Corrosion Protection Of Mild Steel In Sea Water Using Chemical Inhibitor

Science.gov (United States)

Araoyinbo, Alaba O.; Salleh, Mohd Arif Anuar Mohd; Zulerwan Jusof, Muhammad

2018-03-01

The effect of sodium nitrite as a corrosion inhibitor of mild steel in sea water (i.e ASTM standard prepared sea water and sea water obtained from a local river) was investigated, using the weight loss technique. Different amount of sodium nitrite were prepared (i.e 2 % to 10 %) in the inhibition of the mild steel corrosion in sea water exposed to irradiation condition from sunlight exposure. The cut samples of mild steel were exposed to these corrosive media and the corresponding weight loss subsequently obtained was recorded at intervals of 1 to 4 weeks. It was observed that corrosion rate increases with the time of exposure to the corrosive medium exposed to sunlight and that sodium nitrite that was used at the chemical inhibitor was able to retard the corrosion rate of mild steel if the appropriate concentration is applied. The results obtained from the weight loss analysis shows that the optimum percentage of sodium nitrate in sea water that gives the optimum corrosion inhibition of mild steel is 4 %.

Air-sea flux of CO2 in arctic coastal waters influenced by glacial melt water and sea ice

DEFF Research Database (Denmark)

Sejr, Mikael Kristian; Krause-Jensen, Dorte; Rysgaard, Søren

2011-01-01

Annual air–sea exchange ofCO2 inYoung Sound,NEGreenlandwas estimated using pCO2 surface-water measurements during summer (2006–2009) and during an ice-covered winter 2008. All surface pCO2 values were below atmospheric levels indicating an uptake of atmospheric CO2. During sea ice formation...... and thereby efficiently blocked air–sea CO2 exchange. During sea ice melt, dissolution of CaCO3 combined with primary production and strong stratification of the water column acted to lower surface-water pCO2 levels in the fjord. Also, a large input of glacial melt water containing geochemically reactive...... year-to-year variation in annual gas exchange....

Multidecadal variations in the early Holocene outflow of Red Sea Water into the Arabian Sea

Science.gov (United States)

Jung, S. J. A.; Ganssen, G. M.; Davies, G. R.

2001-12-01

We present Holocene stable oxygen isotope data from the deep Arabian Sea off Somalia at a decadal time resolution as a proxy for the history of intermediate/upper deep water. These data show an overall δ18O reduction by 0.5‰ between 10 and ˜6.5 kyr B.P. superimposed upon short-term δ18O variations at a decadal-centennial timescale. The amplitude of the decadal variations is 0.3‰ prior, and up to 0.6‰ subsequent, to ˜8.1 kyr B.P. We conclude from modeling experiments that the short-term δ18O variations between 10 and ˜6.5 kyr B.P. most likely document changes in the evaporation-precipitation balance in the central Red Sea. Changes in water temperature and salinity cause the outflowing Red Sea Water to settle roughly 800 m deeper than today.

Metals extraction from sea water

International Nuclear Information System (INIS)

Chryssostomidis, C.; Larue, G.J.; Morgan, D.T.

1981-01-01

A method and system for continuously extracting metals from sea water by deploying adsorber sheets in a suitable current of sea water, recovering the adsorber sheets after they become loaded with metal and eluting the metal from the recovered sheets. The system involves the use of hollow, perforated bobbins on which the sheets are rolled as they are recovered and through which elutant is introduced

Sensitivity analysis of the model for estimation of the Adriatic sea turnover time using fallout 90Sr as a radioactive tracer

International Nuclear Information System (INIS)

Franic, Z.

2005-01-01

Reliable data on the turnover time of water in the Adriatic Sea (approximately 35000 cubic kilometres) is extremely important for any risk analysis involving various economic activities, tourism, etc. Water exchange through the Strait of Otranto between the Adriatic and the Ionian seas has been the subject of a series of experimental investigations and more recently, of some numerical studies, is extensively presented by Cushman-Roisin et al. [1]. The turnover time of the Adriatic sea water can be easily calculated from the data on water fluxes through the Strait by calculating annual water mass flowing through the Strait and dividing it by the total volume of the Adriatic sea. Literature data on the Adriatic Sea water turnover time range from minimal 0.7 to maximal 5.0 years. Using a model describing the rate of change of 9 0S r activity concentrations in the Adriatic Sea water by function minimisation to long-term experimental data, the turnover time for 9 0S r in the Adriatic was calculated to be 3.3±0.4 years. The uncertainty was estimated by Monte Carlo analysis. As 9 0S r is a reliable radiotracer for seawater, this value also reflects the sea water turnover time. Sensitivity analysis of the model, applied by varying critical parameters over their nominal values, showed that ±25% uncertainty in the estimation of the Adriatic sea water activity results in approximately ±10% change in 9 0S r mean residence time. On the other hand, a larger input of 9 0S r, either by fallout or water influx from the Ionian Sea may lead to a shorter mean residence time.Direct proportionality between 9 0S r input into the Adriatic sea and its mean residence time in the sea water suggests that 3.3 years is the upper limit of the Adriatic sea water turnover time. Namely, re-suspension from sediments could affect 9 0S r activity concentrations, acting as additional input, especially in the northern, relatively shallow part of the Adriatic.(author)

Studies of deep water formation and circulation in the Weddell Sea using natural and anthropogenic tracers

International Nuclear Information System (INIS)

Schlosser, Peter; Bayer, Reinhold

1991-01-01

The application of natural and anthropogenic trace substances in oceanographic studies of the Weddell Sea is reviewed. The potential of some steady-state and transient tracers (tritium, CFC-11 and CFC-12, 18 O, and helium isotopes) for studies of deep water formation and circulation is discussed on the basis of data sets collected mainly on cruises of R/V 'Polastern' to the Weddell Sea during the 1980s. CFC/ tritium ratio dating of young water masses is applied to estimate mean age and transit times of water involved in Weddell Sea Bottom Water formation. The history of the CFC-11/tritium ratio through time is derived for Weddell Sea shelf waters. (author). 36 refs.; 18 figs

Adsorption behavior of radionuclide in water containing sea salts

International Nuclear Information System (INIS)

Kani, Yuko; Kamoshida, Mamoru; Asano, Takashi; Tamata, Shin

2012-01-01

Waste water caused by the Fukushima Dai-ichi Nuclear Reactor accident contains high level radioactive material with impurities of sea water origin, such as chloride, sodium and magnesium. These impurities have the potential to inhibit the adsorption reaction of radioactive cesium and strontium to adsorbents. We have studied adsorption behavior of radioactive cesium and strontium to adsorbents to measure distribution coefficients (Kd) in the condition of different sea water concentrations. For cesium adsorption, the dependence of Kd on the sea water concentration was affected by the adsorption mechanism of adsorbent; the adsorbents which adsorbed cesium by intercalation showed less dependence of Kd on the sea water concentration, while those adsorbed cesium by ion exchange had smaller Kd with increasing the sea water concentration. For strontium adsorption, Kd decreased as the sea water concentration increased for both adsorbents which adsorbed strontium by intercalation and by ion exchange. The inhibition of intercalation and ion exchange reaction of strontium by calcium ion, that exists high concentration in sea water (400 ppm) and similar hydrated ionic radius with strontium, will cause the decrease of Kd for strontium in the sea water with higher concentration. (author)

Sea water strontium isotopes, acid rain, and the cretaceous-tertiary boundary

International Nuclear Information System (INIS)

MacDougall, J.D.

1988-01-01

A large bolide impact at the end of the Cretaceous would have produced significant amounts of nitrogen oxides by shock heating of the atmosphere. The resulting acid precipitation would have increased continental weathering greatly and could be an explanation for the observed high ratio of strontium-87 to strontium-86 in sea water at about this time, due to the dissolution of large amounts of strontium from the continental crust. Spikes to high values in the sea water strontium isotope record at other times may reflect similar episodes. 17 references, 1 figure, 1 table

ANALYSIS OF SEA WATER POLLUTION IN COASTAL MARINE DISTRICT TUBAN TO THE QUALITY STANDARDS OF SEA WATER WITH USING STORET METHOD

Directory of Open Access Journals (Sweden)

Perdana Ixbal Spanton

2017-05-01

Full Text Available The sea water is a component that interacts with the terrestrial environment, where sewage from the land will lead to the sea. Waste containing these pollutants will enter into coastal waters and marine ecosystems. Partially soluble in water, partially sinks to the bottom and was concentrated sediment, and partly into the body tissues of marine organisms. This study was conducted to determine the level of pollution of sea water on the coast in the district of Tuban. This research was conducted in the Coastal Water Tuban, East Java. The main material used in research on Analysis of Water Pollution in Coastal Sea on Tuban. The method used in this research is using storet method and compared to the quality standards of the Environment Decree No. 51 in 2004. Based on the analysis of testing at five sampling point’s seawater around Bodies Tuban, obtained by sea water quality measurement results either in physics, chemistry, and microbiology varied. The level of pollution of sea water around Coastal Tuban obtained by using Storet Method average value of analysis is -4.2 included in class B are lightly blackened, while using values obtained Pollution Index average pollution index of 3.60 is included in the category lightly blackened. Keywords: Analysis of the pollution level of seawater on the coast in Tuban, Quality Standards of Sea Water, Storet Method.

Speciation studies of cobalt in sea water

International Nuclear Information System (INIS)

Toteja, R.S.D.; Sudersanan, M.; Iyer, R.K.

1995-01-01

Recent results on the speciation of cobalt in simulated and actual sea water is reported using ion exchangers. The influence of magnesium ions in affecting the composition of ion exchangers and subsequent interpretation of the results is discussed. The results indicated that Co +2 may predominate in both the simulated and actual sea water and the presence of other constituents in sea water does not affect the nature of complex species present. (author). 2 refs., 3 tabs., 1 fig

Absorption of labelled calcium-45Ca by prawn from sea water

International Nuclear Information System (INIS)

Deshimaru, Osamu; Kuroki, Katsunobu; Sakamoto, Syuichi; Yone, Yasuo.

1978-01-01

In connection with the previous study of the mineral requirements of prawn, Penaeus japonicus, the absorption of radioactive calcium- 45 Ca from surrounding sea water by the prawn fed on a diet without supplemental calcium was compared with that of the prawn fed on a calcium-supplemented diet. The surrounding sea water was prepared to contain labelled calcium- 45 Ca-CaCl 2 . The prawn were first fed on each test diet in ordinary sea water, and one hour after the final mealtime were transferred to sea water in which 45 Ca-CaCl 2 was dissolved. One, four, and twentythree hours later, the prawn were analyzed for the radioactivity incorporated into their bodies. The radioactivity of 45 Ca accumulated in the prawn gradually increased with the lapse of time, and the group fed on the diet without supplemental calcium exhibited faster absorption and higher activity of 45 Ca than the group fed on the diet with calcium. (author)

A Modeling Study of Deep Water Renewal in the Red Sea

Science.gov (United States)

Yao, F.; Hoteit, I.

2016-02-01

Deep water renewal processes in the Red Sea are examined in this study using a 50-year numerical simulation from 1952-2001. The deep water in the Red Sea below the thermocline ( 200 m) exhibits a near-uniform vertical structure in temperature and salinity, but geochemical tracer distributions, such as 14C and 3He, and dissolved oxygen concentrations indicate that the deep water is renewed on time scales as short as 36 years. The renewal process is accomplished through a deep overturning cell that consists of a southward bottom current and a northward returning current at depths of 400-600 m. Three sources regions are proposed for the formation of the deep water, including two deep outflows from the Gulfs of Aqaba and Suez and winter deep convections in the northern Red Sea. The MITgcm (MIT general circulation model), which has been used to simulate the shallow overturning circulations in the Red Sea, is configured in this study with increased resolutions in the deep water. During the 50 years of simulation, artificial passive tracers added in the model indicate that the deep water in the Red Sea was only episodically renewed during some anomalously cold years; two significant episodes of deep water renewal are reproduced in the winters of 1983 and 1992, in accordance with reported historical hydrographic observations. During these renewal events, deep convections reaching the bottom of the basin occurred, which further facilitated deep sinking of the outflows from the Gulfs of Aqaba and Suez. Ensuing spreading of the newly formed deep water along the bottom caused upward displacements of thermocline, which may have profound effects on the water exchanges in the Strait of Bab el Mandeb between the Red Sea and the Gulf of Aden and the functioning of the ecosystem in the Red Sea by changing the vertical distributions of nutrients.

Uptake of uranium from sea water by microalgae

International Nuclear Information System (INIS)

Sakaguchi, Takashi; Horikoshi, Takao; Nakajima, Akira

1978-01-01

The uptake of uranium from aqueous systems especially from sea water by various microalgae was investigated. The freshwater microalgae, Chlorella regularis, Scenedesmus bijuga, Scenedesmus chloreloides, Scenedesmus obliquus, Chlamydomonas angulosa, Chlamydomonas reinhardtii, accumulated relatively large amounts of uranium from the solution containing uranium only. The concentration factors of the above mentioned algae were: Chlorella regularis 3930, Chlamydomonas 2330 - 3400, Scenedesmus 803 - 1920. The uptake of uranium from sea water by Chlorella regularis was inhibited markedly by the co-existence of carbonate ions. Chlorella cells could take up a great quantity of uranium from decarbonated sea water. The uptake of uranium was affected by the pH of sea water, and the amount of uranium absorbed was maximum at pH 5. The experiment was carried out to screen marine microalgae which have the ability to accumulate a large amount of uranium from sea water. The uptake of uranium from sea water by marine microalgae of different species turned out to be in the following decreasing order: Synechococcus > Chlamydomonas >> Chlorella > Dunaliella > Platymonas > Calothrix > Porphyridium. The amount of uranium absorbed differed markedly with different species of marine microalgae. (author)

Sea-ice cover in the Nordic Seas and the sensitivity to Atlantic water temperatures

Science.gov (United States)

Jensen, Mari F.; Nisancioglu, Kerim H.; Spall, Michael A.

2017-04-01

Changes in the sea-ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard-Oeschger events during the last glacial. However, with its proximity to the warm Atlantic water, how a sea-ice cover can persist in the Nordic Seas is not well understood. In this study, we apply an eddy-resolving configuration of the Massachusetts Institute of Technology general circulation model with an idealized topography to study the presence of sea ice in a Nordic Seas-like domain. We assume an infinite amount of warm Atlantic water present in the south by restoring the southern area to constant temperatures. The sea-surface temperatures are restored toward cold, atmospheric temperatures, and as a result, sea ice is present in the interior of the domain. However, the sea-ice cover in the margins of the Nordic Seas, an area with a warm, cyclonic boundary current, is sensitive to the amount of heat entering the domain, i.e., the restoring temperature in the south. When the temperature of the warm, cyclonic boundary current is high, the margins are free of sea ice and heat is released to the atmosphere. We show that with a small reduction in the temperature of the incoming Atlantic water, the Nordic Seas-like domain is fully covered in sea ice. Warm water is still entering the Nordic Seas, however, this happens at depths below a cold, fresh surface layer produced by melted sea ice. Consequently, the heat release to the atmosphere is reduced along with the eddy heat fluxes. Results suggest a threshold value in the amount of heat entering the Nordic Seas before the sea-ice cover disappears in the margins. We study the sensitivity of this threshold to changes in atmospheric temperatures and vertical diffusivity.

Uranium from sea water

International Nuclear Information System (INIS)

Westermark, T.; Forsberg, S.

1980-01-01

The prevalent situation in the field of uranium extraction from the oceans was reviewed from a scientific and technological standpoint and as to legality too. No international convention seems to limit the access to dissolved or suspended matter in free area of the oceans. All publications received through 1979 point to adsorption as the method of choice, at some form of hydrated titanium ''oxide'' as the most promising sorbent, and, generally spoken, at the cost of pumping water through the contacting system as a huge economical problem. A recent Swedish invention may circumvent the pumping problem by making available, in a previously unknown manner, some kind of self-renewing energy from the oceans. A simple economic calculus has resulted in costs from two to six times the present world market price of crude uranium oxide (which is assumed to be US dollar 43.-/1b), with a possibility to compete really after some technical and systematic developments. Results from a small-scale adsorption experiment in genuine sea water are presented: During a few weeks sea water was pumped through tiny, 10 cm high beds of sodium titanate ion exchangers, partly in the hydrogen form. The grain size was 250-500 μm, the flow rate 0.15-0.61 m/min. About 5% of the total amount of uranium passing the columns was retained, resulting in 8-11 μg/Ug. Also, large amounts of manganese, strontium, vanadium and zink were retained. Some of these elements and plankton as well may perhaps be recovered with an economic gain

Spatial and temporal distribution (1987-91) of 125Sb used to trace pathways and transit times of waters entering the North Sea from the English Channel

International Nuclear Information System (INIS)

Guegueniat, P.; Du Bois, P.B.; Gandon, R.; Leon, R.

1994-01-01

The labelling of marine waters off north-western Europe by artificial radionuclides discharged by the nuclear fuel reprocessing plants at Sellafield and La Hague provides a potentially useful tool for the study of hydrodynamic processes. In this context, the present investigation introduces a tracer, 125 Sb, which is conservative within the watermass and which is characteristic of releases from la Hague. Analysis of the data collected between 1987 and 1991 shows that a large part of the channel waters entering the North Sea follow a route along the Belgian, Dutch, German and Danish coasts, while undergoing a low degree of dilution with other marine waters circulating in the central North Sea. The westward extension of the channel plume is variable with time, but the general distribution is in good agreement with the ICES box model. Estimates are given for the transit times from Cap de la Hague to various sectors of the North Sea; it takes 15-17 months for labelled waters to reach the Norwegian Channel. (Author)

Phenolic compounds in Ross Sea water

Science.gov (United States)

Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo; Corami, Fabiana; Kehrwald, Natalie; Capodaglio, Gabriele

2016-04-01

Phenolic compounds are semi-volatile organic compounds produced during biomass burning and lignin degradation in water. In atmospheric and paleoclimatic ice cores studies, these compounds are used as biomarkers of wood combustion and supply information on the type of combusted biomass. Phenolic compounds are therefore indicators of paleoclimatic interest. Recent studies of Antarctic aerosols highlighted that phenolic compounds in Antarctica are not exclusively attributable to biomass burning but also derive from marine sources. In order to study the marine contribution to aerosols we developed an analytical method to determine the concentration of vanillic acid, vanillin, p-coumaric acid, syringic acid, isovanillic acid, homovanillic acid, syringaldehyde, acetosyringone and acetovanillone present in dissolved and particle phases in Sea Ross waters using HPLC-MS/MS. The analytical method was validated and used to quantify phenolic compounds in 28 sea water samples collected during a 2012 Ross Sea R/V cruise. The observed compounds were vanillic acid, vanillin, acetovanillone and p-coumaric acid with concentrations in the ng/L range. Higher concentrations of analytes were present in the dissolved phase than in the particle phase. Sample concentrations were greatest in the coastal, surficial and less saline Ross Sea waters near Victoria Land.

Re-initiation of bottom water formation in the East Sea (Japan Sea) in a warming world.

Science.gov (United States)

Yoon, Seung-Tae; Chang, Kyung-Il; Nam, SungHyun; Rho, TaeKeun; Kang, Dong-Jin; Lee, Tongsup; Park, Kyung-Ae; Lobanov, Vyacheslav; Kaplunenko, Dmitry; Tishchenko, Pavel; Kim, Kyung-Ryul

2018-01-25

The East Sea (Japan Sea), a small marginal sea in the northwestern Pacific, is ventilated deeply down to the bottom and sensitive to changing surface conditions. Addressing the response of this marginal sea to the hydrological cycle and atmospheric forcing would be helpful for better understanding present and future environmental changes in oceans at the global and regional scales. Here, we present an analysis of observations revealing a slowdown of the long-term deepening in water boundaries associated with changes of water formation rate. Our results indicate that bottom (central) water formation has been enhanced (reduced) with more (less) oxygen supply to the bottom (central) layer since the 2000s. This paper presents a new projection that allows a three-layered deep structure, which retains bottom water, at least until 2040, contrasting previous results. This projection considers recent increase of slope convections mainly due to the salt supply via air-sea freshwater exchange and sea ice formation and decrease of open-ocean convections evidenced by reduced mixed layer depth in the northern East Sea, resulting in more bottom water and less central water formations. Such vigorous changes in water formation and ventilation provide certain implications on future climate changes.

A linked hydrodynamic and water quality model for the Salton Sea

Science.gov (United States)

Chung, E.G.; Schladow, S.G.; Perez-Losada, J.; Robertson, Dale M.

2008-01-01

A linked hydrodynamic and water quality model was developed and applied to the Salton Sea. The hydrodynamic component is based on the one-dimensional numerical model, DLM. The water quality model is based on a new conceptual model for nutrient cycling in the Sea, and simulates temperature, total suspended sediment concentration, nutrient concentrations, including PO4-3, NO3-1 and NH4+1, DO concentration and chlorophyll a concentration as functions of depth and time. Existing water temperature data from 1997 were used to verify that the model could accurately represent the onset and breakup of thermal stratification. 1999 is the only year with a near-complete dataset for water quality variables for the Salton Sea. The linked hydrodynamic and water quality model was run for 1999, and by adjustment of rate coefficients and other water quality parameters, a good match with the data was obtained. In this article, the model is fully described and the model results for reductions in external phosphorus load on chlorophyll a distribution are presented. ?? 2008 Springer Science+Business Media B.V.

Extraction of uranium from sea water with the granular composite adsorbent by using the fixed bed

International Nuclear Information System (INIS)

Katoh, Shunsaku; Sakane, Kohji; Hirotsu, Takahiro; Fujii, Ayako; Kitamura, Takao

1981-01-01

To clarify the technical problems existing in the extraction process of uranium from sea water, uranium was extracted from natural sea water, with the granulated C-Ti-OH composite adsorbent. The adsorption of uranium from sea water was carried out by using the fixed bed that had been designed in our laboratory. The uranium recovery from the sea water was 13.9% in the adsorption process of 56 d. The adsorbed uranium was eluted from the adsorbent with 0.5 N NaHCO 3 -0.5N Na 2 CO 3 soln. at 70 0 C. The elution recovery was 97.4% for 35 h. The uranium contained in the eluate was concentrated twenty times as much as in the anion exchange process, and then 100 times in the solvent extraction process with oxine-chloroform and TOA-kerosene. About 0.7 g of yellow cake was prepared from natural sea water, and it was identified to be pure 2UO 2 .NH 3 .3H 2 O by X-ray diffraction method and X-ray fluorometry. (author)

Recovery of uranium resources from sea water

International Nuclear Information System (INIS)

Kurushima, Morihiro

1980-01-01

After the oil crisis in 1973, the development of atomic energy has become important as substitute energy, and the stable acquisition of uranium resources is indispensable, in order to promote smoothly the use of atomic energy. The Ministry of International Trade and Industry has engaged actively in the project ''The survey on the technical development of the system for recovering uranium and others from sea water'' since 1974. 80% of the uranium resources in the world is distributed in USA, Canada, South Africa, Australia and Niger, and in near future, the price of uranium ores may be raised. Japan must promote powerfully the development of foreign uranium resources, but also it is very important to get domestic uranium by efficiently recovering the uranium dissolved in sea water, the amount of which was estimated at 4 billion tons, and its practical use is expected in 1990s. The uranium concentration in sea water is about 3 g in 1000 t sea water. The processes of separation and recovery are as follows: (1) adsorption of uranium to titanic acid powder adsorbent by bringing sea water in contact with it, (2) dissolving the collected uranium with ammonium carbonate, the desorption agent, (3) concentration of uranium solution by ion exchange method or ion flotation method to 2800 ppm. The outline of the model plant is explained. (Kako, I.)

Net removal of dissolved organic carbon in the anoxic waters of the Black Sea

NARCIS (Netherlands)

Margolin, A.R.; Gerringa, L.J.A.; Hansell, D.A.; Rijkenberg, M.J.A.

2016-01-01

Dissolved organic carbon (DOC) concentrations in the deep Black Sea are ~2.5 times higher than found in the globalocean. The two major external sources of DOC are rivers and the Sea of Marmara, a transit point for waters from theMediterranean Sea. In addition, expansive phytoplankton blooms

Importance of the Gulf of Aqaba for the formation of bottom water in the Red Sea

Science.gov (United States)

Plähn, Olaf; Baschek, Burkard; Badewien, Thomas H.; Walter, Maren; Rhein, Monika

2002-08-01

Conductivity-temperature-depth tracer and direct current measurements collected in the northern Red Sea in February and March 1999 are used to study the formation of deep and bottom water in that region. Historical data showed that open ocean convection in the Red Sea can contribute to the renewal of intermediate or deep water but cannot ventilate the bottom water. The observations in 1999 showed no evidence for open ocean convection in the Red Sea during the winter 1998/1999. The overflow water from the Gulf of Aqaba was found to be the densest water mass in the northern Red Sea. An anomaly of the chlorofluorocarbon component CFC-12 observed in the Gulf of Aqaba and at the bottom of the Red Sea suggests a strong contribution of this water mass to the renewal of bottom water in the Red Sea. The CFC data obtained during this cruise are the first available for this region. Because of the new signal, it is possible for the first time to subdivide the deep water column into deep and bottom water in the northern Red Sea. The available data set also shows that the outflow water from the Gulf of Suez is not dense enough to reach down to the bottom of the Red Sea but was found about 250 m above the bottom.

Tables of the velocity of sound in sea water

CERN Document Server

Bark, L S; Meister, N A

1964-01-01

Tables of the Velocity of Sound in Sea Water contains tables of the velocity of sound in sea water computed on a ""Strela-3"" high-speed electronic computer and a T-5 tabulator at the Computational Center of the Academy of Sciences. Knowledge of the precise velocity of sound in sea water is of great importance when investigating sound propagations in the ocean and when solving practical problems involving the use of hydro-acoustic devices. This book demonstrates the computations made for the velocity of sound in sea water, which can be found in two ways: by direct measurement with the aid of s

Adsorption of transuranic elements from large volume sea water

International Nuclear Information System (INIS)

Holm, E.; Ballestra, S.

1976-01-01

Some years ago a sampler for concentrating radionuclides from large volumes of sea water was developed by Silker et al. of the Battelle Northwest Laboratories. They used pure A1 2 O 3 as the adsorbent. The device has been applied successfully to the determination of 238 Pu and 239 Pu in several sea water samples. Our experience on the application of an identical system for the determination of transuranics in Mediterranean sea water was not quite as satisfactory as we had hoped. The chemistry involved in leaching up to 1 kg Al 2 O 3 . with acid, followed by removal of dissolved aluminium from the transuranic fraction, is rather tedious and time-consuming for routine use. The adsorption efficiency of transuranics, checked by dual-bed adsorption did not give consistent results. However, since the principle of the device is attractive enough for handling large volume water samples, it was felt that it was worthwhile to test other types of adsorbents which are easier to handle than Al 2 O 3 . For this purpose, chitosan and manganese dioxide were chosen and series of experiments were conducted in order to examine the suitability of these materials as an adsorbent in the system

Influence of surface condition on the corrosion resistance of copper alloy condenser tubes in sea water

Energy Technology Data Exchange (ETDEWEB)

Sato, S; Nagata, K; Yamauchi, S

1979-07-01

Investigation was made on the influence of various surface conditions of aluminum brass tube. The corrosion behavior of aluminum brass tube, with nine kinds of surface conditions, was studied in stagnant 0.1N NaHCo/sub 3/ solution and flowing sea water (natural, Fe/sup + +/ containing and S/sup - -/ containing water). Surface treatments investigated contained bright annealing, special annealing to form carbon film, hot oxidizing and pickling. Anodic polarization measurements in 0.1N NaHCO/sub 3/ solution showed that the oxidized surface was superior and that the pickled surface was inferior. However, relation between these characteristics and corrosion resistance in sea water has not been established. Electrochemical characteristics in flowing sea water were dependent on the surface conditions in the very beginning of immersion time; nobler corrosion potential for the surface with carbon film, higher polarization resistance for the bright annealed and the oxidized surface, and faster decrease of polarization resistance in S/sup - -/ containing sea water for the pickled surface. However, these differences disappeared in the immersion time of only 2 to 7 days. It was revealed, by the statistical analysis on the corrosion depth in corrosion test in flowing sea water and in jet impingement test, that the corrosion behavior was not influenced by surface conditions, but was significantly influenced by quality of sea water and sponge ball cleaning. Sulfide ion of 0.05 ppm caused severe pitting corrosion, and sponge ball cleaning of 5 chances a week caused erosion corrosion. From above results, it was concluded that surface conditions of aluminum brass were not important to sea water corrosion, and that quality of sea water and operating condition such as sponge ball cleaning were more significant.

Problems especially relating to sea water condensers

International Nuclear Information System (INIS)

Boyer, Raymond.

1975-01-01

Sea water forms a nearly unlimited cold source well adapted to the open circuit cooling of large nuclear power plants. As a counter-part, its physico-chemical and biological characteristics generally require complicated arrangements for preventing: - first, the sea water to enter accidentally, especially as a consequence of corrosions and erosion-corrosions. Indeed, certain materials used in modern plants very badly suffer any introduction of salted water into the cycle steam-water mixture: - secondly, damaging the flow conditions of the cooling water (increase in friction coefficients, restriction of passage cross sections, blocking) and heat exchange parameters (resisting deposits, circulation troubles...) [fr

137Cs inventories in the water column collected from the South and South China Seas

International Nuclear Information System (INIS)

Yamada, M.; Wang, Z.-L.; Zheng, J.

2006-01-01

Seawater samples were collected in the Sulu and South China Seas and their 137 Cs activities were determined by γ spectrometry. A significant difference in intermediate water 137 Cs activities in the 750-1500 m depth was observed between the Sulu and South China Seas. The 137 Cs inventories in the Sulu Sea was 5.7 times higher than that of the integrated deposition density of atmospheric global fallout at the same latitude of 0-10degN. A possible mechanism controlling this extremely high 137 Cs inventories may be inflows of 137 Cs rich North Pacific Tropical Water and upper North Pacific Intermediate Water through the Luzon Straight from the West Philippine Sea, and lateral transport across the Mindoro Strait into the Sulu Sea, then conveyance into the deep layer in the Sulu Sea basin. (author)

Air-sea heat flux control on the Yellow Sea Cold Water Mass intensity and implications for its prediction

Science.gov (United States)

Zhu, Junying; Shi, Jie; Guo, Xinyu; Gao, Huiwang; Yao, Xiaohong

2018-01-01

The Yellow Sea Cold Water Mass (YSCWM), which occurs during summer in the central Yellow Sea, plays an important role in the hydrodynamic field, nutrient cycle and biological species. Based on water temperature observations during the summer from 1978 to 1998 in the western Yellow Sea, five specific YSCWM years were identified, including two strong years (1984 and 1985), two weak years (1989 and 1995) and one normal year (1992). Using a three-dimensional hydrodynamic model, the YSCWM formation processes in these five years were simulated and compared with observations. In general, the YSCWM began forming in spring, matured in summer and gradually disappeared in autumn of every year. The 8 °C isotherm was used to indicate the YSCWM boundary. The modelled YSCWM areas in the two strong years were approximately two times larger than those in the two weak years. Based on the simulations in the weak year of 1995, ten numerical experiments were performed to quantify the key factors influencing the YSCWM intensity by changing the initial water condition in the previous autumn, air-sea heat flux, wind, evaporation, precipitation and sea level pressure to those in the strong year of 1984, respectively. The results showed that the air-sea heat flux was the dominant factor influencing the YSCWM intensity, which contributed about 80% of the differences of the YSCWM average water temperature at a depth of 50 m. In addition, the air-sea heat flux in the previous winter had a determining effect, contributing more than 50% of the differences between the strong and weak YSCWM years. Finally, a simple formula for predicting the YSCWM intensity was established by using the key influencing factors, i.e., the sea surface temperature before the cooling season and the air-sea heat flux during the cooling season from the previous December to the current February. With this formula, instead of a complicated numerical model, we were able to roughly predict the YSCWM intensity for the

Coupling of sea level and tidal range changes, with implications for future water levels.

Science.gov (United States)

Devlin, Adam T; Jay, David A; Talke, Stefan A; Zaron, Edward D; Pan, Jiayi; Lin, Hui

2017-12-05

Are perturbations to ocean tides correlated with changing sea-level and climate, and how will this affect high water levels? Here, we survey 152 tide gauges in the Pacific Ocean and South China Sea and statistically evaluate how the sum of the four largest tidal constituents, a proxy for the highest astronomical tide (HAT), changes over seasonal and interannual time scales. We find that the variability in HAT is significantly correlated with sea-level variability; approximately 35% of stations exhibit a greater than ±50 mm tidal change per meter sea-level fluctuation. Focusing on a subset of three stations with long records, probability density function (PDF) analyses of the 95% percentile exceedance of total sea level (TSL) show long-term changes of this high-water metric. At Hong Kong, the increase in tides significantly amplifies the risk caused by sea-level rise. Regions of tidal decrease and/or amplification highlight the non-linear response to sea-level variations, with the potential to amplify or mitigate against the increased flood risk caused by sea-level rise. Overall, our analysis suggests that in many regions, local flood level determinations should consider the joint effects of non-stationary tides and mean sea level (MSL) at multiple time scales.

Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea.

Directory of Open Access Journals (Sweden)

Claudio Stalder

Full Text Available Cold-water coral (CWC ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago. However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents.

Temporal and Spatial Scales of Labrador Sea Water Formation

Science.gov (United States)

Clarke, R. A.

1984-01-01

Labrador Sea Water is an intermediate water found at the same density and depth range in the North Atlantic as the Mediterranean water. It is formed by convection from the sea surface to depths greather than 2 km in winter in the Western Labrador Sea. The processes leading to deep convection begin with the formation of a 200 km scale cyclonic circulation about denser than average upper layer water in the Western Labrador Sea. This circulation pattern is hypothesized to be driven by an ocean/atmosphere heat exchange that has its maximum in this region. By early March, if deep convection is taking place, one sees that this body of denser upper waters penetrates to the top of the deep temperature/salinity maximum marking the core of the North Atlantic Deep Water. We note that the horizontal scale of this body is still 100-200 km normal to the coastline.

Definition of water exchange zone between the Bohai Sea and Yellow Sea and the effect of winter gale on it

Institute of Scientific and Technical Information of China (English)

SONG Jun; GUO Junru; LI Jing; MU Lin; LIU Yulong; WANG Guosong; LI Yan; LI Huan

2017-01-01

The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System (ROMS) marine numerical model. Using the simulated temperature and salinity, the water exchange zone between the Bohai Sea and Yellow Sea is defined through the Spectral Mixture Model (SMM). The influence of winter gales on the water exchange is also discussed. It is found that the Yellow Sea water masses in winter are distributed in a “tongue” shape in the Bohai Strait region, the water exchange zone presents a zonal distribution along the margin of the “tongue”, with a tendency of running from northwest to southeast, and the water exchange is intensified at the tip of the “tongue”. Besides, the coastal area in the northernmost Yellow Sea does not participate in the water exchange between the Bohai Sea and Yellow Sea. The result shows that the winter gale events play a role in enhancing the water exchange. It is specifically shown by the facts: the Yellow Sea warm current is enhanced to intrude the Bohai Sea by the gale process; the water exchange zone extends into the Bohai Sea; the water exchange belt in the southern part becomes wider; the mixture zone of river runoff with the Bohai Sea water upon its entry is enlarged and shifts northwards. Within two days after the gale process, the exchange zone retreats toward the Yellow Sea and the exchange zone resulted from the Huanghe River (Yellow River) runoff also shrinks back shoreward.

Improved regional sea-level estimates from Ice Sheets, Glaciers and land water storage using GRACE time series and other data

Science.gov (United States)

He, Z.; Velicogna, I.; Hsu, C. W.; Rignot, E. J.; Mouginot, J.; Scheuchl, B.; Fettweis, X.; van den Broeke, M. R.

