检索结果-南通市图书馆

The diel vertical migration of sound scatterers observed by an acoustic doppler current profiler in the Luzon Strait from July 2009 to April 2011

引用

Acta Oceanologica Sinica 2013年第11期32卷 1-9页

作者： YANG Chenghao LIAO Guanghong YUAN Yaochu CHEN Hong ZHU Xiaohua State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration

acoustic doppler current profiler （ADCP） receives echoes from sound scatterers, then their speed is calcu- lated by the doppler effect. In the open ocean, most of these backscatterers are from the plankton. The sound scatterers descend down to depth at around dawn, their mean speed is 2.9 cm/s, then they ascend up to the surface layer at around dusk with a mean speed of 2.1 cm/s, in the Luzon Strait. The descending speed is faster, which suggests that this zooplankton population may accelerate its downward migration under the action of the gravity. The vertical distribution of a mean volume backscattering strength （MVB- S） in the nighttime has two peaks, which locate near the upper and lower boundary layers of halocline, respectively. However, the backscatterers only aggregate near the surface layer in the daytime. The diel ver- tical migration （DVM） of sound scatterers has several characteristic patterns, it is stronger in summer, but weaker in winter, and the maximum peak occurs in September. The DVM occurrence is synchronous with the seawater temperature increasing at around dawn and dusk, it may affect the ocean mixing and water stratification,

关键词： diel vertical migration acoustic doppler current profiler mean volume backscattering strength,Luzon Strait water stratification

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

Quantifying cold front induced water transport of a bay with in situ observations using manned and unmanned boats

引用

Acta Oceanologica Sinica 2018年第11期37卷 1-7页

作者： WEEKS Eddie ROBINSON Mark E LI Chunyan Coastal Studies Institute Department of Oceanography and Coastal Sciences Louisiana State University Department of Geography and Anthropology Louisiana State University

The generation of high-resolution data is increasingly important in understanding the complexities of coastal ocean and developing sound management strategies, especially in view of the long-term impact of severe weather systems. The impact of severe weather systems, when integrated over time, can be significant when compared with tidal oscillations. This paper presents a study of water transport out of Vermilion Bay in response to a short, intense event associated with a passing atmospheric cold front, and reports the application of an acoustic doppler current profiler （ADCP） mounted on an Automated Surface Craft （ASC）, known as the auto-boat or unmanned boat, developed in our lab at the Louisiana State University, to generate high resolution data accurately at a fraction of the cost of a manned boat. In our study, we used a manned boat and an unmanned boat, each for over 24 h to cover an entire diurnal tidal cycle, to measure flow velocity profiles to calculate the total transport. A stationary ADCP was deployed in the Southwest Pass of the Vermilion Bay from May 2009 to April 2012, providing data almost continuously （with only one major gap）, with a 717-day record of water transport between the northern Gulf of Mexico and Vermilion Bay, and demonstrates the importance of the pass in water transport.

关键词： cold fronts unmanned boat Vermillion Bay acoustic doppler current profiler surveys regression on 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

Vertical structure of tidal currents in the Xuliujing Section of Changjiang River Estuary

引用

Acta Oceanologica Sinica 2023年第2期42卷 44-55页

作者： Zhigao Chen Ya Ban Xiaoye Chen Dajun Li Shengping Wang Faculty of Geomatics East China University of TechnologyNanchang330013China Chongqing Academy of Metrology and Quality Inspection Chongqing401120China Nanjing White Shark Surveying and Mapping Technology Co. LtdNanjing210038China Key Laboratory of Marine Environmental Survey Technology and Application Ministry of Natural ResourcesGuangzhou510300China

Three long-term fixed acoustic doppler current profilers were first used for investigating the vertical structure of tidal currents in Xuliujing Section of Changjiang River ***,three different periods(spring,summer and fall)were also considered for investigating seasonal *** semi-diurnal tides were the most energetic,with along-channel speed of up to 80 cm/s for M_(2)constituent,which dominates at all stations with percent energy up to 65%–75%during *** shape of tidal ellipses of the most energetic semi-diurnal constituent M_(2)showed obvious polarization of the flow paralleling to the riverbank,with the minor semi-axis being generally less than 20%of the major *** maximum velocity of mean current is appeared in top layers at all the three stations,and the velocity decreased with the *** seasonal variations of direction are also observed,which is probably caused by complex local topography since the erosion and deposition in *** vertical variation of four parameters of M_(2)ellipses,agreed well with the optimally fit frictional solutions in top and middle ***,there was an obvious difference between frictional model and observed data in the lower water *** are probably on account of stratification,which strengthens in summer and fall due to the freshening influence of the Changjiang River Estuary outflow.

关键词： vertical structure seasonal variations tidal current mean current acoustic doppler current profiler Changjiang River Estuary

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

Observed Suspended Sediment Dynamics during a Tidal Cycle above Submerged Asymmetric Compound Sand Waves

引用

Journal of Environmental Science and Engineering(A) 2016年第7期5卷 333-355页

作者： Ingo Hennings Dagmar Herbers Department of Ocean Circulation and Climate Dynamics GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel 24148 Germany

The data from acoustic doppler current profiler （ADCP） of the three-dimensional current-field, echo intensity, modulation of Suspended Sediment Concentration （SSC）, and related water levels and wind velocities have been analyzed as a function of water depth above submerged asymmetric compound sand waves during a tidal cycle in the Lister Tiefofthe German Bight in the North Sea. Signatures of vertical current component, echo intensities and calculated SSC modulations in the water column depend strongly on wind and current velocity. Bursts of vertical current component and echo intensity are triggered by sand waves itself as well as by superimposed megaripples due to current wave interaction at high current ≥ 1.0 m＇s1 and wind speeds ≥ 10.0 m·s^-1, preferably of opposite directions, measured at high spatial resolution. The magnitude of currents and SSC modulations during ebb and flood tidal current phases are only weakly time dependent, whereas the local magnitudes of these parameters are variable in space above the sand waves. Some hydrodynamic parameters are further investigated and analyzed, showing a consistence of ADCP measurements in the applied theory.

关键词： acoustic doppler current profiler suspended sediment concentration asymmetric compound sand wave dynamic buoyancy density action density.

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

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

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：