检索结果-南通市图书馆

Roles of Equatorial Ocean Currents in Sustaining the Indian Ocean Dipole Peak

Journal of Ocean University of China 2022年第3期21卷 622-632页

作者： XING Huibin wang Weiqiang WANG Dongxiao XU Kang State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou510301China University of Chinese Academy of Sciences Beijing100049China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou511458China Innovation Academy of South China Sea Ecology and Environmental Engineering Chinese Academy of SciencesGuangzhou511458China School of Marine Sciences Sun Yat-sen UniversityZhuhai519082China

In this study,on the basis of the results of the European Centre for Medium-Range Weather Forecasts Ocean Reanalysis System 4,the response of equatorial ocean currents and their roles during the peak phase of the Indian Ocean Dipole(IOD)are comprehensively explored.During the IOD peak season,a series of ocean responses emerge.First,significant meridional divergence in the surface layer and convergence in the subsurface layer are found in the equatorial region.The equatorial easterly winds and offequatorial wind curl anomalies are found to be responsible for the divergence at 55°–80°E and the convergence at 70°–90°E.Second,the meridional divergence and convergence are found to favor a weakened Wyrtki jet(WJ)in the surface layer and an enhanced Equatorial Undercurrent(EUC)in the subsurface layer,respectively.Therefore,these ocean responses provide ocean positive feedback that sustains the IOD peak as the weakened WJ and enhanced EUC help maintain the zonal temperature gradient.Additionally,heat budget analyses indicate that the weakened WJ favors sea surface temperature anomaly warming in the western Indian Ocean,whereas the enhanced EUC maintains the sea surface temperature anomaly cooling in the eastern Indian Ocean.

关键词： surface divergence subsurface convergence equatorial zonal currents the Indian Ocean Dipole positive feedback

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

A numerical model study on multi-species harmful algal blooms coupled with background ecological fields

引用

Acta Oceanologica Sinica 2014年第8期33卷 95-105页

作者： wang Qing ZHU Liangsheng WANG Dongxiao State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of Sciences Naval Architecture and Ocean Engineering R & D Center of Guangdong Province South China University of Technology Graduate University of Chinese Academy of Sciences

Based on systematized physical, chemical, and biological modules, a multi-species harmful algal bloom （HAB） model coupled with background ecological fields was established. This model schematically embod-ied that HAB causative algal species and the background ecological system, quantified as total biomass, were significantly different in terms of the chemical and biological processes during a HAB while the inter-action between the two was present. The model also included a competition and interaction mechanism between the HAB algal species or populations. The Droop equation was optimized by considering tempera-ture, salinity, and suspended material impact factors in the parameterization of algal growth rate with the nutrient threshold. Two HAB processes in the springs of 2004 and 2005 were simulated using this model. Both simulation results showed consistent trends with corresponding HAB processes observed in the East China Sea, which indicated the rationality of the model. This study made certain progress in modeling HABs, which has great application potential for HAB diagnosis, prediction, and prevention.

关键词： background ecological fields multi-species harmful algal bloom numerical model

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

Variations in Dissolved Oxygen Induced by a Tropical Storm Within an Anticyclone in the Northern South China Sea

引用

Journal of Ocean University of China 2022年第5期21卷 1084-1098页

作者： YI Zhenhui WANG Dongxiao QIU Chunhua MAO Huabin YU Jiancheng LIAN Shumin School of Marine Sciences Sun Yat-sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519020China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Pearl River Estuary Marine Ecosystem Research Station Ministry of EducationZhuhai 519020China Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering Zhuhai 519020China

Tropical storms(TSs)can induce sea surface cooling,freshening,and phytoplankton blooms.The dissolved oxygen(DO)concentration response to TSs within an anticyclone is still unclear due to the rarity of in situ observations.In this study,we investi-gate the variations in DO concentration attributed to TS‘Haitang’within an anticyclonic eddy in the northern South China Sea based on Chinese underwater glider data.DO concentrations have a higher value at the edge of eddy than at the core.Influenced by TS,DO concentrations decrease remarkably in the subsurface layer in all three regions(inside,edge,and outside of the anticyclonic eddy).The mean DO concentrations decrease more at the edge of the anticyclone than those inside the anticyclone.The recovery time of DO concentration after TS is around one week at the edge of the anticyclone and is>10 days within the eddy.Our observations show that the DO concentrations decrease above the subsurface chlorophyll a maxima layer.Quantitative analysis shows that variations in DO concentration are dominated by horizontal advection and vertical advection terms in the subsurface layer.