2017-12-01

Changes in ice sheets, glaciers and ice caps (GIC) and land water mass cause regional sea level variations that differ significantly from a uniform re-distribution of mass over the ocean, with a decrease in sea level compared to the global mean sea level contribution (GMSL) near the sources of mass added to the ocean and an increase up to 30% larger than the GMSL in the far field. The corresponding sea level fingerprints (SLF) are difficult to separate from ocean dynamics on short time and spatial scales but as ice melt continues, the SLF signal will become increasingly dominant in the pattern of regional sea level rise. It has been anticipated that it will be another few decades before the land ice SLF could be identified in the pattern of regional sea level rise. Here, we combine 40 years of observations of ice sheet mass balance for Antarctica (1975-present) and Greenland (1978-present), along with surface mass balance reconstructions of glacier and ice caps mass balance (GIC) from 1970s to present to determine the contribution to the SLF from melting land ice (MAR and RACMO). We compare the results with observations from GRACE for the time period 2002 to present for evaluation of our approach. Land hydrology is constrained by GRACE data for the period 2002-present and by the GLDAS-NOAH land hydrology model for the longer time period. Over the long time period, we find that the contribution from land ice dominates. We quantify the contribution to the total SLF from Greenland and Antarctica in various parts of the world over the past 40 years. More important, we compare the cumulative signal from SLF with tide gauge records around the world, corrected for earth dynamics, to determine whether the land ice SLF can be detected in that record. Early results will be reported at the meeting. This work was performed at UC Irvine and at Caltech's Jet Propulsion Laboratory under a contract with NASA's Cryospheric Science Program.

Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

Directory of Open Access Journals (Sweden)

Christian Tamburini

Full Text Available The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

Science.gov (United States)

Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Moscoso, Luciano; Motz, Holger; Neff, Max; Nezri, Emma Nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J M; Stolarczyk, Thierry; Taiuti, Mauro G F; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

2013-01-01

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Geochemical records of salt-water inflows into the deep basins of the Baltic Sea

DEFF Research Database (Denmark)

Neumann, T.; Christiansen, C.; Clasen, S.

1997-01-01

The estuarine circulation system of the Baltic Sea promotes stable stratification and bottom water anoxia in sedimentary basins of the Baltic proper. Ingressions of saline, oxygen-rich waters from the North Sea replace the oxygen depleted deep water. Timing and extent of the ingressions vary...... on time-scales of years to decades, and are largely determined by wind-strength and storm frequency over the North Atlantic Ocean and Europe. Mn/Fe-ratios in sediments from a dated sediment core of the Gotland Deep (250 m water depth) record variations in redox conditions that can be linked to historical......-pressure areas over the North Atlantic in more recent times. The last three events have also been observed by hydrographic measurements. During the long time stagnation periods, Fe and Mn will be segregated into a particulate phase (iron sulfide) which accumulates at the seafloor and a dissolved phase (Mn2...

Separating decadal global water cycle variability from sea level rise.

Science.gov (United States)

Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

2017-04-20

Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

Extraction of lithium from sea water with metallic aluminum

International Nuclear Information System (INIS)

Takeuchi, Takeji

1980-01-01

Extraction of lithium from sea water was investigated. It was found that a corrosion product of metallic aluminum immersed in sea water extracts lithium from it selectively. Effects of the temperature and the pH of sea water, and of the initial concentration of lithium in it were examined. On the basis of the analysis of the surface deposit on aluminum, which is a corrosion product of aluminum, the selectivity coefficients were calculated. For the extraction of lithium from natural sea water, the values of K sub(Na)sup(Li), K sub(Mg)sup(Li), K sub(Ca)sup(Li) and K sub(K)sup(Li) were 9.9 x 10 2 , 1.1 x 10, 4.5 x 10 and 4.4 x 10 2 , respectively. (author)

Development of latent fingerprints on non-porous surfaces recovered from fresh and sea water.

Science.gov (United States)

Madkour, Somaya; Abeer Sheta; El Dine, Fatma Badr; Elwakeel, Yasser; AbdAllah, Nermine

2017-01-01

Criminal offenders have a fundamental goal not to leave any traces at the crime scene. Some may suppose that items recovered underwater will have no forensic value, therefore, they try to destroy the traces by throwing items in water. These traces are subjected to the destructive environmental effects. This can represent a challenge for forensic experts investigating fingerprints. The present study was conducted to determine the optimal method for latent fingerprints development on dry non-porous surfaces submerged in aquatic environments at different time interval. The quality of the developed fingerprints depending on the used method was assessed. In addition, two factors were analyzed in this study; the effects of the nature of aquatic environment and the length of submerged time. Therefore, latent fingerprints were deposited on metallic, plastic and glass objects and submerged in fresh and sea water for 1, 2, and 10 days. After recovery, the items were processed by black powder, small particle reagent and cyanoacrylate fuming and the prints were examined. Each print was evaluated according to fingerprint quality assessment scale. Cyanoacrylate developed latent prints found to have the highest mean visibility score after submersion in fresh and sea water for 1, 2 and 10 days. Mean visibility score of prints developed showed significant decline after 10 days of submersion. Prints submerged in fresh water showed significantly higher mean visibility score than those submerged in sea water using various methods of development and in all time intervals. The study demonstrated that it is possible to recover latent prints submerged in water on different studied dry non porous surfaces with the best visualization method using cyanoacrylate either in fresh or sea water. The duration of submersion affects the quality of fingerprints developed; the longer the duration, the worse the quality is. In addition, this study has revealed that the exposure to high salinity i

Sea Water Characterization at Ujung Kulon Coastal Depth as Raw Water Source for Desalination and Potential Energy

Directory of Open Access Journals (Sweden)

Mugisidi Dan

2018-01-01

Full Text Available Fresh water is basic need for life while the source is limited. Therefore, sea water is used as fresh water through desalination process. Sea water has different physical and chemical properties ranging from the surface to the seabed. The energy potential that can be obtained from the hydrostatic pressure also changes according to the depth. As part of the research of the utilization of sea water into fresh water, the aim of this study is to know the characteristics of sea water in the depth that can be utilized as source of fresh water. The sea water samples were taken at 11km from Ujung Kulon beach with depth of 0m, 20m, 40m, 60m, 80m, and 100m under the surface. The results showed that the physical properties at every depth were below the maximum allowable drinking water except for the amount of dissolved solids. Chemical characteristics at any depth above allowable level were fluoride, hardness (CaCo3, chloride, sodium, sulphate, and (KMnO4. In addition to the properties, pressure is one of the considerations in this study to determine the depth of sea water as sources for desalination. Pressure increased by 36.11% as the depth of the sea increased.

Sea Water Characterization at Ujung Kulon Coastal Depth as Raw Water Source for Desalination and Potential Energy

Science.gov (United States)

Mugisidi, Dan; Heriyani, Okatrina

2018-02-01

Fresh water is basic need for life while the source is limited. Therefore, sea water is used as fresh water through desalination process. Sea water has different physical and chemical properties ranging from the surface to the seabed. The energy potential that can be obtained from the hydrostatic pressure also changes according to the depth. As part of the research of the utilization of sea water into fresh water, the aim of this study is to know the characteristics of sea water in the depth that can be utilized as source of fresh water. The sea water samples were taken at 11km from Ujung Kulon beach with depth of 0m, 20m, 40m, 60m, 80m, and 100m under the surface. The results showed that the physical properties at every depth were below the maximum allowable drinking water except for the amount of dissolved solids. Chemical characteristics at any depth above allowable level were fluoride, hardness (CaCo3), chloride, sodium, sulphate, and (KMnO4). In addition to the properties, pressure is one of the considerations in this study to determine the depth of sea water as sources for desalination. Pressure increased by 36.11% as the depth of the sea increased.

Intrusion of low-salinity water into the Yellow Sea Interior in 2012

Science.gov (United States)

Oh, Kyung-Hee; Lee, Joon-Ho; Lee, Seok; Pang, Ig-Chan

2014-12-01

Abnormally low-salinity water was detected in the surface layer of the central region of the Yellow Sea in August 2012. The presence of such low-salinity water in the Yellow Sea interior has never been reported previously. To understand the origin of this low-salinity water, oceanographic and wind data were analyzed, and the circulation of the surface layer was also examined in the Yellow and East China Seas using a numerical ocean model. The results confirmed that typhoons caused the low-salinity water. Two consecutive typhoons passed from east to west across the East China Sea, around the Changjiang Bank in early August 2012. Strong easterly and southeasterly winds created by the typhoons in the Yellow and East China Seas drove the low-salinity water to the north along the coast of China and northeastward toward the central region of the Yellow Sea, respectively. Usually, the northward drifting of Changjiang Diluted Water along the coast of China ends around the Jiangsu coast, where the drifting is blocked and is turned by the offshore Eulerian residual current. Therefore, the Changjiang Diluted Water does not intrude more into the Yellow Sea interior. However, in 2012, the low-salinity water drifted up to the Shandong Peninsula along the coast of China, and formed massive low-salinity water in the Yellow Sea interior combining with the other low-salinity water extended toward the central region of the Yellow Sea directly from the Changjiang Bank. Thus, the typhoons play a key role in the appearance of abnormally low-salinity water in the Yellow Sea interior and it means that the Yellow Sea ecosystem could be significantly influenced by the Changjiang Diluted Water.

A shell-derived time history of bomb 14C on Georges Bank and its Labrador Sea implications

International Nuclear Information System (INIS)

Weidman, C.R.; Jones, G.A.

1993-01-01

Bomb-produced radiocarbon has been used in the past as an important tracer of ocean circulation and as a valuable tool for calculating CO 2 air-sea exchange. However, previous studies of the ocean's time-varying bomb 14 C record have been confined exclusively to analyzing banded corals, and thus their application has been limited to the lower latitudes. The first time history of bomb 14 C from the high-latitude North Atlantic Ocean is obtained from a 54-year-old mollusc specimen, (Bivalvia) Arctica islandica, which was collected live from Georges Bank (41 degrees N) in 1990. The annual growth bands of its shell were analyzed for Δ 14 C using accelerator mass spectrometry, producing a Δ 14 C time history from 1939 to 1990. The depleted condition of the Georges Bank bomb 14 C signal relative to two coral-derived North Atlantic Δ 14 C time histories suggests a significant deepwater source for the waters on Georges Bank. Supported by previous work linking the origin of waters on Georges Bank to the Labrador Sea, the Δ 14 C budget on Georges Bank is modeled as Labrador Sea water, which largely becomes confined to the shelf and partially equilibrates with the atmosphere during a 1-year transit time from the Labrador Sea to Georges Bank. This model is also used to estimate a time history of bomb 14 C for the Labrador Sea. Prebomb Δ 14 C values calculated for the surface Labrador Sea suggest that a greater inventory of bomb 14 C has accumulated here than has previously been reported. Deduced variations in the ventilation and/or 14 CO 2 uptake rates in the Labrador Sea correspond with observed changes in surface salinity of the Labrador Sea, suggesting a reduction in deepwater formation during the late 1960s and 1970s. 59 refs., 11 figs., 2 tabs

Performance of Control System Using Microcontroller for Sea Water Circulation

Science.gov (United States)

Indriani, A.; Witanto, Y.; Pratama, A. S.; Supriyadi; Hendra; Tanjung, A.

2018-02-01

Now a day control system is very important rule for any process. Control system have been used in the automatic system. Automatic system can be seen in the industrial filed, mechanical field, electrical field and etc. In industrial and mechanical field, control system are used for control of motion component such as motor, conveyor, machine, control of process made of product, control of system and soon. In electrical field, control system can met for control of electrical system as equipment or part electrical like fan, rice cooker, refrigerator, air conditioner and etc. Control system are used for control of temperature and circulation gas, air and water. Control system of temperature and circulation of water also can be used for fisher community. Control system can be create by using microcontroller, PLC and other automatic program [1][2]. In this paper we will focus on the close loop system by using microcontroller Arduino Mega to control of temperature and circulation of sea water for fisher community. Performance control system is influenced by control equipment, sensor sensitivity, test condition, environment and others. The temperature sensor is measured using the DS18S20 and the sea water clarity sensor for circulation indicator with turbidity sensor. From the test results indicated that this control system can circulate sea water and maintain the temperature and clarity of seawater in a short time.

Multidecadal variations in the early Holocene outflow of Red Sea Water into the Arabian Sea

NARCIS (Netherlands)

Jung, S.J.A.; Ganssen, G.M.; Davies, G.R.

2001-01-01

We present Holocene stable oxygen isotope data from the deep Arabian Sea off Somalia at a decadal time resolution as a proxy for the history of intermediate/upper deep water. These data show an overall δ18O reduction by 0.5‰ between 10 and ~6.5 kyr B.P. superimposed upon short-term δ18O variations

Sea water Corrosion of Nickel based Plasma Spray Coating

Science.gov (United States)

Parida, M.; Nanda, S. P.; Bhuyan, S. K.; Mishra, S. C.

2018-03-01

Different types of erosion resistant coatings are applied/deposited on aero components, depending on the operating/working temperatures. Nickel based coating are applied on the air craft (compressor) components, which can sustain up to working temperature of 650°C. In the present investigation, to improve the compatibility between substrate (i.e. the machine component) and the top coat, application of bond coat is there. The application of Nickel based coating by thermal plasma spray technique has proven to be a satisfactory means of producing acceptable sealing surface with excellent abradability. Before the corrosion study, coated sample is subjected to hardness, thickness and porosity testing. Hence the result is being evaluated. The corrosion behavior of coating was studied by sea water immersion with a time period of 16 weeks. It is observed that, up to 9 weeks increase in weight of coating occurs in a sharp trend and then takes a decreasing trend. The weight gain of the samples has varied from 37.23% (with one week immersion in sea water) to a maximum of about 64.36% for six weeks immersion. Coating morphology and composition analysis of the coatings are studied using SEM and EDS. This behavior shows adsorption/deposition of the foreign particles with polygonal shape on the coating surface by sea water interaction. Foreign particles with polygonal shape deposited on the coating and with increase in immersion/treatment time, washing out of the deposited materials starts, which reflects the decreasing trend of weight gain of the specimen.

Pronounced anomalies of air, water, ice conditions in the Barents and Kara Seas, and the Sea of Azov

Directory of Open Access Journals (Sweden)

Gennady G. Matishov

2014-06-01

Full Text Available This paper analyses the anomalous hydrometeorological situation that occurred at the beginning of 2012 in the seas of the Russian Arctic and Russian South. Atmospheric blocking in the temperate zone and the extension of the Siberian High to the Iberian Peninsula (known as the Voeikov et al. axis led to a positive anomaly of air and water temperatures and a decrease in the ice extent in the Barents and Kara Seas. At the same time a prolonged negative air temperature anomaly was recorded in central and southern Europe and led to anomalously severe ice conditions in the Sea of Azov. Winter hydrographic conditions in the Barents and Kara Seas are illustrated by a unique set of observations made using expendable bathythermosalinographs (XCTD.

Sedimentary noise and sea levels linked to land-ocean water exchange and obliquity forcing.

Science.gov (United States)

Li, Mingsong; Hinnov, Linda A; Huang, Chunju; Ogg, James G

2018-03-08

In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ 1 ). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

Halocline water formation in the Barents Sea

Science.gov (United States)

Steele, Michael; Morison, James H.; Curtin, Thomas B.

1995-01-01

Hydrographic data from the first phase of the Coordinated Eastern Arctic Experiment (CEAREX) are analyzed. The data consist of temperature and salinity measurements made by a ship-based conductivity-temperature-depth (CTD) instrument and by a drifting SALARGOS buoy. These data were collected in the autumn and early winter of 1988-1989 in the northern Barents Sea, mostly in ice-covered conditions and then across the marginal ice zone (MIZ). The data show that relatively warm, salty water of Atlantic origin is modified by air cooling and ice melting to produce lighter water that has properties identical to (lower) halocline water found in the Arctic Ocean. This occurs mostly at the MIZ and to a lesser degree within the ice pack itself. At the MIZ the halocline water subjects underneath the lighter meltwater that resides directly under the ice pack; geostrophic velocity calculations indicate that it then turns eastward and flows toward the Kara Sea, in keeping with previous chemical tracer analyses. A rough calculation reveals that the amount of halocline water formed in this way in the Barents Sea and Fram Strait is 30-50% of that formed by ice growth in eastern Arctic polynyas.

The collection of uranium from sea water with hydrous metal oxide, 3

International Nuclear Information System (INIS)

Yamashita, Hisao; Nakajima, Fumito; Ozawa, Yoshihiro; Murata, Toshifumi.

1980-01-01

The effect of diverse ions present in sea water on the uranium adsorption is elucidated in the present paper. The uranium-adsorption experiments were conducted using sea water and a solution containing 0.72 mol dm -3 NaCl and 2.3 x 10 -3 mol dm -3 NaHCO 3 . The uranium uptake was about ten times larger from the NaCl-NaHCO 3 solution than from sea water. The ions which depressed the uranium uptake were the calcium, magnesium, and fluoride present in sea water. Among these ions, calcium had the largest effect on the uranium uptake. The analysis of calcium and carbonate in the adsorbent after the adsorption experiment has revealed that the molar ratio between calcium and carbonate was about one. It was considered that calcium carbonate was deposited on the adsorbent during the uranium adsorption. The specific surface area and the pore volume decreased after the deposition of calcium carbonate. It was supposed that the decrease in the uranium uptake was caused by the coverage of the surface of hydrous titanium(IV) oxide with calcium carbonate. Magnesium ions depressed the uranium uptake in the same manner as calcium ions. The effect of the magnesium ions, however, was relatively small compared with that of the calcium ions. (author)

Sources of the deep water masses in the northern Red Sea

OpenAIRE

Said, M.A.

1998-01-01

The hydrographic structure of the northern Red Sea indicated that, the surface waters of temperature around 22°C, salinity of 40.1OO%o and dt = 28.1 might sink to depths between 400-500 m by convective overturn, contributing to the formation of the mid-deep Red Sea waters. Below the 500 db depth down to the bottom the water column is stable. The geostrophic circulation clearly indicated an inflow of water from the Red Sea towards NNW, along the main axis of the sea. Arriving at the nort...

Investigation of different coastal processes in Indonesian waters using SeaWiFS data

Science.gov (United States)

Hendiarti, Nani; Siegel, Herbert; Ohde, Thomas

2004-01-01

SeaWiFS data were applied to investigate coastal processes in Indonesian waters around the most populated island of Java. Coastal processes due to wind forcing were studied the first time using SeaWiFS-derived chlorophyll and TSM concentrations in combination with AVHRR-derived SST in the period from September 1997 to December 2001. Upwelling events were studied along the southern coast of Java during the southeast monsoon (June to September). Satellite-derived chlorophyll concentrations higher than 0.8 mg/ m3 and sea-surface temperatures lower than 28°C are indications of upwelling. Upwelling events influence the distribution and growth of phytoplankton and provide by that good feeding condition for zooplankton, larvae, juvenile and adult of pelagic fish. Coastal discharge into the western Java Sea contains organic and inorganic materials originating from different sources. Diffuse impacts, particularly from fish farms and aquaculture, as well as coastal erosion influence large coastal areas during the rainy season (December to March), and to a lesser extent during the dry season. Strong Citarum river discharge was observed during the transition phase from the rainy to the dry season (March and April), when the maximum amount of transported material reaches the sea. The river plume is evident from chlorophyll concentrations higher than 2.5 mg/ m3, and suspended particulate matter concentrations of more than 8 mg/dm3. The Sunda Strait is seasonally influenced by water transport from the Java Sea and from the Indian Ocean. The satellite data show that water transport from the Java Sea occurs during the pre-dominantly easterly winds period (June to September). This is characterized by warm water (SST higher than 29.5°C) and chlorophyll concentrations higher than 0.5 mg/ m3. This water transport influences the fish abundance in the Sunda Strait. High fish catches coincide with the presence of Java Sea water, while the surface currents lead to the migration of

Hydrology and water resources in Caspian Sea

Science.gov (United States)

Haddadi Moghaddam, Kourosh

2016-10-01

Precipitation is the main driver of the water balance variability of the water over space and time, and changes in precipitation have very important implications for hydrology and water resources. Variations in precipitation over daily, seasonal, annual, and decadal time scales influence hydrological variability over time in a catchment. Flood frequency is affected by changes in the year-to-year variability in precipitation and by changes in short-term rainfall properties. Desiccation of the Caspian Sea is one of the world's most serious ecosystem catastrophes. The Persian Sturgeon (Acipenser persicus) caught under 10 m depth using bottom trawl net by research vessel during winter 2012, summer and winter 2013 and spring 2014 in east, central and west of southern parts of Caspian Sea, then, their diets were investigated. During 136 trawling in the aimed seasons, Persian sturgeon with 1 to 2 years old and 179.67 × 0.2 g (body weight) and 29.97 ± 0.4 cm (Total length) captured. Examination of stomach contents in the sturgeon specimens revealed that the food spectrum was composed of bony fishes (Neogobius sp., Atherina sp. and Clupeonella delicatula), invertebrates belonging to the family Ampharetidae polychaeta worms including (Hypanai sp. and Nereis diversicolor), various crustaceans (Gammarus sp. and Paramysis sp.). Investigation on stomach contents of sturgeon Acipenser persicus caught under 10 m depth in 2012 to 2013 surveys showed that there is significant difference in the consumed food. The most food diversity have been observed in winter 2013, also Polychaeta is the primary consumed food and crustacean is the secondary one (P > 0.05), no new types of food (such as bony fishes or benthics) have been observed on food chain of Acipenser persicus and shows no significant difference (P > 0.05).

Wintertime Arctic Ocean sea water properties and primary marine aerosol concentrations

Directory of Open Access Journals (Sweden)

J. Zábori

2012-11-01

Full Text Available Sea spray aerosols are an important part of the climate system through their direct and indirect effects. Due to the diminishing sea ice, the Arctic Ocean is one of the most rapidly changing sea spray aerosol source areas. However, the influence of these changes on primary particle production is not known.

In laboratory experiments we examined the influence of Arctic Ocean water temperature, salinity, and oxygen saturation on primary particle concentration characteristics. Sea water temperature was identified as the most important of these parameters. A strong decrease in sea spray aerosol production with increasing water temperature was observed for water temperatures between −1°C and 9°C. Aerosol number concentrations decreased from at least 1400 cm⁻³ to 350 cm⁻³. In general, the aerosol number size distribution exhibited a robust shape with one mode close to dry diameter D_p 0.2 μm with approximately 45% of particles at smaller sizes. Changes in sea water temperature did not result in pronounced change of the shape of the aerosol size distribution, only in the magnitude of the concentrations. Our experiments indicate that changes in aerosol emissions are most likely linked to changes of the physical properties of sea water at low temperatures. The observed strong dependence of sea spray aerosol concentrations on sea water temperature, with a large fraction of the emitted particles in the typical cloud condensation nuclei size range, provide strong arguments for a more careful consideration of this effect in climate models.

Sea water pumping-up power plant system combined with nuclear power plant

International Nuclear Information System (INIS)

Ichiki, Tadaharu; Tanaka, Masayuki.

1991-01-01

It is difficult to find a site suitable to construction for a sea water pumping-up power plant at a place relatively near the electric power consumption area. Then, a nuclear power plant is set at the sea bottom or the land portion of a sea shore near the power consumption area. A cavity is excavated underground or at the bottom of the sea in the vicinity of the power plant to form a lower pond, and the bottom of the sea, as an upper pond and the lower pond are connected by a water pressure pipe and a water discharge pipe. A pump water turbine is disposed therebetween, to which electric power generator is connected. In addition, an ordinary or emergency cooling facility in the nuclear power plant is constituted such that sea water in the cavity is supplied by a sea water pump. Accordingly, the sea water pumping-up plant system in combination with the nuclear power plant is constituted with no injuring from salts to animals and plants on land in the suburbs of a large city. The cost for facilities for supplying power from a remote power plant to large city areas and power loss are decreased and stable electric power can be supplied. (N.H.)

Holocene evolution of a drowned melt-water valley in the Danish Wadden Sea

DEFF Research Database (Denmark)

Pedersen, Jørn Bjarke Torp; Svinth, Steffen; Bartholdy, Jesper

2009-01-01

Cores from the salt marshes along the drowned melt-water valley of river Varde Å in the Danish Wadden Sea have been dated and analysed (litho- and biostratigraphically) to reconstruct the Holocene geomorphologic evolution and relative sea level history of the area. The analysed cores cover...... the total post-glacial transgression, and the reconstructed sea level curve represents the first unbroken curve of this kind from the Danish Wadden Sea, including all phases from the time where sea level first reached the Pleistocene substrate of the area. The sea level has been rising from - 12 m below...... the present level at c. 8400 cal yr BP, interrupted by two minor drops of sea level rise, and the Holocene sequence consists in most places of clay atop...

Corrosion and passivation of copper in artificial sea water

International Nuclear Information System (INIS)

Chon, Jung Kyoon; Kim, Youn Kyoo

2007-01-01

Based on the cyclic voltammograms, potentiodynamic polarizations, transient and steady state Tafel plots and electrochemical impedance spectroscopy, we proposed the copper redox mechanism of the corrosion and passivation in artificial sea water. The copper redox mechanism showed the dependence of the concentration of oxygen in artificial sea water and electrode potentials

On the substantion of permissible concentrations of plutonium isotopes in the water of fresh water and sea water NPP cooling reservoirs

International Nuclear Information System (INIS)

Grachev, M.I.; Gusev, D.I.; Stepanova, V.D.

1985-01-01

Substantiation of maximum permissible concentration (PC) of plutonium isotopes ( 238 Pu, 239 Pu, 240 Pu) in fresh and sea water cooling reservoirs of NPP with fast neutron reactors is given. The main criterion when calculating permissible plutonium content in water of surface reservoirs is the requirement not to exceed the established limits for radiation doses to persons resulted from water use. Data on coefficients of plutonium concentration in sea and fresh water hydrobionts are presented as well as on plutonium PC in water of fresh and sea water cooling reservoirs and bottom sediments of sea water cooling reservoirs. It is shown that doses to critical groups of population doesn't exceed potentially hazardous levels due to plutonium intake through food chains. But the calculation being carried out further should be corrected

Optical measurements in the North Sea-Baltic Sea transition zone. I. On the origin of the deep water in the Kattegat

Science.gov (United States)

Højerslev, N. K.; Holt, N.; Aarup, T.

1996-08-01

In the North Sea-Baltic Sea region, several studies have shown that yellow substance can be treated as a quasi-conservative parameter that is negatively correlated with salinity. A review of more than 5000 historic and recently gathered yellow substance absorption and salinity measurements from the transition zone between the North Sea and the Baltic Sea have been analyzed for the purpose of water mass identification. Salinity-yellow substance scatter plots show that three water masses can be identified in the area: (1) North Sea water (high salinity, low yellow substance content); (2) Baltic Sea water (low salinity, intermediate-high yellow substance content); and (3) German Bight/Southern North Sea water (intermediate-high salinity, high yellow substance content). Based on the volume flow estimates used in a two-layer box-model of the Kattegat (Jørgensen, Continental Shelf Research, 12, 103-114, 1992) and conservation of yellow substance, it is argued that the long-term average composition of the bottom layer inflow to the Kattegat from the Skagerrak consists of about 90% North Sea/Atlantic water and 10% German Bight/Southern North Sea water. The German Bight content estimate is substantially lower than the ones given in earlier studies (50-67%) and implies that the Jutland Coastal Current only has a small impact on the water quality of the Kattegat.

Rn 222 in the Black Sea waters

International Nuclear Information System (INIS)

Arbuzova, A.P.; Batrakov, G.F.; Eremeev, V.N.; Zemlyanoj, A.D.; Ivanova, T.M.

1988-01-01

Results of Rn 222 concentration measurements in the Black Sea waters obtained in the summer of 1986 during the expedition of the Akademik Vernadskij research ship are presented. It is ascertained that the intensity of vertical turbulent exchange produces the main effect on Rn 222 distribution in the sea surface waters. The vertical distribution in a 200 m layer is characterized by the growth of concentration with depth, which is caused by the presence of Ra 226 increased concentration region, that coincides with the boundary layer between oxygen and hydrogen sulfide

Water Mass Classification on a Highly Variable Arctic Shelf Region: Origin of Laptev Sea Water Masses and Implications for the Nutrient Budget

Science.gov (United States)

Bauch, D.; Cherniavskaia, E.

2018-03-01

Large gradients and inter annual variations on the Laptev Sea shelf prevent the use of uniform property ranges for a classification of major water masses. The central Laptev Sea is dominated by predominantly marine waters, locally formed polynya waters and riverine summer surface waters. Marine waters enter the central Laptev Sea from the northwestern Laptev Sea shelf and originate from the Kara Sea or the Arctic Ocean halocline. Local polynya waters are formed in the Laptev Sea coastal polynyas. Riverine summer surface waters are formed from Lena river discharge and local melt. We use a principal component analysis (PCA) in order to assess the distribution and importance of water masses within the Laptev Sea. This mathematical method is applied to hydro-chemical summer data sets from the Laptev Sea from five years and allows to define water types based on objective and statistically significant criteria. We argue that the PCA-derived water types are consistent with the Laptev Sea hydrography and indeed represent the major water masses on the central Laptev Sea shelf. Budgets estimated for the thus defined major Laptev Sea water masses indicate that freshwater inflow from the western Laptev Sea is about half or in the same order of magnitude as freshwater stored in locally formed polynya waters. Imported water dominates the nutrient budget in the central Laptev Sea; and only in years with enhanced local polynya activity is the nutrient budget of the locally formed water in the same order as imported nutrients.

Recovery of uranium from sea-water

International Nuclear Information System (INIS)

Llewelyn, G.I.W.

1976-01-01

The possibility of extraction of uranium from sea-water on a sufficiently large scale to contribute significantly to national UK requirements is placed in perspective. It seems unlikely that there are sites around the UK coast where this could be achieved, and insufficient work has been done to be confident that sites exist anywhere to enable uranium extraction to be carried out on a large scale. Process techniques have been developed on a small scale, but extensive further research work would be necessary to reduce appreciably the present uncertainties. It would be unwise to expect uranium from sea-water to contribute significant amounts to the world's uranium demand for thermal reactors on an acceptable timescale. (author)

Seasonal and inter-annual temperature variability in the bottom waters over the Black Sea shelf

Science.gov (United States)

Shapiro, G. I.; Wobus, F.; Aleynik, D. L.

2011-02-01

Long-term changes in the state of the Bottom Shelf Water (BSW) on the Western shelf of the Black Sea are assessed using analysis of intra- and inter-annual variations of temperature as well as their relations to physical parameters of both shelf and deep-sea waters. First, large data sets of in-situ observations over the 20th century are compiled into high-resolution monthly climatology at different depth levels. Then, the temperature anomalies from the climatic mean are calculated and aggregated into spatial compartments and seasonal bins to reveal temporal evolution of the BSW. For the purpose of this study the BSW is defined as such shelf water body between the seabed and the upper mixed layer (bounded by the σθ = 14.2 isopycnal) which has limited ability to mix vertically with oxygen-rich surface waters during the warm season (May-November) due to the formation of a seasonal pycnocline. The effects of atmospheric processes at the surface on the BSW are hence suppressed as well as the action of the "biological pump". The vertical extent of the near- bottom waters is determined based on energy considerations and the structure of the seasonal pycnocline, whilst the horizontal extent is controlled by the shelf break, where strong along-slope currents hinder exchanges with the deep sea. The BSW is shown to occupy nearly half of the area of the shelf during the summer stratification period. The potential of the BSW to ventilate horizontally during the warm season with the deep-sea waters is assessed using isopycnic analysis of temperature variations. A long-term time series of temperature anomalies in the BSW is constructed from observations during the May-November period for the 2nd half of the 20th century. The results reveal a warm phase in the 1960s/70s, followed by cooling of the BSW during 1980-2001. The transition between the warm and cold periods coincides with a regime shift in the Black Sea ecosystem. While it was confirmed that the memory of winter

Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

Directory of Open Access Journals (Sweden)

Roshan GholamReza

2012-12-01

Full Text Available Abstract The rapid rise of Caspian Sea water level (about 2.25 meters since 1978 has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006 and future (2025-2100 time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3. The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21. The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82 between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations.

Science.gov (United States)

Roshan, Gholamreza; Moghbel, Masumeh; Grab, Stefan

2012-12-12

The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006) and future (2025-2100) time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3). The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site) has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21). The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82) between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm) over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm) by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

Wind-driven export of Weddell Sea slope water

Science.gov (United States)

Meijers, A. J. S.; Meredith, M. P.; Abrahamsen, E. P.; Morales Maqueda, M. A.; Jones, D. C.; Naveira Garabato, A. C.

2016-10-01

The export of waters from the Weddell Gyre to lower latitudes is an integral component of the southern subpolar contribution to the three-dimensional oceanic circulation. Here we use more than 20 years of repeat hydrographic data on the continental slope on the northern tip of the Antarctic Peninsula and 5 years of bottom lander data on the slope at 1000 m to show the intermittent presence of a relatively cold, fresh, westward flowing current. This is often bottom-intensified between 600 and 2000 dbar with velocities of over 20 cm s-1, transporting an average of 1.5 ± 1.5 Sv. By comparison with hydrography on the continental slope within the Weddell Sea and modeled tracer release experiments we show that this slope current is an extension of the Antarctic Slope Current that has crossed the South Scotia Ridge west of Orkney Plateau. On monthly to interannual time scales the density of the slope current is negatively correlated (r > 0.6 with a significance of over 95%) with eastward wind stress over the northern Weddell Sea, but lagging it by 6-13 months. This relationship holds in both the high temporal resolution bottom lander time series and the 20+ year annual hydrographic occupations and agrees with Weddell Sea export variability observed further east. We compare several alternative hypotheses for this wind stress/export relationship and find that it is most consistent with wind-driven acceleration of the gyre boundary current, possibly modulated by eddy dynamics, and represents a mechanism by which climatic perturbations can be rapidly transmitted as fluctuations in the supply of intermediate-level waters to lower latitudes.

Contribution of climate-driven change in continental water storage to recent sea-level rise

Science.gov (United States)

Milly, P. C. D.; Cazenave, A.; Gennero, C.

2003-01-01

Using a global model of continental water balance, forced by interannual variations in precipitation and near-surface atmospheric temperature for the period 1981–1998, we estimate the sea-level changes associated with climate-driven changes in storage of water as snowpack, soil water, and ground water; storage in ice sheets and large lakes is not considered. The 1981–1998 trend is estimated to be 0.12 mm/yr, and substantial interannual fluctuations are inferred; for 1993–1998, the trend is 0.25 mm/yr. At the decadal time scale, the terrestrial contribution to eustatic (i.e., induced by mass exchange) sea-level rise is significantly smaller than the estimated steric (i.e., induced by density changes) trend for the same period, but is not negligibly small. In the model the sea-level rise is driven mainly by a downtrend in continental precipitation during the study period, which we believe was generated by natural variability in the climate system. PMID:14576277

Decomposition of dilute residual active chlorine in sea-water

International Nuclear Information System (INIS)

Yoshinaga, Tetsutaro; Kawano, Kentaro; Yanagase, Kenjiro; Shiga, Akira

1985-01-01

Coastal industries such as power stations require enormous quantities of sea-water for cooling, but the marine organisms in it often result in fouling and/or blockade of the circulating water condenser and pipeworks. To prevent this, chlorine, or hypochlorite by the direct electrolysis of sea-water have been added. Environmental concerns, however, dictate that the residual chlorine concentration at the outlet should be less than the regulated value (0.02 ppm). Methods for decomposing dilute residual chlorine solutions were therefore studied. It was found that: 1) The addition of (raw) sea-water to the sea-water which passed through the condenser lowered the residual chlorine concentration to an greater extent than could be expected by dilution only. 2) Ozonation of the residual chlorine solution led to degradation of OCl - , but in solutions with a residual chlorine concentrations of less than 3 -- 4 ppm, ozonation had no effect. 3) Irradiation with ultra violet light (254 nm) decomposed the residual chlorine. Under the present work conditions (25 0 C: pH 8; depth 10 mm), nearly first order kinetics were to hold [da/dt = ksub((1)) (1-a)sup(n)]. There is a proportional relationship between the kinetic constant (k) and illuminous intensity (L), i.e., ksub((1))[C 0 sup(Cl 2 ): 10 ppm] = 6.56 x 10 -5 L (L = 0 -- 1000 lx). Thus, the use of both sea-water addition and UV irradiation provides a probable method for decomposing a residual chlorine to the expected concentration. (author)

Pliocene cooling enhanced by flow of low-salinity Bering Sea water to the Arctic Ocean.

