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Validation and Coupling of the SWAN Wave Prediction Model by WRF for the Persian Gulf  [PDF]
Mojtaba Zoljoodi
Open Journal of Marine Science (OJMS) , 2017, DOI: 10.4236/ojms.2017.71003
Abstract: Generation of waves is affected by forces that exerted constantly in the oceans. The most obvious reason for the appearance of surface-waves is a process of interaction between atmosphere and sea surface that results in wind generation. Wave predictions are usually issued for a maximum of a few days for using in different fields such as shipping, fishing, oil industry, tourism, and to increase the safety of seafarers and beach habitants, maintaining economic assets and optimal utilization of natural resources. In this study, SWAN model has been run for this research over the Oman sea and the Persian Gulf. For implementation of SWAN, another dynamic model with prediction ability of 99-hours also has been used. In this example, wind field is obtained from the outputs of the WRF model converted to the required format for SWAN model. The computational network of SWAN model has been set to spatial grid points of 6 minutes with 1-hour temporal scale. Standard validation ways, including experimental verification, Multiplicative Bias, Mean Error and Root Mean Square Error are used in this study by comparing together for evaluation of accuracy of the model outputs. The results show that the prediction of wave heights by the model for 9 to 24-hour prediction could be the most accurate.
Numerical simulations of spreading of the Persian Gulf outflow into the Oman Sea  [PDF]
M. Ezam,A. A. Bidokhti,A. H. Javid
Ocean Science (OS) & Discussions (OSD) , 2010, DOI: 10.5194/os-6-887-2010
Abstract: A three dimensional numerical model namely POM (Princeton Ocean Model) and observational data are used to study the Persian Gulf outflow structure and its spreading pathways during 1992. In the model, the monthly wind speed data were taken from ICOADS (International Comprehensive Ocean-Atmosphere Data Set) and the monthly SST (sea surface temperatures) were taken from AVHRR (Advanced Very High Resolution Radiometer) with the addition of monthly net shortwave radiations from NCEP (National Center for Environmental Prediction). The mean monthly precipitation rates from NCEP data and the calculated evaporation rates are used to impose the surface salinity fluxes. At the open boundaries the temperature and salinity were prescribed from the mean monthly climatological values from WOA05 (World Ocean Atlas 2005). Also the four major components of the tide were prescribed at the open boundaries. The results show that the outflow mainly originates from two branches at different depths in the Persian Gulf. The permanent branch exists during the whole year deeper than 40 m along the Gulf axis and originates from the inner parts of the Persian Gulf. The other seasonal branch forms in the vicinity of the shallow southern coasts due to high evaporation rates during winter. Near the Strait of Hormuz the two branches join and form the main outflow source water. The results of simulations reveal that during the winter the outflow boundary current mainly detaches from the coast well before Ras Al Hamra Cape, however during summer the outflow seems to follow the coast even after this Cape. This is due to a higher density of the colder outflow that leads to more sinking near the coast in winter. Thus, the outflow moves to a deeper depth of about 500 m (for which some explanations are given) while the main part detaches and spreads at a depth of about 300 m. However in summer it all moves at a depth of about 200–250 m. During winter, the deeper, stronger and wider outflow is more affected by the steep topography, leading to separation from the coast. While during summer, the weaker and shallower outflow is less influenced by bottom topography and so continues along the boundary.
Sea surface temperature and Ekman transport in the Persian Gulf  [cached]
E. H.,H. N.
Iranian Journal of Physics Research , 2002,
Abstract: The wind drift motion of the water which is produced by the stress of the wind exerted upon the surface of the ocean is described by Ekmans theory (1905). Using the mean monthly values for the wind stress and SST, seasonal Ekman transport for the Persian Gulf was computed and contoured. The geostrophic winds have combined with the SST to estimate the effect of cooling due to Ekman transport of colder northern waters and inflow from the Oman Sea. The monthly SST mainly obtained from the 10 10 grided data of Levitus atlas and Hormuz Cruis Experiment for 1997. Analyses show a NW to SE Ekman transport due to wind stress and significant interannual variability of SST on sea surface in the Persian Gulf. The seasonal variation of SST shows a continental pattern due to severe interaction between the land and sea. But these variations somehow moderates because of Ekman transport in Persian Gulf.
