scholarly journals Injection of Oxygenated Persian Gulf Water Into the Southern Bay of Bengal

2020 ◽  
Vol 47 (14) ◽  
Author(s):  
Peter M. F. Sheehan ◽  
Benjamin G. M. Webber ◽  
Alejandra Sanchez‐Franks ◽  
Adrian J. Matthews ◽  
Karen J. Heywood ◽  
...  
Keyword(s):  
Bay Of Bengal ◽  
Persian Gulf ◽  
Persian Gulf Water

Evidence for the existence of Persian Gulf Water and Red Sea Water in the Bay of Bengal

2016 ◽  
Vol 48 (9-10) ◽  
pp. 3207-3226 ◽  
Author(s):  
Vineet Jain ◽  
D. Shankar ◽  
P. N. Vinayachandran ◽  
A. Kankonkar ◽  
Abhisek Chatterjee ◽  
...  
Keyword(s):  
Red Sea ◽  
Bay Of Bengal ◽  
Persian Gulf ◽  
Sea Water ◽  
Persian Gulf Water

scholarly journals Mesoscale eddies and submesoscale structures of Persian Gulf Water off the Omani coast in spring 2011

Ocean Science ◽  
2016 ◽  
Vol 12 (3) ◽  
pp. 687-701 ◽  
Author(s):  
Pierre L'Hégaret ◽  
Xavier Carton ◽  
Stephanie Louazel ◽  
Guillaume Boutin
Keyword(s):  
Persian Gulf ◽  
Arabian Sea ◽  
Cold Water ◽  
Mesoscale Eddies ◽  
High Salinity Water ◽  
Strait Of Hormuz ◽  
Persian Gulf Water ◽  
Salinity Water ◽  
The Persian Gulf ◽  
Sea Of Oman

Abstract. The Persian Gulf produces high-salinity water (Persian Gulf Water, PGW hereafter), which flows into the Sea of Oman via the Strait of Hormuz. Beyond the Strait of Hormuz, the PGW cascades down the continental slope and spreads in the Sea of Oman under the influence of the energetic mesoscale eddies. The PGW outflow has different thermohaline characteristics and pathways, depending on the season. In spring 2011, the Phys-Indien experiment was carried out in the Arabian Sea and in the Sea of Oman. The Phys-Indien 2011 measurements, as well as satellite observations, are used here to characterize the circulation induced by the eddy field and its impact on the PGW pathway and evolution. During the spring intermonsoon, an anticyclonic eddy is often observed at the mouth of the Sea of Oman. It creates a front between the eastern and western parts of the basin. This structure was observed in 2011 during the Phys-Indien experiment. Two energetic eddies were also present along the southern Omani coast in the Arabian Sea. At their peripheries, ribbons of freshwater and cold water were found due to the stirring created by the eddies. The PGW characteristics are strongly influenced by these eddies. In the western Sea of Oman, in 2011, the PGW was fragmented into filaments and submesoscale eddies. It also recirculated locally, thus creating salty layers with different densities. In the Arabian Sea, a highly saline submesoscale lens was recorded offshore. Its characteristics are analyzed here and possible origins are proposed. The recurrence of such lenses in the Arabian Sea is also briefly examined.

scholarly journals The structure of the Persian Gulf outflow subjected to density variations

2008 ◽  
Vol 5 (2) ◽  
pp. 135-161 ◽  
Author(s):  
A. A. Bidokhti ◽  
M. Ezam
Keyword(s):  
Mass Transport ◽  
Persian Gulf ◽  
Anthropogenic Factors ◽  
Oman Sea ◽  
The Earth ◽  
Salinity Increase ◽  
Persian Gulf Water ◽  
Oceanographic Data ◽  
The Persian Gulf ◽  
Simple Dynamical Model

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.

scholarly journals The life cycle of submesoscale eddies generated by topographic interactions

2019 ◽  
Author(s):  
Mathieu Morvan ◽  
Pierre L'Hégaret ◽  
Xavier Carton ◽  
Jonathan Gula ◽  
Clément Vic ◽  
...  
Keyword(s):  
Life Cycle ◽  
Red Sea ◽  
Persian Gulf ◽  
Sea Water ◽  
Mesoscale Eddies ◽  
Shear Instability ◽  
Gulf Of Oman ◽  
Coherent Vortices ◽  
Persian Gulf Water ◽  
The Persian Gulf

