International Journal of Coastal, Offshore and Environmental Engineering
Volume:7 Issue: 3, Summer 2022

The concentration of chlorophyll in marine environments indicates the quantity of photosynthetic plankton (phytoplankton),found in marine ecosystems.Phytoplankton populations are affected by weather conditions such as Sea Surface Temperature and Winds.They are also influenced by Aerosol Optical Depth (AOD),which can show the existence of dust.Moreover,there are seasonal variations and the correlation between these factors varies according to the depths.Despite the decrease in temperature and an increase in pressure on land areas during winter,which is accompanied by a decrease in strong winds, the formation of atmospheric fronts and strong winds caused the transfer of dust from susceptible springs in Saudi Arabia and the UAE and dust was transferred to it from the southern coast of the Persian Gulf. Investigating the long-term relationship between SST changes and the AOD with chlorophyll concentration on the Persian Gulf coasts as well as the Oman Sea,using daily MODIS products in the period of 2003 to 2020 demonstrates a strong correlation in coastal areas with the lowest depth.trend of SST and AOD on the both Seas is similar, along with the lowest values during the winter, while the seasonal trend show, the highest values of chlorophyll concentrations, in winter.Besides examining long-term chlorophyll concentration behavior over the Sea of Oman and the Persian Gulf, an emphasis was applied to the cold season of the year on February 17-22, 2018 for understanding the relationships between chlorophyll, AOD,and SST, showing the possibility of time delay in the correlation between sea surface temperature and optical depth of aerosols with chlorophyll concentration.

From one point of view; we can divide atmosphere into two mediums. Barotropic medium, that in this medium, density doesn’t change in horizontal direction and isobaric surfaces are parallel to each other in vertical direction. This medium can be motionless, but if in this medium, motion would be taken place, geostrophic wind doesn’t change with respect to height. On the other hand, the baroclinic medium has horizontal gradient of density, and causes various horizontal gradient of pressure with respect to height and implies various horizontal velocity at different levels of the atmosphere. Therefore; geostrophic wind varies with respect to height in this medium. The horizontal gradient of density not only would produce by horizontal gradient of temperature, but also by horizontal gradient of humidity or combination of both. If horizontal gradient of density would be by both horizontal gradient of temperature and horizontal gradient of humidity – as in natural air, not in dry air – in the case; we name vectorial difference of geostrophic wind with respect to height; dense wind. The purpose of this paper is introduction of three versions of dense wind in natural medium of air, not dry air. Basic axis of first version of dense wind is founded by density, second by virtual temperature and third one by thickness of atmospheric layer. Formulae related to each version is derived and every one of them, represents effects of one type of variation of geostrophic wind with respect to height. First version exhibits advection of light or dense air, second represents virtual temperature advection and third one demonstrates advection of thickness in atmospheric layer. Dense wind is powerful tool for consistency of wind field. Therefore, because air is not dry, the variation of the geostrophic wind with respect to height should be describe with better tool, namely dense wind.

Over the past two decades, several ocean color satellites have operated in parallel. The combination of different ocean color satellite sensor products is a vital task for studying the biogeochemistry of seas. In this study, we evaluated the temporal consistency of the monthly time-series and monthly interannual variations of satellite-derived chlorophyll-a concentrations (Chl-a) from four satellite sensors during 2002-2020 period over the Persian Gulf. Statistical correlation between Chl-a time series and anomalies from selected satellite sensors were significantly correlated for 84% area of the Persian Gulf. Correlations were reasonably sensitive to the choice of Chl-a retrieval and atmospheric correction algorithms. The standard algorithms for Chl-a retrieval showed the lowest value of correlations, and it was indicated that these algorithms were not suitable for Chl-a estimations from satellite sensors over the Persian Gulf. The OCI algorithm for Chl-a retrieval showed more consistency among different satellite sensors and it was shown that it is more suitable than previous ones for estimation of Chl-a from selected satellite sensors. Also, it was shown that the SeaDAS and POLYMER atmospheric correction algorithms have a great influence on the Chl-a estimations from selected satellite sensors. It was shown that more than 70% of the study area indicated imperfect consistency between selected atmospheric correction algorithms applied on different satellite sensors. Choosing the best atmospheric correction and Chl-a retrieval algorithms is the most important task in the estimation and utilization of Chl-a in the Persian Gulf.

In this study, changes in the magnetic field and electrical conductivity across the Caspian Sea Basins were investigated using the Princeton Ocean Model (POM). In this model, bathymetry, temperature and salinity and atmospheric flux data were collected from GEBCO08, WOA and ECMWF databases, respectively. This model was implemented for ten years (2009-2019), and temperature, salinity and current velocity were extracted from the model output to calculate the electrical conductivity and simulate the magnetic field anomalies of the Caspian Sea. The calculated electrical conductivity indicates that the dominant factor in electrical conductivity was temperature. In the study area, the highest and lowest electrical conductivity were in the southern Caspian basin (SCB) with a value of 2.3 S/m in summer and in the northern Caspian basin (NCB) about 0.8 S/m in autumn. Also, the results show the highest and lowest magnetic fields in the SCB were 16 nT in March and 12 nT in November, respectively. The distribution of magnetic field anomalies with different values in the middle Caspian basin (MCB) can also be observed for all months. According to the results, the dominant factor in the magnetic field anomalies is the current velocity, which has the most effect on the magnetic field in the western part of the Caspian Sea.

The main source of water in Minab is the shallow aquifer which is part of the coastal aquifer. The quality of the groundwater is extremely deteriorated in terms of salinity. Salinization of groundwater may be caused and influenced by many variables. Studying the relation of between these variables and salinity is often a complex and nonlinear process, making it suitable for artificial intelligence application. The present paper presents a comparison of the hybrid of Adaptive Neuro Fuzzy Inference System (ANFIS) with Partial Swarm Optimization (PSO) model and L-moments regarding their power and efficiency in regional and at-site anticipation of salinity of groundwater at Minab coastal plain. In doing so, electrical conductivity is considered the dependent variable, while, through regression analysis, total cations, magnesium ion, sodium percentage, and level of groundwater are assumed to be independent parameters. Results showed that, in regions with lower heterogeneity criterion, ANFIS-PSO regional forecast were moderately more accurate than at-site anticipations.

This study seeks to empirically explain the effect of public relations strategies in the Ports and Maritime Organization on secure communications. Accordingly, and considering the importance of Iran as a country with 11 ports and a wide range of commercial, military and passenger shipping, it should take appropriate measures for shipping safety; From this point of view, all elements of the organization (internal and external stakeholders) need to be involved in decision-making in a tangible and intangible way. The research method in this research is mixed. In the qualitative part, interview tools were used and experts were interviewed until the theoretical saturation was achieved. Coding was done using MAXQDA software and the dimensions of seafarers' problems, shareholder responsibility, maritime accident management, maritime crisis management, protection of interests Demand for seafaring, maritime culture, reducing seafarers 'concerns, seafaring culture and improving the quality of seafarers' education were identified, which were evaluated by public relations strategies. In a small part, the research hypotheses were evaluated using a questionnaire tool. SPSS and Linear Regression Method Hypotheses were analyzed and all research hypotheses were confirmed.