xiaoyu LONG Jingchao LI Pengyuan XU Jianjun College of Ocean and meteorology Guangdong Ocean UniversityZhanjiang 524088China South China Sea Institute of Marine meteorology Guangdong Ocean UniversityZhanjiang 524088China CMA-GDOU Joint Laboratory for Marine meteorology Guangdong Ocean UniversityZhanjiang 524088China Key Laboratory of Climate Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong ProvinceGuangdong Ocean UniversityZhanjiang 524088China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China department of Marine meteorology Ocean-Atmosphere Interaction and Climate LaboratoryKey Laboratory of Physical OceanographyOcean University of ChinaQingdao 266100China

Explosive cyclones(ECs)occur frequently over the Kuroshio/Kuroshio Extension *** most rapidly intensified EC over the Kuroshio/Kuroshio Extension region during the 42 years(1979-2020)of cold seasons(October-April)was studied to reveal the variations of the key factors at different explosive-developing *** EC had weak low-level baroclinicity,mid-level cyclonic-vorticity advection,and strong low-level water vapor convergence at the initial explosive-developing *** low-level baroclinicity and mid-level cyclonic-vorticity advection increased substantially during the maximum-deepening-rate *** diagnostic analyses using the Zwack-Okossi equation showed that diabatic heating was the main contributor to the initial rapid intensification of this *** cyclonic-vorticity advection and warm-air advection enhanced rapidly in the middle and upper troposphere and contributed to the maximum rapid intensification,whereas the diabatic heating weakened slightly in the mid-low *** relative contribution of the diabatic heating decreased from the initial explosive-developing stage to the maximum-deepening-rate stage due to the enhancement of other factors(the cyclonic-vorticity advection and warm-air advection).Furthermore,the physical factors contributing to this EC varied with the explosive-developing *** non-key factors at the initial explosive-developing stage need attention to forecast the rapid intensification.

关键词： explosive cyclone diabatic heating cyclonic-vorticity advection rapid intensification the Kuroshio/Kuroshio Extension region

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Combinatorial Optimization of Physics Parameterization Schemes for Typhoon Simulation Based on a Simple Genetic Algorithm(SGA)

引用

Journal of Meteorological Research 2024年第1期38卷 10-26页

作者： Zebin LU Jianjun XU Zhiqiang CHEN Jinyi YANG Jeremy Cheuk-Hin LEUNG Daosheng XU Banglin ZHANG China Meteorological Administration–Guangdong Ocean University Joint Laboratory for Marine meteorology South China Sea Institute of Marine MeteorologyGuangdong Ocean UniversityZhanjiang 524088 College of Ocean and meteorology Guangdong Ocean UniversityZhanjiang 524088 Guangzhou Institute of Tropical and Marine meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological AdministrationGuangzhou 510640 Shenzhen Institute of Guangdong Ocean University Shenzhen 518120 College of Atmospheric Science Lanzhou UniversityLanzhou 730000

Each physical process in a numerical weather prediction(NWP)system may have many different parameterization *** studies have shown that the performance of different physical parameterization schemes varies with the weather situation to be ***,it is necessary to select a suitable combination of physical parameterization schemes according to the variation of weather ***,it is rather difficult to identify an optimal combination among millions of possible parameterization scheme *** study applied a simple genetic algorithm(SGA)to optimizing the combination of parameterization schemes in NWP models for typhoon *** feasibility of SGA was verified with the simulation of Typhoon Mujigae(2015)by using the Weather Research and Forecasting(WRF)model and Typhoon Higos(2020)by using the Coupled Ocean–Atmosphere–Wave–Sediment Transport(COAWST)modeling *** results show that SGA can efficiently obtain the optimal combination of *** Typhoon Mujigae(2015),the optimal combination can be found from the 1,304,576 possible combinations by running only 488 *** results can be obtained for Typhoon Higos(2020).Compared to the default combination proposed by the COAWST model system,the optimal combination scheme significantly improves the simulation of typhoon track and *** study provides a feasible way to search for the optimal combinations of physical parameterization schemes in WRF and COAWST for more accurate typhoon *** can help provide references for future development of NWP models,and for analyzing the coordination and adaptability of different physical process parameterization schemes under specific weather backgrounds.

