Wind-Induced Circulation in Semienclosed Homogeneous, Rotating Basins

2005 ◽  
Vol 35 (12) ◽  
pp. 2520-2531 ◽  
Author(s):  
Rosario Sanay ◽  
Arnoldo Valle-Levinson
Keyword(s):  
Three Dimensional ◽  
Ocean Model ◽  
Transverse Component ◽  
Lateral Distribution ◽  
Earth’S Rotation ◽  
Axially Symmetric ◽  
Earth's Rotation ◽  
Regional Ocean Model System ◽  
The Right ◽  
Transverse Circulation

Abstract The wind-induced circulation over laterally varying bathymetry was investigated in homogeneous systems using the three-dimensional Regional Ocean Model System (ROMS). The investigation focused on the influence of the earth’s rotation on the lateral distribution of the flow, with particular emphasis on the transverse circulation. Along-basin wind stress with no rotation caused a circulation dominated by an axially symmetric transverse structure consisting of downwind flow over the shoals and upwind flow in the channel along the whole domain. Transverse circulation was important only at the head of the system where the water sank and reversed direction to move toward the mouth. The wind-induced flow pattern under the effects of the earth’s rotation depended on the ratio of the maximum basin’s depth h to the Ekman depth d. The solution tended to that described in a nonrotating system as h/d remained equal to or below 1. For higher values of h/d, the longitudinal flow was axially asymmetric. Maximum downwind flow was located over the right shoal (in the Northern Hemisphere, looking downwind). The transverse component of velocity described three gyres. The main gyre was clockwise (looking downwind) and occupied the entire basin cross section, as expected from the earth’s rotation and the presence of channel walls. The other two gyres were small and localized and were linked to the lateral distribution of the along-channel velocity component, which in turn was dictated by bathymetry. These results compared favorably with a limited set of observations and are expected to motivate future measurements.

scholarly journals A Linear Theory of Three-Dimensional Land–Sea Breezes

2012 ◽  
Vol 69 (6) ◽  
pp. 1890-1909 ◽  
Author(s):  
Qingfang Jiang
Keyword(s):  
Gravity Waves ◽  
Three Dimensional ◽  
Vertical Motion ◽  
Early Morning ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Motion Patterns ◽  
Sea Breezes ◽  
Differential Heating ◽  
Downwind Side

Abstract Land–sea breezes (LSBs) induced by diurnal differential heating are examined using a three-dimensional linear model employing fast Fourier transform with emphasis on the complex coastline shape and geometry, the earth’s rotation, and background wind effects. It has been demonstrated that the low-level vertical motion associated with LSB can be significantly enhanced over a bay (peninsula) because of convergence of perturbations induced by differential heating along a seaward concave (convex) coastline. The dependence of surface winds and vertical motion patterns and their evolutions on the coastline geometries such as the width and the aspect ratio of the bay, the earth’s rotation, and the background winds are investigated. The LSB induced by an isolated tropical island is characterized by onshore flow and ascent over the island in the afternoon to early evening, with a reversal of direction from midnight to early morning. The diurnal heating–induced vertical motion is greatly enhanced over the island and weakened offshore because of the convergence and divergence of perturbations. In the presence of background flow, stronger diurnal perturbations are found at the downwind side of the island, which can extend far downstream associated with inertia–gravity waves.

The influence of systematic errors of star catalogues on the determination of the irregularities of the earth's rotation

1959 ◽  
Vol 11 ◽  
pp. 23-26
Author(s):  
A. A. Nemiro ◽  
N. N. Pavlov
Keyword(s):  
Systematic Errors ◽  
Earth’S Rotation ◽  
Independent System ◽  
Earth's Rotation ◽  
Fundamental Systems ◽  
The Right

In order to lessen the influence of the errors in the right ascensions of stars of fundamental systems on the results of time determinations, it is proposed that the results of time services observing with transit instruments be used for the determination of an independent system of right ascensions of stars. The participation in this work by a maximum number of observatories of different countries is desirable.