Science.gov (United States)

Horikawa, Keiji; Martin, Ellen E; Basak, Chandranath; Onodera, Jonaotaro; Seki, Osamu; Sakamoto, Tatsuhiko; Ikehara, Minoru; Sakai, Saburo; Kawamura, Kimitaka

2015-06-29

Warming of high northern latitudes in the Pliocene (5.33-2.58 Myr ago) has been linked to the closure of the Central American Seaway and intensification of North Atlantic Deep Water. Subsequent cooling in the late Pliocene may be related to the effects of freshwater input from the Arctic Ocean via the Bering Strait, disrupting North Atlantic Deep Water formation and enhancing sea ice formation. However, the timing of Arctic freshening has not been defined. Here we present neodymium and lead isotope records of detrital sediment from the Bering Sea for the past 4.3 million years. Isotopic data suggest the presence of Alaskan glaciers as far back as 4.2 Myr ago, while diatom and C37:4 alkenone records show a long-term trend towards colder and fresher water in the Bering Sea beginning with the M2 glaciation (3.3 Myr ago). We argue that the introduction of low-salinity Bering Sea water to the Arctic Ocean by 3.3 Myr ago preconditioned the climate system for global cooling.

Evaluation of sea water chlorine demand in condenser cooling water at TAPS 1 and 2

International Nuclear Information System (INIS)

Papachan, Deepa; Gupta, P.K.; Patil, D.P.; Save, C.B.; Anilkumar, K.R.

2008-01-01

To prevent microbiological growth in the condenser tubes, condenser cooling water chlorination is very important. For effective chlorination, chlorine dose rate and frequency of dosing has to be determined on the basis of sea water chlorine demand. TAPS 1 and 2 is located near Arabian sea and draws water from this sea for its condenser cooling. The present practice of chlorine dosing at TAPS 1 and 2, based on the analysis carried out by GE in 1969, is 2500 kg/day/CWpump and 90 kg/day/SSWpump for a contact period of 25 minutes. Normal frequency of dosing is once per 8 hour and booster dose is once in a week at the same rate for 1 hour. The criteria of effective chlorination is to get residual chlorine of 2-3 ppm at the condenser water box outlet during chlorination at water box inlet/CW pump suction header in the recommended dose rate. The other option of chlorination was continuous dosing to get 0.5 ppm residual chlorine. This option has its own limitations as it is more expensive and also that micro organisms get immune to chlorine eventually due to continuous dosing. Nevertheless higher chlorine dosing is detrimental to AI-brass condenser tubes. Therefore the second option was not adopted at TAPS 1 and 2. Tarapur Atomic Power Station-1 is in the process of replacement of condenser tubes due to frequent condenser tube failures in the recent years. It was essential to analyse the present sea water chlorine demand and re-determine the chlorine dose rate because of development of industries under Maharashtra Industrial Development Corporation (MIDC) and simultaneous population growth around this area over a period of three decades. This paper discusses the experimental observations regarding significant change in sea water chlorine demand over this period and the effect of seasonal changes on sea water chlorine demand. (author)

Estimating the Mediterranean Sea Water Budget: impact of RCM design

Science.gov (United States)

Somot, S.; Elguindi, N.; Sanchez-Gomez, E.; Herrmann, M.; Déqué, M.

2009-09-01

The Mediterranean Sea can be considered as a thermodynamic machine that exchanges water and heat with the Atlantic Ocean through the Strait of Gibraltar and with the atmosphere through its surface. Considering the Mediterranean Sea Water Budget (MSWB) multi-year mean, the Mediterranean basin looses water at the surface due to an excess of evaporation over freshwater input (precipitation, river runoff, Black Sea input). Moreover the MSWB largely drives the Mediterranean Sea water mass formation and therefore a large part of its thermohaline circulation. This could even have an impact on the characteristics of the Atlantic thermohaline circulation through the Mediterranean Outflow Waters that flow into the Atlantic at a depth of about 1000 m. From a climate point of view, the MSWB acts as a water source for the Mediterranean countries and therefore plays an important role on the water resources of the region. The regional physical characteristics of the Mediterranean basin (complex orography, strong land-sea contrast, land-atmosphere coupling, air-sea coupling, river inflow, Gibraltar Strait constraint and complex ocean bathymetry) strongly influence the various components of the MSWB. Moreover extreme precipitation events over land and strong evaporation events over the sea due to local winds can play a non-negligible role on the mean MSWB despite their small spatial and temporal scales. Therefore, modelling the mean behaviour, the interannual variability and the trends of the MSWB is a challenging task of the Regional Climate Model community in the context of climate change. It is actually one of the highlighted issues of the HyMex project planned for the 2010-2020 period. We propose here to start investigating some key scientific issues of the regional modelling of the Mediterranean Sea Water Budget using a wide range of regional climate simulations performed at Météo-France or in the framework of FP6 European projects (ENSEMBLES, CIRCE). The addressed

Advective and atmospheric forced changes in heat and fresh water content in the Norwegian Sea, 1951-2010

Science.gov (United States)

Mork, Kjell Arne; Skagseth, Øystein; Ivshin, Victor; Ozhigin, Vladimir; Hughes, Sarah L.; Valdimarsson, Hédinn

2014-09-01

Climate variability in the Norwegian Sea was investigated in terms of ocean heat and fresh water contents of Atlantic water above a reference surface, using hydrographic data during spring 1951-2010. The main processes acting on this variability were examined and then quantified. The area-averaged water mass cooled and freshened, but a deepening of the reference surface resulted in a positive trend in the heat content of 0.3 W m-2. Air-sea heat fluxes explained about half of the interannual variability in heat content. The effect of the advection of Atlantic and Arctic waters on the variability varied with time, apparently due to large-scale changes in the ocean circulation. The data are consistent with the explanation that changing wind patterns caused buffering and then release of Arctic water in the Iceland Sea during the late 1960s to early 1970s, and this caused large hydrographic changes in the Norwegian Sea.

Surfactant control of air-sea gas exchange from North Sea coastal waters and the Atlantic Meridional Transect

Science.gov (United States)

Pereira, R.

2016-02-01

Suppression of gas transfer velocity (kw) by surfactants are well established, both in laboratory wind flumes and purposeful oceanic releases. However, the effects on kw of time and space varying concentrations of natural surfactant are inadequately studied. We have developed an automated gas exchange tank for simultaneous high precision measurement of kw in unmodified seawater samples. Here we present data from two studies along a coastal North Sea transect during 2012-2013 and the Atlantic Meridional Transect (AMT) 24 from September to November 2014. Measurements of surfactant activity (SA), CDOM absorbance and chlorophyll-a have enabled us to characterize the effects of variable amounts of natural surfactant on kw. North Sea coastal waters range in k660 (kw normalized to the value for CO2 in freshwater at 20oC) was 6.8-24.5 cm hr-1 (n=20), with the ranges of SA, total CDOM absorbance (200-450 nm) and chlorophyll-a measured in the surface microlayer (SML) of our seawater samples were 0.08-0.38 mg l-1 T-X-100, 0.13-4.7 and 0.09-1.54 µg l-1, respectively. The AMT k660 ranged from 7.0-23.9 cm hr-1 (n=22), with SA measured in the SML and subsurface water (SSW) of our seawater samples ranging from 0.15-1.08 mg l-1 T-X-100 and 0.07-0.43 mg l-1 T-X-100, respectively. Importantly, we found 12-45% (North Sea) and 1-43% (AMT) k660 suppression relative to Milli-Q water that relate to seasonal and spatial differences in SA. The North Sea demonstrated notable seasonal influences on k660 suppression that were related to CDOM absorbance and chlorophyll-a. The degree of k660 suppression was highest in summer consistent with k660 control by natural surfactant. The degree of k660 suppression decreased with distance offshore in the North Sea and displayed a strong relationship with SA (r2 = 0.51-0.64, p = 0.02, n = 20). The AMT demonstrated notable differences in k660 suppression between hemispheres and across the Longhurst Provinces but the overall relationship between k660

Recent Changes in Land Water Storage and Its Contribution to Sea Level Variations

Science.gov (United States)

Wada, Yoshihide; Reager, John T.; Chao, Benjamin F.; Wang, Jida; Lo, Min-Hui; Song, Chunqiao; Li, Yuwen; Gardner, Alex S.

2016-01-01

Sea level rise is generally attributed to increased ocean heat content and increased rates glacier and ice melt. However, human transformations of Earth's surface have impacted water exchange between land, atmosphere, and ocean, ultimately affecting global sea level variations. Impoundment of water in reservoirs and artificial lakes has reduced the outflow of water to the sea, while river runoff has increased due to groundwater mining, wetland and endorheic lake storage losses, and deforestation. In addition, climate-driven changes in land water stores can have a large impact on global sea level variations over decadal timescales. Here, we review each component of negative and positive land water contribution separately in order to highlight and understand recent changes in land water contribution to sea level variations.

Method of decommissioning nuclear reactor building by utilizing sea water buyoancy

International Nuclear Information System (INIS)

Iwashima, Sumio; Ogoshi, Shigeru; Kobari, Shin-ichi.

1989-01-01

Upon dismantling nuclear reactor buildings, peripheral yards are excavated and channels leading to sea shore are formed. Since the outer walls of the reactor buildings are made of iron-reinforced concretes, the opening poritons are grouted with concretes to attain a tightly such closed structure that radioactive wastes, etc. in the inside are not flown out upon reactor discommisioning. Peripheral buildings at relatively low level of radiation contaminations are dismantled and withdrawn. The fundations of the nuclear reactor buildings were dug out and jacked to separate base rocks and the reactor buildings. Then, sea water is introduced into the water channels to entirely float up the buildings. A water gate is disposed in the water channel on the side of sea shore to control the level of sea water. The buildings are moved and guided to the sea shore and towed to a site optimum as a permanent storage area and then burried in that place. The operation period for the discommissioning work can greatly be shortened and the radiation dose and the amount of the wastes can be reduced. (T.M.)

Microplastics in the Baltic Sea water: fibers everywhere.

Science.gov (United States)

Khatmullina, Lilia; Bagaev, Andrey; Chubarenko, Irina

2017-04-01

Presence of thin synthetic fibres (microfibres, tens of micrometres in diameter) in the surface waters and sediments is documented in different studies; however, the data on their exact abundances in the marine environment are commonly not presented owing to the shortcomings of the sampling procedure and general absence of well-established methodology for microplastics data collection. Nevertheless, we made an attempt to qualitatively analyse the amounts of microplastic fibres in the water column of the Baltic Sea. Water samples acquired during 6 cruises over the Baltic Sea Proper in 2015-2016 were filtered using 174 μm filters, which were subsequently analysed by microscope. From the total of 95 examined filters, 63% contained fibres. They were identified by colour and the reaction to the mechanical action of a thin needle: justification of anthropogenic origin was considered to be enough; any questionable objects were discarded. Fibres comprise more than 90% of the whole microplastic particles found in the near-bottom layers in the coastal zone and around 24% of microplastics in the surface and intermediate waters, with mean concentrations of 0.71 and 0.07 fibres per litre, respectively. Although the methodology still requires a lot of enhancement, even the preliminary results indicate ubiquitous distribution of the microfibres in the water column of the Baltic Sea with surface and bottom layers revealing higher abundances of microfibres in comparison with intermediate layers, and open-sea waters being less contaminated than the coastal ones. Apart from enhancing the sampling technics, we consider that it is crucial to understand principal physical features of fibers behavior in the marine environment (e.g., settling, entrainment by currents), as it would provide an opportunity to parameterize their transport and further on to model distribution of fibers in the water column. The research is supported by the Russian Science Foundation grant number 15-17-10020.

Uptake of uranium from sea water by Synechococcus elongatus

International Nuclear Information System (INIS)

Horikoshi, Takao; Nakajima, Akira; Sakaguchi, Takashi

1979-01-01

Basic features of the uranium uptake by Synechococcus elongatus, and the factors affecting it were examined. Synechococcus elongatus was grown in Roux flasks containing 1 liter of culture solution in light (20,000 lux) and with aeration at 30 deg C. Synechococcus cells in the linear growth phase were collected by centrifugation at 6,000 x g for 5 minutes, washed with sea water, and used for the uranium-uptake experiments. The uptake of uranium from sea water containing 1 ppm of the element was strongly affected by the pH of sea water. The optimum uptake was at pH 5. Presence of carbonate ions markedly inhibited and decarbonation of sea water greatly enhanced the uptake. Absorption of uranium by Synechococcus cells was initially rapid, and reached a plateau within 24 hours. The uranium accumulation capacity of Synechococcus cells was increased by heat treatment, the capacity of scalded cells being about twice as much as that of living cells. Most of the uranium absorbed by Synechococcus was found in the inner space of the cells, and only a small amount was present in the cell walls. (Kaihara, S.)

Modeling caspian sea water level oscilLations Under Diffrent Scenarioes of Increasing Atmospheric Carbon Dioxide Concentrations

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GholamReza Roshan

2012-12-01

Full Text Available The rapid rise of Caspian Sea water level (about 2.25 meters since 1978 has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in thecoastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was stimulated. Variations in environmentalparameters such as temperature, precipitation, evaporation, tmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for bothpast (1951-2006 and future (2025-2100 time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software(version 5.3. The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site has increased by ca. 0.17ºC per decade under the impacts of atmospheric carbon dioxide changes (r=0.21. The Caspian Sea water level has increasedby ca. +36 mm per decade (r=0.82 between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64ºC and precipitation will decrease by ca. 10% (182 mm over the Caspian Sea, whilst in the Volga river basin,temperatures are projected to increase by ca. 4.78ºC and precipitation increase by ca. 12% (58 mm by the year 2100. Finally, statistical modeling of the Caspian Sea water levels projectfuture water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

Corrosion behaviour of non-ferrous metals in sea water

Energy Technology Data Exchange (ETDEWEB)

Birn, Jerzy; Skalski, Igor [Ship Design and Research Centre, Al. Rzeczypospolitej 8, 80-369 Gdansk (Poland)

2004-07-01

The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of alloys are concerned. Contaminants of sea water such as ammonia and hydrogen sulphide are also the cause of common corrosion processes for all copper alloys. Corrosion of copper alloys may be caused also by sulphate reducing bacteria (SRB). Galvanic corrosion caused by a contact with titanium alloys e.g. in plate heat exchangers may cause corrosion of both kinds copper alloys. Bronzes belong to copper alloys of the highest corrosion resistance. Failures that sometimes occur are caused most often by the cavitation erosion, by an incorrect chemical composition of alloys or at last by their inadequate structure. The main problems of aluminium alloys service in sea water are following phenomena: local corrosion (pitting and crevice corrosion), galvanic corrosion, exfoliation and corrosion in the presence of OH- ions. The cause of local corrosion are caused by presence of passive film on the alloy's surface and presence of chlorides in sea water which are able to damage the passive film. Galvanic corrosion is

Determination of uranium in sea and ocean waters by a luminescence method with laser excitation

International Nuclear Information System (INIS)

Preobrazhenskaya, E.B.; Gvgel, E.S.; Stepanov, A.V.

1986-01-01

This paper shows that it is possible to determine uranium insea and ocean waters by a luminescence method with laser excitation. Ocean waters with a low content of luminescent ingredients are analyzed directly by freezing at 77 K to eliminate the quenching effect of the chloride ion. The more polluted waters of inland seas are preferably analyzed at T = 293 K in 1 M H 3 PO 4 after the removal of chloride ions by distillation from a sample containing HNO 3 . The background effect is removed by time selection of the luminescent emission of the uranyl ion. Uranium contents were determined for water from the northwest Atlantic and the North and Baltic Seas

Proposal of a integrated system for the complete usage of sea water

International Nuclear Information System (INIS)

Ohya, Haruhiko; Suzuki, Takashi; Nakao, Shin-ichi; Kato, Shigeru; Tsuji, Masamichi; Sugi, Jiro.

1995-01-01

Very severe troubles of scale formation might be expected to occur when recovery of water from sea water increases. The main constituents of the scale are CaCO 3 , Mg(OH) 2 , CaSO 4 and so on, all of which are salts of alkaline earth metals. Therefore, if a key technology is developed by which the main constituents of the scale, alkaline earth metal ions mentioned above, can be removed and/or separated from sea water, the recovery of desalted water from raw sea water by high-pressure reverse osmosis (HPRO) can be increased up to 75-80%, the solubility limit of the remaining scale components. Then it will be possible to make use of all valuable materials existing in sea water, by an integrated system which combines conventional recovery technologies with a set of the proposed technologies such as HPRO, alkaline earth metal ions removal process, inorganic ion-exchangers for recovery of trace elements and so on. Furthermore, almost complete usage of sea water may be accomplished by irrigation of the brackish water by-product for salt-resistant plants such as mangrove, salt bush and, if possible, gene-recombinated plants. (author)

Application of Low cost Spirulina growth medium using Deep sea water

Science.gov (United States)

Lim, Dae-hack; Kim, Bong-ju; Lee, Sung-jae; Choi, Nag-chul; Park, Cheon-young

2017-04-01

Deep-sea water has a relatively constant temperature, abundant nutrients such as calcium, magnesium, nitrates, and phosphates, etc., and stable water quality, even though there might be some variations of their compositions according to collection places. Thus, deep-sea water would be a good substrate for algal growth and biomass production since it contains various nutrients, including a fluorescent red pigment, and β-carotene, etc. The aim of this study was to investigate the economics of a culture condition through comparative analysis to Spirulina platensis growth characteristic under various medium conditions for cost-effective production of Spirulina sp.. Growth experiments were performed with S. platensis under various culture medium conditions (deep sea water + SP medium). Growth tests for culture medium demonstrated that the deep sea water to SP medium ratio of 50:50(W/W) was effective in S. platensis with the maximum biomass (1.35g/L) and minimum medium making cost per production mass (133.28 KRW/g). Parameter estimation of bio-kinetics (maximum growth rate and yield) for low cost medium results showed that the maximum growth rate and yield of N, P, K were obtained under deep sea water to SP medium ratio of 50:50(W/W) of 0.057 1/day and 0.151, 0.076, 0.123, respectively. Acknowledgment : "This research was a part of the project titled 'Development of microalgae culture technique for cosmetic materials based on ocean deep sea water(20160297)', funded by the Ministry of Oceans and Fisheries, Korea."

Contamination of community water sources by potentially pathogenic vibrios following sea water inundation.

Science.gov (United States)

Kanungo, Reba; Shashikala; Karunasagar, I; Srinivasan, S; Sheela, Devi; Venkatesh, K; Anitha, P

2007-12-01

Potentially pathogenic members of the Vibrionaceae family including Vibrio cholerae and Vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in Southern India. Phenotypic and genotypic studies were done to confirm the identity and detection of toxins. Vibrio-gyr (gyrase B gene) was detected in all sixteen vibrio isolates. Toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not detected in any of the strains, thereby ruling out presence of toxins which could endanger human life. Other potentially pathogenic bacteria Aeromonas and Plesiomonas were also isolated from hand pumps and wells, in a few localities. There was no immediate danger in the form of an outbreak or sporadic gastroenteritis at the time of the study. Timely chlorination and restoration of potable water supply to the flood affected population by governmental and nongovernmental agencies averted waterborne gastroenteritis. Assessment of quality of water and detection of potential virulent organisms is an important public health activity following natural disasters. This work highlights the importance of screening water sources for potentially pathogenic microorganisms after natural disasters to avert outbreaks of gastroenteritis and other infectious diseases.

Anion-exchange enrichment and spectrophotometric determination of uranium in sea-water

International Nuclear Information System (INIS)

Kuroda, Rokuro; Oguma, Koichi; Mukai, Noriko; Iwamoto, Masatoshi

1987-01-01

A method is proposed for the determination of uranium in sea-water. The uranium is strongly sorbed on a strongly basic anion-exchange resin (Cl - form) from acidified sea-water containing sodium azide (0.3M) and is easily eluted with 1M hydrochloric acid. Uranium in the effluent can be determined spectrophotometrically with Arsenazo III. The combined method allows easy and selective determination of uranium in sea-water without using a sophisticated adsorbent. The overall recovery and precision are satisfactory at the 3 μg/1. level. (author)

Anthropogenic radionuclides in sea water

International Nuclear Information System (INIS)

Honda, Teruyuki

1999-01-01

On the basis of data base of IAEA-MEL (International Atomic Energy Agency, Marine Environment Laboratory) and other organizations, the distribution and behavior of anthropogenic radionuclides in sea water, 137 Cs, 90 Sr, 239+240 Pu, 241 Am and 3 H, are explained. 137 Cs (β - , γ: 30.2 y half life) is the most important pollution source and tracer to make clear mixture and diffusion process in seawater. The concentration of 137 Cs in surface seawater of Northern Hemisphere is larger than that of Southern Hemisphere, because many inner space nuclear tests were carried out in the Northern Hemisphere. Especially, the concentration of Northern-east Ocean and Mediterranean Sea are 21 Bq/m 3 and 13 Bq/m 3 , respectively, ten times as much as the other, because of discharge of nuclear fuel reprocessing plants and Chernobyl accident. 2.5 Bq/m 3 137 Cs was observed in North Atlantic Ocean. Behavior of 90 Sr (β - : 29.0 y half life) is the same as 137 Sr in seawater. Secular change of 137 Sr and 90 Sr in seawater in coastal areas of Japan shows decrease of the values from 1964 and reached to 2 to 4 mBq/l and 1 to 3 mBq/l, respectively. 239+240 Pu is the most large load of transuranic elements (TRU) in the earth and originated from nuclear tests. The concentration of 239+240 Pu is 20 to 30 (10 -4 pCi/l, 1968) in the Pacific Ocean and 2.5 to 10.0 μBq/l (1982 to 1993). 241 Am (α: 433 y half life) is generated by decay of 241 Pu. Accordingly, the maximum value is observed after about 100 years. 241 Am/ 239+240 Pu showed less than about 0.3 of fall out, so that emission of 241 Am increases much more than 239+240 Pu. 3 H (β - : 12.3 y half life) has the most short half life in the anthropogenic radionuclides and exists the form as water (HTO) in the sea. The origin of 3 H is hydrogen bomb tests during 1952 and 1975. The concentration of 3 H in sea is average 3.6 TU (1994). The vertical profile of 137 Cs and 90 Sr is similar to each other since both nuclides become ions such

Mixing regime of the residual water basins of the Aral Sea

Science.gov (United States)

Izhitskiy, Alexander; Zavialov, Peter; Kirillin, Georgiy

2017-04-01

The Aral Sea, a terminal salt lake in western Central Asia situated at the border between Uzbekistan and Kazakhstan, was ranked as the fourth largest inland water body in the mid-20th century. However, in the early 1960s, the lake's volume started to decrease rapidly due to severe changes in the Aral's water balance. Thus, the present-day Aral Sea can be considered as a system of separate water bodies with a common origin but very different physical, chemical and biological features. Our previous studies showed that the Large Aral Sea and Lake Tshchebas transformed into hyperhaline water bodies, while the Small Aral Sea was a brackish basin with rather similar to the pre-desiccation environment. On the other hand, the Small Aral Sea and Lake Tshchebas exhibited a mixed vertical structure, whereas the Western Large Aral Sea (especially the Chernyshev Bay) was strongly stratified. The presented study is focused on the seasonal mixing regimes of the residual basins. Isolation of deep waters from the atmosphere together with low rates of photosynthesis produce deep anoxia observed in the Chernyshev Bay and in the Large Aral. The high amount of organic matter provides a rich source of nutrients for anoxic microorganisms favoring methanogenesis in the bottom layer of the basins. In the Small Aral, the water column remains well-oxygenated down to the bottom throughout most of the year and development of anoxia is unlikely. The mixing regimes of the recently formed residual lakes of the former Aral Sea will provide manifold effect on the ongoing development of the aquatic system in the following decades. The study is based on a field data collected during two surveys of Shirshov Institute of Oceanology to the Aral Sea, which took place in October, 2015 and June, 2016. In situ measurements including CTD profiling and water sampling were carried out in the northern extremity of the western Large Aral (the Chernyshev Bay), in Lake Tshchebas, and in the Small Aral Sea

Chemical analysis of useful trace elements in sea water

International Nuclear Information System (INIS)

Katoh, Shunsaku; Fujii, Ayako; Miyai, Yoshitaka; Sakane, Kohji; Ogata, Noboru.

1983-01-01

The methods for the analysis of useful trace elements in sea water which have been tried so far are reviewed, and these methods are described briefly from the standpoint of studying the collection of resources. Ag and Au can be determined by concentrating sea water by ion-exchange method, solvent extraction method and electrodeposition method, then the elements are measured quantitatively by activation analysis and atomic absorption spectrochemical analysis. Sr, B and Li, which exist in relatively high concentration in sea water, are determined easily by atomic absorption spectrochemical analysis and absorption spectrometry. U, Mo and V are measured suitably by concentrating the elements by coprecipitation or solvent extraction method, and measuring by fluorescence analysis and arsenazo-3 method for U and through graphite-atomic absorption analysis for Mo and V. It has been revealed that the concentration of Ag and Au in sea water is extremely low, accordingly the recovery study is not conducted recently. On the other hand, the adsorption method using hydrated titanium oxide and amidoxim adsorbents for U, Mo and V, the adsorption method using aluminum adsorbent for Li, and the adsorption method using magnesium oxide and zirconium hydroxide and the solvent extraction method for B are hopeful to recover these elements. (Yoshitake, I.)

The Change in Black Sea Water Composition and Hydrology during Deglaciation from Multiproxy Reconstructions

Science.gov (United States)

Yanchilina, A.; Ryan, W. B. F.; McManus, J. F.

2014-12-01

This study presents a reconstruction of changes in the water column from the last glacial into the early Holocene using stable isotope, 87Sr/86Sr, 14C, and trace element ratios from mollusks from the shelf area and ostracods from the basin of the Black Sea. The stable isotope record is compared to a thoroughly U/Th dated terrestrial stable isotope record of a nearby cave, Sofular cave in northwestern Turkey. The combination of deep, surface, and terrestrial signals gives valuable insight towards the behavior of the lake water during the deglaciation in multiple dimensions, specifically the water column stratification and hydrological dynamics. The comparison of the stable isotope records of two independent proxies allows to make inferences on the changes in the 14C reservoir of the Black Sea-Lake. Results show that during the glacial period, water from the Black Sea-Lake was outflowing to the Sea of Marmara but the ventilation of the water column was weak as old 14C was not removed and allowed to accumulate giving the lake a large 14C reservoir age. A deglacial pulse of meltwater released from the Eurasian Fennoscandian pro-glacial lakes increased ventilation of the water column. This is seen in lighter δ18O and a spike in radiogenic 87Sr/86Sr in both deep and shallow parts of the water column. The dynamic ventilation and outflow of water into the Sea of Marmara continued until the onset of the Bolling/Allerod as the radiogenic 87Sr/86Sr was almost completely flushed out in a couple hundred years time. During the Bolling/Allerod and Preboreal warming, δ18O got heavier whereas the 87Sr/86Sr stayed constant and the 14C again accumulated and contributed to an older reservoir age. The Younger Dryas period, sandwiched in between the two warming periods, shows a return to glacial conditions in the δ13C and that the water outflowed to the Sea of Marmara as the δ18O only showed a slight change towards a more heavy value.

Estimation of ultratrace level of uranium in sea water by laser fluorimeter

International Nuclear Information System (INIS)

Sahoo, S.K.; Tripathi, R.M.; Mohapatra, S.; Patra, A.C.; Lenka, P.; Puranik, V.D.

2010-01-01

Full text: Uranium, a naturally occurring primordial radionuclide, is imperative in the present Indian Nuclear Power Programme. Seawater may be an alternate source of uranium to meet the future demand. The total estimated quantity of uranium in seawater is around four and a half billion tonnes. Estimation of uranium in sea water is cumbersome and tedious because of ultra-trace concentration of uranium with high salt content and other interfering elements of sea water. Mainly chloride interferes in sea water analysis for estimation of nanogram level uranium because the ion at high concentration in sea water depresses uranyl complex fluorescence. At 500 ppm of chloride, the fluorescence response from a given uranium level is reduced by nearly 50%. Dilution method may be used in order to minimize the interference effect but it can't be implemented in this case as sea water contains 19000 ppm chloride but only 2-3 ppb of uranium. Thus, the separation of the interfering elements is necessary to analyze nanogram level of uranium in sea water. In the present study, an attempt has been made to analyze uranium in sea water by laser fluorimeter. Sample was treated with potassium persulphate to remove chloride ion and subsequent measurement was carried out after pH adjustment. The method was used for analysis of uranium content in 23 seawater samples ranged from 0.2 ± 0.1 μg/l to 2.2 ± 0.4 μg/l with a mean value of 1.01 ± 0.11 μg/l

Modeling the buoyancy-driven Black Sea Water outflow into the North Aegean Sea

Directory of Open Access Journals (Sweden)

Nikolaos Kokkos

2016-04-01

Full Text Available A three-dimensional numerical model was applied to simulate the Black Sea Water (BSW outflux and spreading over the North Aegean Sea, and its impact on circulation and stratification–mixing dynamics. Model results were validated against satellite-derived sea surface temperature and in-situ temperature and salinity profiles. Further, the model results were post-processed in terms of the potential energy anomaly, ϕ, analyzing the factors contributing to its change. It occurs that BSW contributes significantly on the Thracian Sea water column stratification, but its signal reduces in the rest of the North Aegean Sea. The BSW buoyancy flux contributed to the change of ϕ in the Thracian Sea by 1.23 × 10−3 W m−3 in the winter and 7.9 × 10−4 W m−3 in the summer, significantly higher than the corresponding solar heat flux contribution (1.41 × 10−5 W m−3 and 7.4 × 10−5 W m−3, respectively. Quantification of the ϕ-advective term crossing the north-western BSW branch (to the north of Lemnos Island, depicted a strong non-linear relation to the relative vorticity of Samothraki Anticyclone. Similar analysis for the south-western branch illustrated a relationship between the ϕ-advective term sign and the relative vorticity in the Sporades system. The ϕ-mixing term increases its significance under strong winds (>15 m s−1, tending to destroy surface meso-scale eddies.

Spectral analysis of optical emission of microplasma in sea water

Science.gov (United States)

Gamaleev, Vladislav; Morita, Hayato; Oh, Jun-Seok; Furuta, Hiroshi; Hatta, Akimitsu

2016-09-01

This work presents an analysis of optical emission spectra from microplasma in three types of liquid, namely artificial sea water composed of 10 typical agents (10ASW), reference solutions each containing a single agent (NaCl, MgCl2 + H2O, Na2SO4, CaCl2, KCl, NaHCO3, KBr, NaHCO3, H3BO3, SrCl2 + H2O, NaF) and naturally sampled deep sea water (DSW). Microplasma was operated using a needle(Pd)-to-plate(Pt) electrode system sunk into each liquid in a quartz cuvette. The radius of the tip of the needle was 50 μm and the gap between the electrodes was set at 20 μm. An inpulse generator circuit, consisting of a MOSFET switch, a capacitor, an inductor and the resistance of the liquid between the electrodes, was used as a pulse current source for operation of discharges. In the spectra, the emission peaks for the main components of sea water and contaminants from the electrodes were detected. Spectra for reference solutions were examined to enable the identification of unassigned peaks in the spectra for sea water. Analysis of the Stark broadening of H α peak was carried out to estimate the electron density of the plasma under various conditions. The characteristics of microplasma discharge in sea water and the analysis of the optical emission spectra will be presented. This work was supported by JSPS KAKENHI Grant Number 26600129.

Continuous Flow of Upper Labrador Sea Water around Cape Hatteras.

Science.gov (United States)

Andres, Magdalena; Muglia, Mike; Bahr, Frank; Bane, John

2018-03-14

Six velocity sections straddling Cape Hatteras show a deep counterflow rounding the Cape wedged beneath the poleward flowing Gulf Stream and the continental slope. This counterflow is likely the upper part of the equatorward-flowing Deep Western Boundary Current (DWBC). Hydrographic data suggest that the equatorward flow sampled by the shipboard 38 kHz ADCP comprises the Upper Labrador Sea Water (ULSW) layer and top of the Classical Labrador Sea Water (CLSW) layer. Continuous DWBC flow around the Cape implied by the closely-spaced velocity sections here is also corroborated by the trajectory of an Argo float. These findings contrast with previous studies based on floats and tracers in which the lightest DWBC constituents did not follow the boundary to cross under the Gulf Stream at Cape Hatteras but were diverted into the interior as the DWBC encountered the Gulf Stream in the crossover region. Additionally, our six quasi-synoptic velocity sections confirm that the Gulf Stream intensified markedly at that time as it approached the separation point and flowed into deeper waters. Downstream increases were observed not only in the poleward transport across the sections but also in the current's maximum speed.

Contaminants of emerging concern in the open sea waters of the Western Mediterranean

International Nuclear Information System (INIS)

Brumovský, Miroslav; Bečanová, Jitka; Kohoutek, Jiří; Borghini, Mireno; Nizzetto, Luca

2017-01-01

Pollution by chemical substances is of concern for the maintenance of healthy and sustainable aquatic environments. While the occurrence and fate of numerous emerging contaminants, especially pharmaceuticals, is well documented in freshwater, their occurrence and behavior in coastal and marine waters is much less studied and understood. This study investigates the occurrence of 58 chemicals in the open surface water of the Western Mediterranean Sea for the first time. 70 samples in total were collected in 10 different sampling areas. 3 pesticides, 11 pharmaceuticals and personal care products and 2 artificial sweeteners were detected at sub-ng to ng/L levels. Among them, the herbicide terbuthylazine, the pharmaceuticals caffeine, carbamazepine, naproxen and paracetamol, the antibiotic sulfamethoxazole, the antibacterial triclocarban and the two artificial sweeteners acesulfame and saccharin were detected in all samples. The compound detected at the highest concentration was saccharin (up to 5.23 ng/L). Generally small spatial differences among individual sampling areas point to a diffuse character of sources which are likely dominated by WWTP effluents and runoffs from agricultural areas or even, at least for pharmaceuticals and artificial food additives, from offshore sources such as ferries and cruising ships. The implications of the ubiquitous presence in the open sea of chemicals that are bio-active or toxic at low doses on photosynthetic organisms and/or bacteria (i.e., terbuthylazine, sulfamethoxazole or triclocarban) deserve scientific attention, especially concerning possible subtle impacts from chronic exposure of pelagic microorganisms. - Highlights: • First report on several classes of emerging contaminants in the open Mediterranean Sea. • 3 pesticides, 11 PPCPs and 2 artificial sweeteners detected in the surface marine water. • Saccharin, naproxen and DEET detected at the highest concentrations. • Spatial distribution independent of distance

On the variability of sea drag in finite water depth

Science.gov (United States)

Toffoli, A.; Loffredo, L.; Le Roy, P.; LefèVre, J.-M.; Babanin, A. V.

2012-11-01

The coupling between the atmospheric boundary layer and the ocean surface in large-scale models is usually parameterized in terms of the sea drag coefficient, which is routinely estimated as a function of mean wind speed. The scatter of data around such parametric dependencies, however, is very significant and imposes a serious limitation on the forecasts and predictions that make use of sea surface drag parameterizations. The analysis of an atmospheric and wave data set collected in finite water depth at the Lake George measurement site (Australia) suggests that this variability relates to a number of parameters at the air-sea interface other than wind speed alone. In particular, results indicate that the sea drag depends on water depth and wave steepness, which make the wave profile more vertically asymmetric, and the concentration of water vapor in the air, which modifies air density and friction velocity. These dependencies are used to derive parametric functions based on the combined contribution of wind, waves and relative humidity. A standard statistical analysis confirms a substantial improvement in the prediction of the drag coefficient and sea surface roughness when additional parameters are taken into account.

The distribution of artificial radionuclides in the waters of the Norwegian-Greenland Sea in 1985

International Nuclear Information System (INIS)

Wedekind, C.; Gabriel, H.; Goroncy, I.; Framcke, G.

1997-01-01

In the summer of 1985, sea water samples were taken to determine 3 H, 90 Sr, 134 Cs, 137 Cs and transuranics within a grid of 165 stations including 16 depth series down to the seafloor, covering all ice-free areas. The distribution of the activity concentrations and the nuclide ratios reveal the contamination pathway into the surface and deeper layers of the Norwegian-Greenland Sea from nuclear weapon fallout and civil nuclear technology. Moreover, the investigations show that: (1) a yearly discharge of 1 TBq (10 12 Bq) 90 Sr into the Irish Sea (English Channel) is diluted on its way to the southern Norwegian Sea, raising the concentration by about 0.04 m Bql -1 ; (2) the drift time to this sea area is around 4 years; (3) about 40% of the 137 Cs discharged does not reach the Norwegian Sea and (4) a further 30% leaves the Norwegian-Greenland Sea via the North Cape and flows into the Barents Sea. Investigations into the vertical distribution and stratification of the radioactivity indicate the time scale on which the radionuclides travel to the deeper layers. (author)

Relative Sea Level, Tidal Range, and Extreme Water Levels in Boston Harbor from 1825 to 2016

Science.gov (United States)

Talke, S. A.; Kemp, A.; Woodruff, J. D.

