scholarly journals The circulation of the Persian Gulf: a numerical study

Ocean Science ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 27-41 ◽  
Author(s):  
J. Kämpf ◽  
M. Sadrinasab

Abstract. We employ a three-dimensional hydrodynamic model (COHERENS) in a fully prognostic mode to study the circulation and water mass properties of the Persian Gulf – a large inverse estuary. Our findings, which are in good agreement with observational evidence, suggest that the Persian Gulf experiences a distinct seasonal cycle in which a gulf-wide cyclonic overturning circulation establishes in spring and summer, but this disintegrates into mesoscale eddies in autumn and winter. Establishment of the gulf-wide circulation coincides with establishment of thermal stratification and strengthening of the baroclinic exchange circulation through the Strait of Hormuz. Winter cooling of extreme saline (>45) water in shallow regions along the coast of United Arab Emirates is a major driver of this baroclinic circulation.

2005 ◽  
Vol 2 (3) ◽  
pp. 129-164 ◽  
Author(s):  
J. Kämpf ◽  
M. Sadrinasab

Abstract. We employ a three-dimensional hydrodynamic model (COHERENS) to study the circulation and water mass properties of the Persian Gulf, which is a large inverse estuary. Our findings suggest that the Persian Gulf experiences a distinct seasonal cycle in which a Gulf-wide cyclonic overturning circulation establishes in spring and summer, but this disintegrates into mesoscale eddies in autumn and winter. Establishment of the Gulf-wide circulation coincides with establishment of thermal stratification and strengthening of the baroclinic exchange circulation through the Strait of Hormuz. The latter is associated with winter cooling of extreme saline (>45 psu) water in shallow regions along the coast of United Arab Emirates. To validate the model results, we present a detailed comparison with observational evidence.


Author(s):  
Masoud Sadrinasab ◽  
Karim Kenarkoohi

The Persian Gulf connects to the Indian Ocean via the Strait of Hormuz. In this study, a three-dimensional hydrodynamic model (COHERENS) is employed in a fully prognostic mode to derive sound velocity profiles in the Persian Gulf, an evaporation-driven inverse estuary that is governed by import of surface water from the adjacent ocean and export of saline bottom gulf water through the Strait of Hormuz. During spring and summer, a cyclonic overturning circulation establishes along the full length of the Gulf. During autumn and winter, this circulation breaks up into mesoscale eddies, laterally stirring most of the Gulf’s surface waters. Output of the model shows that sound velocity in the Persian Gulf depends mainly on the temperature in the surface layer whereas the bottom layer as well as the southern part of the Gulf depends on temperature and salinity. Maximum sound velocity occurs during summer in the Persian Gulf which decreases gradually moving from Strait of Hormuz to the north western part of the Gulf. A gradual decrease in sound velocity profiles with depth was commonly observed almost at all stations in the Gulf. However, an exception occurred in Strait of Hormuz during winter. The results of the model are very close to previous observations.


2021 ◽  
Vol 73 (1) ◽  
pp. 169-178
Author(s):  
M. Alipour Amroabadi ◽  
E. Rahimi ◽  
A. Shakerian ◽  
H. Momtaz

ABSTRACT Foodborne viruses including hepatitis A virus (HAV), norovirus (NoV), rotavirus (RoV) and hepatitis E virus (HEV) are easily transmitted through contaminated seafoods. The current research was done to assess the incidence of RoV, NoV GI and GII,hAV and hEV in fish and shrimp samples caught from the Persian Gulf, Iran. Three-hundred and twenty fish and shrimp samples were collected. The presence of foodborne viruses were assessed by the real-time PCR. Forty-nine out of 320 (15.31%) fish and shrimp samples were positive for foodborne viruses. Distribution of hAV, NoV GI and NoV GII amongst all studied samples were 0.93%, 5.93% and 8.43%, respectively. hEV and RoV viruses were not found in studied samples. Parastromateus niger and Scomberomorus commerson fish and Penaeus monodon shrimp were the most frequently contaminated samples. Simultaneous incidence of hAV and NoV GI and hAV and NoV GII were 0.31% and 0.93%, respectively. Distribution of foodborne viruses in samples collected through spring, summer, autumn and winter seasons were 14.28%, 9.33%, 11.76% and 24.44%, respectively. Findings revealed that the incidence of foodborne viruses was significantly associated with seafood species and also season of sampling.


2014 ◽  
Vol 694 ◽  
pp. 187-192
Author(s):  
Jin Xiang Wu ◽  
Jian Sun ◽  
Xiang Gou ◽  
Lian Sheng Liu

The three-dimensional coupled explicit Reynolds Averaged Navier–Stokes (RANS) equations and the two equation shear-stress transport k-w (SST k-w) model has been employed to numerically simulate the cold flow field in a special-shaped cavity-based supersonic combustor. In a cross-section shaped rectangular, hypersonic inlet with airflow at Mach 2.0 chamber, shock structures and flow characteristics of a herringbone-shaped boss and a herringbone-shaped cavity models were discussed, respectively. The results indicate: Firstly, according to the similarities of bevel-cutting shock characteristics between the boss case and the cavity case, the boss structure can serve as an ideal alternative model for shear-layer. Secondly, the eddies within cavity are composed of herringbone-spanwise vortexes, columnar vortices in the front and main-spanwise vortexes in the rear, featuring tilting, twisting and stretching. Thirdly, the simulated bottom-flow of cavity is in good agreement with experimental result, while the reverse flow-entrainment resulting from herringbone geometry and pressure gradient. However, the herringbone-shaped cavity has a better performance in fuel-mixing.