scholarly journals Seasonal spreading and transport of buoyant plumes in the shelf off Kochi, South west coast of India- A modeling approach

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. Seena ◽  
K. R. Muraleedharan ◽  
C. Revichandran ◽  
S. Abdul Azeez ◽  
Sebin John
Keyword(s):  
Large Scale ◽  
Southwest Monsoon ◽  
Ocean Model ◽  
Earth’S Rotation ◽  
Coastal Current ◽  
Wind Condition ◽  
Northeast Monsoon ◽  
Wet Season ◽  
Earth's Rotation ◽  
Buoyant Plumes

AbstractWe investigated the seasonal spreading and transport of buoyant plume in the shelf off Kochi using Finite Volume Community Ocean Model (FVCOM). The modelled river plume typically consisted of an offshore bulge and a coastal current. The spreading of the bulge extended up to a distance of 19 km from inlet during the summer monsoon to <10 km in the spring inter-monsoon. The Kelvin number varied between 0.1 and 0.9 which revealed that the plume exhibited both the features of small and large scale plumes, resulting in a highly complicated plume pattern. During the southwest monsoon the plume fringe twisted towards the south, while during the northeast monsoon it twisted towards north according to the reversal of monsoonal winds. The fresh water transport with respect to coastal currents varied in accordance with seasonal river discharge such that the value peaked in the wet season and dropped in the dry season. During the non-realistic (no wind) condition the plume initiated barotropic and baroclinic flow, after which it was acted upon by earth’s rotation so that the plume propagated in the direction of Coriolis force (towards north), as geostrophic currents. The model run ‘with wind’ and ‘without wind’ condition revealed that in the shelf off Kochi the plume is transported in accordance with monsoonal winds/currents by nullifying the effect of earth’s rotation. The categorization of plume influenced area and realization of the direction of plume transport can be used for interpreting the dynamically and potentially active zones in the shelf off Kochi.

Baer's Law of Stream Deflection

2004 ◽  
Vol 23 (2) ◽  
pp. 278-282 ◽  
Author(s):  
Andrew Goudie
Keyword(s):  
Nineteenth Century ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Fluvial Geomorphology ◽  
Theoretical Work ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
The Law ◽  
The Right

Baer's Law of Stream Deflection was a concept that was introduced in the mid-nineteenth century, whereby it was believed that the Earth's rotation influenced the ability of streams to erode their banks preferentially to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. A number of examples of this tendency were produced, and experimental and theoretical work was used to elaborate the idea. Various authors suggested that the influence of the tendency was small and that other factors (e.g., wind and eolian deposition) could account for stream course asymmetry, but no convincing rebuttal of the law has ever been produced. However, modern treatments of fluvial geomorphology largely ignore it.

The Three-Dimensional Dynamic Characteristics on the South of Subei Radiation Shoal Waters

2013 ◽  
Vol 353-356 ◽  
pp. 2746-2754
Author(s):  
Bei Zhang ◽  
Pan Jun Du ◽  
Hui Zhang ◽  
Yue Jun Fei ◽  
Wen Jun Xiao ◽  
...  
Keyword(s):  
Flow Structure ◽  
Dynamic Characteristics ◽  
Three Dimensional ◽  
Ocean Model ◽  
Computation Method ◽  
The South ◽  
Spiral Flow ◽  
Quantitative Evidence ◽  
Result Show ◽  
Transverse Circulation

Based on the high precision terrain datas , high resolution FVCOM(Finite-Volume Coastal Ocean Model) numerical model was established to simulation for tide current and study three-dimensional dynamic characteristics of the south of Radiation shoal waters. Result show that transverse circulation was easy to produce in channel and groove. The vorticity and helicity computation method was applied in the area for the frist time. Transverse circulation and helical flow characteristics of typical sections were preliminary studied, and result show the quantitative evidence for the existence of the Spiral flow.Deep groove is not always appear double reverse spiral flow structure, it changes with the main flow velocity. Shoal grooves appear, a main spiral flow structure, and show great adaptability to the terrain, which is the reflection of the spiral flow to the terrain maintain mechanism .

