A study of the seasonal changes of the water mass of Christchurch Harbour, England

1966 ◽  
Vol 46 (3) ◽  
pp. 561-578 ◽  
Author(s):  
J. W. Murray
Keyword(s):  
Biological Activity ◽  
Seasonal Changes ◽  
Bottom Water ◽  
Water Mass ◽  
Sea Water ◽  
Salinity Stratification ◽  
Tidal Regime ◽  
Biological Removal ◽  
Shallow Estuary ◽  
Calcium And Magnesium

Detailed sampling of the bottom water of Christchurch Harbour, England, was undertaken in conjunction with a study of the living and dead foraminiferids (to be described later). The Harbour is a shallow estuary with an unusual tidal regime of four high tides daily. During the winter the flow of fresh water from the rivers prevents sea water from entering much of the estuary. During the spring, summer and autumn, when drier conditions prevail on land, the sea enters the estuary as a salt wedge and there is pronounced salinity stratification. In addition to determinations of chlorinity, pH, dissolved oxygen and temperature, analyses of calcium were made during the spring, and of calcium and magnesium in the summer. It was found that calcium was preferentially removed from the bottom water, thus upsetting the calcium-chlorinity ratio. The cause of the calcium removal is thought to be biological activity. Magnesium was not affected by this process. A discussion of the results is presented and it is suggested that biological removal of calcium from the bottom water is particularly well developed in Christchurch Harbour owing to the extensive areas of shoal water favouring biological activity. Estuaries of this type may not be very common.

scholarly journals Water masses in the Atlantic Ocean: characteristics and distributions

Ocean Science ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 463-486
Author(s):  
Mian Liu ◽  
Toste Tanhua
Keyword(s):  
Atlantic Ocean ◽  
Deep Water ◽  
Bottom Water ◽  
Water Mass ◽  
Sea Water ◽  
Weddell Sea ◽  
Water Masses ◽  
Global Ocean ◽  
Intermediate Water ◽  
The North

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

MEASURES FOR ENVIRONMENT CONSERVATION IN ENCLOSED COASTAL SEAS

2017 ◽  
Author(s):  
Keizo Negi ◽  
Keizo Negi ◽  
Takuya Ishikawa ◽  
Takuya Ishikawa ◽  
Kenichiro Iba ◽  
...  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Water Mass ◽  
Sea Water ◽  
Red Tide ◽  
Water Environment ◽  
Quality Standard ◽  
Tokyo Bay ◽  
View Point ◽  
High Concentration

Japan experienced serious water pollution during the period of high economic growth in 1960s. It was also the period that we had such damages to human health, fishery and living conditions due to red tide as much of chemicals, organic materials and the like flowing into the seas along the growing population and industries in the coastal areas. Notable in those days was the issues of environment conservation in the enclosed coastal seas where pollutants were prone to accumulate inside due to low level of water circulation, resulting in the issues including red tide and oxygen-deficient water mass. In responding to these issues, we implemented countermeasures like effluent control with the Water Pollution Control Law and improvement/expansion of sewage facilities. In the extensive enclosed coastal seas of Tokyo Bay, Ise Bay and the Seto Inland Sea, the three areas of high concentration of population, we implemented water quality total reduction in seven terms from 1979, reducing the total quantities of pollutant load of COD, TN and TP. Sea water quality hence has been on an improvement trend as a whole along the steady reduction of pollutants from the land. We however recognize that there are differences in improvement by sea area such as red tide and oxygen-deficient water mass continue to occur in some areas. Meanwhile, it has been pointed out that bio-diversity and bio-productivity should be secured through conservation/creation of tidal flats and seaweed beds in the view point of “Bountiful Sea” To work at these challenges, through the studies depending on the circumstances of the water environment in the enclosed coastal seas, we composed “The Policy of Desirable State of 8th TPLCS” in 2015. We have also added the sediment DO into the water quality standard related to the life-environmental items in view of the preservation of aquatic creatures in the enclosed water areas. Important from now on, along the Policy, is to proceed with necessary measures to improve water quality with good considerations of differences by area in the view point of “Beautiful and bountiful Sea”.

