Water exchange and renewal times of a micro-tidal fjord in isohaline coordinates

2021 ◽  
Author(s):  
Xaver Lange ◽  
Markus Jochum
Keyword(s):  
Water Exchange ◽  
Layer Structure ◽  
High Sensitivity ◽  
Ocean Model ◽  
Grid Turbulence ◽  
Exchange Flow ◽  
Transitional Area ◽  
The North ◽  
Coastal Ocean Model ◽  
Horizontal Density Gradient

<p>In micro-tidal coastal systems, the hydrodynamics in fjords reduce to a competition between horizontal density gradient, friction and wind stress. Depending on the depth of the entrance sill, the importance of these factors for water exchange varies within the vertical layer structure of fjords. This study investigates these renewals of water bodies in an isohaline framework, using the example of the Gullmar Fjord on the west coast of Sweden, a transitional area between the brackish Baltic Sea and the northeastern region of the North Sea.</p><p>To estimate the influence of wind and baroclinic pumping on volume and salinity transport and their importance on the exchange time scales, a well-validated, realistic, and highly resolved 3D coastal ocean model (GETM) is used, calibrated with especially designed observations. Simulations were combined with passive numerical tracers and evaluated with the mathematical analysis framework of the Total Exhange Flow (TEF).</p><p>The results highlight the advantage of isohaline coordinates in the study of water mass transformations within the fjord, compared to geographic coordinates, and the high sensitivity of the exchange flow to sub-grid turbulence.</p>

scholarly journals Vulnerability of the Indus River Delta of the North Arabian Sea, Pakistan

2016 ◽  
Vol 18 (3) ◽  
pp. 599-610 ◽  
Keyword(s):  
Seawater Intrusion ◽  
Social Impact ◽  
Sea Water ◽  
River Estuary ◽  
Weather Conditions ◽  
Ocean Model ◽  
Indus River ◽  
The North ◽  
Meteorological Observations ◽  
Coastal Ocean Model

<div> <p>Seawater intrusion has been a serious problem in the Indus River Estuary (IRE) for decades. The literature reviews, hydrological and meteorological observations were analyzed to examine and discuss the causes and consequences of seawater intrusion in the IRE. Both sea water intrusion and coastal erosion are having a devastating environmental and social impact and the whole ecosystem of the Indus Delta is facing serious threat. The Indus deltaic region is not only threatened by continuing activities upstream but also by the neighboring sea in the south, due to the impacts of local weather conditions. Observational results suggest that seawater intrusion reaches 84 km upstream in the IRE during the dry season. Extensive field investigations and a high resolution coastal ocean model are urgently needed for future study.</p> </div> <p>&nbsp;</p>

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

Use competition and water exchange in Marina Baja district, Alicante, Spain

2005 ◽  
Vol 5 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
T.T. Martí
Keyword(s):  
Water Exchange ◽  
Citrus Fruit ◽  
Water Markets ◽  
Tourist Industry ◽  
Related Services ◽  
Integrated Water Management ◽  
The North ◽  
Increasing Demand ◽  
Water Problems ◽  
Water Uses

The water problems in Marina Baja district, located in the north of Alicante Province, southeast Spain, gives rise to very interesting practices in the management of this scarce resource. The key issue in water use both in the Júcar Catchment and in Marina Baja district is the growing demand for water in inland areas for intensive crop irrigation (principally fruit, medlars and citrus fruit) and the growth in demand for water for urban use, as well as for use in the tourist industry and its related services mainly in the towns in the coastal areas, due to strong growth in tourism. This trend of increasing demand has created a tense situation as well as conflict between existing water uses and the need for integrated water management in the area. This step implies that procedures for water exchange contracts have to be developed, that are significantly different from emerging water markets.

scholarly journals Thinner Sea Ice Contribution to the Remarkable Polynya Formation North of Greenland in August 2018

2021 ◽  
Author(s):  
Xiaoyi Shen ◽  
Chang-Qing Ke ◽  
Bin Cheng ◽  
Wentao Xia ◽  
Mengmeng Li ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Mean Value ◽  
Ocean Model ◽  
North Coast ◽  
Average Value ◽  
The North ◽  
Wind Sea ◽  
The One

AbstractIn August 2018, a remarkable polynya was observed off the north coast of Greenland, a perennial ice zone where thick sea ice cover persists. In order to investigate the formation process of this polynya, satellite observations, a coupled ice-ocean model, ocean profiling data, and atmosphere reanalysis data were applied. We found that the thinnest sea ice cover in August since 1978 (mean value of 1.1 m, compared to the average value of 2.8 m during 1978–2017) and the modest southerly wind caused by a positive North Atlantic Oscillation (mean value of 0.82, compared to the climatological value of −0.02) were responsible for the formation and maintenance of this polynya. The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind. Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.

A GPU accelerated finite volume coastal ocean model

2017 ◽  
Vol 29 (4) ◽  
pp. 679-690 ◽  
Author(s):  
Xu-dong Zhao ◽  
Shu-xiu Liang ◽  
Zhao-chen Sun ◽  
Xi-zeng Zhao ◽  
Jia-wen Sun ◽  
...  
Keyword(s):  
Finite Volume ◽  
Coastal Ocean ◽  
Ocean Model ◽  
Coastal Ocean Model

scholarly journals An Unstructured Grid, Finite-Volume Coastal Ocean Model (FVCOM) System

Oceanography ◽  
2006 ◽  
Vol 19 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Changsheng Chen ◽  
Roberet Beardsley ◽  
Geoffrey Cowles
Keyword(s):  
Finite Volume ◽  
Unstructured Grid ◽  
Coastal Ocean ◽  
Ocean Model ◽  
Coastal Ocean Model

scholarly journals A Numerical Simulation of Extratropical Storm Surge and Hydrodynamic Response in the Bohai Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yumei Ding ◽  
Lei Ding
Keyword(s):  
Storm Surge ◽  
Bohai Sea ◽  
Model Simulation ◽  
Three Dimensional ◽  
Wrf Model ◽  
Ocean Model ◽  
Tidal Currents ◽  
The Bohai Sea ◽  
Hydrodynamic Response ◽  
Coastal Ocean Model

A hindcast of typical extratropical storm surge occurring in the Bohai Sea in October 2003 is performed using a three-dimensional (3D) Finite Volume Coastal Ocean Model (FVCOM). The storm surge model is forced by 10 m winds obtained from the Weather Research Forecasting (WRF) model simulation. It is shown that the simulated storm surge and tides agree well with the observations. The nonlinear interaction between the surge and astronomical tides, the spatial distribution of the maximum surge level, and the hydrodynamic response to the storm surge are studied. The storm surge is the interaction of the surge and the astronomical tides. The currents change rapidly during the storm surge and turn to be the unidirectional at some places where the tidal currents are usually rectilinear. The results show that the local surge current velocity in each depth, with a magnitude of the same order as the astronomic tidal currents, increases or decreases rapidly depending on the relationship between the winds and current directions. Furthermore, the current pattern gets more complicated under the influence of the direction of the winds, which might affect sand movement in the coastal water of the Bohai Sea.

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