Abstract. The Persian Gulf Water and Red Sea Water are salty and dense waters recirculating at subsurface in the Gulf of Oman and the Gulf of Aden respectively, under the influence of mesoscale eddies which dominate the surface flow in both semi-enclosed basins. In situ measurements combined with altimetry indicate that the Persian Gulf Water is driven by mesoscale eddies in the form of filaments and submesoscale structures. In this paper, we study the formation and the life cycle of intense submesoscale vortices and their impact on the spread of Persian Gulf Water and Red Sea Water. We use a three-dimensional hydrostatic model with submesoscale-resolving resolution to study the evolution of submesoscale vortices. Our configuration is an idealized version of the Gulf of Oman and Aden: a zonal row of mesoscale vortices interacting with north and south topographic slopes. Intense submesoscale vortices are generated in the simulations along the continental slopes due to two different mechanisms. The first mechanism is due to frictional generation of vorticity in the bottom boundary layer, which detaches from the topography, forms an unstable vorticity filament, and undergoes horizontal shear instability that leads to the formation of submesoscale coherent vortices. The second mechanism is inviscid and implies arrested topographic Rossby waves breaking and forming submesoscale coherent vortices where a mesoscale anticyclone interacts with the topographic slope. Submesoscale vortices subsequently drift away, merge and form larger vortices. They can also pair with opposite signed vortices and travel across the domain. They can weaken or disappear via several mechanisms, in particular fusion into the larger eddies or erosion on the topography. Particle patches are advected and sheared by vortices and are entrained into filaments. Their size first grows as the square root of time, a signature of the merging processes, then it increases linearly with time, corresponding to their ballistic advection by submesoscale eddies. On the contrary, witout intense submesoscale eddies, particles are mainly advected by mesoscale eddies; this implies a weaker dispersion of particles than in the previous case. This shows the important role of submesoscale eddies in spreading Persian Gulf Water and Red Sea Water.

scholarly journals Deoxygenation in Marginal Seas of the Indian Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
S. Wajih A. Naqvi
Keyword(s):  
Indian Ocean ◽  
Oxygen Content ◽  
Red Sea ◽  
Bay Of Bengal ◽  
Persian Gulf ◽  
Oxygen Demand ◽  
Andaman Sea ◽  
Marginal Seas ◽  
The Indian Ocean ◽  
Oxygen Minimum

This article describes oxygen distributions and recent deoxygenation trends in three marginal seas – Persian Gulf and Red Sea in the Northwestern Indian Ocean (NWIO) and Andaman Sea in the Northeastern Indian Ocean (NEIO). Vertically mixed water column in the shallow Persian Gulf is generally well-oxygenated, especially in winter. Biogeochemistry and ecosystems of Persian Gulf are being subjected to enormous anthropogenic stresses including large loading of nutrients and organic matter, enhancing oxygen demand and causing hypoxia (oxygen < 1.4 ml l–1) in central and southern Gulf in summer. The larger and deeper Red Sea is relatively less affected by human activities. Despite its deep water having remarkably uniform thermohaline characteristics, the central and southern Red Sea has a well-developed perennial oxygen minimum at mid-depths. The available data point to ongoing deoxygenation in the northern Red Sea. Model simulations show that an amplified warming in the marginal seas of the NWIO may cause an intensification of the Arabian Sea oxygen minimum zone (OMZ). Increases in particulate organic carbon and decreases in oxygen contents of the outflows may also have a similar effect. In the Andaman Sea, waters above the sill depth (∼1.4 km) have characteristics similar to those in the Bay of Bengal, including an intense OMZ. As in the case of the Bay of Bengal, oxygen concentrations within the Andaman Sea OMZ appear to have declined slightly but significantly between early 1960s and 1995. The exceedingly isothermal and isohaline water that fills the deep Andaman Basin is also remarkably homogenous in terms of its oxygen content. A very slight but statistically significant decrease in oxygen content of this water also seems to have occurred over three decades preceding 1995. New information is badly needed to assess the extent of further change that may have occurred over the past 25 years. There have been some reports of coastal “dead zones” having developed in the Indian Ocean marginal seas, but they are probably under-reported and the effects of hypoxia on the rich and diverse tropical ecosystems – coral reefs, seagrasses, and mangroves – in these seas remain to be investigated.

scholarly journals The structure of the Persian Gulf outflow subjected to density variations

Ocean Science ◽  
2009 ◽  
Vol 5 (1) ◽  
pp. 1-12 ◽  
Author(s):  
A. A. Bidokhti ◽  
M. Ezam
Keyword(s):  
Mass Transport ◽  
Persian Gulf ◽  
Anthropogenic Factors ◽  
Oman Sea ◽  
The Earth ◽  
Salinity Increase ◽  
Persian Gulf Water ◽  
Oceanographic Data ◽  
The Persian Gulf ◽  
Simple Dynamical Model

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.

First record of the heart urchin Metalia persica (Mortensen, 1940) (Spatangoida: Brissidae) from the Chennai coast, India

Zootaxa ◽  
2019 ◽  
Vol 4624 (2) ◽  
pp. 296-300
Author(s):  
CHAMUNDEESWARI KANAGARAJ ◽  
RICH MOOI ◽  
DEEPAK SAMUEL VIJAY KUMAR ◽  
HRISHIKESH PREMACHANDRAN ◽  
ABHILASH KOTTARATHIL RAJENDRAN ◽  
...  
Keyword(s):  
Bay Of Bengal ◽  
Persian Gulf ◽  
Arabian Gulf ◽  
First Record ◽  
Single Specimen ◽  
The Family ◽  
Indian Waters ◽  
By Catch ◽  
The Persian Gulf ◽  
First Time

The irregular urchin, Metalia persica (Mortensen, 1940), a heart urchin of the family Brissidae, is reported for the first time from the southeastern coast of India. A single specimen was collected from fishing by-catch at Chinna Neelankarai (12º 56’ 29.7” N, 80º 15’ 36.6” E),  Chennai on April 5, 2018. Metalia persica was previously recorded only from the Persian Gulf (Arabian Gulf). This study records Metalia persica for the first time from Indian waters, in the Bay of Bengal, and elucidates features of the anal fasciole. 

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