Mercury in the Marine Environment: Concentration in Sea Water and in a Pelagic Food Chain

1973 ◽  
Vol 30 (2) ◽  
pp. 293-295 ◽  
Author(s):  
P. M. Williams ◽  
H. V. Weiss
Keyword(s):  
Biological Activity ◽  
Bottom Sediment ◽  
Food Chain ◽  
Mercury Concentration ◽  
Vertical Profile ◽  
Sea Water ◽  
Mercury Content ◽  
Trophic Levels ◽  
Single Station ◽  
Almost All

Mercury in seawater, in a pelagic food chain, and in bottom sediment was determined at a single station 430 km southeast of San Diego, California. The concentration of mercury in zooplankton slightly increased with depth of collection. The mercury content in almost all of the higher trophic levels of organisms collected at greater depths was indistinguishable from the concentration of mercury in zooplankton at these depths. Mercury concentration in the seawater column was essentially constant below 100 m and significantly higher at the surface. This vertical profile of mercury content is not ascribable to biological activity.

The Regulation of Calcium and Magnesium in the Brackish Water Polychaete Nereis Diversicolor O.F.M

1970 ◽  
Vol 53 (2) ◽  
pp. 425-443
Author(s):  
C. R. FLETCHER
Keyword(s):  
Brackish Water ◽  
Calcium Concentration ◽  
Sea Water ◽  
Calcium Influx ◽  
Coelomic Fluid ◽  
Nereis Diversicolor ◽  
Active Uptake ◽  
Calcium And Magnesium ◽  
Electrochemical Potentials

1. Nereis diversicolor tolerates changes in the concentration of calcium and magnesium in its coelomic fluid proportional to the concentrations in the medium between chlorosities of 100-1000 mM/kg of water. 2. In lower salinities both ions are maintained relatively constant providing that the ratios of these ions to chloride in the medium are similar to the ratios in sea water. 3. The ratio of the concentration of calcium in the coelomic fluid to the concentration in the medium is a function of the salinity of the medium but not of the calcium concentration. 4. Both calcium and magnesium are at lower electrochemical potentials in the coelomic fluid than in the medium, indicating that it is not necessary to invoke active uptake. 5. The rate of calcium influx is substantial. 6. In salinities below to mM of chloride/kg of water the urine must contain less calcium than the coelomic fluid. 7. The significance of these results is discussed.

scholarly journals Detecting changes in Labrador Sea Water through a water mass analysis of BATS data

2005 ◽  
Vol 2 (4) ◽  
pp. 417-435 ◽  
Author(s):  
A. Henry-Edwards ◽  
M. Tomczak
Keyword(s):  
Water Mass ◽  
Sea Water ◽  
Source Region ◽  
Labrador Sea ◽  
Sargasso Sea ◽  
Mass Analysis ◽  
Data Set ◽  
Water Mass Analysis ◽  
Quadratic Programming Method ◽  
Labrador Sea Water

Abstract. A new water mass analysis technique is used to analyse the BATS oceanographic data set in the Sargasso Sea of 1988-1998 for changes in Labrador Sea Water (LSW) properties. The technique is based on a sequential quadratic programming method and requires careful definition of constraints to produce reliable results. Variations in LSW temperature and salinity observed in the Labrador Sea are used to define the constraints. It is shown that to minimize the residuals while matching the observed temperature and salinity changes in the source region the nitrate concentration in the Labrador Sea has to be allowed to vary as well. It is concluded that during the period of investigation nitrate underwent significant variations in the Labrador Sea.

scholarly journals Controls on Weddell Sea water mass Nd isotope signatures and their export to the subantarctic Southern Ocean

2021 ◽  
Author(s):  
Marcus Gutjahr ◽  
Huang Huang ◽  
Jörg Rickli ◽  
Gerhard Kuhn ◽  
Anton Eisenhauer
Keyword(s):  
Southern Ocean ◽  
Water Mass ◽  
Sea Water ◽  
Weddell Sea ◽  
Nd Isotope

scholarly journals WATER MASSES CHARACTERISTICS AT THE SANGHIE TALAUD ENTRY PASSAGE OF INDONESIAN THROUGHFLOW USING INDEX SATAL DATA 2010

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Ivonne M Radjawane ◽  
Paundra P Hadipoetranto
Keyword(s):  
North Pacific ◽  
Water Mass ◽  
Sea Water ◽  
Core Layer ◽  
South Pacific ◽  
New Guinea ◽  
Water Masses ◽  
Coastal Current ◽  
Indonesian Throughflow ◽  
Pacific Water

