The present study investigates residual CURRENTs in the Persian Gulf using field data measurement of Mt. Mitchell 1992. For this order temperature, salinity, density and direct velocity of CURRENT meter were obtained in southern Persian Gulf. Velocity spectrum time scale and tidal CURRENTs were obtained too. The residual CURRENTs during March-May indicate a surface flow into and a deep flow out of the Gulf through the Strait of Hormuz. Establishment of the Gulf-wide CIRCULATION coincides with establishment of thermal stratification and thermocline and strengthening of the baroclinic exchange CIRCULATION through the Persian Gulf. The velocity of the surface residual is about 10 cm/s and the tidal CURRENT is 50 cm/s.

This paper presents an efficient method based on the adaptive virtual impedance and distributed communication link with a hierarchical control system in the resistive AC islanding micrigrids for accurate power sharing and circulating CURRENT reduction. In existing methods, the adaptive virtual resistance can take negative values and violate the assumption of feeders’ resistive dominance based on which the droop controller is designed, and as a result, deteriorate its performance. Besides, the negative virtual resistance, with a reduction in the system overall damping, can reduce the stability margin and lead to side effects on the closed-loop system performance, especially during transients. In the proposed method, the problems associated with the negative virtual resistance are removed via the intelligent implementation of a new distributed communication link among microgrid inverters. The advantages of the proposed method include: circulating CURRENT elimination, accurate power sharing among distributed generators proportional to their rated capacities, prevention of voltage and frequency deviations from their reference values in point of power coupling (PCC) bus, guarantee of the resistive or inductive dominance of the feeder impedance in various operating points, decoupling between active and reactive powers, and as a result, guarantee of a desirable performance for droop controller in different operating points, performance and stability improvement, and finally using a simple, one-sided and a low bandwidth communication link instead of the complex, two-sided, and centralized communication system. Simulation results in MATLAB/SIMULINK environment demonstrate that the proposed control strategy has obviated effectively the shortcomings of the conventional droop and adaptive virtual impedance controllers.

In this research, the CIRCULATION of Gulf of Oman and the Persian Gulf dense water outflow front to the Gulf of Oman have been modeled using MITgcm which is a nonlinear 3D numerical model. The main domain is between and and was discretized by a non-uniform orthogonal grid of 480*342 points. Spatial resolution along the longitudinal axis ranges between 500m (near the sill region) to 1000 m and along the latitudinal axis is 1000m. The model has 32 z levels with the thickness of layers increasing from the surface to the bottom. In this investigation the Massachusetts Institute of Technology general CIRCULATION model (MITgcm) has been used. This model solves the fully nonlinear, non-hydrostatic Navier-Stokes equations under the Boussinesq approximation for an incompressible fluid with a spatial finite volume discretization on an orthogonal computational grid. The model formulation includes implicit free surface and partial step topography. The MITgcm formulation has been addressed in detail by Marshal et al. (1997a, 1997b) and its source code and documentation are available at the MITgcm group Website. The selected advection scheme for this study is a third-order direct space-time flux limited scheme (Hundsdorfer et al., 1995), which is unconditionally stable. Topographic data has been obtained from Iranian National Cartographic Center (NCC) with the high resolution bathymetry chart. No-slip conditions were imposed at the bottom and lateral solid boundaries. Initial conditions for temperature and salinity were obtained from the World Ocean Database (WOD) and World Ocean Atlas (WOA) Series [WOD group, 2013] for the month of June. The monthly averages of Sea Surface Temperature (SST) and Sea Surface Salinity (SSS) were derived from the WOA Database and the climatological data (wind and heat budget components) were derived from the NOAA Database [Noaa, 2013]. This data was prescribed in the model for all 12 months of the year. The model domain has two open boundaries at west and east sides. The west open boundary condition imposed by hourly observational data of salinity, temperature and CURRENT profiles from the surface to the bottom layer with 10 m interval and the east open boundary forced by hourly observational data of Sea Surface Height (SSH) predicted data of salinity, temperature and CURRENT profiles. This data was prescribed in the open boundary condition section of the model. To validate the MITgcm model, the monthly averages of temperature and salinity profiles for January obtained from WOA program are compared to MITgcm simulation results. Some of beneficial results of this modeling are achievement of the Persian Gulf outflow pattern and Gulf of Oman fronts. The modeling results show a clockwise CIRCULATION in the surface layer of Gulf of Oman. Also, two small counterclockwise gyres have been formed in the west of this clockwise gyre. One gyre, situated in the southwestern corner runs from surface to bottom. In depths of more than 500 meters the CIRCULATION is counterclockwise which is opposing of surface CIRCULATION. The results of this modeling also show the two layer exchange between the Persian Gulf and the Gulf of Oman.