2017 ◽  
Vol 32 (4) ◽  
pp. 268-280 ◽  
Author(s):  
Rasmus Gjedssø Bertelsen ◽  
Shayegheh Ashourizadeh ◽  
Kent Wickstrøm Jensen ◽  
Thomas Schøtt ◽  
Yuan Cheng

Purpose Entrepreneurs are networking with others to get advice for their businesses. The networking differs between men and women; notably, men are more often networking for advice in the public sphere and women are more often networking for advice in the private sphere. The purpose of this study is to account for how such gendering of entrepreneurs’ networks of advisors differs between societies and cultures. Design/methodology/approach Based on survey data from the Global Entrepreneurships Monitor, a sample of 16,365 entrepreneurs is used to compare the gendering of entrepreneurs’ networks in China and five countries largely located around the Persian Gulf, namely Yemen, Iran, Saudi Arabia, Qatar and the United Arab Emirates. Findings Analyses show that female entrepreneurs tend to have slightly larger private sphere networks than male entrepreneurs. The differences between male and female entrepreneurs’ networking in the public sphere are considerably larger. Societal differences in the relative prominence of networking in the public and private spheres, and the gendering hereof, correspond well to cultural and socio-economic societal differences. In particular, the authors found marked differences among the religiously conservative and politically autocratic Gulf states. Research limitations/implications As a main limitation to this study, the data disclose only the gender of the entrepreneur, but not the gender of each advisor in the network around the entrepreneur. Thus, the authors cannot tell the extent to which men and women interact with each other. This limitation along with the findings of this study point to a need for further research on the extent to which genders are structurally mixed or separated as entrepreneurs network for advice in the public sphere. In addition, the large migrant populations in some Arab states raise questions of the ethnicity of entrepreneurs and advisors. Originality/value Results from this study create novel and nuanced understandings about the differences in the gendering of entrepreneurs’ networking in China and countries around Persian Gulf. Such understandings provide valuable input to the knowledge of how to better use the entrepreneurial potential from both men and women in different cultures. The sample is fairly representative of entrepreneur populations, and the results can be generalized to these countries.


2012 ◽  
Vol 23 (04) ◽  
pp. 1250030 ◽  
Author(s):  
FAYÇAL HAMMAMI ◽  
NADER BEN-CHEIKH ◽  
ANTONIO CAMPO ◽  
BRAHIM BEN-BEYA ◽  
TAIEB LILI

In this work, a numerical study devoted to the two-dimensional and three-dimensional flow of a viscous, incompressible fluid inside a lid-driven cavity is undertaking. All transport equations are solved using the finite volume formulation on a staggered grid system and multi-grid acceleration. Quantitative aspects of two and three-dimensional flows in a lid-driven cavity for Reynolds number Re = 1000 show good agreement with benchmark results. An analysis of the flow evolution demonstrates that, with increments in Re beyond a certain critical value Rec, the steady flow becomes unstable and bifurcates into unsteady flow. It is observed that the transition from steadiness to unsteadiness follows the classical Hopf bifurcation. The time-dependent velocity distribution is studied in detail and the critical Reynolds number is localized for both 2D and 3D cases. Benchmark solutions for 2D and 3D lid-driven cavity flows are performed for Re = 1500 and 6000.


Author(s):  
Gawdat Bahgat

The period from early 2000s to 2014 witnessed unprecedented and sustained high oil prices transforming the main oil and gas exporters in the Persian Gulf into major players in global finance. The Islamic Republic of Iran and the six GCC member states (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates) have been using these massive oil revenues to assert their economic and political leverage on the regional and international scene. A key component of this effort has been the creation of sovereign wealth funds (SWFs). This chapter examines the SWFs in Iran and the GCC states. It includes discussion of the emergence and evolution of the oil and gas industry in the region, analysis of the sharp drop in oil prices since 2014 and how this cycle is different from previous ones, and detailed examination (based on limited data availability) of Iran’s and the GCC’s major SWFs.


2019 ◽  
Vol 12 (5) ◽  
pp. 1475-1486 ◽  
Author(s):  
A. Rahnemania ◽  
A. A. Bidokhti ◽  
M. Ezam ◽  
K. Lari ◽  
S. Ghader ◽  
...  

1993 ◽  
Vol 18 ◽  
pp. 135-141 ◽  
Author(s):  
Takahiko Uematsu

A three-dimensional, numerical simulation model for snow transport and drift formation is proposed in which saltation as well as suspension are considered as dynamic behavioral factors of moving snow particles. The procedure for simulation is as follows: (1) Air flow field is simulated solving the Reynolds equations and the continuity equation. (2) Using the result of the air field flow simulation, the blown-snow density field is simulated using the diffusion equations in which the fall velocity of blown snow particles is considered. In the boundary conditions, the particle movement of saltation is taken into consideration. (3) Finally, the snowdrift rate is computed based on the amount of snow particles not transported by saltation. This model was quantitatively tested for the phenomenon of snowdrift development. The computed results showed good agreement with observations.


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