<p><strong><em>ABSTRACT</em></strong></p> <p><em>Measurement of ocean physical param</em><em>eter</em><em>s using the CTD was conducted by </em><em>deep water expedition </em><em>INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. Th</em><em>e</em><em> </em><em>aim of this </em><em>study wa</em><em>s to</em><em> determine the characteristics of water masses around the Sangihe Talaud Water where the</em><em>re </em><em>wa</em><em>s an entry passage of </em><em> Indonesian throughflow (ITF) </em><em>at</em><em> </em><em>the </em><em>west </em><em>path</em><em>way that passed through the </em><em>primary</em><em> pathway i.e., </em><em>the Sulawesi</em><em> Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was  processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. </em></p> <p><em> </em></p> <p><strong><em>Keywords</em></strong><em>: Index-Satal 2010, Northern Pacific Water Mass</em><em>es</em><em>, Southern Pacific Water </em></p> <em> Masses, Sangihe Talaud</em>

Attenuated carbon sequestration by Weddell Sea dense waters over the 21st century – an assessment with FESOM-REcoM

2021 ◽  
Author(s):  
Cara Nissen ◽  
Ralph Timmermann ◽  
Mario Hoppema ◽  
Judith Hauck
Keyword(s):  
Carbon Sequestration ◽  
Sea Ice ◽  
Continental Shelf ◽  
Bottom Water ◽  
Water Mass ◽  
Weddell Sea ◽  
Ice Shelf ◽  
Deep Waters ◽  
Water Formation ◽  
Water Mass Transformation

&lt;p&gt;Deep and bottom water formation regions have long been recognized to be efficient vectors for carbon transfer to depth, leading to carbon sequestration on time scales of centuries or more. Precursors of Antarctic Bottom Water (AABW) are formed on the Weddell Sea continental shelf as a consequence of buoyancy loss of surface waters at the ice-ocean or atmosphere-ocean interface, which suggests that any change in water mass transformation rates in this area affects global carbon cycling and hence climate. Many of the models previously used to assess AABW formation in present and future climates contained only crude representations of ocean-ice shelf interaction. Numerical simulations often featured spurious deep convection in the open ocean, and changes in carbon sequestration have not yet been assessed at all. Here, we present results from the global model FESOM-REcoM, which was run on a mesh with elevated grid resolution in the Weddell Sea and which includes an explicit representation of sea ice and ice shelves. Forcing this model with ssp585 scenario output from the AWI Climate Model, we assess changes over the 21&lt;sup&gt;st&lt;/sup&gt; century in the formation and northward export of dense waters and the associated carbon fluxes within and out of the Weddell Sea. We find that the northward transport of dense deep waters (&amp;#963;&lt;sub&gt;2&lt;/sub&gt;&gt;37.2 kg m&lt;sup&gt;-3&lt;/sup&gt; below 2000 m) across the SR4 transect, which connects the tip of the Antarctic Peninsula with the eastern Weddell Sea, declines from 4 Sv to 2.9 Sv by the year 2100. Concurrently, despite the simulated continuous increase in surface ocean CO&lt;sub&gt;2&lt;/sub&gt; uptake in the Weddell Sea over the 21&lt;sup&gt;st&lt;/sup&gt; century, the carbon transported northward with dense deep waters declines from 3.5 Pg C yr&lt;sup&gt;-1&lt;/sup&gt; to 2.5 Pg C yr&lt;sup&gt;-1&lt;/sup&gt;, demonstrating the dominant role of dense water formation rates for carbon sequestration. Using the water mass transformation framework, we find that south of SR4, the formation of downwelling dense waters declines from 3.5 Sv in the 1990s to 1.6 Sv in the 2090s, a direct result of the 18% lower sea-ice formation in the area, the increased presence of modified Warm Deep Water on the continental shelf, and 50% higher ice shelf basal melt rates. Given that the reduced formation of downwelling water masses additionally occurs at lighter densities in FESOM-REcoM in the 2090s, this will directly impact the depth at which any additional oceanic carbon uptake is stored, with consequences for long-term carbon sequestration.&lt;/p&gt;

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