2017-12-01

Long time series of water-level measurements made by tide gauges provide a rich and valuable observational history of relative sea-level change, the frequency and height of extreme water levels and evolving tidal regimes. However, relatively few locations have available tide-gauge records longer than 100 years and most of these places are in northern Europe. This spatio-temporal distribution hinders efforts to understand global-, regional- and local-scale trends. Using newly-discovered archival measurements, we constructed a 200 year, instrumental record of water levels, tides, and storm surges in Boston Harbor. We detail the recovery, datum reconstruction, digitization, quality assurance, and analysis of this extended observational record. Local, decadally-averaged relative sea-level rose by 0.28 ± 0.05 m since the 1820s, with an acceleration of 0.023 ±0.009 mm/yr2. Approximately 0.13 ± 0.02 m of the observed RSL rise occurred due to ongoing glacial isostatic adjustment, and the remainder occurred due to changes in ocean mass and volume associated with the onset of modern mean sea-level rise. Change-point analysis of the new relative sea level record confirms that anthropogenic rise began in 1924-1932, which is in agreement with global mean sea level estimates from the global tide gauge network. Tide range decreased by 5.5% between 1830 and 1910, likely due in large part to anthropogenic development. Storm tides in Boston Harbor are produced primarily by extratropical storms during the November-April time frame. The three largest storm tides occurred in 1851, 1909, and 1978. Because 90% of the top 20 storm tides since 1825 occurred during a spring tide, the secular change in tide range contributes to a slight reduction in storm tide magnitudes. However, non-stationarity in storm hazard was historically driven primarily by local relative sea-level rise; a modest 0.2 m increase in relative sea level reduces the 100 year high water mark to a once-in-10 year event.

Microphysical and chemical characteristics of near-water aerosol over White and Kara Seas

Science.gov (United States)

Terpugova, S. A.; Polkin, V. V.; Panchenko, M. V.; Golobokova, L. P.; Kozlov, V. S.; Shmargunov, V. P.; Shevchenko, V. P.; Lisitzin, A. P.

2009-04-01

The results are presented of five-year-long (2003-2007) study of the spatial - temporal variability of the near-water aerosol in the water area of White and Kara Seas (55, 64, 71 and 80-th cruises of RV "Professor Shtockman"; 53 and 54-th cruises of RV "Akademik Mstislav Keldysh"). Measurements of aerosol microphysical characteristics were carried out by means of the automated mobile aerosol complex consisting of nephelometer, photoelectric counter and aethalometer. The aerosol disperse composition was studied with photoelectric counter in 256 size intervals from 0.4 to 10 m. About 1500 series of measurements were carried out in White Sea, and about 1400 series in Kara Sea. Chemical characteristics of aerosol were determined from samples collected on aerosol filters (92 samples were collected in White Sea and 48 in Kara Sea). The ion composition was determined under laboratory conditions. The H+, Na+, K+, Ca2+, Mg2+, NH4+, Cl-, NO3-, HCO3-, SO42- ions were under examination. Comparing aerosol characteristics of two seas, one can note that the mean values of the aerosol content parameters in Kara Sea are less than in White Sea. The ratio of the aerosol mass concentration are from 2 (Yamal Peninsula, northern part of Novaya Zemlya) to 9 times (Blagopoluchia Bay, Ob' Gulf). The differences in the concentration of black carbon vary from 3 (Yamal Peninsula) to 17 times (Blagopoluchia Bay). The differences in the aerosol number concentration NA are not so big. The values NA near Kara Gate, Yamal Peninsula and northern part of Novaya Zemlya are practically the same as in White Sea. The concentration NA at Ob' gulf is one order of magnitude less than in White sea. The obtained aerosol volume size distributions were approximated by the sums of two fractions, submicron and coarse, with lognormal size distributions. The mean volume size distribution of submicron fraction in White Sea is approximated by the distribution with the variance of the radius logarithm s=0.6 and modal

Speciation of 137Cs in the Baltic sea water

International Nuclear Information System (INIS)

Lujaniene, G.; Morkuniene, R.; Styra, D.

1998-01-01

A possibility of application of Filtrac 391 and Nuclepore filters, Ky-2-8-C exchanger and the Mtilon-T fiber impregnated with Fe, Co, Ni ferrocyanides for separation of particulate and ionic 137 Cs in the sea water was investigated. Physico-chemical forms of 137 Cs were investigated in the Baltic Sea water during 1995-1997. It was determined that 137 Cs was mainly present in ionic form (62-93 %) both in the near-shore and open waters. Concentration of particulate 137 Cs ranged from 255 to 625 Bq/kg (dry weight).The distribution coefficient (K d ) of radiocaesium reached values of 2100-9700. (author)

Effect of multiple freeze-thaw cycles on the quality of instant sea cucumber: Emphatically on water status of by LF-NMR and MRI.

Science.gov (United States)

Tan, Mingqian; Lin, Zhuyi; Zu, Yinxue; Zhu, Beiwei; Cheng, Shasha

2018-07-01

Instant sea cucumber has become one popular product due to its convenience to eat, favourable taste and minimal loss of nutrients and bioactive components. However, there was rare information about the water dynamic of instant sea cucumber subjected to multiple freeze-thaw cycles. In this study, low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance image (MRI) were employed to investigate the effect of freeze-thaw cycles on water status of instant sea cucumber. Four water populations corresponding to strongly bound water, weakly bound water, immobile water and free water were observed in instant sea cucumber. With the increase of freeze-thaw cycles, the transverse relaxation time of immobile and free water increased, while the peak area of free water decreased significantly. MRI enabled the visualization of water migration of instant sea cucumber during multiple freeze-thaw cycles. Multiple freeze-thaw cycles also led to significant changes of other quality properties including thawing loss, WHC, color parameters, texture and protein content, and enlarge the interspace between fiber network in microstructure. Good correlations between T 22 , A 22 , A 23 and thaw loss, WHC, L*, hardness and collagen content (0.873 ≤ r ≤ 0.958) revealed LF-NMR may be an effective real-time monitoring method of these physicochemical parameters as a non-destructive technique. Copyright © 2018 Elsevier Ltd. All rights reserved.

Seasonal and inter-annual temperature variability in the bottom waters over the western Black Sea shelf

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G. I. Shapiro

2011-09-01

Full Text Available Long-term changes in the state of the Bottom Shelf Water (BSW on the Western shelf of the Black Sea are assessed using analysis of intra-seasonal and inter-annual temperature variations. For the purpose of this study the BSW is defined as such shelf water mass between the seabed and the upper mixed layer (bounded by the σ_θ = 14.2 isopycnal which has limited ability to mix vertically with oxygen-rich surface waters during the warm season due to formation of a seasonal pycnocline. A long-term time series of temperature anomalies in the BSW is constructed from in-situ observations taken over the 2nd half of the 20th century. The BSW is shown to occupy nearly half of the shelf area during the summer stratification period (May–November.The results reveal a warm phase in the 1960s/70s, followed by a cold phase between 1985 and 1995 and a further warming after 1995. The transition between the warm and cold periods coincides with a regime shift in the Black Sea ecosystem. While it was confirmed that the memory of winter convection is well preserved over the following months in the deep sea, the signal of winter cooling in the BSW significantly reduces during the warm season. The potential of the BSW to ventilate horizontally during the warm season with the deep-sea waters is assessed using isopycnic analysis of temperature variations. It is shown that temperature in the BSW is stronger correlated with the temperature of Cold Intermediate Waters (CIW in the deep sea than with the severity of the previous winters, thus indicating that the isopycnal exchanges with the deep sea are more important for inter-annual/inter-decadal variability of the BSW on the western Black Sea shelf than effects of winter convection on the shelf itself.

Climatology and decadal variability of the Ross Sea shelf waters

Directory of Open Access Journals (Sweden)

A. Russo

2011-06-01

Full Text Available The World Ocean Database 2001 data located in the Ross Sea (named WOD01 and containing data in this region since 1928 are merged with recent data collected by the Italian expeditions (CLIMA dataset in the period November 1994-February 2004 in the same area. From this extended dataset, austral summer climatologies of the main Ross Sea subsurface, intermediate and bottom water masses: High Salinity Shelf Water (HSSW, Low Salinity Shelf Water (LSSW, Ice Shelf Water (ISW and Modified Circumpolar Deep Water (MCDW have been drawn. The comparison between the WOD01_1994 climatologies (a subset of the WOD01 dataset until April 1994 and the CLIMA ones for the period 1994/95-2003/04 showed significant changes occurred during the decade. The freshening of the Ross Sea shelf waters which occurred during the period 1960-2000, was confirmed by our analysis in all the main water masses, even though with a spatially varying intensity. Relevant variations were found for the MCDW masses, which appeared to reduce their presence and to deepen; this can be ascribed to the very limited freshening of the MCDW core, which allowed an increased density with respect to the surrounding waters. Variations in the MCDW properties and extension could have relevant consequences, e.g. a decreased Ross Ice Shelf basal melting or a reduced supply of nutrients, and may also be indicative of a reduced thermohaline circulation within the Ross Sea. Shelf Waters (SW having neutral density γn > 28.7 Kg m-3, which contribute to form the densest Antarctic Bottom Waters (AABW, showed a large volumetric decrease in the 1994/95-2003/04 decade, most likely as a consequence of the SW freshening.

Salinization and dilution history of ground water discharging into the Sea of Galilee, the Dead Sea Transform, Israel

International Nuclear Information System (INIS)

Bergelson, G.; Nativ, R.; Bein, A.

1999-01-01

The mechanism governing salinization of ground water discharging into the Sea of Galilee in Israel has been the subject of debate for several decades. Because the lake provides 25% of the water consumed annually in Israel, correct identification of the salt sources is essential for the establishment of suitable water-management strategies for the lake and the ground water in the surrounding aquifers. Existing salinization models were evaluated in light of available and newly acquired data including general chemistry, and O, H, C and Cl isotopes. Based on the chemical and isotopic observations, the proposed salt source is an ancient, intensively evaporated brine (21- to 33-fold seawater) which percolated through the valley formations from a lake which had formed in the Rift Valley following seawater intrusion during the late Miocene. Low Na:Cl and high Br:Cl values support the extensive evaporation, whereas high Ca:Cl and low Mg:Cl values indicate the impact of dolomitization of the carbonate host rock on the residual solution. Based on radiocarbon and other isotope data, the dilution of the original brine occurred in two stages: the first took place similar30andpuncsp; omitted000 a ago by slightly evaporated fresh-to-brackish lake water to form the Sea of Galilee Brine. The second dilution phase is associated with the current hydrological regime as the Sea of Galilee Brine migrates upward along the Rift faults and mixes with the actively circulating fresh ground water to form the saline springs. The spatially variable chemical and isotopic features of the saline springs suggest not only differential dilution by fresh meteoric water, but also differential percolation timing of the original brine into the tectonically disconnected blocks, registering different evaporation stages in the original brine. Consequently, various operations to reduce the brine contribution to the lake may be differentially effective in the various areas. (Copyright (c) 1999 Elsevier Science

Isolation and identification of radiation resistant yeasts from sea water

International Nuclear Information System (INIS)

Park, Jong Cheon; Jeong, Yong Uk; Kim, Du Hong; Jo, Eun A

2011-12-01

This study was conducted to isolate radiation-resistant yeasts from sea water for development of application technology of radiation-resistant microorganism. · Isolation of 656 yeasts from sea water and selection of 2 radiation-resistant yeasts (D 10 value >3) · Identification of isolated yeasts as Filobasidium elegans sharing 99% sequence similarity · Characterization of isolated yeast with ability to repair of the DNA damage and membrane integrity to irradiation

Practical Application of Sea Water Quality Mathematical Model for the Black Sea Coast of Sochi

Directory of Open Access Journals (Sweden)

Oleg A. Burunin

2013-01-01

Full Text Available The article deals with an application of the developed model of the sea water quality for forecasting of coastal waters indicators change in the artificial coastal water areas of Sochi. Results of the researches conducted in relation to yacht port «Grand Marina Sochi» are considered.

Antibiotics in the offshore waters of the Bohai Sea and the Yellow Sea in China: Occurrence, distribution and ecological risks

International Nuclear Information System (INIS)

Zhang, Ruijie; Tang, Jianhui; Li, Jun; Zheng, Qian; Liu, Di; Chen, Yingjun; Zou, Yongde; Chen, Xiaoxiang; Luo, Chunling; Zhang, Gan

2013-01-01

The ocean is an important sink of land-based pollutants. Previous studies showed that serious antibiotic pollution occurred in the coastal waters, but limited studies focused on their presence in offshore waters. In this study, eleven antibiotics in three different categories were investigated in offshore waters of the Bohai Sea and the Yellow Sea in China. The results indicated that three antibiotics dehydration erythromycin, sulfamethoxazole and trimethoprim occurred throughout the offshore waters at concentrations of 0.10–16.6 ng L −1 and they decreased exponentially from the rivers to the coastal and offshore waters. The other antibiotics all presented very low detection rates ( −1 ). Although the concentrations were very low, risk assessment based on the calculated risk quotients (RQs) showed that sulfamethoxazole, dehydration erythromycin and clarithromycin at most of sampling sites posed medium or low ecological risks (0.01 −1 . ► Their concentrations decreased exponentially from the rivers to the offshore waters. ► Some antibiotics in the offshore water posed medium or low risks to some organisms. -- Some antibiotics were ubiquitous in the offshore waters of the Bohai Sea and the Yellow Sea in China and posed medium or low ecological risks to some sensitive organisms

The methods of cesium-137 determination in sea water

International Nuclear Information System (INIS)

Gedeonov, L.I.; Krylov, V.N.; Stepanov, A.V.

1978-01-01

New express procedures of Cs-137 determination in sea water using selective sorbents are described. One of them is based on the use of natural radioactive potassium-40 as internal standard. Another one allows to perform Cs-137 determination without use of any standards, by pumping a certain amount of water through several successive identical cells filled with sorbent. The positive feature of the procedures consists in that it is no longer necessary chemical treatment of samples in Cs-133 determination in the sorbent and sea water. The danger of polution of samples by alkali metals which can be introduced with reactive agents in the process of chemical treatment is reduced to minimum

Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

International Nuclear Information System (INIS)

Watanabe, Y.W.

1997-01-01

Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO 2 in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO 2 released from human activities after the industrial era. (author)

Behaviors of sea water studied with chemical transient tracers. Lecture by the member awarded the Okada prize of the Oceanographic Society of Japan for 1996

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Y.W. [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

1997-02-01

Chemical tracers are useful tools for clarifying the behaviors of sea water in the ocean. The present article reviews my works concerning chemical tracers. Based on my chemical tracers data, it was concluded that the turnover time of the Japan Sea deep water and the residence time of water within the Japan Sea were about 100 years and 1000 years, respectively, and that the exchange coefficient of CO{sub 2} in the Japan Sea was smaller than that in the North Pacific. Furthermore, chemical tracers and carbonate species data set in the North Pacific suggested that the production rate of intermediate water in the North Pacific was about 24 Sv and that the North Pacific subpolar region was an important sink of CO{sub 2} released from human activities after the industrial era. (author)

Origin and residence time of water in the Lima aquifer

International Nuclear Information System (INIS)

Montoya, Modesto; Mamani, Enoc

2013-01-01

The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of 2 H and 18 O are used to identify the origins of the waters from those wells, and the 3 H and 14 C contents are used to estimate the time after they fall as rain. (authors).

Microbial and chemical characterization of underwater fresh water springs in the Dead Sea.

Directory of Open Access Journals (Sweden)

Danny Ionescu

Full Text Available Due to its extreme salinity and high Mg concentration the Dead Sea is characterized by a very low density of cells most of which are Archaea. We discovered several underwater fresh to brackish water springs in the Dead Sea harboring dense microbial communities. We provide the first characterization of these communities, discuss their possible origin, hydrochemical environment, energetic resources and the putative biogeochemical pathways they are mediating. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods showed that the spring community originates from the Dead Sea sediments and not from the aquifer. Furthermore, it suggested that there is a dense Archaeal community in the shoreline pore water of the lake. Sequences of bacterial sulfate reducers, nitrifiers iron oxidizers and iron reducers were identified as well. Analysis of white and green biofilms suggested that sulfide oxidation through chemolitotrophy and phototrophy is highly significant. Hyperspectral analysis showed a tight association between abundant green sulfur bacteria and cyanobacteria in the green biofilms. Together, our findings show that the Dead Sea floor harbors diverse microbial communities, part of which is not known from other hypersaline environments. Analysis of the water's chemistry shows evidence of microbial activity along the path and suggests that the springs supply nitrogen, phosphorus and organic matter to the microbial communities in the Dead Sea. The underwater springs are a newly recognized water source for the Dead Sea. Their input of microorganisms and nutrients needs to be considered in the assessment of possible impact of dilution events of the lake surface waters, such as those that will occur in the future due to the intended establishment of the Red Sea-Dead Sea water conduit.

Seasonal signatures in SFG vibrational spectra of the sea surface nanolayer at Boknis Eck Time Series Station (SW Baltic Sea

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K. Laß

2013-08-01

Full Text Available The very thin sea surface nanolayer on top of the sea surface microlayer, sometimes just one monomolecular layer thick, forms the interface between ocean and atmosphere. Due to the small dimension and tiny amount of substance, knowledge about the development of the layer in the course of the year is scarce. In this work, the sea surface nanolayer at Boknis Eck Time Series Station (BE, southwestern Baltic Sea, has been investigated over a period of three and a half years. Surface water samples were taken monthly by screen sampling and were analyzed in terms of organic content and composition by sum frequency generation spectroscopy, which is specifically sensitive to interfacial layers. A yearly periodicity has been observed with a pronounced abundance of sea surface nanolayer material (such as carbohydrate-rich material during the summer months. On the basis of our results we conclude that the abundance of organic material in the nanolayer at Boknis Eck is not directly related to phytoplankton abundance alone. We speculate that indeed sloppy feeding of zooplankton together with photochemical and/or microbial processing of organic precursor compounds is responsible for the pronounced seasonality.

Seasonal signatures in SFG vibrational spectra of the sea surface nanolayer at Boknis Eck Time Series Station (SW Baltic Sea)

Science.gov (United States)

Laß, K.; Bange, H. W.; Friedrichs, G.

2013-08-01

The very thin sea surface nanolayer on top of the sea surface microlayer, sometimes just one monomolecular layer thick, forms the interface between ocean and atmosphere. Due to the small dimension and tiny amount of substance, knowledge about the development of the layer in the course of the year is scarce. In this work, the sea surface nanolayer at Boknis Eck Time Series Station (BE), southwestern Baltic Sea, has been investigated over a period of three and a half years. Surface water samples were taken monthly by screen sampling and were analyzed in terms of organic content and composition by sum frequency generation spectroscopy, which is specifically sensitive to interfacial layers. A yearly periodicity has been observed with a pronounced abundance of sea surface nanolayer material (such as carbohydrate-rich material) during the summer months. On the basis of our results we conclude that the abundance of organic material in the nanolayer at Boknis Eck is not directly related to phytoplankton abundance alone. We speculate that indeed sloppy feeding of zooplankton together with photochemical and/or microbial processing of organic precursor compounds is responsible for the pronounced seasonality.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

Science.gov (United States)

Sant, T.; Buhagiar, D.; Farrugia, R. N.

2014-06-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

International Nuclear Information System (INIS)

Sant, T; Buhagiar, D; Farrugia, R N

2014-01-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

Cooling-water chlorination: the kinetics of chlorine, bromine, and ammonia in sea water

International Nuclear Information System (INIS)

Johnson, J.D.; Inman, G.W. Jr.; Trofe, T.W.

1982-11-01

The major inorganic reaction pathways for the chlorination of saline waters were measured by a variety of techniques including: (1) amperometric titration, (2) amperometric membrane covered electrode, (3) uv spectrophotometry, (4) conventional kinetics methods for slow reactions, and (5) stopped-flow kinetics measurements with a microcomputer data acquisition system. The major reactions studied were: (1) the competitive reactions of ammonia and bromide ion with hypochlorous acid, (2) bromide oxidation by hypochlorous acid, (3) monochloramine formation in sea water, (4) monobromamine formation and subsequent disproportionation to form dibromamine, and (5) monochloramine oxidation of bromide to form bromochloramine. Reaction rates were determined in sodium chloride and sea water as a function of reactant concentration, pH, salinity, and ammonia concentration. Rate constants and corresponding rate laws and mechanisms were developed for each reaction

Specific chelating reagent to extract uranium from the sea water

International Nuclear Information System (INIS)

Tabushi, Iwao; Kobuke, Yoshiaki

1982-01-01

The behavior of uranyl ions as seen from the chemistry of complex as the object of molecule recognition was examined on the basis of the research of structure and equilibrium in solution, in an attempt for the search of specific ligands and the molecular design of adsorbents. What is the most essential for the extraction of uranyl ions from sea water is the development of an excellent adsorbent with rapid adsorption, large equilibrium adsorption and high physical-chemical stability. Based on this appreciation, attempt has been made to find out the molecular design of an excellent adsorbent, starting with the chemistry of complex of uranyl ions. For the purpose, the following matters are reviewed: uranium in nature, the chemistry of complex of uranyl ions, specific ligands for the uranyl ions in sea water, the adsorbent resins for sea-water uranium, the proposals for an adsorbent system. (Mori, K.)

Aquifer Treatment of Sea Water to Remove Natural Organic Matter Before Desalination

KAUST Repository

Dehwah, Abdullah

2016-10-18

An investigation of a sea water reverse osmosis desalination facility located in western Saudi Arabia has shown that aquifer treatment of the raw sea water provides a high degree of removal of natural organic matter (NOM) that causes membrane biofouling. The aquifer is a carbonate system that has a good hydraulic connection to the sea and 14 wells are used to induce sea water movement 400 to 450 m from the sea to the wells. During aquifer transport virtually all of the algae, over 90% of the bacteria, over 90% of the biopolymer fraction of NOM, and high percentages of the humic substance, building blocks, and some of the low molecular weight fractions of NOM are removed. Between 44 and over 90% of the transparent exopolymer particles (TEP) are removed with a corresponding significant reduction in concentration of the colloidal fraction of TEP. The removal rate for TEP appears to be greater in carbonate aquifers compared to siliciclastic systems. Although the production wells range in age from 4 months to 14 years, no significant difference in the degree of water treatment provided by the aquifer was found.

Aquifer Treatment of Sea Water to Remove Natural Organic Matter Before Desalination

KAUST Repository

Dehwah, Abdullah; Almashharawi, Samir; Ng, Kim Choon; Missimer, Thomas M.

2016-01-01

An investigation of a sea water reverse osmosis desalination facility located in western Saudi Arabia has shown that aquifer treatment of the raw sea water provides a high degree of removal of natural organic matter (NOM) that causes membrane biofouling. The aquifer is a carbonate system that has a good hydraulic connection to the sea and 14 wells are used to induce sea water movement 400 to 450 m from the sea to the wells. During aquifer transport virtually all of the algae, over 90% of the bacteria, over 90% of the biopolymer fraction of NOM, and high percentages of the humic substance, building blocks, and some of the low molecular weight fractions of NOM are removed. Between 44 and over 90% of the transparent exopolymer particles (TEP) are removed with a corresponding significant reduction in concentration of the colloidal fraction of TEP. The removal rate for TEP appears to be greater in carbonate aquifers compared to siliciclastic systems. Although the production wells range in age from 4 months to 14 years, no significant difference in the degree of water treatment provided by the aquifer was found.

Electrical guidance efficiency of downstream-migrating juvenile Sea Lamprey decreases with increasing water velocity

Science.gov (United States)

Miehls, Scott M.; Johnson, Nicholas; Haro, Alexander

2017-01-01

We tested the efficacy of a vertically oriented field of pulsed direct current (VEPDC) created by an array of vertical electrodes for guiding downstream-moving juvenile Sea Lampreys Petromyzon marinus to a bypass channel in an artificial flume at water velocities of 10–50 cm/s. Sea Lampreys were more likely to be captured in the bypass channel than in other sections of the flume regardless of electric field status (on or off) or water velocity. Additionally, Sea Lampreys were more likely to be captured in the bypass channel when the VEPDC was active; however, an interaction between the effects of VEPDC and water velocity was observed, as the likelihood of capture decreased with increases in water velocity. The distribution of Sea Lampreys shifted from right to left across the width of the flume toward the bypass channel when the VEPDC was active at water velocities less than 25 cm/s. The VEPDC appeared to have no effect on Sea Lamprey distribution in the flume at water velocities greater than 25 cm/s. We also conducted separate tests to determine the threshold at which Sea Lampreys would become paralyzed. Individuals were paralyzed at a mean power density of 37.0 µW/cm3. Future research should investigate the ability of juvenile Sea Lampreys to detect electric fields and their specific behavioral responses to electric field characteristics so as to optimize the use of this technology as a nonphysical guidance tool across variable water velocities.

The Structure of Sea Water and Gelatinous Water in the Deep Ocean

Science.gov (United States)

Peltzer, E. T.; Walz, P. M.; Wojciechowicz, M.; Brewer, P. G.

2016-12-01

Gelatinous life forms are common in the deep sea and are able to maintain a careful combination of body integrity and easy fluidity of motion over a wide range of T and P. They accomplish this in part by modifying the molecular structure of water. Both the transparent body of the organism (the mesoglea) and the structure of the immediate surrounding sea water were investigated by in situ laser Raman spectroscopy at depths from 300m to 2,800m. The structure of water is reasonably well known; the basic unit is a hydrogen bonded pentamer with defined stretching and bending modes. The spectrum of the bending band is separable into two components while the stretching band spectrum is composed of five components representing both intra- and inter-molecular vibrations. The effect of temperature on the various vibrational modes is complex. While the effect of pressure on the bending modes is small, but the effect of temperature and pressure on the stretching modes is significant and can be modeled as a van `t Hoff function. Our in situ experiments were conducted using MBARI's ROV Ventana and ROV Doc Ricketts. We collected cnidarians and ctenophores into a 6 L glass detritus sampler fitted with a metal grid plate. Once the animal was captured, we introduced argon gas through the lid of the sampler displacing the contained sea water and leaving a motionless sea water free specimen for spectroscopy. The laser beam was focused through the glass wall of the container and the focal point adjusted to be inside the gelatinous body. Our results very clearly show that:i) The gelatinous mass effectively excludes salts with zero sulfate ion being detected.ii) The water bending modes are absent from the gelatinous spectra.iii) The water stretching modes are highly modified from the typical 5 band liquid pentamer structure with only 3 vibrational modes observable. These results stand in marked contrast to the familiar household gelatin which is typically derived from bovine sources

Responses of three tomato cultivars to sea water salinity 1. Effect of ...

African Journals Online (AJOL)

The effect of sea water salinity (1500, 2500 and 3500 ppm) on the growth of tomato (Lycopersicon esculentum) cultivars (Trust, Grace and Plitz) was studied. The sea water salinity delayed seed germination and reduced germination percentage especially with increasing salinity level. Chlorophyll b content was higher than ...

Physical-chemical modeling of elements' behavior in mixing sea and fresh waters of minor rivers in the White Sea catchment area.

Science.gov (United States)

Maksimova, Victoria V; Mazukhina, Svetlana I; Cherepanova, Tatiana A; Gorbacheva, Tamara T

2017-07-29

The physical-chemical stage of marginal filters in minor rivers of the White Sea catchment area by the example of the Umba River, flowing to Kandalaksha Gulf, has been explored. Application of the method of physical-chemical modeling on the basis of field data allowed establishing migration forms of a number of elements in the "river-sea" system and deposition of solid phases when mixing waters. The mixing of river and sea water is accompanied by the sedimentation of predominantly goethite, hydromuscovite, and hydroxylapatite. Sediments in mixing river and sea waters were found to be mainly composed by goethite, hydromuscovite, and hydroxylapatite. The research has added to the knowledge of the role of the abiotic part in the marginal filters of small rivers in the Arctic.

Past and present Aral Sea

Science.gov (United States)

Dukhovniy, Viktor; Stulina, Galina; Eshchanov, Odylbek

2013-04-01

organized in 2005-2009 sixth expeditions for complex remote sensing and ground investigations Aral Sea former bottom that were complemented in 2010 -2011 by two expeditions with GFZ. As a result, the landscape, soils and environment mapping was done with determination of ecologically unstable zones and assessment total change of lands situation compared with the pre-independence time. Moreover - methodic of monitoring water, environment and hydro geological indicators on the all deltas area was elaborated, organized its testing and combined with remote sensing data on Amudarya delta for 2009-2012. It permits to SIC ICWC to organize systematic permanent (decadal) monitoring and recording of size, volume and level of water in Aral Sea. Since the beginning of regular observations over the Aral Sea level, 2 periods can be emphasized: 1. Conditionally natural period - 1911-1960 - characterized by a relatively stable hydrological regime, with fluctuations in the level around 53 m and the range of inter-annual fluctuations at no more than 1 m., when the sea received annually about a half of the run-off in the Syrdarya and Amudarya Rivers, i.e. 50-60 km3/yr. 2. Intensive anthropogenic impact period - since the 1960s, a vast extension of irrigable land was carried out in Central Asia that resulted in intensive diversion of river run-off. Since then, the sea level has been falling steadily, causing a dramatic reduction in the water surface area, a decrease in water volume and depths, great changes in shoreline configuration and an expansion of the desert areas adjacent to the Aral Sea. From 1960-1985, when the sea was an integral water body, slight lowering in the sea level took place until the 1970s, when the sea-level decreased with the mean level lowering 1 m. The desiccation process accelerated visibly from the mid 1970s. In 1975-1980, the level decreased by 0.65 m a year on average. Moreover, the level dropped greatly, when the run-off of the Amudarya did not reach the Aral Sea

Distribution and ventilation of water masses in the western Ross Sea inferred from CFC measurements

Science.gov (United States)

Rivaro, Paola; Ianni, Carmela; Magi, Emanuele; Massolo, Serena; Budillon, Giorgio; Smethie, William M.

2015-03-01

During the CLIMA Project (R.V. Italica cruise PNRA XVI, January-February 2001), hydrographic and chlorofluorocarbons (CFCs) observations were obtained, particularly in the western Ross Sea. Their distribution demonstrated water mass structure and ventilation processes in the investigated areas. In the surface waters (AASW) the CFC saturation levels varied spatially: CFCs were undersaturated in all the areas (range from 80 to 90%), with the exception of few stations sampled near Ross Island. In particular, the Terra Nova Bay polynya, where high salinity shelf water (HSSW) is produced, was a low-saturated surface area (74%) with respect to CFCs. Throughout most of the shelf area, the presence of modified circumpolar deep water (MCDW) was reflected in a mid-depth CFC concentration minima. Beneath the MCDW, CFC concentrations generally increased in the shelf waters towards the seafloor. We estimated that the corresponding CFCs saturation level in the source water region for HSSW was about 68-70%. Waters with high CFC concentrations were detected in the western Ross Sea on the down slope side of the Drygalski Trough, indicating that AABW was being supplied to the deep Antarctic Basin. Estimates of ventilation ages depend strongly on the saturation levels. We calculated ventilation ages using the saturation level calibrated tracer ratio, CFC11/CFC12. We deduced a mean residence time of the shelf waters of about 6-7 years between the western Ross Sea source and the shelf break.

Coccolithophore assemblage response to Black Sea Water inflow into the North Aegean Sea (NE Mediterranean)

Science.gov (United States)

Karatsolis, B.-Th.; Triantaphyllou, M. V.; Dimiza, M. D.; Malinverno, E.; Lagaria, A.; Mara, P.; Archontikis, O.; Psarra, S.

2017-10-01

This study aims to presents the species composition of living coccolithophore communities in the NE Aegean Sea, investigating their spatial and temporal variations along a north-south transect in the area receiving the inflowing surface Black Sea Water (BSW) over the deeper Levantine Water (LW) layer. Coccolithophores in the area were relatively diverse and a total of 95 species over 3 sampling periods studied were recognized using Scanning Electron Microscope (SEM) techniques. R-mode hierarchical cluster analysis distinguished two coccolithophore Groups (I, IIa, IIb, IIc) with different ecological preferences. Emiliania huxleyi was the most abundant species of Group I, whereas Syracosphaera spp., Rhabdosphaera spp. and holococcolithophores were prevailing in the highly diversified Group II assemblages. Biometric analysis conducted on E. huxleyi coccoliths from Aegean water column and Black Sea sediment trap samples, indicated that during autumn, NE Aegean specimens in samples under BSW influence were featured by unimodal distribution concerning the coccolith relative tube width, with values similar to those provided by the Black Sea specimens. In early spring, coccoliths in the stations with increased BSW influx displayed a bimodal pattern of relative tube width with smaller values found mostly in the surface layers, while the distribution became again unimodal and dominated by larger values within the deeper LW layers. In the summer period, the typical LW holococcolithophore species (Group II) presented low cell numbers in the surface layer (huxleyi was almost absent in the NE Aegean during the summer sampling period.

Black sea annual and inter-annual water mass variations from space

DEFF Research Database (Denmark)

Yildiz, H.; Andersen, Ole Baltazar; Simav, M.

2011-01-01

influenced by the leakage of hydrological signals from the surrounding land. After applying the corresponding correction, we found a good agreement with water mass variations derived from steric-corrected satellite altimetry observations. Both GRACE and altimetry show significant annual water mass variations......This study evaluates the performance of two widely used GRACE solutions (CNES/GRGS RL02 and CSR RL04) in deriving annual and inter-annual water mass variations in the Black Sea for the period 2003–2007. It is demonstrated that the GRACE derived water mass variations in the Black Sea are heavily...

Formation and spreading of Arabian Sea high-salinity water mass

Digital Repository Service at National Institute of Oceanography (India)

PrasannaKumar, S.; Prasad, T.G.

The formation and seasonal spreading of the Arabian Sea High-Salinity Water (ASHSW) mass were studied based on the monthly mean climatology of temperature and salinity in the Arabian Sea, north of the equator and west of 80 degrees E, on a 2 degrees...

BC SEA Solar Hot Water Acceleration project

Energy Technology Data Exchange (ETDEWEB)

Harris, N.C. [BC Sustainable Energy Association, Victoria, BC (Canada)

2005-07-01

Although solar hot water heating is an environmentally responsible technology that reduces fossil fuel consumption and helps mitigate global climate change, there are many barriers to its widespread use. Each year, domestic water heating contributes nearly 6 million tonnes of carbon dioxide towards Canada's greenhouse gas emissions. The installation of solar water heaters can eliminate up to 2 tonnes of carbon dioxide emissions per household. The BC SEA Solar Hot Water Acceleration project was launched in an effort to demonstrate that the technology has the potential to be widely used in homes and businesses across British Columbia. One of the main barriers to the widespread use of solar hot water heating is the initial cost of the system. Lack of public awareness and understanding of the technology are other barriers. However, other jurisdictions around the world have demonstrated that the use of renewables are the product of conscious policy decisions, including low-cost financing and other subsidies that have created demand for these technologies. To this end, the BC SEA Solar Hot Water Acceleration project will test the potential for the rapid acceleration of solar water heating in pilot communities where barriers are removed. The objective of the project is to install 100 solar water systems in homes and 25 in businesses and institutions in communities in British Columbia by July 2007. The project will explore the financial barriers to the installation of solar hot water systems and produce an action plan to reduce these barriers. In addition to leading by example, the project will help the solar energy marketplace, mitigate climate change and improve energy efficiency.

