Department of Marine Physics (2013 - Present)
Oceanography
Integrated Coastal Zone Management, Russian State Hydrometeorological University, Saint Petersburg, Russia
Marine Physics
Marine Physics, Tarbiat Modares University, Tehran, Iran
Applied Physics
Physics, Razi University, Kermanshah, Iran
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Research field: Numerical Modeling, Programing, Mathematical Modeling
Expert: Dr. A. Rashidi Ebrahim Hesari
Phone: +981144998139
Address:
Research field: Numerical Modeling, Programing, Mathematical Modeling
Expert: Dr. A. Rashidi Ebrahim Hesari
Phone: +981144998139
Address:
Having completed his elementary to pre-university education, he successfully obtained bachelors degree in applied physics from Razi University of Kermanshah, Iran. Then, he continued studying at the masters degree in marine sciences and technologies marine physics at Tarbiat Modares University, and then was employed in the Iranian National Meteorological Organization. He passed the higher-level course on meteorological forecasting at the RMTC center and worked for two years in the research and marine meteorology department of the General Directorate of Meteorology of Mazandaran province. In 2009, being granted scholarship award for 100 top students for study in Ph.D. by Ministry of Sciences, he started his Ph.D. in RSHU University of Russia, and successfully completed his doctoral thesis in the ICZM department and shirshov institute of oceanology - St. Petersburg branch. He has been working as a lecturer and academic staff at Marine Sciences Faculty of Tarbiat Modares University since 2013. In addition to education, since childhood he has pursued professional activities in the field of silk carpet weaving, carpentry, painting and music.
Aims: In the present study, a three-dimensional numerical hydrodynamic model with capability to simulate the diffusion of chemical pollutants released in marine basins was developed and used to simulate the diffusion of phosphate released by fish culture cages located in the Sisangan marine basin.Materials & Methods: The equations of the model including momentum equations, continuity of mass equation, temperature, salinity, representative of vertical velocity, tendency of bottom pressure equations and an extra three-dimensional advection-diffusion equation for simulation of pollutant’s diffusion rewritten in the earth’s spherical coordinates with a vertical Sigma coordinate were solved using finite difference method. To provide the open
In this research, a modified version of three dimensional hydrostatic finite element QUODDY-4 was used to calculate the spatial variation of bottom friction coefficient in the Persian Gulf. It differs from original one in using an external module for calculation of bottom friction coefficient which was added to the model. Spatial variation of bottom friction coefficient is calculated using a hydrodynamic approach in which relation between wave friction factor and other characteristics of bottom boundary layer is described with non-dimensional parameters like surface Rossby number, Reynolds number for flow and relative inertial frequencies. Results show that friction coefficient varies from 0.0005 to 0.006 in the Persian Gulf and in most pla
Identification and characteristics of Internal Waves (IWs) are widely used in a variety of industries, including shipbuilding, maritime, as well as oil and marine engineering. In this study, IWs have been detected using field measurement and satellite remote sensing in the Persian Gulf during the period 2000–2015. In order to identify the potential areas for IWs after vertical changes in the physical parameters such as temperature, salinity, and sigma-T (σT) resulted by field measurements, the areas where high stratifications of seawater were identified. Satellite images corresponding to the identified areas were then prepared and the required modifications were made to the images. IWs were then manifested by such images in
A modified version of the QUODDY-4 three-dimensional finite element model was used for investigation of spatial distribution of bottom roughness effects on tidal dynamics in the Persian Gulf. A Hydrodynamic approach called Kagan’s method was used to calculate the spatial distribution of bottom friction coefficient for rough, not completely rough and smooth bottoms. This method has reduced disadvantages of hydraulic and semi-empirical approaches and provides a hydrodynamic approach for calculation of bottom friction coefficient using controlling factors of Bottom Boundary Layer and upper than it. Carrying out several numerical simulations and implementation of spatial variation of bottom friction coefficient, it was determined the effect o
To study the emission of environmental pollutants, including urban and industrial wastewater of Bandar Abbas, through Gorsuzan estuary to the coastal waters of Bandar Abbas, located in the northeastern part of the Persian Gulf, a three-dimensional hydrodynamic numerical model was developed. This is to predict the pattern of chemical pollutant emission. The governing equations of this model are rewritten in the spherical coordinate earth system with a vertical sigma array. In order to validate the model, nitrate and nitrite measurements were performed spectrophotometrically at six stations on the coastal water of Bandar Abbas for a period of one year. The simulations showed that these pollutants are mostly spread in the areas of fishery pier
In this research, density, temperature and salinity fields were investigated in different seasons using observational data of ROPME Marine Cruise in the Persian Gulf (PG). Based on in-situ measurements, areas with density stratification were identified. Having analyzed Landsat and SAR satellite images, internal waves (IW) were detected in different regions of the Persian Gulf and more frequently in the eastern part of the PG related to seawater stratification. Based on analysis of satellite images, it is shown that the length of internal waves crest detected in the north-eastern part of Al-Zhahirah (Qatar) was more than 120 km; while it’s in range of 5 to 20 km in the south and east of Larak Island, 15 to 40 km in the north-east of Abu Mu
In order to numerically simulate transmission of oil spilled in Caspian Sea from Turkmenistan oil fields, wind induced currents in the sea were simulated using an unstructured grid Finite Volume Community Ocean Model (FVCOM) in the summer and spring of 2012. The results of the model in the fall season were then compared to the measured data for surface currents in three stations of Astara, Roudsar, and Amirabad. Comparison of the measured data and the current model output revealed that implementing turbulence closure module produces more accurate results than when the module was excluded. Later on, in order to determine the destination for the oil spilled from Turkmenistan oil fields, the output of flow model was imported into the GNOME com