关键词： simple genetic algorithm(SGA) combinatorial optimization typhoon forecast numerical weather prediction(NWP)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of the Complex Terrain in Beijing on Formation of Low-Level Jets

引用

Journal of Meteorological Research 2024年第1期38卷 138-150页

作者： Li’ao ZHOU Chenggang WANG Shiguang MIAO Ju LI School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Institute of Urban meteorology China Meteorological AdministrationBeijing 100089 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

This study investigated how the Taihang Mountains and the Yanshan Mountains affect low-level jets(LLJs)in the Beijing area,based on conventional radiosonde observations from Nanjiao Observatory(2016–2017)and high-resolution Weather Research and Forecasting–Advanced Research WRF(WRF-ARW)model *** of radiosonde observations indicated that LLJs in the study area are mainly from the southwest and northwest directions,with occurrence frequency of 44.6%and 33.0%,***(northwest)LLJs are aligned parallel(perpendicular)to the orientation of the Taihang Mountain *** sensitivity experiments using the WRF-ARW model were then conducted to examine the effects of terrain forcing on the northwest and southwest LLJs,with adopted terrain heights of 100%and 50%.The results showed that for northwest LLJs,reduction in the elevation of the Taihang Mountain Range led to weakening of jet intensity by approximately 20%and reduction in jet maximum height by approximately 250 m;lowering the Yanshan Mountain Range had minor influence on the northwest LLJs,with only a 5.2%reduction in intensity and no substantial change in jet maximum *** southwest LLJs,reduction in the elevation of both the Taihang and Yanshan Mountain ranges resulted in minor changes in the intensity and height of the *** analysis revealed that the topography in the Beijing area could modulate the height and intensity of the stable layer by altering the inversion structure within the boundary *** LLJs can develop rapidly within the stable layer,and both the location and the scale of the jet core exhibited reasonable agreement with the extent of the stable layer.

关键词： low-level jets(LLJs) mesoscale numerical simulation terrain forcing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Global Change in Agricultural Flash Drought over the 21st Century

引用

Advances in Atmospheric Sciences 2024年第2期41卷 209-220,I0002-I0019页

作者： Emily BLACK national Centre for Atmospheric Science Fairbairn House71-75 Clarendon RoadLeedsLS29PHU.K department of meteorology Brian Hoskins BuildingUniversity of ReadingWhiteknights campusReadingRG66ETU.K.

Agricultural flash droughts are high-impact phenomena, characterized by rapid soil moisture dry down. The ensuing dry conditions can persist for weeks to months, with detrimental effects on natural ecosystems and crop cultivation. Increases in the frequency of these rare events in a future warmer climate would have significant societal impact. This study uses an ensemble of 10 Coupled Model Intercomparison Project(CMIP) models to investigate the projected change in agricultural flash drought during the 21st century. Comparison across geographical regions and climatic zones indicates that individual events are preceded by anomalously low relative humidity and precipitation, with long-term trends governed by changes in temperature, relative humidity, and soil moisture. As a result of these processes, the frequency of both upperlevel and root-zone flash drought is projected to more than double in the mid-and high latitudes over the 21st century, with hot spots developing in the temperate regions of Europe, and humid regions of South America, Europe, and southern Africa.

关键词： flash drought climate change soil moisture agricultural drought CMIP

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

6DOF pose estimation of a 3D rigid object based on edge-enhanced point pair features

引用

Computational Visual Media 2024年第1期10卷 61-77页

作者： Chenyi Liu Fei Chen Lu Deng Renjiao Yi Lintao Zheng Chenyang Zhu Jia Wang Kai Xu College of Computing National University of Defense TechnologyChangsha410073China department of Spine Surgery the Second Xiangya HospitalCentral South UniversityChangsha410011China Clinical Nursing Teaching and Research Section the Second Xiangya HospitalChangsha410011China College of meteorology and Oceanography National University of Defense TechnologyChangsha410073China Beijing Institute of Tracking and Communication Technology Beijing100094China

The point pair feature(PPF)is widely used for 6D pose *** this paper,we propose an efficient 6D pose estimation method based on the PPF *** introduce a well-targeted down-sampling strategy that focuses on edge areas for efficient feature extraction for complex geometry.A pose hypothesis validation approach is proposed to resolve ambiguity due to symmetry by calculating the edge matching *** perform evaluations on two challenging datasets and one real-world collected dataset,demonstrating the superiority of our method for pose estimation for geometrically complex,occluded,symmetrical *** further validate our method by applying it to simulated punctures.

关键词： point pair feature(PPF) pose estimation object recognition 3D point cloud

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Impact of Local Climate Zones on the Urban Heat and Dry Islands in Beijing:Spatial Heterogeneity and Relative Contributions

引用

Journal of Meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang ZHENG Fu LUO Nana LI Hua GAO Yuanjian YANG Institute of Urban meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83 automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban Beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of Beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate Beijing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：