The Carbon Dioxide System in the Baltic Sea Surface Waters

Energy Technology Data Exchange (ETDEWEB)

Wesslander, Karin

2011-05-15

The concentration of carbon dioxide (CO{sub 2}) in the atmosphere is steadily increasing because of human activities such as fossil fuel burning. To understand how this is affecting the planet, several pieces of knowledge of the CO{sub 2} system have to be investigated. One piece is how the coastal seas, which are used by people and influenced by industrialization, are functioning. In this thesis, the CO{sub 2} system in the Baltic Sea surface water has been investigated using observations from the last century to the present. The Baltic Sea is characterized of a restricted water exchange with the open ocean and a large inflow of river water. The CO{sub 2} system, including parameters such as pH and partial pressure of CO{sub 2} (pCO{sub 2}), has large seasonal and inter-annual variability in the Baltic Sea. These parameters are affected by several processes, such as air-sea gas exchange, physical mixing, and biological processes. Inorganic carbon is assimilated in the primary production and pCO{sub 2} declines to approx150 muatm in summer. In winter, pCO{sub 2} levels increase because of prevailing mineralization and mixing processes. The wind-mixed surface layer deepens to the halocline (approx60 m) and brings CO{sub 2}- enriched water to the surface. Winter pCO{sub 2} may be as high as 600 muatm in the surface water. The CO{sub 2} system is also exposed to short-term variations caused by the daily biological cycle and physical events such as upwelling. A cruise was made in the central Baltic Sea to make synoptic measurements of oceanographic, chemical, and meteorological parameters with high temporal resolution. Large short-term variations were found in pCO{sub 2} and oxygen (O{sub 2}), which were highly correlated. The diurnal variation of pCO{sub 2} was up to 40 muatm. The CO{sub 2} system in the Baltic Sea changed as the industrialization increased around 1950, which was demonstrated using a coupled physical-biogeochemical model of the CO{sub 2} system

Origin and residence time of water in the Lima aquifer

Energy Technology Data Exchange (ETDEWEB)

Montoya, Modesto [Instituto Peruano de Energia Nuclear, Av. Canada 1470, San Borja, Lima (Peru); Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Rimac, Lima (Peru); Mamani, Enoc [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Av. Jose Saco km 12.5, Carabayllo, Lima (Peru)

2013-07-01

The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of {sup 2}H and {sup 18}O are used to identify the origins of the waters from those wells, and the {sup 3}H and {sup 14}C contents are used to estimate the time after they fall as rain. (authors).

18O/16O ratios of the pore water of Baltic Sea sediments

International Nuclear Information System (INIS)

Foerstel, H.

1983-01-01

Two cores of Baltic Sea sediment were collected in 1975. The 18 O/ 16 O ratio of the water enclosed in the sediment (pore water) was measured after the separation of the liquid from the solid phase. The results may support the discussion about the history of the Baltic Sea. At the top of the core the 18 O/ 16 O ratio of the water represents the oxygen isotope composition of the sea water above. Towards the deeper parts of the sediment, independently of the salt content, the 18 O/ 16 O ratio decreases towards values observed in the precipitation of the surrounding land areas. (author)

Origin and residence time of water in the Lima Aquifer

OpenAIRE

Montoya, Modesto; Mamani, Enoc

2014-01-01

The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of H-2 and O-18 are used to identify the origins of the w...

Influence of sea ice cover and icebergs on circulation and water mass formation in a numerical circulation model of the Ross Sea, Antarctica

Science.gov (United States)

Dinniman, Michael S.; Klinck, John M.; Smith, Walker O.

2007-11-01

Satellite imagery shows that there was substantial variability in the sea ice extent in the Ross Sea during 2001-2003. Much of this variability is thought to be due to several large icebergs that moved through the area during that period. The effects of these changes in sea ice on circulation and water mass distributions are investigated with a numerical general circulation model. It would be difficult to simulate the highly variable sea ice from 2001 to 2003 with a dynamic sea ice model since much of the variability was due to the floating icebergs. Here, sea ice concentration is specified from satellite observations. To examine the effects of changes in sea ice due to iceberg C-19, simulations were performed using either climatological ice concentrations or the observed ice for that period. The heat balance around the Ross Sea Polynya (RSP) shows that the dominant term in the surface heat budget is the net exchange with the atmosphere, but advection of oceanic warm water is also important. The area average annual basal melt rate beneath the Ross Ice Shelf is reduced by 12% in the observed sea ice simulation. The observed sea ice simulation also creates more High-Salinity Shelf Water. Another simulation was performed with observed sea ice and a fixed iceberg representing B-15A. There is reduced advection of warm surface water during summer from the RSP into McMurdo Sound due to B-15A, but a much stronger reduction is due to the late opening of the RSP in early 2003 because of C-19.

Multidecadal variations in the early Holocene outflow of Red Sea Water into the Arabian Sea

OpenAIRE

Jung, S.J.A.; Ganssen, G.M.; Davies, G.R.

2001-01-01

We present Holocene stable oxygen isotope data from the deep Arabian Sea off Somalia at a decadal time resolution as a proxy for the history of intermediate/upper deep water. These data show an overall δ18O reduction by 0.5‰ between 10 and ~6.5 kyr B.P. superimposed upon short-term δ18O variations at a decadal-centennial timescale. The amplitude of the decadal variations is 0.3‰ prior, and up to 0.6‰ subsequent, to ~8.1 kyr B.P. We conclude from modeling experiments that the short-term δ18O v...

Measurements of distribution coefficient for U and Th on sand stone in synthesized sea water and distilled water

International Nuclear Information System (INIS)

Nakazawa, Toshiyuki; Okada, Kenichi; Saito, Yoshihiko; Shibata, Masahiro; Sasamoto, Hiroshi

2005-01-01

Japan Nuclear Cycle Development Institute (JNC) has developed the sorption database for bentonite and rocks in order to assess the retardation property of important radioactive elements in natural and engineered barriers in the H12 report. However, there are not enough distribution coefficient data for radioactive elements in saline type groundwater in the database. Thus the batch sorption tests were performed for uranium (U) and thorium (Th) in saline type groundwater. For these elements, there are little registration numbers in the JNC's sorption database, and also these elements are important to evaluate the safety of disposal system. The experiments for each radioactive element were performed on the following conditions; U: Kd measurements using the solutions (synthesized sea water and distilled water) reacted with sand stone as a function of carbonate concentration, under reducing conditions. Th: Kd measurements using the solutions (synthesized sea water and distilled water) reacted with sand stone. The results of the experiments are summarized below; In the case of U, Kd was approximately 6.5E-01 - 9.2E-01 m 3 /kg in synthesized sea water. On the other hand, Kd was 2.2E-02 - 2.4E-02 m 3 /kg in the high carbonate solution. And also, Kd was 6.5E-02 - 7.2E-02 m 3 /kg in synthesized sea water adjusted pH 10 and 3.4E-02 - 4.1E-02 m 3 /kg in distilled water adjusted pH 10, respectively. In the case of Th, Kd was measured in synthesized sea water adjusted to pH 10 and in distilled water adjusted to pH 10. At the sorption measurements of Th, precipitation might be occurred by very low solubility of Th. (author)

Denitrification in the water column of the central Baltic Sea

DEFF Research Database (Denmark)

Dalsgaard, Tage; De Brabandere, Loreto; Hall, Per O. J.

2013-01-01

Removal of fixed nitrogen in the water column of the eastern Gotland Basin, central Baltic Sea, was studied during two cruises in September 2008 and August 2010. The water column was stratified with anoxic sulfidic bottom water meeting oxic nitrate containing water at the oxic–anoxic interface......3 or sulfide concentrations were converted to in situ rates using the measured water column concentrations of NO3 and sulfide and the actual measured relations between NO3 and sulfide concentrations and enitrification rates. In situ denitrification ranged from 0.24 to 15.9 nM N2 h1. Assuming...... area. Even with an active denitrification layer of 3–6 m thickness the pelagic denitrification per unit area clearly exceeded sediment denitrification rates elsewhere in the Baltic Sea. When extrapolated to the entire Baltic Proper (BP) denitrification in the water column was in the range of 132...

New records of Decapod Crustaceans (Decapoda: Pontoniinae and Inachidae associated with sea anemones in Turkish waters

Directory of Open Access Journals (Sweden)

Z. DURIS

2013-10-01

Full Text Available Three anemone-associated decapod crustaceans, two shrimp species, Periclimenes amethysteus and P. aegylios (Caridea: Palaemonidae: Pontoniinae, and the crab Inachus phalangium (Brachyura: Inachidae, all collected from the Dardanelles, are reported for the first time from Turkish coasts. Another inachid crab, Macropodia czernjawskii is also reported for the first time to occur in association with the sea anemone, Anemonia viridis. Periclimenes scriptus was the fifth decapod species recorded associated with sea anemones within the present study, and while this species has already been reported from Turkish waters, this is the first time it is recorded from the Dardanelles (the Turkish Straits System.

Standardization of solvent extraction procedure for determination of uranium in sea water

International Nuclear Information System (INIS)

Maity, Sukanta; Dusane, C.B.; Sahu, S.K.; Pandit, G.G.

2014-01-01

Marine ecosystem is becoming polluted by heavy metals and naturally occurring radionuclides due to rapid industrialization and human activities. Many contaminants such as heavy metals and naturally occurring radionuclides though occur at extremely low concentration in sea water, are accumulated by marine organisms and concentrations in their body tissue can be hundreds of times greater than sea water. As human being consume different marine organisms like biota, can lead potential health problem to human being. Uranium is a naturally occurring radioactive element which is important for nuclear technology. However, mineral resources for uranium are limited. Seawater is a major source of uranium. The total estimated quantity of uranium in seawater is around four and a half billion tones. Thus, the oceans have the potential to become the most eco-friendly and long sustainable resource for uranium. A number of countries in the world are in search of techniques to recover uranium from seawater economically. For this purpose and also for the environmental monitoring, the determination of uranium in seawater is very much important. Seawater contains very high concentrations of salts and its uranium content is very low. Accordingly, the separation and preconcentration of uranium is usually involved in the analytical procedures used for the determination of uranium in seawater. In the present study solvent extraction procedure was adopted for the determination of uranium in sea water collected from different locations across Thane Creek area, Mumbai, India

Links Between the Deep Western Boundary Current, Labrador Sea Water Formation and Export, and the Meridional Overturning Circulation

Science.gov (United States)

Myers, Paul G.; Kulan, Nilgun

2010-05-01

Based on an isopyncal analysis of historical data, 3-year overlapping triad fields of objectively analysed temperature and salinity are produced for the Labrador Sea, covering 1949-1999. These fields are then used to spectrally nudge an eddy-permitting ocean general circulation model of the sub-polar gyre, otherwise forced by inter annually varying surface forcing based upon the Coordinated Ocean Reference Experiment (CORE). High frequency output from the reanalysis is used to examine Labrador Sea Water formation and its export. A number of different apprpoaches are used to estimate Labrador Sea Water formation, including an instanteous kinematic approach to calculate the annual rate of water mass subduction at a given density range. Historical transports are computed along sections at 53 and 56N for several different water masses for comparison with recent observations, showing a decline in the stength of the deep western boundary current with time. The variability of the strength of the meridional overturning circulation (MOC) from the reanalysis is also examined in both depth and density space. Linkages between MOC variability and water mass formation variability is considered.

Reconstruction of Redox Conditions and Productivity in Coastal Waters of the Bothnian Sea during the Holocene

Science.gov (United States)

Dijkstra, N.; Quintana Krupinski, N. B.; Slomp, C. P.

2014-12-01

Hypoxia is a growing problem in coastal waters worldwide, and is a well-known cause of benthic mortality. The semi-enclosed Baltic Sea is currently the world's largest human-induced dead zone. During the early Holocene, it experienced several periods of natural hypoxia following the intrusion of seawater into the previous freshwater lake. Recent studies suggest that at that time, the hypoxia expanded north to include the deep basin of the Bothnian Sea. In this study, we assess whether the coastal zone of the Bothnian Sea was also hypoxic during the early Holocene. We analysed a unique sediment record (0 - 30 mbsf) from the Ångermanälven estuary, which was retrieved during the International Ocean Discovery Programme (IODP) Baltic Sea Paleoenvironment Expedition 347 in 2013. Using geochemical proxies and foraminifera abundances, we reconstruct the changes in redox conditions, salinity and productivity in the estuary. Our preliminary results suggest that bottom waters in this coastal basin became anoxic upon the intrusion of brackish seawater in the early Holocene and that the productivity was elevated. The presence of benthic foraminifera in this estuary during the mid-Holocene suggests more saline conditions in the Bothnian Sea than today. Due to isostatic uplift, the estuary likely gradually became more isolated from the Bothnian Sea, which itself became more isolated from the Baltic Sea. Both factors likely explain the subsequent re-oxygenation of bottom waters and gradual refreshening of the estuary as recorded in the sediments. Interestingly, the upper meters of sediment are enriched in minerals that contain iron, phosphorus and manganese. We postulate that the refreshening of the estuary triggered the formation of these minerals, thereby increasing the phosphorus retention in these sediments and further reducing primary productivity. This enhanced retention linked to refreshening may contribute to the current oligotrophic conditions in the Bothnian Sea.

Water transparency measurements in the deep Ionian Sea

CERN Document Server

Anassontzis, E G; Belias, A; Fotiou, A; Grammatikakis, G; Kontogiannis, H; Koske, P; Koutsoukos, S; Lykoussis, V; Markopoulos, E; Psallidas, A; Resvanis, L K; Siotis, I; Stavrakakis, S; Stavropoulos, G; Zhukov, V A

2010-01-01

A long optical base line spectrophotometer designed to measure light transmission in deep sea waters is described. The variable optical path length allows measurements without the need for absolute or external calibration. The spectrophotometer uses eight groups of uncollimated light sources emitting in the range 370–530 nm and was deployed at various depths at two locations in the Ionian Sea that are candidate sites for a future underwater neutrino telescope. Light transmission spectra at the two locations are presented and compared.

Potential Osteoporosis Recovery by Deep Sea Water through Bone Regeneration in SAMP8 Mice

Directory of Open Access Journals (Sweden)

Hen-Yu Liu

2013-01-01

Full Text Available The aim of this study is to examine the therapeutic potential of deep sea water (DSW on osteoporosis. Previously, we have established the ovariectomized senescence-accelerated mice (OVX-SAMP8 and demonstrated strong recovery of osteoporosis by stem cell and platelet-rich plasma (PRP. Deep sea water at hardness (HD 1000 showed significant increase in proliferation of osteoblastic cell (MC3T3 by MTT assay. For in vivo animal study, bone mineral density (BMD was strongly enhanced followed by the significantly increased trabecular numbers through micro-CT examination after a 4-month deep sea water treatment, and biochemistry analysis showed that serum alkaline phosphatase (ALP activity was decreased. For stage-specific osteogenesis, bone marrow-derived stromal cells (BMSCs were harvested and examined. Deep sea water-treated BMSCs showed stronger osteogenic differentiation such as BMP2, RUNX2, OPN, and OCN, and enhanced colony forming abilities, compared to the control group. Interestingly, most untreated OVX-SAMP8 mice died around 10 months; however, approximately 57% of DSW-treated groups lived up to 16.6 months, a life expectancy similar to the previously reported life expectancy for SAMR1 24 months. The results demonstrated the regenerative potentials of deep sea water on osteogenesis, showing that deep sea water could potentially be applied in osteoporosis therapy as a complementary and alternative medicine (CAM.

On the use of GPS tomography to investigate water vapor variability during a Mistral/sea breeze event in southeastern France

Science.gov (United States)

Bastin, Sophie; Champollion, Cédric; Bock, Olivier; Drobinski, Philippe; Masson, Frédéric

2005-03-01

Global Positioning System (GPS) tomography analyses of water vapor, complemented by high-resolution numerical simulations are used to investigate a Mistral/sea breeze event in the region of Marseille, France, during the ESCOMPTE experiment. This is the first time GPS tomography has been used to validate the three-dimensional water vapor concentration from numerical simulation, and to analyze a small-scale meteorological event. The high spatial and temporal resolution of GPS analyses provides a unique insight into the evolution of the vertical and horizontal distribution of water vapor during the Mistral/sea-breeze transition.

Extratropical Influence of Sea Surface Temperature and Wind on Water Recycling Rate Over Oceans and Coastal Lands

Science.gov (United States)

Hu, Hua; Liu, W. Timothy

1999-01-01

Water vapor and precipitation are two important parameters confining the hydrological cycle in the atmosphere and over the ocean surface. In the extratropical areas, due to variations of midlatitude storm tracks and subtropical jetstreams, water vapor and precipitation have large variability. Recently, a concept of water recycling rate defined previously by Chahine et al. (GEWEX NEWS, August, 1997) has drawn increasing attention. The recycling rate of moisture is calculated as the ratio of precipitation to total precipitable water (its inverse is the water residence time). In this paper, using multi-sensor spacebased measurements we will study the role of sea surface temperature and ocean surface wind in determining the water recycling rate over oceans and coastal lands. Response of water recycling rate in midlatitudes to the El Nino event will also be discussed. Sea surface temperature data are derived from satellite observations from the Advanced Very High Resolution Radiometer (AVHRR) blended with in situ measurements, available for the period 1982-1998. Global sea surface wind observations are obtained from spaceborne scatterometers aboard on the European Remote-Sensing Satellite (ERS1 and 2), available for the period 1991-1998. Global total precipitable water provided by the NASA Water Vapor Project (NVAP) is available for the period 1988-1995. Global monthly mean precipitation provided by the Global Precipitation Climatology Project (GPCP) is available for the period 1987-1998.

Development of Speciality polymer to extract uranium from sea water

International Nuclear Information System (INIS)

Tabushi, Iwao

1983-01-01

Polymer adsorbents were designed to extract uranium efficiently from sea water. The unique coordination structure of uranyl ion was suggested from x-ray crystallography and determining factors influencing equilibrium constants were elucidated. A quantitative estimation of the ligand efficiency was obtained. Based on these considerations on the coordination chemistry of uranyl ion, new polymer adsorbents were prepared and found to show excellent adsorption characteristics. The macrocyclic ligands mimicking crystallographic structure of the complex: planer headentate, were found to show large equilibrium constants as well as high selectivities toward metal ions. Direct usage of sea current was proposed as a most economical way of treating a huge amount of sea water. The polymer adsorbent could recover uranium with large adsorption rate just by immersing the resin into Kuroshio. (author)

Needs and processes for the sea water desalination

International Nuclear Information System (INIS)

Livet, F.

2007-11-01

The author shows the needs of the sea water desalination for the dry countries. The main technique is the reverse osmosis. It requires electricity and its development needs big electric power plants. For economical and ecological reasons, the nuclear energy seems well appropriate. Libya is for instance very interested in this technique, because of their water shortage problem. (A.L.B.)

Migration of trace heavy metals at the sea water/sediment interface

International Nuclear Information System (INIS)

Terada, Kikuo; Tomiyama, Chisato

1984-01-01

Migration behavior of some trace heavy metals such as Co(II), Cu(II), Mn(II) and Zn(II) at the sea water/sediment interface was investigated by tank experiments. The sea water which was doped with these metal ions (ppb to ppm levels) allowed to contact with the raw-, ignited- and autoclaved-marine sediments and the change of the concentration of each metal was traced at definite time intervals. At the end of the experiments, a core sample of the sediment was taken and analyzed for each metal in every 1 mm thick segment. On the other hand, the surface sediment was submitted to partial extraction with various kinds of reagents to estimate the chemical species of the metals captured in the sediment. While every metal ion was quickly adsorbed on surface of the raw sediment, a concentration gradient from surface to bottom of the water phase occurred in the ignited sediment system. The migration of manganese to the sediment phase was assumed to be concerned with bacterial activity in the sediment. Copper and zinc seemed to be adsorbed very quickly onto some fine sediment particles by the formation of organometallic complexes with some organic materials existing in the sediments. Cobalt migrated relatively fast downward within the sediment phase after its deposition. (author)

Trace elements and stable isotope ratios (δ13C and δ15N) in fish from deep-waters of the Sulu Sea and the Celebes Sea

International Nuclear Information System (INIS)

Asante, Kwadwo Ansong; Agusa, Tetsuro; Kubota, Reiji; Mochizuki, Hiroko; Ramu, Karri; Nishida, Shuhei; Ohta, Suguru; Yeh, Hsin-ming; Subramanian, Annamalai; Tanabe, Shinsuke

2010-01-01

Trace elements (TEs) and stable isotope ratios (δ 15 N and δ 13 C) were analyzed in fish from deep-water of the Sulu Sea, the Celebes Sea and the Philippine Sea. Concentrations of V and Pb in pelagic fish from the Sulu Sea were higher than those from the Celebes Sea, whereas the opposite trend was observed for δ 13 C. High concentrations of Zn, Cu and Ag were found in non-migrant fish in deep-water, while Rb level was high in fish which migrate up to the epipelagic zone, probably resulting from differences in background levels of these TEs in each water environment or function of adaptation to deep-water by migrant and non-migrant species. Arsenic level in the Sulu Sea fish was positively correlated with δ 15 N, indicating biomagnification of arsenic. To our knowledge, this is the first study on relationship between diel vertical migration and TE accumulation in deep-water fish.

Depletion of barium and radium-226 in Black Sea surface waters over the past thirty years

International Nuclear Information System (INIS)

Kenison Falkner, K.K.; Edmond, J.M.; O'Neill, D.J.; Todd, J.F.; Moore, W.S.

1991-01-01

The nearly landlocked waters of the Black Sea support a valuable fishery, but are also particularly vulnerable to anthropogenic disturbance. Here we use dissolved barium and radium-226 as tracers, to investigate the biogeochemical health of the sea. Both elements are brought to surface waters by vertical mixing of deeper, enriched waters, and by rivers; these inputs should ordinarily be balanced by outflow of surface waters at the Bosphorus, and by biologically mediated removal of 226 Ra-bearing barite. We show, however, that surface-water inventories have been substantially depleted over the past few decades: recent (1988-89) barium concentrations were 1.6 times lower than in 1958 and 1967. These observations suggest that steady-state cycling of these elements has been perturbed by increased primary productivity, presumably fuelled by nutrients from industry and agricultural runoff, and to a lesser extent by decreased fluvial sediment loads owing to extensive impoundment of rivers in the region. (author)

Seasonal to Mesoscale Variability of Water Masses in Barrow Canyon,Chukchi Sea

Science.gov (United States)

Nobre, C.; Pickart, R. S.; Moore, K.; Ashjian, C. J.; Arrigo, K. R.; Grebmeier, J. M.; Vagle, S.; Itoh, M.; Berchok, C.; Stabeno, P. J.; Kikuchi, T.; Cooper, L. W.; Hartwell, I.; He, J.

2016-02-01

Barrow Canyon is one of the primary conduits by which Pacific-origin water exits the Chukchi Sea into the Canada Basin. As such, it is an ideal location to monitor the different water masses through the year. At the same time, the canyon is an energetic environment where mixing and entrainment can occur, modifying the pacific-origin waters. As part of the Distributed Biological Observatory (DBO) program, a transect across the canyon was occupied 24 times between 2010-2013 by international ships of opportunity passing through the region during summer and early-fall. Here we present results from an analysis of these sections to determine the seasonal evolution of the water masses and to investigate the nature of the mesoscale variability. The mean state shows the clear presence of six water masses present at various times through the summer. The seasonal evolution of these summer water masses is characterized both in depth space and in temperature-salinity (T-S) space. Clear patterns emerge, including the arrival of Alaskan coastal water and its modification in early-fall. The primary mesoscale variability is associated with wind-driven upwelling events which occur predominantly in September. The atmospheric forcing of these events is investigated as is the oceanic response.

Winter atmospheric circulation signature for the timing of the spring bloom of diatoms in the North Sea

Science.gov (United States)

Lohmann, Gerrit; Wiltshire, Karen

2015-04-01

Analysing long-term diatom data from the German Bight and observational climate data for the period 1962-2005, we found a close connection of the inter-annual variation of the timing of the spring bloom with the boreal winter atmospheric circulation. We examined the fact that high diatom counts of the spring bloom tended to occur later when the atmospheric circulation was characterized by winter blocking over Scandinavia. The associated pattern in the sea level pressure showed a pressure dipole with two centres located over the Azores and Norway and was tilted compared to the North Atlantic Oscillation. The bloom was earlier when the cyclonic circulation over Scandinavia allowed an increased inflow of Atlantic water into the North Sea which is associated with clearer, more marine water, and warmer conditions. The bloom was later when a more continental atmospheric flow from the east was detected. At Helgoland Roads, it seems that under turbid water conditions (= low light) zooplankton grazing can affect the timing of the phytoplankton bloom negatively. Warmer water temperatures will facilitate this. Under clear water conditions, light will be the main governing factor with regard to the timing of the spring bloom. These different water conditions are shown here to be mainly related to large-scale weather patterns. We found that the mean diatom bloom could be predicted from the sea level pressure one to three months in advance. Using historical pressure data, we derived a proxy for the timing of the spring bloom over the last centuries, showing an increased number of late (proxy-) blooms during the eighteenth century when the climate was considerably colder than today. We argue that these variations are important for the interpretation of inter-annual to centennial variations of biological processes. This is of particular interest when considering future scenarios, as well to considerations on past and future effects on the primary production and food webs.

RADIOECOLOGICAL STUDIES IN MARINE ENVIRONMENT. A STUDY ON THE CONCENTRATION OF MIXED FISSION PRODUCTS IN GREEK SEA WATERS AND OF 137CS IN FISH AND SEA PLANTS

International Nuclear Information System (INIS)

DANALI-KOTSAKI, S.; FLOROU-GAZI, H.

1982-12-01

Full text: The concentrations of mixed fission products in sea water and of 137 Cs in fish and sea plants are different for samples collected from different sampling areas. This difference is more remarkable the year where the level of the world wide fall-out is higher, especially with regards to M. F. P. concentrations in sea water samples. Increases or decreases to M.F.P. concentrations in sea water samples result to increases or decreases of 137 Cs in fish and sea plants. (author)

Radiation influence on heterogenous processes in stainless steel contact with sea-water

International Nuclear Information System (INIS)

Agayev, T.N.; Garibov, A.A.; Velibekova, G.Z.; Aliyev, A.Q.; Aliyev, S.M.

2005-01-01

Full text: Austenitic stainless steel (s.s.) with Cr content 16 %, Ni - 15 % is widely used in nuclear reactors as construction material, for fuel cladding production and also is used in oil and gas production and transportation. They possess comparatively large section of slow neutron capture and as a result high corrosion resistance. In real exploitation condition of nuclear reactors s.s. are exposed to ionizing radiation influence in contact of different media. That's why during their corrosion and destruction processes the surface defect formation processes and further heterogenous processes with their participation are of great importance. The research results of mechanism during radiation-heterogenous processes in nuclear reactor stainless steel contact with sea-water under the influence of γ-radiation in temperature interval 300-1074 K are represented in the given work. Radiolytic processes in water are comprehensively studied and therefore it was taken as model system for dating the surface defects and secondary electrons emitted from metal. The same model system was applied also in sea-water radiolysis processes. It's been established that radiation processes in s.s. lead to molecular hydrogen yield increase and at T=300 K up to 6.5 molec./100 eV. With the temperature increase molecular hydrogen yield increase up to 25.3 molec./100 eV at T≤773 K. During the further temperature increase up to 1073 K radiation constituent of radiation-thermal process in comparison with thermal becomes unnoticeable and W T (H 2 )≅W p (H 2 ). The kinetics of oxide phase formation of investigated sample surface in the result of thermal and radiation-thermal processes in their contact with sea-water has been studied. At that it's been shown that radiation leads to protective oxidation process rate increase and promotes the beginning of stainless steel destruction oxidation in contact with sea-water. At T≥573 K insoluble oxide phase is formed on metal surface that promotes

Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

OpenAIRE

X. Carton; P. L'Hegaret

2011-01-01

By analysing ARGO float data over the last four years, some aspects of the mesoscale variability of water masses in the Arabian Sea are described.

The Red Sea Water outflow is strong in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found there between 600 and 1000 m depths. The Red Sea Water is more dilute in the eastern part of the Gulf, and fragments of this ...

Femtosecond laser-induced breakdown spectroscopy of sea water

International Nuclear Information System (INIS)

Ilyin, Alexey A.; Golik, Sergey S.

2013-01-01

The composition of the line and band spectra of the plasma induced by a femtosecond laser pulse on the surface of sea water is determined. The temporal behaviors of the intensity of the continuum and the Ca II, Mg II and Na I lines are investigated. It is shown that the time dependence of the intensity of the Na I line is described by a monoexponential function. The characteristic decay times of the line intensities of Mg II and Na I were used to estimate the three-body recombination times. Using these values, we estimate the electron number density and the feasibility of Local Thermodynamic Equilibrium (LTE) criterion. A method involving excitation rate constants is proposed for the comparison of detection limits. For a plasma generated on a liquid surface, the following relation among detection limits will be obtained: LOD(Na) 2 were recorded. • Recombination determines characteristic decay time of line intensity. • Three-body recombination time was used to estimate electron density. • Excitation rate constants allow to determine relation of detection limits

Seasonal variability of sea surface chlorophyll-a of waters around ...

Indian Academy of Sciences (India)

days during 1978--1986 are processed to produce sea surface chlorophyll maps ... shallow water areas, in particular waters in Palk Bay and Gulf of Mannar, should be carried out in order .... The circulation penetrates deeper, affecting the.

Decadal shifts in autumn migration timing by Pacific Arctic beluga whales are related to delayed annual sea ice formation.

Science.gov (United States)

Hauser, Donna D W; Laidre, Kristin L; Stafford, Kathleen M; Stern, Harry L; Suydam, Robert S; Richard, Pierre R

2017-06-01

Migrations are often influenced by seasonal environmental gradients that are increasingly being altered by climate change. The consequences of rapid changes in Arctic sea ice have the potential to affect migrations of a number of marine species whose timing is temporally matched to seasonal sea ice cover. This topic has not been investigated for Pacific Arctic beluga whales (Delphinapterus leucas) that follow matrilineally maintained autumn migrations in the waters around Alaska and Russia. For the sympatric Eastern Chukchi Sea ('Chukchi') and Eastern Beaufort Sea ('Beaufort') beluga populations, we examined changes in autumn migration timing as related to delayed regional sea ice freeze-up since the 1990s, using two independent data sources (satellite telemetry data and passive acoustics) for both populations. We compared dates of migration between 'early' (1993-2002) and 'late' (2004-2012) tagging periods. During the late tagging period, Chukchi belugas had significantly delayed migrations (by 2 to >4 weeks, depending on location) from the Beaufort and Chukchi seas. Spatial analyses also revealed that departure from Beaufort Sea foraging regions by Chukchi whales was postponed in the late period. Chukchi beluga autumn migration timing occurred significantly later as regional sea ice freeze-up timing became later in the Beaufort, Chukchi, and Bering seas. In contrast, Beaufort belugas did not shift migration timing between periods, nor was migration timing related to freeze-up timing, other than for southward migration at the Bering Strait. Passive acoustic data from 2008 to 2014 provided independent and supplementary support for delayed migration from the Beaufort Sea (4 day yr -1 ) by Chukchi belugas. Here, we report the first phenological study examining beluga whale migrations within the context of their rapidly transforming Pacific Arctic ecosystem, suggesting flexible responses that may enable their persistence yet also complicate predictions of how

Circulation and hydrological characteristics of the North Aegean Sea: a contribution from real-time buoy measurements

Directory of Open Access Journals (Sweden)

K. NITTIS

2002-06-01

Full Text Available In the framework of the POSEIDON Project, a network of open sea oceanographic buoys equipped with meteorological and oceanographic sensors has been operational in the Aegean Sea since 1998. The analysis of upper-ocean physical data (currents at 3m, temperature and salinity at 3-40m depths collected during the last 2 years from the stations of the North Aegean basin indicates a strong temporal variability of flow field and hydrological characteristics in both synoptic and seasonal time scales. The northern part of the basin is mainly influenced by the Black Sea Water outflow and the mesoscale variability of the corresponding thermohaline fronts, while the southern stations are influenced by the general circulation of the Aegean Sea with strong modulations caused by the seasonally varying atmospheric forcing.

Recovery of uranium from sea water

International Nuclear Information System (INIS)

Tabushi, Iwao; Kobuke, Yoshiaki

1984-01-01

The present status of technology for the recovery of uranium has been reviewed. Adsorbent qualities were discussed in terms of three important criteria: adsorption rate, equilibrium adsorption and chemical as well as physical stability. It was elucidated that a significant improvement of the adsorption rate is most important. Efforts were made to clarify factors influencing the adsorption rate. A method to treat a tremendous amount of sea water is of much importance as well. Pumping-up and direct use of sea currents were compared with each other. It has been emphasized that the active utilization of the various advantages of the latter method is crucial for the realization of the recovery project. The physical capability of the method was illustrated. Some composite systems with electric power generation plants were also discussed. (author)

Assessment of sea water inundation along Daboo creek area in Indus Delta Region, Pakistan

Science.gov (United States)

Zia, Ibrahim; Zafar, Hina; Shahzad, Muhammad I.; Meraj, Mohsin; Kazmi, Jamil H.

2017-12-01

Indus Deltaic Region (IDR) in Pakistan is an erosion vulnerable coast due to the high deep water wave energy. Livelihood of millions of people depends on the fisheries and mangrove forests in IDR. IDR consists of many creeks where Daboo is a major creek located at southeast of the largest city of Pakistan, Karachi. Unfortunately, there has been no detailed study to analyze the damages of sea water intrusion at a large temporal and spatial scale. Therefore, this study is designed to estimate the effects of sea water inundation based on changing sea water surface salinity and sea surface temperature (SST). Sea surface salinity and SST data from two different surveys in Daboo creek during 1986 and 2010 are analyzed to estimate the damages and extent of sea water intrusion. Mean salinity has increased 33.33% whereas mean SST decreased 13.79% from 1987 to 2010. Spatio-temporal analysis of creek area using LANDSAT 5 Thematic mapper (TM) data for the years 1987 and 2010 shows significant amount of erosion at macro scale. Creek area has increased approximately 9.93% (260.86 m2 per year) which is roughly equal to 60 extensive sized shrimp farms. Further Land Use Land Cover (LULC) analyses for years 2001 and 2014 using LANDSAT 7 Enhanced Thematic Mapper Plus (ETM+) has indicated 42.3% decrease in cultivated land. Wet mud flats have spread out at the inner mouth of creek with enormous increase of 123.3%. Significant sea water intrusion has increased the area of barren land by 37.9%. This also resulted in overall decrease of 6.7% in area covered by mangroves. Therefore, this study recorded a significant evidence of sea water intrusion in IDR that has caused serious damages to community living in the area, economical losses. Additionally, it has also changed the environment by reducing creek biological productivity as reported by earlier studies over other regions of the world.

Sea water desalination utilizing waste heat by low temperature evaporation

International Nuclear Information System (INIS)

Raha, A.; Srivastava, A.; Rao, I.S.; Majumdar, M.; Srivastava, V.K.; Tewari, P.K.

2007-01-01

Economics of a process is controlled by management of energy and resources. Fresh water has become most valued resource in industries. Desalination is a process by which fresh water resource is generated from sea water or brackish water, but it is an energy intensive process. The energy cost contributes around 25-40% to the total cost of the desalted water. Utilization of waste heat from industrial streams is one of the ecofriendly ways to produce low cost desalted water. Keeping this in mind Low Temperature Evaporation (LTE) desalination technology utilizing low quality waste heat in the form of hot water (as low as 50 deg C) or low pressure steam (0.13 bar) has been developed for offshore and land based applications to produce high purity water (conductivity < 2μS/cm) from sea water. The probability of the scale formation is practically eliminated by operating it at low temperature and controlling the brine concentration. It also does not require elaborate chemical pretreatment of sea water except chlorination, so it has no environmental impact. LTE technology has found major applications in nuclear reactors where large quantity of low quality waste heat is available to produce high quality desalted water for make up water requirement replacing conventional ion exchange process. Successful continuous operation of 30 Te/day LTE desalination plant utilizing waste heat from nuclear research reactor has demonstrated the safety, reliability, extreme plant availability and economics of nuclear desalination by LTE technology. It is also proposed to utilize waste heat from Main Heat Transport (MHT) purification circuit of Advanced Heavy Water Reactor (AHWR) to produce about 250 Te/ day high quality desalinated water by Low Temperature Evaporation (LTE) process for the reactor make up and plant utilization. Recently we have commissioned a 50 Te/day 2-effect low temperature desalination plant with cooling tower where the specific energy and cooling water requirement are

Proposal and technological breakthrough of an integrated system for the complete usage of sea water

International Nuclear Information System (INIS)

Ohya, Haruhiko; Suzuki, Takashi; Nakao, Shin-ichi; Kato, Shigeru; Tsuji, Masamichi; Sugi, Jiro.