关键词： dissolved oxygen Chinese underwater glider anticyclonic eddy tropical storm physical process

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

Influence of Coriolis Parameter Variation on Langmuir Turbulence in the Ocean Upper Mixed Layer with Large Eddy Simulation

引用

Advances in Atmospheric Sciences 2022年第9期39卷 1487-1500页

作者： dongxiao wang Guojing LI Lian SHEN Yeqiang SHU State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Department of Mechanical Engineering and St.Anthony Falls Laboratory University of MinnesotaMinneapolisMinnesota 55455USA Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 510301China

Langmuir turbulence is a complex turbulent process in the ocean upper mixed layer.The Coriolis parameter has an important effect on Langmuir turbulence through the Coriolis-Stokes force and Ekman effect,however,this effect on Langmuir turbulence has not been systematically investigated.Here,the impact of the Coriolis parameter on Langmuir turbulence with a change of latitude(LAT)from 20°N to 80°N is studied using a non-hydrostatic large eddy simulation model under an ideal condition.The results show that the ratio of the upper mixed layer depth to Ekman depth scale(RME)RME=0.266(LAT=50°N)is a key value(latitude)for the modulation effect of the Coriolis parameter on the mean and turbulent statistics of Langmuir turbulence.It is found that the rate of change of the sea surface temperature,upper mixed layer depth,entrainment flux,crosswind velocity,downwind vertical momentum flux,and turbulent kinetic energy budget terms associated with Langmuir turbulence are more evident at RME≤0.266(LAT≤50°N)than at RME≥0.266(LAT≥50°N).However,the rate of change of the depth-averaged crosswind vertical momentum flux does not have a clear variation between RME≤0.266 and RME≥0.266.The complex changes of both Langmuir turbulence characteristics and influence of Langmuir turbulence on the upper mixed layer with latitude presented here may provide more information for further improving Langmuir turbulence parameterization.

关键词： Langmuir turbulence Coriolis parameter the upper mixed layer large eddy simulation

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

Two kinds of average approximation accuracy

引用

CAAI Transactions on Intelligence Technology 2024年第2期9卷 481-490页

作者： Qingzhao Kong Wanting wang dongxiao Zhang Wenbin Zhang Department of Science Jimei UniversityXiamenChina Digital Fujian Big Data Modeling and Intelligent Computing Institute Jimei UniversityXiamenChina Department of Computer Science Michigan Technological UniversityHoughtonMichiganUSA

Rough set theory places great importance on approximation accuracy,which is used to gauge how well a rough set model describes a target concept.However,traditional approximation accuracy has limitations since it varies with changes in the target concept and cannot evaluate the overall descriptive ability of a rough set model.To overcome this,two types of average approximation accuracy that objectively assess a rough set model’s ability to approximate all information granules is proposed.The first is the relative average approximation accuracy,which is based on all sets in the universe and has several basic properties.The second is the absolute average approximation accuracy,which is based on undefinable sets and has yielded significant conclusions.We also explore the relationship between these two types of average approximation accuracy.Finally,the average approximation accuracy has practical applications in addressing missing attribute values in incomplete information tables.

关键词： rough sets rough set theory

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

Tracking the evolution processes and behaviors of mesoscale eddies in the South China Sea：a global nearest neighbor filter approach

引用

Acta Oceanologica Sinica 2017年第11期36卷 27-37页

作者： YI Jiawei DU Yunyan WANG Dongxiao ZHOU Chenghu State Key Laboratory of Resources and Environmental Information System Institute of Geographic Science and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Tropical Oceanography (LTO) South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China

The eddy tracking approach is developed using the global nearest neighbor filter（GNNF） to investigate the evolution processes and behaviors of mesoscale eddies in the South China Sea（SCS）. Combining the Kalman filter and optimal data association technologies, the GNNF algorithm is able to reduce pairing errors to 0.2% in tracking synthetic eddy tracks, outperforming other existing methods. A total of 4 913 eddy tracks that last more than a week are obtained by the GNNF during 1993–2012. The analysis of a growth and a decay based on 3 445 simple eddy tracks show that eddy radius, amplitude, and vorticity smoothly increase during the first half of lifetime and decline during the second half following a parabola opening downwards. The genesis of eddies mainly clusters northwest and southwest of Luzon Island whereas the dissipations concentrate the Xisha Islands where the underwater bay traps and terminates eddies. West of the Luzon Strait, northwest of Luzon Island, and southeast of Vietnam are regions where eddy splits and mergers are frequently observed. Short disappearances mainly distribute in the first two regions. Moreover, eddy splits generally result in a decrease of the radius and the amplitude whereas eddy mergers induce growing up. Eddy intensity and vorticity, on the contrary, are strengthened in the eddy splits and diminished in mergers.

关键词： mesoscale ocean eddies eddy tracking eddy split eddy merger South China Sea

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

Ocean Model Open Boundary Conditions with Volume, Heat and Salinity Conservation Constraints

引用

Advances in Atmospheric Sciences 2014年第1期31卷 188-196页

作者： wang Qiang ZHOU Weidong WANG Dongxiao DONG Danpeng State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences

Open boundary conditions （OBCs） for a regional ocean model that can be integrated stably over a long timeframe, as well as satisfy the volume, heat and salinity conservation constraints, were developed. First, the idea that the inward and outward flux information can be treated separately in the OBCs was adopted. Second, in order to maintain the property that the volume, heat and salinity remains conserved in the simulation domain, conservation constraints were added to the OBCs, and an inverse method utilized to solve the constraint equations. Ideal experiments were designed to investigate the conservation property, and the OBCs were found to work efficiently to maintain the volume, heat and salinity conservation. It was found that simulations were comparable to observations when the OBCs were applied to a regional ocean model.