Zonal and tesseral harmonic perturbations of an artificial satellite

1966 ◽  
Vol 25 ◽  
pp. 323-325 ◽  
Author(s):  
B. Garfinkel
Keyword(s):  
Angular Velocity ◽  
Spherical Harmonics ◽  
Artificial Satellite ◽  
Compact Form ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Secular Variations ◽  
Tesseral Harmonics

The paper extends the known solution of the Main Problem to include the effects of the higher spherical harmonics of the geopotential. The von Zeipel method is used to calculate the secular variations of orderJmand the long-periodic variations of ordersJm/J2andnJm,λ/ω. HereJmandJm,λare the coefficients of the zonal and the tesseral harmonics respectively, withJm,0=Jm, andωis the angular velocity of the Earth's rotation. With the aid of the theory of spherical harmonics the results are expressed in a most compact form.

Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms

2007 ◽  
Vol 42 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Zhi Chen ◽  
Lin Zhao ◽  
Kenneth Lee ◽  
Charles Hannath
Keyword(s):  
Random Walk ◽  
Produced Water ◽  
Model Development ◽  
Three Dimensional ◽  
Monitoring Program ◽  
Ecological Monitoring ◽  
Numerical Approach ◽  
Ocean Model ◽  
Scale Model ◽  
Water Stream

Abstract There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.

scholarly journals Right-sided Bochdalek hernia in an adult with hepatic malformation and intestinal malrotation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Naoki Enomoto ◽  
Kazuhiko Yamada ◽  
Daiki Kato ◽  
Shusuke Yagi ◽  
Hitomi Wake ◽  
...  
Keyword(s):  
Elective Surgery ◽  
Abdominal Cavity ◽  
Three Dimensional ◽  
Simulation Software ◽  
3D Simulation ◽  
Diaphragmatic Defect ◽  
Intestinal Malrotation ◽  
Intestinal Loop ◽  
Bochdalek Hernia ◽  
The Right

Abstract Background Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely.

scholarly journals Alteration within the Hippocampal Volume in Patients with LHON Disease—7 Tesla MRI Study

2020 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Cezary Grochowski ◽  
Kamil Jonak ◽  
Marcin Maciejewski ◽  
Andrzej Stępniewski ◽  
Mansur Rahnama-Hezavah
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Molecular Layer ◽  
Three Dimensional ◽  
Hippocampal Volume ◽  
7 Tesla ◽  
Diagnostic Process ◽  
Resonance Imaging ◽  
The Right

Purpose: The aim of this study was to assess the volumetry of the hippocampus in the Leber’s hereditary optic neuropathy (LHON) of blind patients. Methods: A total of 25 patients with LHON were randomly included into the study from the national health database. A total of 15 patients were selected according to the inclusion criteria. The submillimeter segmentation of the hippocampus was based on three-dimensional spoiled gradient recalled acquisition in steady state (3D-SPGR) BRAVO 7T magnetic resonance imaging (MRI) protocol. Results: Statistical analysis revealed that compared to healthy controls (HC), LHON subjects had multiple significant differences only in the right hippocampus, including a significantly higher volume of hippocampal tail (p = 0.009), subiculum body (p = 0.018), CA1 body (p = 0.002), hippocampal fissure (p = 0.046), molecular layer hippocampus (HP) body (p = 0.014), CA3 body (p = 0.006), Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)–GC ML DG body (p = 0.003), CA4 body (p = 0.001), whole hippocampal body (p = 0.018), and the whole hippocampus volume (p = 0.023). Discussion: The ultra-high-field magnetic resonance imaging allowed hippocampus quality visualization and analysis, serving as a powerful in vivo diagnostic tool in the diagnostic process and LHON disease course assessment. The study confirmed previous reports regarding volumetry of hippocampus in blind individuals.

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