A three-dimensional primitive equation model has been developed to study wind-driven currents in the Caspian Sea (CS). The equations were solved in the spherical coordinate system with a vertical array of pressure-sigma using a finite difference Method on a staggered modified Arakawa c grid. Simulations showed that there is an anticyclonic eddy over the deep water of South Caspian Basin (SCB), which extended from surface to subsurface and persist throughout the year. The model successfully produced the coastal current along the eastern coast of the Middle Caspian Basin (MCB) with a prevailing southward component, resulting in upwelling on these coasts to compensate the surface drift. The results indicate that the bottom topography has a key
Evolutionary forces during domestication process and breed formation have led to remarkable differences between wild and domestic sheep genomes. In this study, we compared genetic diversity of 13 Iranian Mouflons (Ovis orientalis) and 20 Iranian domestic sheep (Ovis aries) based on 86 candidate genes putatively involved in the domestication of sheep. Mean nucleotide diversity and mean expected heterozygosity of candidate genes calculated by means of VCF tools and statistical analysis were performed via IBM SPSS software. Our results showed that Mouflon was superior for both calculated diversity parameters in the majority of candidate genes under study. In fact, wild group showed higher mean nucleotide diversity and mean heterozygosity in 69
The purpose of this study was to design and develop a three-dimensional numerical model using primitive equations in spherical coordinates of the Earth with the Sigma pressure vertical array to simulate currents in the Caspian Sea. In this study, the finite difference method was used for numerical solution and discretization of equations using the two step Lax-Wendroff scheme for advection terms and DuFort-Frankel scheme for diffusion terms. The results of the study showed that the clockwise eddy in the middle and the counterclockwise alongshore current near the western coast of the southern Caspian Sea continued throughout the year. Furthermore, due to the steeper slope of the bed in this basin, it is more stable than the currents pattern
The aim of this study was to design and develop a three-dimensional numerical baroclinic model with the ability to accept complex bottom topography and variable wind in space and time to investigation wind-induced current at 10 layers in the south Caspian Sea. The finite difference method Was used for numerical solution of the primitive equation in spherical Sigma pressure coordinate system on staggered modified Arakawa C grid. The wind data available from ECMWF ERA 15 data sets and the bathymetric data obtained from the JEBCO data sets with spatial resolutions of 0.125 o were utilized in the model. The result shows there are found a cyclonic eddy in middle of the basin and an anticyclonic current in close of the western coast that continue
In this research, a modified version of the 3D finite-element hydrostatic model QUODDY-4 is used to assessment of sensitivity of dynamics of the M2 semidiurnal tide to spatial variations of bottom roughness in the Hormuz Strait. This version differs from the original one, as it introduces a module providing calculation of the drag coefficient. Spatial variation of the drag coefficient is calculated using a hydrodynamic approach, which describes the relation between wave friction factor as well as other resistance characteristics and dimensionless parameters like surface Rossby number, Reynolds number for currents and relative inertial frequency. Comparing the results of numerical simulations with observed amplitude and phase values showed t
An investigation into the interaction of surface M 2 tides in the system of marginal seas of the North European Basin is carried out using the three-dimensional finite-element hydrostatic model QUODDY-4. Three numerical experiments are performed for this purpose. In the first (control), the model equations are solved in the system of the Norwegian, Greenland, Barents, and White seas; thereby the interaction of the tides in these seas is explicitly taken into account. In the second experiment, the White Sea is excluded from consideration and the no-flux condition is posed at the entrance to the sea. The third experiment uses an approach in which the observed tidal elevations that determine the existence of a fi
To find variations in the dynamics of the surface M 2 tide in the White Sea induced by the spatially inhomogeneity of the resistance coefficient, we use a modified version of the QUODDY-4 three-dimensional finite-element hydrostatic model. This version differs from the original version in that it has a module introduced to calculate the resistance coefficient in the bottom boundary layer (BBL). The resistance coefficient is found from resistance laws for an oscillating rotating turbulent BBL over hydrodynamically rough and partially rough (smoothly rough) underlying surfaces describing the dependence of the resistance coefficient and other integral characteristics of resistance on dimensionless similarity para
A modified version of the 3D finite-element hydrostatic model QUODDY-4 is used to quantify the changes in the dynamics and energetics of the M 2 surface tide in the North European Basin, induced by the spatial variability in bottom roughness. This version differs from the original one, as it introduces a module providing evaluation of the drag coefficient in the bottom boundary layer (BBL) and by accounting for the equilibrium tide. The drag coefficient is found from the resistance laws for an oscillatory rotating turbulent BBL over hydrodynamically rough and incompletely rough underlying surfaces, describing how the wave friction factor as well as other resistance character
Wind is a major factor which induces oceanic currents and many theories including the Ekman theory have considered the wind induces currents. In this paper a numerical process has been used for forecasting of oceanic currents based on this theory. The survey has been done in an artificial five layer oceanic basin with smooth bottom of 120 meters, considering the geographic position of Persian Gulf. Primitive equations were solved on earth’s spherical coordinates system with sigma as vertical coordinate by finite element method. Vertical profile of predicted current vectors showed the complete formation of Ekman Spiral in the basin. This experimental simulation is a new approach for confirmation of Ekman Theory.
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