The structure of the Persian Gulf outflow subjected to density variations  [PDF]
A. A. Bidokhti,M. Ezam
Ocean Science (OS) & Discussions (OSD) , 2009,
Abstract: Oceanographic data and a dynamic model are used to consider the structure of Persian Gulf outflow. This outflow influences the physical properties of Oman seawater which appear in the CTD profiles of the Oman Sea. The observations show that thickness of the outflow, which is banked against the Oman coasts due to the earth rotation, is about 200 m with tongues extending east and north that may be due to the internal waves. A simple dynamical model of the outflow based on potential vorticity conservation is used to find the horizontal extension of the outflow from the coast. Typical mass transport estimate by the outflow is about 0.4 Sv, which is larger than those reported by others. This may be due to the fact the model is inviscid but the outflow is influenced by the bottom friction. Variability of the outflow structure may reflect the changing ecosystem of the Persian Gulf. Any change of the outflow source, the Persian Gulf Water (PGW), say salinity increase due to excessive evaporation (climate factor) or desalination (anthropogenic factors) of the PGW may change the outflow structure and the product waters in the Oman Sea. Hence, one can test different scenarios of changing the outflow source, the Persian Gulf Water (PGW), say by salinity increase due to excessive evaporation or desalination to estimate changes in the outflow structure and the product waters in the Oman Sea. The results of the model show that these can increase the outflow width and mass transport substantially.
The structure of the Persian Gulf outflow subjected to density variations  [PDF]
A. A. Bidokhti,M. Ezam
Ocean Science Discussions (OSD) , 2008,
Abstract: Oceanographic data and a dynamic model are used to consider the structure of Persian Gulf outflow. This outflow influences the physical properties of Oman seawater which appear in the CTD profiles of the Oman Sea. The observations show that thickness of the outflow, which is banked against the Oman coasts due to the earth rotation, is about 200 m with tongues extending east and north that may be due to the internal waves. A simple dynamical model of the outflow based on potential vorticity conservation is used to find the horizontal extension of the outflow from the coast. Typical mass transport estimate by the outflow is about 0.4 Sv, which is larger than those reported by others. This may be due to the fact the model is inviscid but the outflow is influenced by the bottom friction. Variability of the outflow structure may reflect the changing ecosystem of the Persian Gulf. Any change of the outflow source, the Persian Gulf Water (PGW), say salinity increase due to excessive evaporation (climate factor) or desalination (anthropogenic factors) of the PGW may change the outflow structure and the product waters in the Oman Sea. Hence, one can test different scenarios of changing the outflow source, the Persian Gulf Water (PGW), say by salinity increase due to excessive evaporation or desalination (ecosystem factors) of the PGW to estimate changes in the outflow structure and the product waters in the Oman Sea. The results of the model show that these can increase the outflow width and mass transport substantially.
The Accuracy of SST Retrievals from NOAA-AVHRR in the Persian Gulf  [PDF]
A. Ahmadabadi,A. Fathnia,M. Karimi Ahmadabad,M. Farajzadeh
Journal of Applied Sciences , 2009,
Abstract: In the present study, sea surface temperature of the Persian Gulf was estimated using NOAA-14- AVHRR data during the period of 1996-2000. The Persian Gulf, despite being a major economic and political region has not systematic marine measurement in particular that of sea surface temperature. In order to estimate sea surface temperature in areas where no data was available, an attempt has been made to use AVHRR (Advanced Very High Resolution Radiometer) data from NOAA (National Ocean and Atmosphere Administration) satellite 14. After computing SST from AVHRR data with the use Murty, Gowda and national center of remote sensing Australia algorithms were assessed with in situ Boushehr buoy sea surface temperature and a linear correlation was formulated to estimate sea surface temperature with a residual mean error of ±0.43 and R2 = 0.994. Finally, this modified formula was tested in 2 months (September and December 1999) of NOAA-14 AVHRR images and Sea Surface Temperature (SST) was computed in the Persian Gulf. Considering this amount of error, time series temperature can be created with this method.
Cluster and Principal Components Analyses on the Contents of (Total and Sorbed) Trace Metals in Fresh Marine Sediments from the Southwest of the Gulf of Mexico  [PDF]
De Lorenz-Santos Fernando Jesús,Vázquez Felipe,Fernández-Villagómez Georgina,Cervini-Silva Javiera
Ingeniería, investigación y tecnología , 2013,
Abstract: The amounts of total and sorbed Al, Ba, Cr, Fe, Mn, Ni, and V present in three sediment cores from the South of the Gulf of Mexico (N1, N2, and N3) were determined. Of the three samples studied herein (N1. N2, and N3), one of them (N2) is associated to a natural “chapopotera”. ICP/MS analyses show that total concentrations of Al, Fe, Mn, Ba, Cr, Ni, Pb, and V for N1 and N3 were found to be ca. 4.2, 2.3, 206.5, 165, 91, 72, 14 and 97 mg kg-1, and ca. 5.2 (Al2O3), 4, 401.50, 269, 89, 62, 18, and 118 mg kg-1 for N2. As evidenced by the correla- tion matrices, there is a positive association among metals distribution, except for the case of Mn, regardless of the sediment core. Nevertheless, Cluster and Principal Components Analyses denote variability in metal-spatial distribu- tion, signature variability in the composition of the water column. Magnitude values for the enrichment factor (EF) relative to background values found in the Southern Gulf of Mexico (bulk seawater) for Al, Fe, Mn, Ba, Cr, Ni, Pb, and V were estimated. The outcome of this work show distinctive EF values, ran- ging from moderate to high EF values, regardless of the core source.