1996-01-01

Serious troubles regarding scale formation may occur when the amount of recovered water from sea water increases. The main constituents of the scale are CaCO 3 , Mg(OH) 2 , CaSO 4 and so on, all of which are salts of alkaline earth metals. Therefore, if a key technology is developed with which the main constituents of the scale, alkaline earth metal ions such as CaCO 3 , Mg(OH) 2 , CaSO 4 and so on, can be removed and/or separated from sea water the recovery of desalted water from raw sea water using high-pressure reverse osmosis (HPRO) can be increased up to 75-80%, the solubility limit of the remaining scale components. Then it will be possible to make use of all valuable materials that exist in sea water, using an integrated system that combines conventional recovery technologies with a set of the proposed technologies such as HPRO, an alkaline earth metal ions removal process, inorganic ion exchangers for recovering trace elements and so on. Furthermore, almost complete utilization of sea water may be accomplished by using of the brackish water by product for salt-resistant plants such as mangrove, salt bush and, if possible, gene-recombinated plants. (author)

Elephant overflows: Multi-annual variability in Weddell Sea Deep Water driven by surface forcing

Science.gov (United States)

Meijers, Andrew; Meredith, Michael; Abrahamsen, Povl; Naviera-Garabato, Alberto; Ángel Morales Maqueda, Miguel; Polzin, Kurt

2015-04-01

The volume of the deepest and densest water mass in Drake Passage, Lower Weddell Sea Deep Water (LWSDW), is shown to have been decreasing over the last 20 years of observations, with an associated reduction in density driven by freshening. Superimposed on this long term trend is a multi-annual oscillation with a period of 3-5 years. This variability only appears in Drake Passage; observations in the east of the Scotia Sea show a similar long term trend, but with no apparent multi-annual variability. Clues as to the source of this variability may be found on the continental slope at approximately 1000 m immediately north of Elephant Island on the northern tip of the Antarctic Peninsula. Here there is an intermittent westward flowing cold/fresh slope current whose volume and properties are strongly correlated with the LWSDW multi-annual variability, although leading the LWSDW by around one year. As the slope current and LWSDW are separated from each other both geographically and in water mass characteristics, their co-variability implies that they are responding to a common forcing, while the lag between deep LWSDW and shallow slope current provides information on the timescale of this response. A newly available high resolution temperature and salinity multi-year time series from the Elephant Island slope at 1000 m is compared with reanalysis and model derived surface fluxes, sea ice extent and wind stress. We find that there are strong positive relationships between the surface wind stress and heat flux over the shelf at the tip of the Antarctic Peninsula and the properties of the slope current at 1000 m on seasonal to annual timescales. We use tracer release experiments in the Southern Ocean State Estimate (SOSE) model to investigate the lag between the slope current and LWSDW timeseries and hypothesise that the observed multi-annual variability in both water masses is driven by surface forcing over the shelf and the overflow of modified water from the slope in

Management-focused approach to investigating coastal water-quality drivers and impacts in the Baltic Sea

Science.gov (United States)

Vigouroux, G.; Destouni, G.; Chen, Y.; Bring, A.; Jönsson, A.; Cvetkovic, V.

2017-12-01

Coastal areas link human-driven conditions on land with open sea conditions, and include crucial and vulnerable ecosystems that provide a variety of ecosystem services. Eutrophication is a common problem that is not least observed in the Baltic Sea, where coastal water quality is influenced both by land-based nutrient loading and by partly eutrophic open sea conditions. Robust and adaptive management of coastal systems is essential and necessitates integration of large scale catchment-coastal-marine systems as well as consideration of anthropogenic drivers and impacts, and climate change. To address this coastal challenge, relevant methodological approaches are required for characterization of coupled land, local coastal, and open sea conditions under an adaptive management framework for water quality. In this paper we present a new general and scalable dynamic characterization approach, developed for and applied to the Baltic Sea and its coastal areas. A simple carbon-based water quality model is implemented, dividing the Baltic Sea into main management basins that are linked to corresponding hydrological catchments on land, as well as to each other though aggregated three-dimensional marine hydrodynamics. Relevant hydrodynamic variables and associated water quality results have been validated on the Baltic Sea scale and show good accordance with available observation data and other modelling approaches. Based on its scalability, this methodology is further used on coastal zone scale to investigate the effects of hydrodynamic, hydro-climatic and nutrient load drivers on water quality and management implications for coastal areas in the Baltic Sea.

NOAA NDBC SOS, 2006-present, sea_water_temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have sea_water_temperature data. Because of the nature of SOS requests,...

The circulation of deep water in the Tasman and Coral seas

International Nuclear Information System (INIS)

Harries, J.R.

1976-07-01

The physical oceanography of the Tasman and Coral Seas is reviewed with an emphasis on the deep currents. There are many uncertainties in the deep circulation pattern. The available data are used to develop an idealised circulation to estimate the likely path taken by water flowing from a depth of 5000 m in the Tasman Sea. The model suggests that the water would finally reach the surface layers south of the Antarctic Convergence with a median delay of 600 years. (author)

The subtle effects of sea water acidification on the amphipod Gammarus locusta

Directory of Open Access Journals (Sweden)

J. Williams

2009-08-01

Full Text Available We report an investigation of the effects of increases in pCO2 on the survival, growth and molecular physiology of the neritic amphipod Gammarus locusta which has a cosmopolitan distribution in estuaries. Amphipods were reared from juvenile to mature adult in laboratory microcosms at three different levels of pH in nominal range 8.1–7.6. Growth rate was estimated from weekly measures of body length. At sexual maturity the amphipods were sacrificed and assayed for changes in the expression of genes coding for a heat shock protein (hsp70 gene and the metabolic enzyme glyceraldehyde-3-phosphate dehydrogenase (gapdh gene. The data show that the growth and survival of this species is not significantly impacted by a decrease in sea water pH of up to 0.5 units. Quantitative real-time PCR analysis indicated that there was no significant effect of growth in acidified sea water on the sustained expression of the hsp70 gene. There was a consistent and significant increase in the expression of the gapdh gene at a pH of ~7.5 which, when combined with observations from other workers, suggests that metabolic changes may occur in response to acidification. It is concluded that sensitive assays of tissue physiology and molecular biology should be routinely employed in future studies of the impacts of sea water acidification as subtle effects on the physiology and metabolism of coastal marine species may be overlooked in conventional gross "end-point" studies of organism growth or mortality.

A study on evaluation and analytical methods for groundwater flow with considering sea/fresh-water boundary. 1

International Nuclear Information System (INIS)

Anezaki, S.

1998-03-01

Sea/fresh-water boundary caused by density and concentration balance of sea-water and fresh-water is an important item for groundwater flow evaluation in deep underground near the coast. Also, in order to evaluate groundwater quality, it is important to understand the characteristics of sea/fresh-water boundary, for example boundary shape, salt distribution. In order to establish the evaluation and analytical methods for groundwater flow with considering sea/fresh-water boundary, we investigated the following items in this study. (1) Literature survey and data collection. (2) Investigation of analytical methods. (3) Planning of further study. (author). 78 refs

The path of the Levantine intermediate water to the Alboran sea

Science.gov (United States)

Font, Jordi

1987-10-01

The Levantine Intermediate Water (LIW) traditionally has been assumed to reach the Alboran Sea as a counter-current along the North African coast. Here data are presented that confirm the LIW flow through the sill that separates the Balearic Islands from the mainland, after contouring cyclonically the western Mediterranean along the continental slope. This seems to be a seasonal phenomenon related to the process of deep water formation in the northwestern Mediterranean and to fluctuations in the Ligurian Current. In winter the LIW can circulate across the Catalan Sea without remarkable dilution, while in summer the intermediate outflow has almost lost the LIW water mass characteristics.

Sea truth validation of sea WiFS ocean colour sensor in the coastal waters of the eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Desa, E.S.; Suresh, T.; Matondkar, S.G.P.; Desa, E.

In this paper we report bio-optical measurements made during an ocean colour validation cruise SK 149C in November 1999 of the research vessel Sagar Kanya in the coastal waters of the Eastern Arabian Sea. The chlorophyll concentration...

Long-term post-Chernobyl 90Sr and 137Cs profiles as the indicators of the large scale vertical water mixing in the Black Sea

International Nuclear Information System (INIS)

Egorov, V.N.; Stokozov, N.A.; Mirzoyeva, N.Y.

2002-01-01

The radioactive and chemical pollutions, eutrophic elements come to the surface water layer of the Black Sea from the territory of 22 countries. The self-purification of the surface water layer essentially depends from the vertical water mixing. The atmospheric fallout in the May 1986 after Chernobyl NPP accident were main source of the 137 Cs input in the Black Sea. The 90 Sr input to the Black Sea was caused by atmospheric fallout as well as the Dnieper River and Danube River runoff during of consequent years. 90 Sr and 137 Cs are conservative elements in a marine environment and could be used as tracers of the hydrological processes, including vertical water mixing. The aim of our investigations was an assessment of the large-scale vertical water exchange in the Black Sea on base of analysis time-series 90 Sr and 137 Cs vertical profiles

Optimizing desalinated sea water blending with other sources to meet magnesium requirements for potable and irrigation waters.

Science.gov (United States)

Avni, Noa; Eben-Chaime, Moshe; Oron, Gideon

2013-05-01

Sea water desalination provides fresh water that typically lacks minerals essential to human health and to agricultural productivity. Thus the rising proportion of desalinated sea water consumed by both the domestic and agricultural sectors constitutes a public health risk. Research on low-magnesium water irrigation showed that crops developed magnesium deficiency symptoms that could lead to plant death, and tomato yields were reduced by 10-15%. The World Health Organization (WHO) reported on a relationship between sudden cardiac death rates and magnesium intake deficits. An optimization model, developed and tested to provide recommendations for Water Distribution System (WDS) quality control in terms of meeting optimal water quality requirements, was run in computational experiments based on an actual regional WDS. The expected magnesium deficit due to the operation of a large Sea Water Desalination Plant (SWDP) was simulated, and an optimal operation policy, in which remineralization at the SWDP was combined with blending desalinated and natural water to achieve the required quality, was generated. The effects of remineralization costs and WDS physical layout on the optimal policy were examined by sensitivity analysis. As part of the sensitivity blending natural and desalinated water near the treatment plants will be feasible up to 16.2 US cents/m(3), considering all expenses. Additional chemical injection was used to meet quality criteria when blending was not feasible. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Red Sea Outflow Experiment (REDSOX): Descent and initial spreading of Red Sea Water in the northwestern Indian Ocean

Science.gov (United States)

Bower, A.; Johns, W.; Peters, H.; Fratantoni, D.

2003-04-01

Two comprehensive surveys were carried out during 2001 to investigate the dense overflow and initial spreading of Red Sea Water (RSW) in the Gulf of Aden. The cruises were timed to coincide with the climatological maximum (February) and minimum (August) periods of outflow transport. The surveys included high-resolution CTD/lowered ADCP/shipboard ADCP observations in the descending plume and in the western gulf, and trajectories from 50 acoustically-tracked RAFOS floats released at the center of the equilibrated RSW (650 m). The measurements reveal a complicated descending plume structure in the western gulf with three main pathways for the high salinity RSW. Different mixing intensities along these pathways lead to variable penetration depths of the Red Sea plume between 450-900 m in the Gulf of Aden. The observations also revealed the hydrographic and velocity structure of large, energetic, deep-reaching mesoscale eddies in the gulf that fundamentally impact the spreading rates and pathways of RSW. Both cyclones and anticyclones were observed, with horizontal scales up to 250 km and azimuthal speeds as high as 0.5 m/s. The eddies appear to reach nearly to the sea floor and entrain RSW from the western gulf at mid-depth. Post-cruise analysis of SeaWiffs imagery suggests that some of these eddies form in the Indian Ocean and propagate into the gulf.

Determination of trace amounts of cadmium in sea water by a flameless atomic absorption method

International Nuclear Information System (INIS)

Yamazoe, Seigo; Oshima, Shozo

1975-01-01

Determination of trace amounts of cadmium in sea water has been developed by a flameless atomic absorption method using a carbon rod atomizer. Sea water is diluted with isopropyl alcohol and the white salt formed is removed by filtration, then the filtrate is fed to the instrument as a sample for measurement. A complete separation of the salt is not needed in this pre-treatment. The effect of the residual salt can be avoided by separating the atomic absorption of cadmium and the molecular absorption of the residual salt by means of controlling the temperature and the time of ashing and atomization of the sample in the carbon rod. The repeatability and the accuracy are 2.0--8.5% in the coefficient of variation and 0.8--5.3% respectively. (auth.)

An improved model for the dielectric constant of sea water at microwave frequencies

Science.gov (United States)

Klein, L. A.; Swift, C. T.

1977-01-01

The advent of precision microwave radiometry has placed a stringent requirement on the accuracy with which the dielectric constant of sea water must be known. To this end, measurements of the dielectric constant have been conducted at S-band and L-band with a quoted uncertainty of tenths of a percent. These and earlier results are critically examined, and expressions are developed which will yield computations of brightness temperature having an error of no more than 0.3 K for an undisturbed sea at frequencies lower than X-band. At the higher microwave and millimeter wave frequencies, the accuracy is in question because of uncertainties in the relaxation time and the dielectric constant at infinite frequency.

Transport and hydraulically-induced recycling of phosphorous in the North Sea-Baltic Sea transition zone

DEFF Research Database (Denmark)

Kepp, Rikke; Struve, Anke; Christiansen, Christian

2006-01-01

to barotropic and tidal currents the gross transport is 5 times larger. The net transport is directed towards the North Sea mainly in the top 32 m of the water column but towards the Baltic Sea it occurs in the lower 5 m of the water column. The resulting transport of phosphorus is strongly affected by vertical...

Sea water desalination by horizontal tubes evaporator

International Nuclear Information System (INIS)

Mohammadi, H.K.; Mohit, M.

1986-01-01

Desalinated water supplies are one of the problems of the nuclear power plants located by the seas. This paper explains saline water desalination by a Horizontal Tube Evaporator (HTE) and compares it with flash evaporation. A thermo compressor research project using HTE method has been designed, constructed, and operated at the Esfahan Nuclear Technology Center ENTC. The poject's ultimate goal is to obtain empirical formulae based on data gathered during operation of the unit and its subsequent development towards design and construction of desalination plants on an industrial scale

Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

KAUST Repository

Bougouffa, Salim; Yang, J. K.; Lee, O. O.; Wang, Y.; Batang, Zenon B.; Al-Suwailem, Abdulaziz M.; Qian, P. Y.

2013-01-01

Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

KAUST Repository

Bougouffa, Salim

2013-03-29

Atlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from the Alphaproteobacteria-dominated deep sea to the Planctomycetaceae- or Deferribacteres-dominated interfaces to the Gammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

On the dense water spreading off the Ross Sea shelf (Southern Ocean)

Science.gov (United States)

Budillon, G.; Gremes Cordero, S.; Salusti, E.

2002-07-01

In this study, current meter and hydrological data obtained during the X Italian Expedition in the Ross Sea (CLIMA Project) are analyzed. Our data show a nice agreement with previous data referring to the water masses present in this area and their dynamics. Here, they are used to further analyze the mixing and deepening processes of Deep Ice Shelf Water (DISW) over the northern shelf break of the Ross Sea. In more detail, our work is focused on the elementary mechanisms that are the most efficient in removing dense water from the shelf: either classical mixing effects or density currents that interact with some topographic irregularity in order to drop to deeper levels, or also the variability of the Antarctic Circumpolar Current (ACC) which, in its meandering, can push the dense water off the shelf, thus interrupting its geostrophic flow. We also discuss in detail the (partial) evidence of dramatic interactions of the dense water with bottom particulate, of geological or biological origin, thus generating impulsive or quasi-steady density-turbidity currents. This complex interaction allows one to consider bottom particular and dense water as a unique self-interacting system. In synthesis, this is a first tentative analysis of the effect of bottom particulate on the dense water dynamics in the Ross Sea.

Effective ecological half-lives of Cs-137 for fishes controlled by their surrounding sea-waters

International Nuclear Information System (INIS)

Morita, T.; Yoshida, K.

2004-01-01

National Research Institute of Fisheries Science (NRIFS) has carried out the long term monitoring program for radioactive pollution in marine organisms caught around Japan in order to confirm the safety of marine organisms as food source. Main radionuclide in our monitoring program is Cs-137 because it has the relatively high radiotoxicity and the long term physical half-life (about 30.1 y), and tends to accumulate in the muscle. Recently, the effective ecological half-lives have been introduced to estimate the recovery time from radioactive pollution, and been applicable to various ecosystems. In this study, effective ecological half-lives of Cs-137 for some fishes were calculated from our long term monitoring data. It is known that fish species have each effective ecological half-lives. However, it has been unclear what change the effective ecological half-lives of Cs-137 for fishes. Fishes intake Cs-137 through food chain and directly from their surrounding sea-waters. Accordingly, the effective ecological half-lives of Cs-137 for some fishes would be controlled by the effective environment half-lives of Cs-137 for their surrounding sea-waters. There is difference in effective environment half-lives of Cs-137 between the open ocean and the coastal sea-waters because they have the different input sources of Cs-137. Some fishes move between the open ocean and the coastal areas, and therefore their effective ecological half-lives of Cs-137 are influenced by the effective environment half-lives of Cs-137 for sea-waters of both areas. Consequently, the differences in effective ecological half-lives of Cs-137 among fish species would depend the rate of coastal area in their lives. (author)

Water mass census in the Nordic seas using climatological and observational data sets

International Nuclear Information System (INIS)

Piacsek, S.; Allard, R.; McClean, J.

2008-01-01

We have compared and evaluated the water mass census in the Greenland-Iceland-Norwegian (Gin) Sea area from climatologies, observational data sets and model output. The four climatologies evaluated were: the 1998 and 2001 versions of the World Ocean Atlas (WOA98, WOA01), and the United States Navy's GDEM90 (Generalized Digital Environmental Model) and MODAS01 (Modular Ocean Data Assimilation System) climatologies. Three observational data sets were examined: the multidecadal (1965-1995) set contained on the National Oceano- graphic Data Centre's (NODC) WOD98 (World Ocean Data) Cd-Rom, and two seasonal data sets extracted from observations taken on six cruises by the SACLANT Research Center (SACLANTCEN) of NATO/Italy between 1986-1989. The model data is extracted from a global model run at 1/3 degree resolution for the years 1983-1997, using the Pop (Parallel Ocean Program) model of the Los Alamos National Laboratory. The census computations focused on the Norwegian Sea, in the southern part of the Gin Sea, between 10 0 W-10 0 E and 60 0 N-70 0 N, especially for comparisons with the hydro casts and the model. Cases of such evaluation computations included: (a) short term comparisons with quasi-synoptic CTD surveys carried out over a 4-year period in the southeastern Gin Sea; (b) climatological comparisons utilizing all available casts from the WOD98 Cd-Rom, with four climatologies; and (c) a comparison between the WOA01 climatology and the Pop model output ending in 1997. In this region in the spring, the fraction of ocean water that has salinity above 34.85 is ∼94%, and that has temperatures above 0 0 C is ∼33%. Three principal water masses dominated the census: the Atlantic water A W, the deep water D W and an intermediate water mass defined as Lower Arctic Intermediate Water (LAIW). Besides these classes, both the climatologies and the observations exhibited the significant presence of deep water masses with T-S characteristics that do not fall into the named

Splitting of Atlantic water transport towards the Arctic Ocean into the Fram Strait and Barents Sea Branches - mechanisms and consequences

Science.gov (United States)

Beszczynska-Möller, Agnieszka; Skagseth, Øystein; von Appen, Wilken-Jon; Walczowski, Waldemar; Lien, Vidar

2016-04-01

Greenland Seas, strengthening the coherent shelf break current along the eastern rim of the Nordic Seas. However, long-term moored observations in the Barents Sea Opening and the northern Fram Strait reveal that Atlantic water transport in both branches vary with the opposite phase on the inter-annual time scale. This suggests that in the periods of weaker Atlantic water flow in the shelf break current, the increased transport in the Barents Sea Branch can also further weaken the Fram Strait Branch. The anomalously warm AW inflow in the Fram Strait Branch has a strong impact on sea ice conditions in the southern Nansen Basin, while positive transport anomalies in the Barents Sea Branch increase availability of oceanic heat in the Barents Sea and subsequently influence its sea ice cover. Here we present the results of the Polish-Norwegian project PAVE, focusing on variability and recent warming of the Atlantic Water inflow through Fram Strait and Barents Sea, and addressing mechanisms that govern the AW split between both branches and its potential consequences.

Note On The Ross Sea Shelf Water Downflow Processes (antarctica)

Science.gov (United States)

Bergamasco, A.; Defendi, V.; Spezie, G.; Budillon, G.; Carniel, S.

In the framework of the CLIMA Project of the Italian National Program for Research in Antarctica, three different experimental data sets were acquired along the continental shelf break; two of them (in 1997 and 2001) close to Cape Adare, the 1998 one in the middle of the Ross Sea (i.e. 75 S, 177 W). The investigations were chosen in order to explore the downslope flow of the bottom waters produced in the Ross Sea, namely the High Salinity Shelf Water (HSSW, the densest water mass of the southern ocean coming from its formation site in the polynya region in Terra Nova bay), and the Ice Shelf Water (ISW, originated below the Ross Ice Shelf and outflowing northward). Both bottom waters spill over the shelf edge and mix with the Circumpolar Deep Water (CDW) contributing to the formation of the Antarctic Bottom Waters (AABW). Interpreting temperature, salinity and density maps in terms of cascading processes, both HSSW and ISW overflows are evidenced during, respectively, 1997 and 1998. During the 2001 acquisition there is no presence of HSSW along the shelf break, nevertheless distribution captures the evidence of a downslope flow process.

Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

DEFF Research Database (Denmark)

Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

1986-01-01

Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were co...

Analysis of Polluted Oily Water Management in Klaipėda Sea Port Klaipėda sea port contaminated oily water management analysis

OpenAIRE

Goda Zobėlaitė; Jolanta Dvarionienė; Gediminas Stonkus

2010-01-01

Lithuania is one of the countries that have ratified the Marpol 73/78 Convention which foresees the tools of reduction and prevention of sea pollution with bilge water and other substances. The Directive of the European Parliament and Council 2000/59/EB is addressed to the reduction of waste on board of ships and its wash overboard..
Analysis of the ships entering Klaipėda Sea Port has estimated that oil waste comprises about 74 % of the whole collected waste amount. The analysis o...

Desalination of brackish and sea water

International Nuclear Information System (INIS)

Shukla, Dilip R.

2005-01-01

In Pali, Rajasthan, a population of 4 lacs gets about 6 million liters of water. Only 34 out of 116 municipalities in AP get regular water. Desalination found acceptance because of the decreasing water table leading to high salinity and making conventional treatment methods irrelevant. While choosing amongst the competitive desalination techniques that are available today for conversion of large quantities of saline water, Reverse Osmosis (RO) and distillation techniques stand out. RO rules the brackish water market where feed salinity is over 700 mg/L. Waste heat is nowadays a non-entity in power plants due to the developments of waste heat recovery systems in power plant technology. Most of the large plants tend to choose thermal desalination. Improved RO economics have in turn increased the attractiveness and use of seawater reverse osmosis (SWRO) technology for many large drinking water projects through out the world. Energy cost is the single largest factor in the cost of Sea Water System (usually 20 to 30% of total cost of water). Nuclear Power Corporation, Kudankulam proposed to build a SW desalination system based on RO technology to meet the water requirement of the Anu Vijay Nagar township and Nuclear Power Station. Energy recovery turbine helps reduce the overall system energy requirement. (author)

Rapid changes in surface water carbonate chemistry during Antarctic sea ice melt

Science.gov (United States)

Jones, Elizabeth M.; Bakker, Dorothee C. E.; Venables, Hugh J.; Whitehouse, Michael J.; Korb, Rebecca E.; Watson, Andrew J.

2010-11-01

ABSTRACT The effect of sea ice melt on the carbonate chemistry of surface waters in the Weddell-Scotia Confluence, Southern Ocean, was investigated during January 2008. Contrasting concentrations of dissolved inorganic carbon (DIC), total alkalinity (TA) and the fugacity of carbon dioxide (fCO2) were observed in and around the receding sea ice edge. The precipitation of carbonate minerals such as ikaite (CaCO3.6H2O) in sea ice brine has the net effect of decreasing DIC and TA and increasing the fCO2 in the brine. Deficits in DIC up to 12 +/- 3 μmol kg-1 in the marginal ice zone (MIZ) were consistent with the release of DIC-poor brines to surface waters during sea ice melt. Biological utilization of carbon was the dominant processes and accounted for 41 +/- 1 μmol kg-1 of the summer DIC deficit. The data suggest that the combined effects of biological carbon uptake and the precipitation of carbonates created substantial undersaturation in fCO2 of 95 μatm in the MIZ during summer sea ice melt. Further work is required to improve the understanding of ikaite chemistry in Antarctic sea ice and its importance for the sea ice carbon pump.

Mineralization sources of surface and subsurface waters at the southeastern edges of dead sea basin in Jordan

International Nuclear Information System (INIS)

AbdEl-Samie, S.G.; EL-Shahat, M.F.; Al-Nawayseh, K.M.

2004-01-01

Surface and ground waters within the shallow-Alluvial and deep- Kurnub aquifers in four areas (Issal, Mazraa, Safi and Haditha) in the southeastern edge of the Dead Sea basin were evaluated according to Salinity changes and water quality degradation. Chemical and isotopic parameters were integrated to follow the chemical evolutionary trend and sources of mineralization in these waters. The isotopic results indicated that the main recharge sources Issal. Mazraa and Safi groundwaters are the flash flood and base flow water from the eastern highland through wadies. In Safi area, the groundwater that mixed with other depleted source could be paleowater seeped from older formation. The depletion in stable isotopic values with low d-parametewr (less than 10%) for Haditha groundwater confirms that the replenishment to the aquifer (Kurnub sandstone) had been formed during the pluvial time. The chemical data showed that the base flow water from the eastern highland is denoted by the least salinity values, whereas drainage water acquired the highest values as aa result of receiving a considerable amount of the remaining water from salt extraction processes. The groundwater in Safi wells has low salt content with respect to the other areas taping the same aquifer. The elevation in Ca and Mg ions reflects the dissolution of Ca-Mg rich minerals that actively reached saturation with respect to calcite and dolomite in all samples except Haditha deep aquifer due to its low ph values. In spite of the meteoric origin of the recharge source, the presence of MgCl 2 and CaCl 2 salts in almost all samples changed the water character to be old or recent marine genesis. This points to the effect of Dead Sea in both surface and ground waters. The obvious depletion in O-18 and isotopes for all ground waters samples with respect to the positive values of Dead Sea sample is good indicative for non mixing trend with Dead Sea water in the Alluvial and Kurnub aquifers

Basin Economic Allocation Model (BEAM): An economic model of water use developed for the Aral Sea Basin

Science.gov (United States)

Riegels, Niels; Kromann, Mikkel; Karup Pedersen, Jesper; Lindgaard-Jørgensen, Palle; Sokolov, Vadim; Sorokin, Anatoly

2013-04-01

The water resources of the Aral Sea basin are under increasing pressure, particularly from the conflict over whether hydropower or irrigation water use should take priority. The purpose of the BEAM model is to explore the impact of changes to water allocation and investments in water management infrastructure on the overall welfare of the Aral Sea basin. The BEAM model estimates welfare changes associated with changes to how water is allocated between the five countries in the basin (Kazakhstan, Kyrgyz Republic, Tajikistan, Turkmenistan and Uzbekistan; water use in Afghanistan is assumed to be fixed). Water is allocated according to economic optimization criteria; in other words, the BEAM model allocates water across time and space so that the economic welfare associated with water use is maximized. The model is programmed in GAMS. The model addresses the Aral Sea Basin as a whole - that is, the rivers Syr Darya, Amu Darya, Kashkadarya, and Zarafshan, as well as the Aral Sea. The model representation includes water resources, including 14 river sections, 6 terminal lakes, 28 reservoirs and 19 catchment runoff nodes, as well as land resources (i.e., irrigated croplands). The model covers 5 sectors: agriculture (crops: wheat, cotton, alfalfa, rice, fruit, vegetables and others), hydropower, nature, households and industry. The focus of the model is on welfare impacts associated with changes to water use in the agriculture and hydropower sectors. The model aims at addressing the following issues of relevance for economic management of water resources: • Physical efficiency (estimating how investments in irrigation efficiency affect economic welfare). • Economic efficiency (estimating how changes in how water is allocated affect welfare). • Equity (who will gain from changes in allocation of water from one sector to another and who will lose?). Stakeholders in the region have been involved in the development of the model, and about 10 national experts, including

Combining urbanization and hydrodynamics data to evaluate sea level rise impacts on coastal water resources

Science.gov (United States)

Young, C. R.; Martin, J. B.

2016-02-01

Assessments of the potential for salt water intrusion due to sea level rise require consideration of both coastal hydrodynamic and human activity thresholds. In siliciclastic systems, sea level rise may cause salt intrusion to coastal aquifers at annual or decadal scales, whereas in karst systems salt intrudes at the tidal scalse. In both cases, human activity impacts the freshwater portion of the system by altering the water demand on the aquifer. We combine physicochemical and human activity data to evaluate impact of sea level rise on salt intrusion to siliclastic (Indian River Lagoon, Fl, USA) and karst (Puerto Morelos, Yucatan, Mexico) systems under different sea level rise rate scenarios. Two hydrodynamic modeling scenarios are considered; flux controlled and head controlled. Under a flux controlled system hydraulic head gradients remain constant during sea level rise while under a head controlled system hydraulic graidents diminish, allowing saltwater intrusion. Our model contains three key terms; aquifer recharge, groundwater discharge and hydraulic conductivity. Groundwater discharge and hydraulic conductivity were calculated based on high frequency (karst system) and decadal (siliciclastic system) field measurements. Aquifer recharge is defined as precipitation less evapotranspiration and water demand was evaluated based on urban planning data that provided the regional water demand. Water demand includes agricultural area, toursim, traffic patterns, garbage collection and total population. Water demand was initially estimated using a partial leaset squares regression based on these variables. Our model indicates that water demand depends most on agricultural area, which has changed significantly over the last 30 years. In both systems, additional water demand creates a head controlled scenario, thus increaseing the protential fo salt intrusion with projected sea level rise.

Water circulation and recharge pathways of coastal lakes along the southern Baltic Sea in northern Poland

Directory of Open Access Journals (Sweden)

Cieśliński Roman

2016-12-01

Full Text Available The purpose of this paper is to describe water circulation patterns for selected lakes found along the Baltic coast in northern Poland and to determine primary recharge mechanisms or pathways that produce an influx or loss of lake water. A secondary purpose of the paper is to determine the magnitude of recharge for each studied source of water – river water influx, surface runoff from direct catchments, forced influx from polders surrounding lakes, and periodic marine water intrusions from the nearby Baltic Sea. It is also important to determine the magnitude of water outflow from lakes to the sea via existing linkages as well as to compare horizontal influx and outflow data. The study area consisted of five lakes located along the Baltic Sea in northern Poland: Łebsko, Gardno, Bukowo, Kopań, Resko Przymorskie. The main driving force of the studied lakes are large rivers that drain lake catchment areas and periodic brackish water intrusions by the Baltic Sea.

Distribution of total alkalinity and pH in the Ross Sea (Antarctica waters during austral summer 2008

Directory of Open Access Journals (Sweden)

Paola Rivaro

2014-10-01

Full Text Available Measurements of total alkalinity (AT and pH were made in the Ross Sea in January–February 2008 in order to characterize the carbonate system in the Ross Sea and to evaluate the variability associated with different water masses. The main water masses of the Ross Sea, Antarctic Surface Water, High Salinity Shelf Water (HSSW, Deep Ice Shelf Water, Circumpolar Deep Water (CDW and Antarctic Bottom Water, were identified on the basis of the physical and chemical data. In particular, the AT ranged between 2275 and 2374 µmol kg−1 with the lowest values in the surface waters (2275–2346 µmol kg−1, where the influence of the sea-ice melting and of the variability of the physical properties was significant. In the deep layers of the water column, the AT maxima were measured in correspondence to the preferential pathways of the spreading HSSW. The pH had variable values in the surface layer (7.890–8.033 with the highest values in Terra Nova Bay and Ross Sea polynyas. A low pH (7.969±0.025 traced the intrusion of the CDW in the Ross Sea shelf area. All samples revealed waters that were oversaturated with respect to both calcite and aragonite, but near corrosive levels of aragonite saturation state (Ω ca. 1.1–1.2 were associated with the entrainment of CDW over the slope. Aragonite undersaturation is of particular concern for the zooplankton species comprising to calcifying organisms such as pteropods. The partial pressure of CO2 at the sea surface was undersaturated with respect to the atmospheric value, particularly in Terra Nova Bay and the Ross Sea polynyas, but a large variability in the sea–air CO2 fluxes was observed associated with different responses in the strength of the biological and physical processes.

Kinetics of marine surfactant adsorption at an air water interface. Baltic Sea studies

Directory of Open Access Journals (Sweden)

Stanis³aw J. Pogorzelski

2001-12-01

Full Text Available The paper contains the results of studies of natural surface film adsorption kinetics carried out in inland waters and in shallow offshore regions of the Baltic Sea during 2000-01 under calm sea conditions. The novel approach presented here for the adsorption dynamics is based on the mixed kinetic-diffusion model and analyses of the surface pressure-time plots at short (t ->0 and long( t -> ∞ adsorption time intervals. Values of the effective relative diffusion coefficient Deff / D (= 0.008-0.607 and energy barrier for adsorption Ea / RT (= 0.49-7.10 agree well with the data reported for model non-ionic surfactant solutions of pre-cmc concentrations. Wind speed is one of the factors affecting the adsorption barrier via the increased surface pressure of the natural film exposed to wind shear stress (~ U102, and enters the relation Ea / RT = 1.70 U101/3.

Synthetic sea water - An improved stress corrosion test medium for aluminum alloys

Science.gov (United States)

Humphries, T. S.; Nelson, E. E.

1973-01-01

A major problem in evaluating the stress corrosion cracking resistance of aluminum alloys by alternate immersion in 3.5 percent salt (NaCl) water is excessive pitting corrosion. Several methods were examined to eliminate this problem and to find an improved accelerated test medium. These included the addition of chromate inhibitors, surface treatment of specimens, and immersion in synthetic sea water. The results indicate that alternate immersion in synthetic sea water is a very promising stress corrosion test medium. Neither chromate inhibitors nor surface treatment (anodize and alodine) of the aluminum specimens improved the performance of alternate immersion in 3.5 percent salt water sufficiently to be classified as an effective stress corrosion test method.

Application of anion-exchange techniques to the determination of traces of molybdenum in sea-water

International Nuclear Information System (INIS)

Kiriyama, T.; Kuroda, R.

1984-01-01

A combined ion-exchange spectrophotometric method has been developed for the determination of molybdenum in sea-water. Molybdenum is sorbed strongly on Amberlite CG 400 (Cl - ) at pH 3 from sea-water containing ascorbic acid and is easily eluted with 6 M nitric acid. Molybdenum in the effluent can be determined spectrophotometrically with potassium thiocyanate and stannous chloride. The combined method allows selective and sensitive determination of traces of molybdenum in sea-water. The precision of the method is 2% at a molybdenum level of approx. 10 μg/l. (author)

Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports.

Science.gov (United States)

Daryabor, Farshid; Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

2016-01-01

A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.

Saharan Dust Deposition May Affect Phytoplankton Growth in the Mediterranean Sea at Ecological Time Scales

Science.gov (United States)

Gallisai, Rachele; Peters, Francesc; Volpe, Gianluca; Basart, Sara; Baldasano, José Maria

2014-01-01

The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer. PMID:25333783

Caspian Sea water balance and dynamics studies using anthropogenic radionuclides: Implications for environmental changes

International Nuclear Information System (INIS)

Oregioni, B.; Gastaud, J.; Pham, M.K.; Povinec, P.P.

2002-01-01

Full text: Environmental changes in the Caspian Sea have recently become of great interest in connection with fluctuations in sea level changes. Radioactive and stable isotopes have been used as powerful tracers to investigate water balance and dynamics and have contributed significantly to understanding climatically driven environmental changes in the Caspian Sea. The Caspian Sea is the world largest inland water body with a surface area of about 386000 km 2 and a volume of about 67000 km 3 , located in a large continental depression about 28 m below sea level. With no surface outlet, the Caspian Sea is particularly sensitive to climatic variations. The drainage area of the Caspian Sea is approximately 3.7 million square kilometers. The Volga, Ural and Terek empty into the North Caspian, with their combined annual flow accounting for 88% of all water entering the sea. The Sulak, Samur, Kura and a number of small rivers contribute about 7% of the inflow, the remainder comes from the rivers of the Iranian shore. The Caspian Sea is divided into three basins with approximately the same surface. The North Caspian Basin, maximum depth 15 m, average depth 5 m, contains 1% of the total water. The Middle Caspian (or Central) Basin has a maximum depth of 800 m and contains 22% of the total water. The South Caspian Basin, maximum depth 1024 m, average depth 330 m, contains 77% of the total Caspian Sea water. Recently there have been concerns over the environmental conditions of the Caspian Sea, especially over observed sea level changes, which have had a strong impact on the region. Anthropogenic radionuclides like 90 Sr, 137 Cs and 239 , 240 Pu are particularly useful tracers for the investigation of water dynamics. Two research-training cruises were carried out in September 1995 and August-September 1996. At every station, 60-70 liters samples of seawater from different depths were processed for sequential separation of plutonium, cesium and strontium isotopes. This was

Use of adsorption colloidal flotation for sea water microelement extraction

International Nuclear Information System (INIS)

Zhorov, V.A.; Barannik, V.P.; Lyashenko, S.V.; Kirchanova, A.I.; Kobylyanskaya, A.G.