关键词： open boundary conditions modeling inverse method ocean circulation

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

Investigation of saltwater intrusion and salinity stratification in winter of 2007/2008 in the Zhujiang River Estuary in China

引用

Acta Oceanologica Sinica 2012年第3期31卷 31-46页

作者： ZHOU Wei WANG Dongxiao LUO Lin Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of OceanologyChinese Academy of ScienceGuangzhou 510301China Graduate School Chinese Academy of SciencesBeijing 100049China

Saltwater intrusion is a serious environmental problem in the Zhujiang River Estuary (ZRE),which threatens the water supply of fifteen million people. The hydrological observations as well as meteorological and tidal forcing in the winter of 2007/2008 were analyzed to examine the saltwater intrusion in the ZRE.The observational results suggest that the maximum vertical difference of salinity can reach 10 in the Humen Channel during neap tide,but is very small in the Hengmen Channel. The vertically averaged salinity from time series stations during spring tide is higher than that during neap tide.A three-dimensional finite difference model was developed based on the environmental fluid dynamic code (EFDC) to study the mechanism of saltwater intrusion and salinity stratification in the ZRE.By analyzing the salt transport and the temporal variation of saltwater intrusion,the authors found that the net salt transport due to the estuarine circulation during neap tide was more than that during spring tide.This caused salt to advance more into the estuary during neap tide.However,saltwater intrusion was stronger during spring tide than that during neap tide because the spring-neap variation in salt transport was small relative to the total length of the saltwater intrusion.The physical mechanism causing this saltwater intrusion was investigated by a series of sensitivity experiments,in order to examine saltwater intrusion in response to river discharge and winds.The freshwater source was a dominant influencing factor to the saltwater intrusion and controlled salinity structure,vertical stratification and length of the saltwater intrusion.The prevailing northeast monsoon during winter could increase the saltwater intrusion in the ZRE.Though the southwest wind was uufavorable to saltwater intrusion during spring tide,it could increase stratification and saltwater intrusion during neap tide.

关键词： saltwater intrusion,spring tide,neap tide,salt transport

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

Spring mesoscale high in the western South China Sea

引用

Acta Oceanologica Sinica 2013年第6期32卷 1-5页

作者： HE Zhigang ZHANG Yan WANG Dongxiao State Key Laboratory of Tropical Oceanography (LTO) South China Sea Institute of Oceanology Chinese Academy of Sciences College of Ocean and Earth Sciences Xiamen University South China Sea Marine Engineering Surveying Center South China Sea Branch State Oceanic Administration

A recurring spring mesoscale eddy in the western South China Sea （SCS） is studied using remote sensing data and historical in situ observations. The feature first appears east of the central Vietnam coast in Febru- ary as a high sea-level anomaly, grows rapidly to a well-developed anticyclonic eddy by March, matures in April, and decays in May. Besides the warm-core feature, it also has an inherent low-salinity property, so it is named ＂spring mesoscale high （SMH）＂. Though with clear interannual variation in terms of intensity and spatial coverage, the SMH always emerges in the region between ll0~E and l14~E and between 12~N and 16~N. The formation of SMH is ascribed to the combined effects of wind forcing and releasing of po- tential energy set up by winter monsoon. In particular, the wind-stress curl plays an important role in its development, maintenance, and dissipation.

关键词： spring western South China Sea warm eddy

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

Almost periodic dynamics of delayed prey-predator model with discontinuous harvesting policies and Hassell-Varley type functional response

引用

International Journal of Biomathematics 2018年第7期11卷 1-36页

作者： dongxiao Chen Dongshu wang Fujian Province University Key Laboratory of Computation Science School of Mathematical Sciences Huaqiao University QuanzhouFujian 362021P.R.China

In this study,a class of delayed prey-predator model with Hassell-Varley type functional response is investigated,in which the harvesting policies are modeled by discontinuous functions.Based on functional differential inclusions and set-valued analysis theories,the local and global existence of positive solution in sense of Filippov is given.By employing theory of functional differential inclusions and generalized differential inequalities,some sufficient conditions which guarantee the permanence of the system are obtained.Accord- ing to non-smooth analysis theory with generalized Lyapunov functional approach,a series of useful criteria on existence,uniqueness and global asymptotic stability of the almost positive periodic solution to the system are derived.Some suitable examples together with their numerical simulations are given to illustrate the effectiveness of our results by using MATLAB.

关键词： Discontinuous harvesting policy functional differential inclusions HassellVarley type functional response permanence almost positive periodic solution global attractivity.

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

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：