Design and Simulation of a Secure and Robust Underwater Acoustic Communication System in the Persian Gulf  [PDF]
Abdollah Doosti Aref, Mohammad Javad Jannati, Vahid Tabataba Vakili
Communications and Network (CN) , 2011, DOI: 10.4236/cn.2011.32012
Abstract: In recent years, underwater acoustic (UWA) communications have received much attention as their applications have begun to shift from military toward commercial. Digital communications through UWA channels differ substantially from those in other media, such as radio channels, due to severe signal degradations caused by multipath propagation and high temporal and spatial variability of the channel conditions. This paper describes a project designed, based on the results obtained from extensive laboratory and field experiments on sound speed profile in different depths of the Persian Gulf, to investigate and demonstrate an underwater acoustic communication system. Transmitted data are acoustic signals to which for more safety in transmission and low frequency bandwidth, Rivest cipher cryptography algorithm and linear prediction coding are applied, respectively. In transmitter, Quadrature Phase Shift Keying (QPSK) signaling is employed to make efficient use of the available channel bandwidth. In the channel, a comprehensive model for short-range shallow water multipath acoustic channel is presented. The mathematical modeling of the multi-path effects is based on the ray tracing and the image method. Also, the attenuations due to wave scatterings at the surface and their bottom reflections are accounted for. In addition, we consider the loss due to the frequency absorption of different materials and the presence of ambient noises such as the sea state noise, shipping noise, thermal noise and turbulences. In the receiver, to overcome the difficulties of inter symbol interference, adaptive equalization using Decision Feedback Equalizer (DFE) is applied.
Security Policies of the Islamic Republic of Iran in the Persian Gulf
Hamid Jahanara
International Journal of Nations Research , 2018, DOI: -
Abstract: The Persian Gulf as one of the main sources of energy is considered by the regional and trans-regional world’s powers. Hence, the security of The Persian Gulf, more than regional dimensions is important in international as well. In this context, it has additional importance to understand both the security policies of the Islamic Republic of Iran as a major actor in the region and the reasons for adopting this Policies. This article’s question focuses on understanding the security policies of the Islamic Republic of Iran in the Persian Gulf and the reasons for adopting these policies. Security policies in the Persian Gulf includes: Emphasizing on regional’s order and oppose with the presence of foreign powers in the Persian Gulf, Supporting the movements and Shia groups in the region and increasing the power of military and arms. this Policies is formed based on the superiority of Iranian power in the region and the orientation of its foreign policy to change the status of current situation. The method in this research is based on the nature of explanatory research and the data and information needed are collected in library.
Phylogenetic analysis of anemone fishes of the Persian Gulf using mtDNA sequences
SA Ghorashi, SM Fatemi, F Amini, M Houshmand, RS Tabar, K Hazaie
African Journal of Biotechnology , 2008,
Abstract: Anemone fishes are a group of 28 species of coral reef fishes belonging to the family, Pomacentridae; subfamily, Amphiprioninae and all have an obligate symbiotic relationship with sea anemones. Two species of these small ornamental fishes have been identified in the Persian Gulf including Amphiprion clarkii and Amphiprion sebae. The phylogenetic relationship between Amphiprion species of the Persian Gulf was studied by collecting 15 samples from three Iranian islands, Larak, Farur and Kish. DNA was extracted from each sample and a part of mtDNA was amplified. Two pairs of primers were designed to amplify a final target of 400 bp by nested-PCR. Each amplican was sequenced, aligned and genetic diversity among samples was investigated by phylogenetic analysis. Results show that there is no significant genetic variation among A. clarkii individuals; however, A. sebae individuals from Larak were different from other fishes of the same species. Most probably this is due to the ability of A. clarkii to be symbiotant with all 10 species of host sea anemones which enables it to spread its own population in the 3 islands. However, A. sebae is observed to be symbiotant only with one host in the sea, therefore, has one option that reduces its distribution.
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