1976-01-01

The colloidal flotation is studied of copper, molybdenum and uranium from sea water, a hydrated iron oxide being used as a sorbent. Used as particle collectors are octadecanoic and indolyloleic acids, and as foamers-''Stearox 6''. Optimal conditions for the separation of copper, uranium and molybdenum from sea water have been found. The sorption isotherm equation is shown as being suitable for the description of the flotation process as regards these elements. The colloidal flotation process for the case under study is shown to obey the law of mass action in the pH range 0.5 to 0.7 and on the sorbent mass variation from 0.1 to 5.0 mg

Plastic in surface waters of the Inside Passage and beaches of the Salish Sea in Washington State.

Science.gov (United States)

Davis, Wallace; Murphy, Anne G

2015-08-15

We summarize results of two independent studies on plastic pollution in the marine environment that overlap in time and space. One study evaluated the abundance of anthropogenic debris on 37 sandy beaches bordering the Salish Sea in Washington State while the other characterized plastic debris in surface waters of the Salish Sea and the Inside Passage to Skagway, Alaska. Both studies concluded that foam, primarily expanded polystyrene was the dominant pollutant. Plastic was found in surface waters the full length of the Inside Passage but was concentrated near harbors. At the wrack line, an average square meter of Washington's 1180km of sandy beaches in the Salish Sea had 61 pieces of anthropogenic debris weighing approximately 5g. The total loading for the entire 1m wide band is estimated to be 72,000,000 pieces and 5.8metric tons. Most anthropogenic debris on beaches is generated within the region. Copyright © 2015 Elsevier Ltd. All rights reserved.

Decline of deep and bottom water ventilation and slowing down of anthropogenic carbon storage in the Weddell Sea, 1984-2011

NARCIS (Netherlands)

Huhn, Oliver; Rhein, Monika; Hoppema, Mario; van Heuven, Steven

We use a 27 year long time series of repeated transient tracer observations to investigate the evolution of the ventilation time scales and the related content of anthropogenic carbon (C-ant) in deep and bottom water in the Weddell Sea. This time series consists of chlorofluorocarbon (CFC)

The ships' ballast water impact on the Black Sea marine environment

Science.gov (United States)

Acomi, Nicoleta; Acomi, Ovidiu

2015-04-01

Ships use ballast water to provide stability during voyages. This type of seawater loaded on board from one geographical area and discharged in very different port areas as ballasting practice, turned into a vector for spreading the non-native sea life species. The reduction and limitation of invasive species is a problem that the modern world addresses. Thus, the International Maritime Organization (IMO) developed the BWM 2004 Convention. Adopting international regulations influences the socio-economic sector and this is the reason why the ballast water, the subject of this paper, has been on the IMO Marine Environment Protection Committee's agenda for more than 10 years, while the Convention has not yet been ratified and enforced. Although the Black Sea was subject to incidents regarding the invasive species the Romanian Government, as member of the IMO, did not ratify the Convention. The Black Sea was the subject of four major incidents regarding the ships' ballast water. One of them refers to the North American Comb Jelly, native from the Eastern Seaboard of America, introduced in the Black, Azov and Caspian Seas and seriously affecting the Romanian coastal environment in the 1990's. This invasive species has negative impacts: it reproduces rapidly under favourable conditions, it feeds excessively on zooplankton, it depletes zooplankton stocks, altering the food web and the ecosystem functionality, and contributed significantly to the collapse of Black and Azov Sea fisheries in the 1990s, with massive economic and social impact. There are studies for identifying the invasive species for the Black sea, structured in a database for marine species - the Black Sea Red Data Book. For these invasive species, there have been identified and developed charts to emphasize their ways of migration into the Black Sea. This paper aims to analyse the marine traffic in Romanian ports, broken down according with seasons and types of vessels, and to assess its relationship with

An Excel Macro to Plot the HFE-Diagram to Identify Sea Water Intrusion Phases.

Science.gov (United States)

Giménez-Forcada, Elena; Sánchez San Román, F Javier

2015-01-01

A hydrochemical facies evolution diagram (HFE-D) is a multirectangular diagram, which is a useful tool in the interpretation of sea water intrusion processes. This method note describes a simple method for generating an HFE-D plot using the spreadsheet software package, Microsoft Excel. The code was applied to groundwater from the alluvial coastal plain of Grosseto (Tuscany, Italy), which is characterized by a complex salinization process in which sea water mixes with sulfate or bicarbonate recharge water. © 2014, National GroundWater Association.

129I/127I ratios in Scottish coastal surface sea water: Geographical and temporal responses to changing emissions

International Nuclear Information System (INIS)

Schnabel, Christoph; Olive, Valerie; Atarashi-Andoh, Mariko; Dougans, Andrew; Ellam, Robert M.; Freeman, Stewart; Maden, Colin; Stocker, Martin; Synal, Hans-Arno; Wacker, Lukas; Xu Sheng

2007-01-01

This work constitutes the first survey of I isotope ratios for Scottish sea water including the first data for the west of Scotland. These data are of importance because of the proximity to the world's second largest emission source of 129 I to the sea, the Sellafield nuclear reprocessing plant, because of the increasing importance of the sea to land transfer of 129 I and also as input data for dose estimates based on this pathway of 129 I. 129 I/ 127 I ratios in SW Scotland reached 3 x 10 -6 in 2004. No strong variation of I isotope ratios was found from 2003 to 2005 in Scottish sea waters. Iodine isotope ratios increased by about a factor of 6 from 1992 to 2003 in NE Scotland, in agreement with the increase of liquid 129 I emissions from Sellafield over that time period. It is demonstrated that 129 I/ 127 I ratios agree better than 129 I concentrations for samples from similar locations taken in very close temporal proximity, indicating that this ratio is more appropriate to interpret than the radionuclide concentration

Spatial distribution of per- and polyfluoroalkyl compounds in coastal waters from the East to South China Sea

International Nuclear Information System (INIS)

Cai Minghong; Zhao Zhen; Yang Haizhen; Yin Zhigao; Hong Qingquan; Sturm, Renate; Ebinghaus, Ralf; Ahrens, Lutz; Cai Minggang; He, Jianfeng; Xie Zhiyong

2012-01-01

The spatial distribution of per- and polyfluoroalkyl compounds (PFCs) were investigated in coastal waters collected onboard research vessel Snow Dragon from the East to South China Sea in 2010. All samples were prepared by solid-phase extraction and analyzed using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(−)ESI-MS/MS). Concentrations of 9 PFCs, including C 4 and C 8 (PFBS, PFOS) perfluoroalkyl sulfonate (PFSAs), C 5 –C 9 and C 13 (PFPA, PFHxA, PFHpA, PFOA, PFNA, PFTriDA) perfluoroalkyl carboxylates (PFCAs), and N-ethyl perfluorooctane sulfonamide (EtFOSA) were quantified. The ΣPFC concentrations ranged from 133 pg/L to 3320 pg/L, with PFOA (37.5–1541 pg/L), PFBS (23.0–941 pg/L) and PFHpA (0–422 pg/L) as dominant compounds. Concentrations of PFCs were greater in coastal waters along Shanghai, Ningbo, Taizhou, Xiamen and along coastal cities of the Guangdong province compared to less populated areas along the east Chinese coast. Additionally, the comparison with other seawater PFC measurements showed lower levels in this study. - Highlights: ► Concentrations of various ionic PFCs were firstly quantified in coastal waters of China Sea for the first time. ► PFOA and PFBS, PFHxA, PFNA, PFOS, PFHpA were positively correlated which indicates that the same sources. ► The result of this study is useful for global transport models of PFCs. - Concentrations of 9 PFCs were quantified in coastal waters from the East to South China Sea for the first time.

Thermal biology of sea snakes and sea kraits.

Science.gov (United States)

Heatwole, Harold; Grech, Alana; Monahan, John F; King, Susan; Marsh, Helene

2012-08-01

Temperature probably had no direct effect on the evolution of sea kraits within their center of origin, a geologically stable thermal zone straddling the equator, but may have indirectly affected expansions and contractions in distributions beyond that zone through global fluctuations that caused alternation of higher and lower sea levels. The northern limit of the Laticauda colubrina complex seems to be the 20°C isotherm; in the south, the range does not reach that isotherm because there is no land (also a habitat requirement of sea kraits) within the zone of suitable temperature. The relationship of temperature to the pattern of geographic variation in morphology supports either the hypothesis of peripheral convergence or the developmental hypothesis but does not distinguish between them. Quadratic surfaces relating cumulative scores for coloration and morphological characters to global position showed a strong latitudinal component and an even stronger longitudinal one in which the direction of the latitudinal effect was reversed between east and west. A multivariate analysis revealed that while morphological characters vary significantly by location and climate when tested separately, when the influence of location on morphology is taken into account, no residual relationship between climate and morphology remains. Most marine snakes have mean upper temperature tolerances between 39°C and 40°C and operate at temperatures much nearer their upper thermal limits than their lower limits but still avoid deleterious extremes by diving from excessively hot water to deeper, cooler strata, and by surfacing when water is cold. At the surface in still water in sunlight, Pelamis can maintain its body temperature slightly above that of the water, but whether this is significant in nature is questionable. As temperature falls below 18-20°C, survival time is progressively reduced, accompanied by the successive occurrence of cessation of feeding, cessation of swimming, and

Cloud screening and melt water detection over melting sea ice using AATSR/SLSTR

Science.gov (United States)

Istomina, Larysa; Heygster, Georg

2014-05-01

With the onset of melt in the Arctic Ocean, the fraction of melt water on sea ice, the melt pond fraction, increases. The consequences are: the reduced albedo of sea ice, increased transmittance of sea ice and affected heat balance of the system with more heat passing through the ice into the ocean, which facilitates further melting. The onset of melt, duration of melt season and melt pond fraction are good indicators of the climate state of the Arctic and its change. In the absence of reliable sea ice thickness retrievals in summer, melt pond fraction retrieval from satellite is in demand as input for GCM as an indicator of melt state of the sea ice. The retrieval of melt pond fraction with a moderate resolution radiometer as AATSR is, however, a non-trivial task due to a variety of subpixel surface types with very different optical properties, which give non-unique combinations if mixed. In this work this has been solved by employing additional information on the surface and air temperature of the pixel. In the current work, a concept of melt pond detection on sea ice is presented. The basis of the retrieval is the sensitivity of AATSR reflectance channels 550nm and 860nm to the amount of melt water on sea ice. The retrieval features extensive usage of a database of in situ surface albedo spectra. A tree of decisions is employed to select the feasible family of in situ spectra for the retrieval, depending on the melt stage of the surface. Reanalysis air temperature at the surface and brightness temperature measured by the satellite sensor are analyzed in order to evaluate the melting status of the surface. Case studies for FYI and MYI show plausible retrieved melt pond fractions, characteristic for both of the ice types. The developed retrieval can be used to process the historical AATSR (2002-2012) dataset, as well as for the SLSTR sensor onboard the future Sentinel-3 mission (scheduled for launch in 2015), to keep the continuity and obtain longer time sequence

Strontium-90 and cesium-137 in sea water; April, 1978 to March, 1979

International Nuclear Information System (INIS)

1979-01-01

The samples of rain and dry fallout, air-borne dust, service water and fresh water, soil, sea water, sea sediment, total diet, rice, milk, vegetables, tea, fish, shellfishes and seaweed, and fresh water fishes, their sampling and prior treatment are described. The methods of separating Sr-90 and Cs-137 and their measurement are explained. The estimations of stable Sr, K and Ca are made by atomic absorption spectroscopy, flame spectrophotometry and potassium permanganate titration, respectively. The general plan of radioactivity survey in Japan is shown. As the environmental data, the results of Sr-90 and Cs-137 in sea water obtained from April, 1978, to March, 1979, and the locations of sampling are given. In a table, the months and the locations of sampling, Cl (%), sample volume analyzed (l), and the amounts of Sr-90 and Cs-137 (pCi/l) are shown. The maximum values are 0.21 pCi/l of Sr-90 found in Osaka Bay in August, 1978, and 0.19 pCi/l of Cs-137 off Niigata Port in July, 1978. (Kako, I.)

Transport of radionuclides from the Kara Sea. Potential ''shortcuts'' in space and time

International Nuclear Information System (INIS)

Phirman, S.L.; Koegler, J.W.; Anselme, B.

1995-01-01

Satellite images from the Kara Sea show that, until July, fast ice extends along the coast and fills the estuaries of the Ob and Yenisey rivers. It is separated from offshore drift ice by a region of open water, comprising a flaw lead/polynya. By August, much of the fast and drift ice has melted and retreated from the southwestern Kara Sea, leaving behind a persistent patch of ice east of Novaya Zemlya. The authors of the paper discuss the potential for exchange of water, ice and contaminants with the Barents Sea through Kara Gate (Karsikye Vorota), south of Novaya Zemlya, in the context of the temperature and turbidity distribution observed in the satellite images. 19 refs

Extraction of uranium from sea water by means of fibrous complex adsorbents

International Nuclear Information System (INIS)

Miyamatsu, Tokuhisa; Oguchi, Noboru; Kanchiku, Yoshihiko; Aoyagi, Takanobu

1982-01-01

Fibrous complex adsorbents for uranium extraction from sea water were prepared by introducing titanic acid or basic zinc carbonate as effective constituents into fibrous ion exchangers. A fibrous chelate type adsorbent was also tested. Among the adsorbents examined, the following ones demonstrated excellent properties for the recovery of uranium from sea water. a) A fibrous, weakly acidic cation exchanger was treated with titanyl sulfate in aqueous sulfuric acid solution, which was followed by neutralization to afford a fibrous adsorbent containing titanic acid (QC-1f(Ti)). The adsorption capacity for uranium in sea water was estimated by extrapolation to be 50μg-U/g-Ad or 1170 μg-U/g-Ti. b) A fibrous, strongly acidic cation exchanger was treated in a similar way to afford another type of fibrous adsorbent with titanic acid incorporated (QCS-Ti). The adsorption capacity was estimated by extrapolation to be 20-30 μg-U/g-Ad. (author)

Brest sea level record: a time series construction back to the early eighteenth century

Science.gov (United States)

Wöppelmann, Guy; Pouvreau, Nicolas; Simon, Bernard

2006-12-01

The completeness and the accuracy of the Brest sea level time series dating from 1807 make it suitable for long-term sea level trend studies. New data sets were recently discovered in the form of handwritten tabulations, including several decades of the eighteenth century. Sea level observations have been made in Brest since 1679. This paper presents the historical data sets which have been assembled so far. These data sets span approximately 300 years and together constitute the longest, near-continuous set of sea level information in France. However, an important question arises: Can we relate the past and the present-day records? We partially provide an answer to this question by analysing the documents of several historical libraries with the tidal data using a ‘data archaeology’ approach advocated by Woodworth ( Geophys Res Lett 26:1589 1592, 1999b). A second question arises concerning the accuracy of such records. Careful editing was undertaken by examining the residuals between tidal predictions and observations. It proved useful to remove the worst effects of timing errors, in particular the sundial correction to be applied prior to August 1, 1714. A refined correction based on sundial literature [Savoie, La gnomique, Editions Les Belles Lettres, Paris, 2001] is proposed, which eliminates the systematic offsets seen in the discrepancies in timing of the sea level measurements. The tidal analysis has also shown that shallow-water tidal harmonics at Brest causes a systematic difference of 0.023 m between mean sea level (MSL) and mean tide level (MTL). Thus, MTL should not be mixed with the time series of MSL because of this systematic offset. The study of the trends in MTL and MSL however indicates that MTL can be used as a proxy for MSL. Three linear trend periods are distinguished in the Brest MTL time series over the period 1807 2004. Our results support the recent findings of Holgate and Woodworth ( Geophys Res Lett) of an enhanced coastal sea level

Air-sea heat exchange, an element of the water cycle

Science.gov (United States)

Chahine, M. T.

1984-01-01

The distribution and variation of water vapor, clouds and precipitation are examined. Principal driving forces for these distributions are energy exchange and evaporation at the air-sea interface, which are also important elements of air-sea interaction studies. The overall aim of air-sea interaction studies is to quantitatively determine mass, momentum and energy fluxes, with the goal of understanding the mechanisms controlling them. The results of general circulation simulations indicate that the atmosphere in mid-latitudes responds to changes in the oceanic surface conditions in the tropics. This correlation reflects the strong interaction between tropical and mid-latitude conditions caused by the transport of heat and momentum from the tropics. Studies of air-sea exchanges involve a large number of physica, chemical and dynamical processes including heat flux, radiation, sea-surface temperature, precipitation, winds and ocean currents. The fluxes of latent heat are studied and the potential use of satellite data in determining them evaluated. Alternative ways of inferring heat fluxes will be considered.

Bonding capacity of the GFRP-S on strengthened RC beams after sea water immersion

Science.gov (United States)

Sultan, Mufti Amir; Djamaluddin, Rudy

2017-11-01

Construction of concrete structures that located in extreme environments are such as coastal areas will result in decreased strength or even the damage of the structures. As well know, chloride contained in sea water is responsible for strength reduction or structure fail were hence maintenance and repairs on concrete structure urgently needed. One popular method of structural improvements which under investigation is to use the material Glass Fibre Reinforced Polymer which has one of the advantages such as corrosion resistance. This research will be conducted experimental studies to investigate the bonding capacity behavior of reinforced concrete beams with reinforcement GFRP-S immersed in sea water using immersion time of one month, three months, six months and twelve months. Test specimen consists of 12 pieces of reinforced concrete beams with dimensions (150x200x3000) mm that had been reinforced with GFRP-S in the area of bending, the beam without immersion (B0), immersion one month (B1), three months (B3), six months (B6) and twelve months (B12). Test specimen were cured for 28 days before the application of the GFRP sheet. Test specimen B1, B3, B6 and B12 that have been immersed in sea water pool with a immersion time each 1, 3, 6 and 12 months. The test specimen without immersion test by providing a static load until it reaches the failure, to record data during the test strain gauge mounted on the surface of the specimen and the GFRP to collect the strain value. From the research it obvious that there is a decrease bonding capacity on specimens immersed for one month, three months, six months and twelve months against the test object without immersion of 8.85%; 8.89%; 9.33% and 11.04%.

Contrasting trends in North Atlantic deep-water formation in the Labrador Sea and Nordic Seas during the Holocene

NARCIS (Netherlands)

Renssen, H.; Goosse, H.; Fichefet, T.

2005-01-01

The Holocene North Atlantic deep-water formation is studied in a 9,000-year long simulation with a coupled climate model of intermediate complexity, forced by changes in orbital forcing and atmospheric trace gas concentrations. During the experiment, deep-water formation in the Nordic Seas is

Optimization of Counting Times, Figure of Merit and Mass Thickness for Low-background Alpha/beta Proportional Counter in Sea Water

International Nuclear Information System (INIS)

Pakkong, Pannee; Wongsanit, Sarinya; Tumnoi, Yutthana; Udomsomporn, Suchin

2011-06-01

Full text: The determination of gross alpha and beta activity in environmental aqueous samples can be done by using a low-background alpha/beta proportional counter with multiple detector type (Bert hold LB770). The co precipitate sea water samples were considered for optimal regime of counting time, the minimum detectable activity (MDA), mass thickness of samples (mg/cm-2) and figure of merit (FOM). The result showed that the MDA of the measurements were estimated to be 0.07 Bq/l for gross alpha and 0.05 Bq/l for gross beta at counting time of 100 and 200 minute, respectively. The thickness of samples prepared by coprecipitation technique indicated more parochial range when compared to evaporation to dryness method. In addition, the samples were in the suitable range that can be corrected by the previous self-absorption correction factor (F a ) as 0.0003w 2 -0.0414 w+1.692; where F a is the self-absorption correction factor and w is the weight of the final precipitate in milligrams

NOAA NDBC SOS, 2007-present, sea_water_practical_salinity

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have sea_water_practical_salinity data. Because of the nature of SOS...

Radioactivity of fission products in cistern waters along the Croatian coast of the Adriatic Sea

International Nuclear Information System (INIS)

Franic, Z.; Marovic, G.

1997-01-01

Measurements of radioactive contamination of water samples from cisterns collecting rainwater from roofs etc. with fission products have been carried out along the Croatian coast of the Adriatic Sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium.After the nuclear accident at Chernobyl, higher levels of 137 Cs and 90 Sr were detected again, cistern waters being the only environmental samples in Croatia in which elevated 90 Sr activities persisted for several years. For the pre-Chernobyl period, the mean residence time of 90 Sr in cistern waters being order of magnitude several years was similar to that calculated for fallout.Contrary, for the post-Chernobyl time, S r mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time.Therefore, the pre-Chernobyl) and the post-Chernobyl mean residence times of 90 Sr in cistern waters reflect the mechanism by which strontium was released to the atmosphere. The annual dose for the critical adult population received from 90 Sr, 137 Cs and 90 Cs by drinking cistern water was estimated to be a few per cent of the dose from natural background radiation. (authors)

Determination of vanadium in sea water by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite

International Nuclear Information System (INIS)

Shimizu, Tokuo; Sakai, Kaoru

1981-01-01

The trace amount of vanadium in sea water was determined by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite. To correct the background absorption, a deuterium lamp with a higher-brilliant thermal cathode was used. The sensitivity for vanadium increased 10 -- 20 fold by the use of the tube coated with pyrolytic graphite, and the utility lifetime of the tube was greatly extended. Vanadium(V) - 4-(2-pyridylazo)resorcinol (PAR) complexes were extracted into chloroform as an ion-pair with benzyldimethyltetradecylammonium (Zephiramine) cation alternatively. The sample of sea water, which was made to 0.1 N in sulfuric acid and 0.1% in hydrogen peroxide, was loaded onto the column of Dowex 1-X 4 resin (SO 4 2- -form). Vanadium was then eluted from the resin with 1 N sulfuric acid-0.1% hydrogen peroxide or 1 N hydrochloric acid-0.1% hydrogen peroxide evaporated to dry. After dissolution of the elute in 0.2 N nitric acid, vanadium was extracted. Secondly, the sample of sea water was adjusted to pH 5.0, and loaded onto the column of Chelex-100 resin. Vanadium was eluted from the resin with 2 N ammonia. The above two methods took much time, but the coprecipitation method was not so and recommended for the determination of vanadium in sea water. Vanadium was coprecipitated with iron(III) hydroxide-hydrous titanium(IV) oxide at pH 6.0. The precipitate was digested with nitric acid-hydrogen peroxide. The solution was diluted to 50 ml with water. The resulting solutions were employed to determine the vanadium concentration by the graphite furnace atomic absorption measurement. The trace amounts of vanadium in various kinds of the coastal sea water were determined by the coprecipitation method. (author)

Comparison of sup(115m)Cd accumulation from sediments and sea water by polychaete worms

International Nuclear Information System (INIS)

Ueda, Taishi; Nakamura, Ryoichi; Suzuki, Yuzuru

1976-01-01

To know the role played by marine sediments in influencing the fate of discharged metals, (1) the interaction of metals between sediments and deposit-feeder marine worms (Nereis japonica), and (2) uptake and excretion of metals by worms were examined by laboratory experiments using sup(115m)Cd. Worms directly in contact with sup(115m)Cd-sediments accumulated sup(115m)Cd six times more than worms that were not in contact with the sup(115m)Cd sediments during the 8 days of experimentation and 12% of sup(115m)Cd in sediments were noted to be transfered to worms per unit. Comparing the concentration factor of 22 (from sea water) with accumulation from sediments, it was assumed that sup(115m)Cd in sediments would give the effect of 1/200 to the accumulation of sup(115m)Cd by worms in sea water to the accumulation of sup(115m)Cd. Further, to simulate these results close to that occuring in the natural ecosystem, the distribution of sup(115m)Cd in sea water, sediments and alga were also examined by means of a curve analysis of the distribution pattern by a three compartment model. It proved that the activity ratios of sup(115m)Cd were 9 for sediments and 21 for alga, which was similar to 22 for worms. (auth.)

WATER TEMPERATURE and other data from DERWENT, HOBART and other platforms in the Coral Sea, Tasman Sea and other waters from 1984-09-02 to 1993-01-31 (NODC Accession 9300047)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected in Coral Sea, Indian Ocean, South Pacific Ocean, and Tasman Sea from multiple Australian and New Zealand ships by...

Air-sea fluxes and satellite-based estimation of water masses formation

Science.gov (United States)

Sabia, Roberto; Klockmann, Marlene; Fernandez-Prieto, Diego; Donlon, Craig

2015-04-01

Recent work linking satellite-based measurements of sea surface salinity (SSS) and sea surface temperature (SST) with traditional physical oceanography has demonstrated the capability of generating routinely satellite-derived surface T-S diagrams [1] and analyze the distribution/dynamics of SSS and its relative surface density with respect to in-situ measurements. Even more recently [2,3], this framework has been extended by exploiting these T-S diagrams as a diagnostic tool to derive water masses formation rates and areas. A water mass describes a water body with physical properties distinct from the surrounding water, formed at the ocean surface under specific conditions which determine its temperature and salinity. The SST and SSS (and thus also density) at the ocean surface are largely determined by fluxes of heat and freshwater. The surface density flux is a function of the latter two and describes the change of the density of seawater at the surface. To obtain observations of water mass formation is of great interest, since they serve as indirect observations of the thermo-haline circulation. The SSS data which has become available through the SMOS [4] and Aquarius [5] satellite missions will provide the possibility of studying also the effect of temporally-varying SSS fields on water mass formation. In the present study, the formation of water masses as a function of SST and SSS is derived from the surface density flux by integrating the latter over a specific area and time period in bins of SST and SSS and then taking the derivative of the total density flux with respect to density. This study presents a test case using SMOS SSS, OSTIA SST, as well as Argo ISAS SST and SSS for comparison, heat fluxes from the NOCS Surface Flux Data Set v2.0, OAFlux evaporation and CMORPH precipitation. The study area, initially referred to the North Atlantic, is extended over two additional ocean basins and the study period covers the 2011-2012 timeframe. Yearly, seasonal

Ra-226 and Rn-222 in saline water compartments of the Aral Sea region

International Nuclear Information System (INIS)

Schettler, Georg; Oberhänsli, Hedi; Hahne, Knut

2015-01-01

Highlights: • 222 Rn and 226 Ra concentrations in different water compartments of the Aral Sea region. • 226 Ra-analysis based on 222 Rn-ingrowth versus MS-analysis after solid-phase extraction. • 226 Ra in different groundwater types of the Aral Sea Basin. • 222 Rn distribution in the Aral Sea, western basin. - Abstract: The Aral Sea has been shrinking since 1963 due to extensive irrigation and the corresponding decline in the river water inflow. Understanding of the current hydrological situation demands an improved understanding of the surface water/groundwater dynamics in the region. 222 Rn and 226 Ra measurements can be used to trace groundwater discharge into surface waters. Data of these radiometric parameters were not previously available for the study region. We determined 222 Rn activities after liquid phase extraction using Liquid Scintillation Counting (LSC) with peak-length discrimination and analyzed 226 Ra concentrations in different water compartments of the Amu Darya Delta (surface waters, unconfined groundwater, artesian water, and water profiles from the closed Large Aral Sea (western basin). The water samples comprise a salinity range between 1 and 263 g/l. The seasonal dynamics of solid/water interaction under an arid climate regime force the hydrochemical evolution of the unconfined groundwater in the Amu Darya Delta to high-salinity Na(Mg)Cl(SO 4 ) water types. The dissolved radium concentrations in the waters were mostly very low due to mineral over-saturation, extensive co-precipitation of radium and adsorption of radium on coexisting solid substrates. The analysis of very low 226 Ra concentrations (<10 ppq) at remote study sites is a challenge. We used the water samples to test and improve different analytical methods. In particular, we modified a procedure developed for the α-spectrometric determination of 226 Ra after solid phase extraction of radium using 3M Empore™ High Performance Extraction Disks (Purkl, 2002) for the

Bacterial activity in sea ice and open water of the Weddell Sea, Antarctica: A microautoradiographic study.

Science.gov (United States)

Grossmann, S

1994-07-01

Metabolic activity of bacteria was investigated in open water, newly forming sea ice, and successive stages of pack ice in the Weddell Sea. Microautoradiography, using [(3)H]leucine as substrate, was compared with incorporation rates of [(3)H]leucine into proteins. Relation of [(3)H]leucine incorporation to the biomass of active bacteria provides information about changes of specific metabolic activity of cells. During a phytoplankton bloom in an ice-free, stratified water column, total numbers of bacteria in the euphotic zone averaged 2.3 × 10(5) ml(-1), but only about 13% showed activity via leucine uptake. Growth rate of the active bacteria was estimated as 0.3-0.4 days(-1). Total cell concentration of bacteria in 400 m depth was 6.6 × 10(4) ml(-1). Nearly 50% of these cells were active, although biomass production and specific growth rate were only about one-tenth that of the surface populations. When sea ice was forming in high concentrations of phytoplankton, bacterial biomass in the newly formed ice was 49.1 ng C ml(-1), exceeding that in open water by about one order of magnitude. Attachment of large bacteria to algal cells seems to cause their enrichment in the new ice, since specific bacterial activity was reduced during ice formation, and enrichment of bacteria was not observed when ice formed at low algal concentration. During growth of pack ice, biomass of bacteria increased within the brine channel system. Specific activity was still reduced at these later stages of ice development, and percentages of active cells were as low as 3-5%. In old, thick pack ice, bacterial activity was high and about 30% of cells were active. However, biomass-specific activity of bacteria remained significantly lower than that in open water. It is concluded that bacterial assemblages different to those of open water developed within the ice and were dominated by bacteria with lower average metabolic activity than those of ice-free water.

Installation of deep water sub-sea equipment

Energy Technology Data Exchange (ETDEWEB)

Pollack, Jack; Demian, Nabil [SBM-IMODCO Inc., Houston, TX (UNited States)

2004-07-01

Offshore oil developments are being planned in water depths exceeding 2000 m. Lowering and positioning large, heavy sub sea hardware, using conventional methods, presents new technical challenges in these ultra deep waters. In 3000 m a safe lift using conventional steel cables will require more capacity to support the cable self weight than the static payload. Adding dynamic loads caused by the motions of the surface vessel can quickly cause the safe capacity of the wire to be exceeded. Synthetic ropes now exist to greatly reduce the lowering line weight. The lower stiffness of these synthetic ropes aggravate the dynamic line tensions due to vessel motions and relatively little is known about the interaction of these ropes on the winches and sheaves required for pay-out and haul-in of these lines under dynamic load. Usage of conventional winches would damage the synthetic rope and risk the hardware being deployed. Reliable and economic installation systems that can operate from existing installation vessels are considered vital for ultra deep-water oil development. The paper describes a Deep Water Sub-Sea Hardware Deployment system consisting of a buoy with variable, pressure-balanced buoyancy, which is used to offset most of the payload weight as it is lowered. The buoyant capacity is controlled by air pumped into the tank from the surface vessel through a reinforced hose. The buoy and payload motion are isolated from the deployment line surface dynamics using a simple passive heave compensator mounted between the buoy and the bottom of the deployment rope. The system components, functionality and dynamic behavior are presented in the paper. (author)

The caesium 137 content in the water of the North Sea during the years 1969 to 1975

International Nuclear Information System (INIS)

Kautsky, H.

1976-01-01

In April 1975, about 34,000 Ci Caesium 137 in a water mass of about 30,500 km 3 was found in the area of the North Sea that we investigated between 51 0 N to 60 0 N and 4 0 W to 10 0 E. This represented a mean concentration of about 1.1 Ci/km 3 or 1.1 pCi/l water. Concentration variations of between 0.44 to 2.2 pCi/l in the different areas of the North Sea were measured. As compared with ICRP Standards, 137 Cs concentrations in sea water of up to some 900 pCi/l may be viewed as a still permissible limit (IAEA, 1970). The development of the 137 Cs content in the North Sea from 1969 to 1975 is discussed. Especially, the temporal changes in concentrations in different sections of the North Sea will be compared. These clearly show the different influence in different sections of the radioactive waste waters of the three coastal European nuclear fuel reprocessing plants on the content of radioactive fission products as well as their spreading in the water of the North Sea. (orig./HP) [de

Effect of climate change on sea water intrusion in coastal aquifers

Science.gov (United States)

Sherif, Mohsen M.; Singh, Vijay P.

1999-06-01

There is increasing debate these days on climate change and its possible consequences. Much of this debate has focused in the context of surface water systems. In many arid areas of the world, rainfall is scarce and so is surface runoff. These areas rely heavily on groundwater. The consequences of climate change on groundwater are long term and can be far reaching. One of the more apparent consequences is the increased migration of salt water inland in coastal aquifers. Using two coastal aquifers, one in Egypt and the other in India, this study investigates the effect of likely climate change on sea water intrusion. Three realistic scenarios mimicking climate change are considered. Under these scenarios, the Nile Delta aquifer is found to be more vulnerable to climate change and sea level rise.

Application of two-barrier model of radioactive agent transport in sea water for analyzing artificial radionuclide release from containers with radioactive waste dumped in Kara Sea

Energy Technology Data Exchange (ETDEWEB)

Grishin, Denis S.; Laykin, Andrey I.; Kuchin, Nickolay L.; Platovskikh, Yuri A. [Krylov State Research Center, Saint Petersburg, 44 Moskovskoe shosse, 196158 (Russian Federation)

2014-07-01

Modeling of artificial radionuclide transport in sea water is crucial for prognosis of radioecological situation in regions where dumping of radioactive waste had been made and/or accidents with nuclear submarines had taken place. Distribution of artificial radionuclides in bottom sediments can be a detector of radionuclide release from dumped or sunk objects to marine environment. Proper model can determine the dependence between radionuclide distribution in sediments and radionuclide release. Following report describes two-barrier model of radioactive agent transport in sea water. It was tested on data from 1994 - 2013 expeditions to Novaya Zemlya bays, where regular dumping of solid radioactive waste was practiced by the former USSR from the early 1960's until 1990. Two-barrier model agrees with experimental data and allows more accurate determination of time and intensity of artificial radionuclide release from dumped containers. (authors)

Time-lapse seismic analysis of the North Sea Fulmar Field

Energy Technology Data Exchange (ETDEWEB)

Johnston, David H.; McKenny, Robert S.; Burkhart, Tucker D.

1998-12-31

Time-lapse seismic analysis has been applied to two 3-D seismic surveys acquired over the central North Sea Fulmar field in a pre-production survey shot in 1977, reprocessed in 1987, and a survey in 1992. The Upper Jurassic reservoirs in the field have been under production since 1982. Differences in averaged impedance between the 1977 and 1992 surveys clearly show the effects of water influx and pressure decline. The changes observed in the seismic data are overall consistent with predictions obtained from a full-field, history-matched simulation. Differences in details may suggest areas of bypassed oil. Dta quality is not sufficient to serve as the sole basis for drilling decisions. 1 ref., 6 figs.

Desorption of cesium ions from vermiculite with sea water by hydrothermal process

International Nuclear Information System (INIS)

Yin, Xiangbiao; Takahashi, Hideharu; Inaba, Yusuke; Takeshita, Kenji

2016-01-01

Cesium ions (Cs + ) strongly intercalated in vermiculite clay (Verm) had been effectively removed using sea water for its free utility, totally environmental friendly feature, and within containing numerous salt by the hydrothermal treatment process (HTT), which can help significantly promote desorption by the cation-exchange mechanism in subcritical condition. >74-100% removal was achieved to the interacted Cs + for a loading capacity of 4.8-50 mg g −1 . XRD results indicated that cation exchange proceeded between the intercalated Cs + and various cations in sea water during HTT. (author)

Radiochemical analysis of radio-nuclides in sea water collected near Bikini Atoll

Energy Technology Data Exchange (ETDEWEB)

Miyake, Y; Sugiura, Y

1955-01-01

A radiochemical analysis of sea water containing fission materials collected near Bikini Atoll in June, 1954, was performed. The sea water was boiled with hydrochloric acid, iron and lanthanum salts each 5 mg as Fe and La were added to it. They were precipitated as hydroxide, which was dissolved in hydrochloric acid and ferric chloride was extracted with ethyl ether. The remaining solution was evaporated to dryness and the residue was dissolved in hydrochloric acid. Using the latter solution the group separation was done with cation exchanger resins.

Use of reactor plants of enhanced safety for sea water desalination, industrial and district heating

International Nuclear Information System (INIS)

Panov, Yu.; Polunichev, V.; Zverev, K.

1997-01-01

Russian designers have developed and can deliver nuclear complexes to provide sea water desalination, industrial and district heating. This paper provides an overview of these designs utilizing the ABV, KLT-40 and ATETS-80 reactor plants of enhanced safety. The most advanced nuclear powered water desalination project is the APVS-80. This design consists of a special ship equipped with the distillation desalination plant powered at a level of 160 MW(th) utilizing the type KLT-40 reactor plant. More than 20 years of experience with water desalination and reactor plants has been achieved in Aktau and Russian nuclear ships without radioactive contamination of desalinated water. Design is also proceeding on a two structure complex consisting of a floating nuclear power station and a reverse osmosis desalination plant. This new technology for sea water desalination provides the opportunity to considerably reduce the specific consumption of power for the desalination of sea water. The ABV reactor is utilized in the ''Volnolom'' type floating nuclear power stations. This design also features a desalinator ship which provides sea water desalination by the reverse osmosis process. The ATETS-80 is a nuclear two-reactor cogeneration complex which incorporates the integral vessel-type PWR which can be used in the production of electricity, steam, hot and desalinated water. (author). 9 figs

Microplastic pollution in the surface waters of the Bohai Sea, China

International Nuclear Information System (INIS)

Zhang, Weiwei; Zhang, Shoufeng; Wang, Juying; Wang, Yan; Mu, Jingli; Wang, Ping; Lin, Xinzhen; Ma, Deyi

2017-01-01

The ubiquitous presence and persistency of microplastics in aquatic environments is of particular concern because these pollutants represent an increasing threat to marine organisms and ecosystems. An identification of the patterns of microplastic distribution will help to understand the scale of their potential effect on the environment and on organisms. In this study, the occurrence and distribution of microplastics in the Bohai Sea are reported for the first time. We sampled floating microplastics at 11 stations in the Bohai Sea using a 330 μm trawling net in August 2016. The abundance, composition, size, shape and color of collected debris samples were analyzed after pretreatment. The average microplastic concentration was 0.33 ± 0.34 particles/m 3 . Micro-Fourier transform infrared spectroscopy analysis showed that the main types of microplastics were polyethylene, polypropylene, and polystyrene. As the size of the plastics decreased, the percentage of polypropylene increased, whereas the percentages of polyethylene and polystyrene decreased. Plastic fragments, lines, and films accounted for most of the collected samples. Accumulation at some stations could be associated with transport and retention mechanisms that are linked to wind and the dynamics of the rim current, as well as different sources of the plastics. - Highlights: • First evaluation of microplastic in the surface water of the Bohai Sea. • The microplastics in Bohai is at medium-low level in contrast to other sea regions. • With the size of the plastics decreased, the proportion of polypropylene gradually increased. - This research indicates that microplastics are distributed widely in the Bohai Sea. As the size of the plastics decreased, the percentage of polypropylene increased.

Effects of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida

Science.gov (United States)

Langevin, Christian D.; Zygnerski, Michael

2013-01-01

A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt water intrusion near the well field, and that historical sea-level rise, which is similar to lower-bound projections of future sea-level rise, exacerbated the extent of salt water intrusion. Average 2005 hydrologic conditions were used for 100-year sensitivity simulations aimed at quantifying the effect of projected rises in sea level on fresh coastal groundwater resources near the well field. Use of average 2005 hydrologic conditions and a constant sea level result in total dissolved solids (TDS) concentration of the well field exceeding drinking water standards after 70 years. When sea-level rise is included in the simulations, drinking water standards are exceeded 10 to 21 years earlier, depending on the specified rate of sea-level rise.

Deep and intermediate mediterranean water in the western Alboran Sea

Science.gov (United States)

Parrilla, Gregorio; Kinder, Thomas H.; Preller, Ruth H.

1986-01-01

Hydrographic and current meter data, obtained during June to October 1982, and numerical model experiments are used to study the distribution and flow of Mediterranean waters in the western Alboran Sea. The Intermediate Water is more pronounced in the northern three-fourths of the sea, but its distribution is patchy as manifested by variability of the temperature and salinity maxima at scales ≤10 km. Current meters in the lower Intermediate Water showed mean flow toward the Strait at 2 cm s -1. A reversal of this flow lasted about 2 weeks. A rough estimate of the mean westward Intermediate Water transport was 0.4 × 10 6 m 3 s -1, about one-third of the total outflow, so that the best estimates of the contributions of traditionally defined Intermediate Water and Deep Water account for only about one-half of the total outflow. The Deep Water was uplifted against the southern continental slope from Alboran Island (3°W) to the Strait. There was also a similar but much weaker banking against the Spanish slope, but a deep current record showed that the eastward recirculation implied by this banking is probably intermittent. Two-layer numerical model experiments simulated the Intermediate Water flow with a flat bottom and the Deep Water with realistic bottom topography. Both experiments replicated the major circulation features, and the Intermediate Water flow was concentrated in the north because of rotation and the Deep Water flow in the south because of topographic control.

Hourly changes in sea surface salinity in coastal waters recorded by Geostationary Ocean Color Imager

Science.gov (United States)

Liu, Rongjie; Zhang, Jie; Yao, Haiyan; Cui, Tingwei; Wang, Ning; Zhang, Yi; Wu, Lingjuan; An, Jubai

2017-09-01

In this study, we monitored hourly changes in sea surface salinity (SSS) in turbid coastal waters from geostationary satellite ocean color images for the first time, using the Bohai Sea as a case study. We developed a simple multi-linear statistical regression model to retrieve SSS data from Geostationary Ocean Color Imager (GOCI) based on an in situ satellite matched-up dataset (R2 = 0.795; N = 41; Range: 26.4 to 31.9 psμ). The model was then validated using independent continuous SSS measurements from buoys, with the average percentage difference of 0.65%. The model was applied to GOCI images from the dry season during an astronomical tide to characterize hourly changes in SSS in the Bohai Sea. We found that the model provided reasonable estimates of the hourly changes in SSS and that trends in the modeled and measured data were similar in magnitude and direction (0.43 vs 0.33 psμ, R2 = 0.51). There were clear diurnal variations in the SSS of the Bohai Sea, with a regional average of 0.455 ± 0.079 psμ (0.02-3.77 psμ). The magnitude of the diurnal variations in SSS varied spatially, with large diurnal variability in the nearshore, particularly in the estuary, and small variability in the offshore area. The model for the riverine area was based on the inverse correlation between SSS and CDOM absorption. In the offshore area, the water mass of the North Yellow Sea, characterized by high SSS and low CDOM concentrations, dominated. Analysis of the driving mechanisms showed that the tidal current was the main control on hourly changes in SSS in the Bohai Sea.

Sea Cucumber Resources At Tanjung Pai Waters Padaido Biak Numfor Papua

Directory of Open Access Journals (Sweden)

Eddy Yusron

2004-12-01

Full Text Available Observation on sea cucumber diversity was carried out at coastal waters of Pai and Imbeyomi Islands in the Padaido Island Biak Numfor. Sampling was done by using a transect quadrant of 1 m x 1 m. This sampling and observation on its microhabitat were conducted by snorkling. Analyses on the sea cucumber community structure were based on its frequency of occurance, diversity, and density. The results showed that at both locations 10 species of sea cucumber were found where Holothuria edulis, H. atra, and H. nobilis were predominant common and more evenly distributed than the other species.

Forecasting Sea Water Levels at Mukho Station, South Korea Using Soft Computing Techniques

Directory of Open Access Journals (Sweden)

Ozgur Kisi

2014-12-01

Full Text Available The accuracy of three different data-driven methods, namely, Gene Expression Programming (GEP, Adaptive Neuro-Fuzzy Inference System (ANFIS and Artificial Neural Networks (ANN, is investigated for hourly sea water level prediction at the Mukho Station in the East Sea (Sea of Japan. Current and four previous level measurements are used as input variables to predict sea water levels up to 1, 24, 48, 72, 96 and 120 hours ahead. Three statistical evaluation parameters, namely, the correlation coefficient, the root mean square error and the scatter index are used to assess how the models perform. Investigation results indicate that, when compared to measurements, for +1h prediction interval, all three models perform well (with average values of R = 0.993, RMSE = 1.3 cm and SI = 0.04, with slightly better results produced by the ANNs and ANFIS, while increasing the prediction interval degrades model performance.

Effects of sea-ice and biogeochemical processes and storms on under-ice water fCO2 during the winter-spring transition in the high Arctic Ocean: Implications for sea-air CO2 fluxes

Science.gov (United States)

Fransson, Agneta; Chierici, Melissa; Skjelvan, Ingunn; Olsen, Are; Assmy, Philipp; Peterson, Algot K.; Spreen, Gunnar; Ward, Brian

2017-07-01

We performed measurements of carbon dioxide fugacity (fCO2) in the surface water under Arctic sea ice from January to June 2015 during the Norwegian young sea ICE (N-ICE2015) expedition. Over this period, the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first winter-time under-ice water fCO2 observations in this region. The observed under-ice fCO2 ranged between 315 µatm in winter and 153 µatm in spring, hence was undersaturated relative to the atmospheric fCO2. Although the sea ice partly prevented direct CO2 exchange between ocean and atmosphere, frequently occurring leads and breakup of the ice sheet promoted sea-air CO2 fluxes. The CO2 sink varied between 0.3 and 86 mmol C m-2 d-1, depending strongly on the open-water fractions (OW) and storm events. The maximum sea-air CO2 fluxes occurred during storm events in February and June. In winter, the main drivers of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In June, in addition to these processes, primary production and sea-air CO2 fluxes were important. The cumulative loss due to CaCO3 dissolution of 0.7 mol C m-2 in the upper 10 m played a major role in sustaining the undersaturation of fCO2 during the entire study. The relative effects of the total fCO2 change due to CaCO3 dissolution was 38%, primary production 26%, vertical mixing 16%, sea-air CO2 fluxes 16%, and temperature and salinity insignificant.

Arctic sea ice decline: Projected changes in timing and extent of sea ice in the Bering and Chukchi Seas

Science.gov (United States)

Douglas, David C.

2010-01-01

The Arctic region is warming faster than most regions of the world due in part to increasing greenhouse gases and positive feedbacks associated with the loss of snow and ice cover. One consequence has been a rapid decline in Arctic sea ice over the past 3 decades?a decline that is projected to continue by state-of-the-art models. Many stakeholders are therefore interested in how global warming may change the timing and extent of sea ice Arctic-wide, and for specific regions. To inform the public and decision makers of anticipated environmental changes, scientists are striving to better understand how sea ice influences ecosystem structure, local weather, and global climate. Here, projected changes in the Bering and Chukchi Seas are examined because sea ice influences the presence of, or accessibility to, a variety of local resources of commercial and cultural value. In this study, 21st century sea ice conditions in the Bering and Chukchi Seas are based on projections by 18 general circulation models (GCMs) prepared for the fourth reporting period by the Intergovernmental Panel on Climate Change (IPCC) in 2007. Sea ice projections are analyzed for each of two IPCC greenhouse gas forcing scenarios: the A1B `business as usual? scenario and the A2 scenario that is somewhat more aggressive in its CO2 emissions during the second half of the century. A large spread of uncertainty among projections by all 18 models was constrained by creating model subsets that excluded GCMs that poorly simulated the 1979-2008 satellite record of ice extent and seasonality. At the end of the 21st century (2090-2099), median sea ice projections among all combinations of model ensemble and forcing scenario were qualitatively similar. June is projected to experience the least amount of sea ice loss among all months. For the Chukchi Sea, projections show extensive ice melt during July and ice-free conditions during August, September, and October by the end of the century, with high agreement

Structures for the release of sea water from the nuclear plants of Paluel and Flamanville

International Nuclear Information System (INIS)

Pliskin, Lucien

1981-01-01

Nuclear plants necessitate large amounts of cooling water. This explains why Electricite de France, the French Electricity Authority, is currently building several such plants along the Channel coast, using sea water. This paper describes the design and the beginning of the construction of the discharge outlets of the nuclear plants of Paluel and Flamanville. These outlets consist in vertical shafts 40 to 60 m deep bored at a distance of about 1000 m from the shore in the open sea. The shafts are covered with a light concrete diffusor whose function is to spread out the hot water flow into sea water. The paper puts emphasis on the tool used for the construction of these shafts which is a small movable gravity platform made of a concrete caisson supporting a self-elevating steel deck [fr

Ability of sea-water bacterial consortium to produce electricity and denitrify water

Science.gov (United States)

Maruvada, Nagasamrat V. V.; Tommasi, Tonia; Kaza, Kesava Rao; Ruggeri, Bernardo

Sea is a store house for varied types of microbes with an ability to reduce and oxidize substances like iron, sulphur, carbon dioxide, etc. Most of these processes happen in the sea water environment, but can be applied for purification of wastewater. In the present paper, we discuss the use of a consortium of seawater bacteria in a fuel cell to produce electricity by oxidizing organic matter and reducing nitrates. We also discuss how the growth of the bacterial consortium can lead to an increased electricity production and decreased diffusional resistance in the cell. The analysis was done using electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Here, we use bicarbonate buffered solution, which is the natural buffering agent found in sea. We show that the seawater bacterial consortium can be used in both the anode and cathode parts of the cell. The results confirm the adaptability of the seawater bacteria to different environments and can be used for various applications. Heritage, Erasmus Mundus Programme, European Commission.

Mesozoic Compressional Folds of the Nansha Waters, Southern South China Sea

Science.gov (United States)

Zhu, R.; Liu, H.; Yao, Y.; Wang, Y.

2017-12-01

As an important part of the South China Sea, the southern margin of the South China Sea is fundamental to understand the interaction of the Eurasian, Pacific and Indian-Australian plates and the evolution of the South China Sea. Some multi-channel seismic profiles of the Nansha waters together with published drillings and dredge data were correlated for interpretation. The strata of the study region can be divided into the upper, middle and lower structural layers. The upper and middle structural layers with extensional tectonics are Cenozoic; the lower structural layer suffered compression is Mesozoic. Further structural restoration was done to remove the Cenozoic tectonic influence and to calculate the Mesozoic tectonic compression ratios. The results indicate that two diametrically opposite orientations of compressive stress, S(S)E towards N(N)W orientation and N(N)W towards S(S)E orientation respectively, once existed in the lower structural layer of the study area and shared the same variation trend. The compression ratio values gradually decrease both from the north to the south and from the west to the east in each stress orientation. The phenomena may be related to the opening of the proto-South China Sea (then located in south of the Nansha block) and the rate of the Nansha block drifted northward in Late Jurassic to Late Cretaceous, which had pushed the Nansha block drifted northward until it collided and sutured with the Southern China Margin. Thus the opening of the present-day South China Sea may be related to this suture zone, which was tectonically weakness zone.Key words: Mesozoic compression; structural restoration; proto-South China Sea; Nansha waters; Southern South China Sea; Acknowledgements: The work was granted by the National Natural Science Foundation of China (Grant Nos. 41476039, 91328205, 41576068 and 41606080).

Sensitivity of open-water ice growth and ice concentration evolution in a coupled atmosphere-ocean-sea ice model

Science.gov (United States)

Shi, Xiaoxu; Lohmann, Gerrit

2017-09-01

A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity.

Extraction of uranium (VI) from sea water using hydrous metalic oxide binded with hydrophilic polymers

International Nuclear Information System (INIS)

Shigetomi, Yasumasa; Kojima, Takehiro; Kamba, Hideaki

1978-01-01

In the past five years, many researches have been made to extract U(VI) from sea water. This is a report of the extraction of U(VI) from sea water using hydrous titanium oxide binded with hydrophilic polymers, the apparatus for the adsorption and the separation of U(VI) by means of ion exchange. (author)

Tracing Atlantic Water Signature in the Arctic Sea Ice Cover East of Svalbard

Directory of Open Access Journals (Sweden)

Vladimir V. Ivanov

2012-01-01

Full Text Available We focus on the Arctic Ocean between Svalbard and Franz Joseph Land in order to elucidate the possible role of Atlantic water (AW inflow in shaping ice conditions. Ice conditions substantially affect the temperature regime of the Spitsbergen archipelago, particularly in winter. We test the hypothesis that intensive vertical mixing at the upper AW boundary releases substantial heat upwards that eventually reaches the under-ice water layer, thinning the ice cover. We examine spatial and temporal variation of ice concentration against time series of wind, air temperature, and AW temperature. Analysis of 1979–2011 ice properties revealed a general tendency of decreasing ice concentration that commenced after the mid-1990s. AW temperature time series in Fram Strait feature a monotonic increase after the mid-1990s, consistent with shrinking ice cover. Ice thins due to increased sensible heat flux from AW; ice erosion from below allows wind and local currents to more effectively break ice. The winter spatial pattern of sea ice concentration is collocated with patterns of surface heat flux anomalies. Winter minimum sea ice thickness occurs in the ice pack interior above the AW path, clearly indicating AW influence on ice thickness. Our study indicates that in the AW inflow region heat flux from the ocean reduces the ice thickness.

Method for recovering uranium from sea water

International Nuclear Information System (INIS)

Schwochau, K.; Astheimer, L.; Schenk, H.J.; Schmitz, J.

1977-04-01

In view of the augmenting uranium demand for energy supply and of the anticipated depletion of the actually assured and economic uranium resources the possibility of recovering uranium from sea water receives increasing attention. It is the purpose of the present report to give a detailed discussion of fundamental problems involved and a critical survey of hitherto proposed processes of recovery and to recommend some general directives for further work. (orig.) [de

The impact of water loading on postglacial decay times in Hudson Bay

Science.gov (United States)

Han, Holly Kyeore; Gomez, Natalya

2018-05-01

Ongoing glacial isostatic adjustment (GIA) due to surface loading (ice and water) variations during the last glacial cycle has been contributing to sea-level changes globally throughout the Holocene, especially in regions like Canada that were heavily glaciated during the Last Glacial Maximum (LGM). The spatial and temporal distribution of GIA, as manifested in relative sea-level (RSL) change, are sensitive to the ice history and the rheological structure of the solid Earth, both of which are uncertain. It has been shown that RSL curves near the center of previously glaciated regions with no ongoing surface loading follow an exponential-like form, with the postglacial decay times associated with that form having a weak sensitivity to the details of the ice loading history. Postglacial decay time estimates thus provide a powerful datum for constraining the Earth's viscous structure and improving GIA predictions. We explore spatial patterns of postglacial decay time predictions in Hudson Bay by decomposing numerically modeled RSL changes into contributions from water and ice loading effects, and computing their relative impact on the decay times. We demonstrate that ice loading can contribute a strong geographic trend on the decay time estimates if the time window used to compute decay times includes periods that are temporally close to (i.e. contemporaneous with, or soon after) periods of active loading. This variability can be avoided by choosing a suitable starting point for the decay time window. However, more surprisingly, we show that across any adopted time window, water loading effects associated with inundation into, and postglacial flux out of, Hudson Bay and James Bay will impart significant geographic variability onto decay time estimates. We emphasize this issue by considering both maps of predicted decay times across the region and site-specific estimates, and we conclude that variability in observed decay times (whether based on existing or future data

Measurement and Elemental Analysis of Muria Sea Water for Primary Water of PWR

International Nuclear Information System (INIS)

Dwi Biyantoro; Kris Tri Basuki

2007-01-01

Treatment process of water of free mineral and study area of processing of sea water to meet the need of water cooling of PWR. Desalination is a separation process used to reduce the dissolved salt content of saline water. All desalination processes involve three liquid streams: the saline feedwater (brackish water or seawater), low salinity product water, and very saline concentrate. Seawater Muria Jepara is feed type 1 with content salt is low and relative suspension and weight metals is low. There are two types of membrane process used for desalination: reverse osmosis (RO) and electrodialysis (ED). The starting of process is difficult and expensive. However, starting since 1950, desalination process appear to be economically practical for ordinary use. There are 3 key elements significantly affect to the technical performance and long term characteristic type, i.e. 1) energy, 2) corrosivity of seawater, and 3) desalination process technology. These elements closely inter related and important for design improvements and technical performance optimization. From the analysis of sea water of gulf Muria Jepara was found as follows : Fe = 0.176 ± 0.012 ppm, Pb = 0.612 ± 0.017 ppm, Cd = 52.567 ± 0.750 ppm, Cu = 0.044 ± 0.005 ppm, Zn = 0.061 ± 0.003 ppm, Mn = 0.057 ± 0.003 ppm, Ca between = 365.256 - 368.654 ppm, Na between = 9572.000 - 9775.000 ppm, Mg between 759.000 - 779.00 ppm and Ni = 0.524 ± 0.005 ppm. Cost production of process using reverse osmosis as around 0.9 - 1 US$/m3, while using electrodialysis is around 1.2 US$/m3, and by using evaporation process or distillation process is around 1.4 - 1.6 US$/m3. (author)

Optimization of desalting process with centrifugation for condensation process of uranium from sea water

International Nuclear Information System (INIS)

Yamamoto, Tatsuya; Takase, Hisao; Fukuoka, Fumio

1984-01-01

Optimization of desalting of the slurry on the condensation process by the deposited slurry method for the recovery of uranium from sea water was studied. We have already published that the uranium rich deposit containing seven ppm uranium could be made on the sea bottom by the deposited slurry method. Uranium can be transferred to the anion exchange resin from titanic acid in the slurry. But in this case Cl - ions obstruct the adsorption of uranium on the anion exchange resin, so the slurry must be desalted before RIP method. It is considered that the cost of desalting of the slurry stage would be a large portion of the capital cost for the recovery of uranium from sea water. The cost of water required is comparable to the cost of energy so that the objective function consists of the cost of energy and the quantity of water. The consumption of energy and water required for desalting of the slurry with the multi-stage centrifugation were oprimized based on dynamic programming. (author)

Strontium-90 and cesium-137 in sea water (from Jul 1984 to Sep 1984)

International Nuclear Information System (INIS)

1984-01-01

Monitoring results are presented on strontium-90 and cesium-137 contents in sea water of 11 sampling points all over Japan from Hokkaido to Okinawa coast. Sampling points were selected by the criterion that the effect of terrestrial fresh water and atmospheric precipitation was expected to be ignorable. Sample collection was carried out in the Period from July to September, 1984. With a special care for prevention of any contamination. The collected sea water samples were acidified immediately and they were served for radiochemical separation and purification of strontium-90 and cesium-137. Radiation counting was made for yttrium-90 hydroxide sample and cesium chloroplatinate sample with a low background beta counter normally for 60 minutes. As for strontium-90 contents in sea water, they were ranged from 0.07 +- 0.010 pCi/l (Mutsu Bay, Aomori) to 0.11 +- 0.012 pCi/l (Off Niigata Port, Niigata) and the average value was 0.09 pCi/l. As for cesium-137 contents, they were ranged from 0.08 +- 0.011 pCi/l (Ise Bay, Aichi) to 0.14 +- 0.012 pCi/l (Yamaguchi Bay, Yamaguchi) and the average value was 0.106 pCi/l. It is clarified that no abnormal values were determined for strontium-90 or cesium-137 contents in coastal sea water around Japan from a fallout origin. (Takagi, S.)

Impact of water temperature on the growth and fatty acid profiles of juvenile sea cucumber Apostichopus japonicus (Selenka).

Science.gov (United States)

Yu, Haibo; Zhang, Cheng; Gao, Qinfeng; Dong, Shuanglin; Ye, Zhi; Tian, Xiangli

2016-08-01

The present study determined the changes in the fatty acid (FA) profiles of juvenile sea cucumber Apostichopus japonicus in response to the varied water temperature. Sea cucumbers with similar size (4.02±0.11g) were cultured for 8 weeks at 14°C, 18°C, 22°C and 26°C, respectively. At the end of the experiment, the specific growth rate (SGR) and the profiles of FAs in neutral lipids and phospholipids of the juvenile sea cucumbers cultured at different temperatures were determined. The SGRs of the sea cucumbers cultured at 26°C significantly decreased 46.3% compared to thos cultured at 18°C. Regression analysis showed that the SGR-temperature (T) relationship can be expressed as SGR=-0.0073T(2)+0.255T -1.0231 (R(2)=0.9936) and the highest SGR was predicted at 17.5°C. For the neutral lipids, the sum of saturated FAs (SFAs), monounsaturated FAs (MUFAs) or polyunsaturated FAs (PUFAs) of the sea cucumbers that were cultured at the water temperature from 18°C-26°C did not change significantly, indicating the insensitivity of FA profiles for the neutral lipids of sea cucumbers in response to increasing water temperature. For phospholipids, the sum of PUFAs in the sea cucumbers dramatically decreased with the gradually increased water temperature. The sum of SFAs and MUFAs of sea cucumbers, however, increased with the gradually elevated water temperature. In particular, the contents of highly unsaturated fatty acids (HUFAs), including eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA), in the phospholipids of the sea cucumbers decreased 37.2% and 26.1%, respectively, when the water temperature increased from 14°C to 26°C. In summary, the sea cucumbers A. japonicus can regulate the FA compositions, especially the contents of EPA and DHA, in the phospholipids so as to adapt to varied water temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida.

Science.gov (United States)

Langevin, Christian D; Zygnerski, Michael

2013-01-01

A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt water intrusion near the well field, and that historical sea-level rise, which is similar to lower-bound projections of future sea-level rise, exacerbated the extent of salt water intrusion. Average 2005 hydrologic conditions were used for 100-year sensitivity simulations aimed at quantifying the effect of projected rises in sea level on fresh coastal groundwater resources near the well field. Use of average 2005 hydrologic conditions and a constant sea level result in total dissolved solids (TDS) concentration of the well field exceeding drinking water standards after 70 years. When sea-level rise is included in the simulations, drinking water standards are exceeded 10 to 21 years earlier, depending on the specified rate of sea-level rise. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Investigating the Interannual Variability of the Circulation and Water Mass Formation in the Red Sea

Science.gov (United States)

Sofianos, S. S.; Papadopoulos, V. P.; Denaxa, D.; Abualnaja, Y.

2014-12-01

The interannual variability of the circulation and water mass formation in the Red Sea is investigated with the use of a numerical model and the combination of satellite and in-situ observations. The response of Red Sea to the large-scale variability of atmospheric forcing is studied through a 30-years simulation experiment, using MICOM model. The modeling results demonstrate significant trends and variability that are mainly located in the central and northern parts of the basin. On the other hand, the exchange pattern between the Red Sea and the Indian Ocean at the strait of Bab el Mandeb presents very weak interannual variability. The results verify the regularity of the water mass formation processes in the northern Red Sea but also show significant variability of the circulation and thermohaline conditions in the areas of formation. Enhanced water mass formation conditions are observed during specific years of the simulation (approximately five years apart). Analysis of recent warm and cold events in the northernmost part of the basin, based on a combination of atmospheric reanalysis results and oceanic satellite and in-situ observations, shows the importance of the cyclonic gyre that is prevailing in this part of the basin. This gyre can effectively influence the sea surface temperature (SST) and intensify or mitigate the winter effect of the atmospheric forcing. Upwelling induced by persistent periods of the gyre functioning drops the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme atmospheric forcing. These mechanisms are crucial for the formation of intermediate and deep water masses in the Red Sea and the strength of the subsequent thermohaline cells.

SeaWiFS data from oceanic waters around New Zealand: Validation and applications

Science.gov (United States)

Richardson, K.; Boyd, P.; Gall, M.; Pinkerton, M.

Satellite observations of ocean colour are the only realistic way to measure phytoplankton abundance at regional and global scales. NASA's Sea-viewing Wide Field -o f-view Sensor (SeaWiFS) began operation in September 1997 and is still providing data today. The data are of particular value to New Zealand, which has the fourth largest Exclusive Economic Zone (EEZ) in the world (some 4 million km2 ). Analysis of moderate resolution (9 km) SeaWiFS monthly Standard Mapped Images has substantially increased knowledge of the dynamics of chlorophyll concentrations around New Zealand. SeaWiFS data over nearly three years shows that northern New Zealand Subtropical and Tasman Sea waters follow a classical cycle of spring and autumn chlorophyll blooms consistent with production being co-limited by nitrate and light. Subantarctic Waters south of New Zealand had a low-magnitude annual cycle of chlorophyll abundance that peaked in early autumn, consistent with production being principally iron-limited. Chlorophyll was generally highest in the Subtropical Front either side of New Zealand where Subtropical and Subantarctic waters mix. NIWA (National Institute of Water and Atmospheric Research) has been receiving and processing high resolution (1.1 km) SeaWiFS data for the NZ region since May 2000. In addition to this, extensive bio-optical data from a number of NIWA cruises are being used to validate the satellite data and assess the accuracy of the ocean products in New Zealand open ocean and coastal waters. The performance of the SeaWiFS chlorophyll-a algorithm (OC4v4) has been investigated by comparing high-precision in situ measurements of the underwater radiation field with measurements of phytoplankton pigment concentration. Analyses of these results suggest that the algorithm may be performing well in the open ocean for chlorophyll- a concentrations below 0.3-0.4 mg m-3 but overestimating by a factor of two or more at higher concentrations. NIWA believes that ocean colour

Biogenic Properties of Deep Waters from the Black Sea Reduction (Hydrogen Sulphide) Zone for Marine Algae

OpenAIRE

Polikarpov, Gennady G.; Lazorenko, Galina Е.; Тereschenko, Natalya N.

2015-01-01

Abstract Generalized data of biogenic properties investigations of the Black Sea deep waters from its reduction zone for marine algae are presented. It is shown on board and in laboratory that after pre-oxidation of hydrogen sulphide by intensive aeration of the deep waters lifted to the surface of the sea, they are ready to be used for cultivation of the Black Sea unicellular, planktonic, and multicellular, benthic, algae instead of artificial medium. Naturally balanced micro- and macroeleme...

Stability of stearic acid monolayers on artificial sea water

NARCIS (Netherlands)

Brzozowska, A.M.; Duits, Michael H.G.; Mugele, Friedrich Gunther

2012-01-01

We studied the formation and stability of stearic acid (SA) based films on aqueous sub-phases via Langmuir trough and imaging ellipsometry experiments. The aqueous phase was based on Artificial Sea Water (ASW), a multicomponent salt solution with a total molarity of 0.53. The composition of this

Mass-induced [|#8#|]Sea Level Variations in the Red Sea from Satellite Altimetry and GRACE

Science.gov (United States)

Feng, W.; Lemoine, J.; Zhong, M.; Hsu, H.

2011-12-01

We have analyzed mass-induced sea level variations (SLVs) in the Red Sea from steric-corrected altimetry and GRACE between January 2003 and December 2010. The steric component of SLVs in the Red Sea calculated from climatological temperature and salinity data is relatively small and anti-phase with the mass-induced SLV. The total SLV in the Red Sea is mainly driven by the mass-induced SLV, which increases in winter when the Red Sea gains the water mass from the Gulf of Aden and vice versa in summer. Spatial and temporal patterns of mass-induced SLVs in the Red Sea from steric-corrected altimetry agree very well with GRACE observations. Both of two independent observations show high annual amplitude in the central Red Sea (>20cm). Total mass-induced SLVs in the Red Sea from two independent observations have similar annual amplitude and phase. One main purpose of our work is to see whether GRGS's ten-day GRACE results can observe intra-seasonal mass change in the Red Sea. The wavelet coherence analysis indicates that GRGS's results show the high correlation with the steric-corrected SLVs on intra-seasonal time scale. The agreement is excellent for all the time-span until 1/3 year period and is patchy between 1/3 and 1/16 year period. Furthermore, water flux estimates from current-meter arrays and moorings show mass gain in winter and mass loss in summer, which is also consistent with altimetry and GRACE.

Assessment of water exchange between a discharge region and the open sea A comparison of different methodological concepts

Science.gov (United States)

Döös, Kristofer; Engqvist, Anders

2007-09-01

Two different methods of estimating the water exchange through the Baltic coastal region of Laxemar have been used, consisting of particle trajectories and passive tracers. Water is traced from and to a small discharge region near the coast. The discharge material in this region is treated as zero-dimensional particles or tracers with neutral buoyancy. The real discharge material could be a leakage of radio-nuclides through the sea floor from an underground repository of nuclear waste. Water exchange rates between the discharge region and the model domain are estimated using both forward and backward trajectories as well as passive tracers. The Lagrangian trajectories can account for the time evolution of the water exchange while the tracers give one average age per model grid box. Water exchange times such as residence time, age and transient times have been calculated with trajectories but only the average age (AvA) for tracers. The trajectory calculations provide a more detailed time evolution than the tracers. On the other hand the tracers are integrated "on-line" simultaneously in the sea circulation model with the same time step while the Lagrangian trajectories are integrated "off-line" from the stored model velocities with its inherent temporal resolution, presently 1 h. The sub-grid turbulence is parameterised as the Laplacian diffusion for the passive tracers and with an extra stochastic velocity for trajectories. The importance of the parameterised sub-grid turbulence for the trajectories is estimated to give an extra diffusion of the same order as the Laplacian diffusion by comparing the Lagrangian dispersions with and without parameterisation. The results of the different methods are similar but depend on the chosen diffusivity coefficient with a slightly higher correlation between trajectories and tracers when integrated with a lower diffusivity coefficient.

MOD2SEA: A Coupled Atmosphere-Hydro-Optical Model for the Retrieval of Chlorophyll-a from Remote Sensing Observations in Complex Turbid Waters

Directory of Open Access Journals (Sweden)

Behnaz Arabi

2016-09-01

Full Text Available An accurate estimation of the chlorophyll-a (Chla concentration is crucial for water quality monitoring and is highly desired by various government agencies and environmental groups. However, using satellite observations for Chla estimation remains problematic over coastal waters due to their optical complexity and the critical atmospheric correction. In this study, we coupled an atmospheric and a water optical model for the simultaneous atmospheric correction and retrieval of Chla in the complex waters of the Wadden Sea. This coupled model called MOD2SEA combines simulations from the MODerate resolution atmospheric TRANsmission model (MODTRAN and the two-stream radiative transfer hydro-optical model 2SeaColor. The accuracy of the coupled MOD2SEA model was validated using a matchup data set of MERIS (MEdium Resolution Imaging SpectRometer observations and four years of concurrent ground truth measurements (2007–2010 at the NIOZ jetty location in the Dutch part of the Wadden Sea. The results showed that MERIS-derived Chla from MOD2SEA explained the variations of measured Chla with a determination coefficient of R2 = 0.88 and a RMSE of 3.32 mg·m−3, which means a significant improvement in comparison with the standard MERIS Case 2 regional (C2R processor. The proposed coupled model might be used to generate a time series of reliable Chla maps, which is of profound importance for the assessment of causes and consequences of long-term phenological changes of Chla in the turbid Wadden Sea area.

A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan

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Kwang-Tsao Shao

2014-12-01

Full Text Available The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the “Database of Taiwan’s Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/” as part of the “Fish Database of Taiwan,” can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity.

A new perspective on origin of the East Sea Intermediate Water: Observations of Argo floats

Science.gov (United States)

Park, JongJin; Lim, Byunghwan

2018-01-01

The East Sea Intermediate Water (ESIW), defined as the salinity minimum in the East Sea (hereafter ES) (Sea of Japan), is examined with respect to its overall characteristics and its low salinity origin using historical Argo float data from 1999 to 2015. Our findings suggest that the ESIW is formed in the western Japan Basin (40-42°N, 130-133°E), especially west of the North Korean front in North Korean waters, where strong negative surface wind stress curl resides in wintertime. The core ESIW near the formation site has temperatures of 3-4 °C and less than 33.98 psu salinity, warmer and fresher than that in the southern part of the ES. In order to trace the origin of the warmer and fresher water at the sea surface in winter, we analyzed the data in three different ways: (1) spatial distribution of surface water properties using monthly climatology from the Argo float data, (2) seasonal variation of heat and salt contents at the formation site, and (3) backtracking of surface drifter trajectories. Based on these analyses, it is likely that the warmer and fresher surface water properties found in the ESIW formation site are attributed to the low-salinity surface water advected from the southern part of the ES in autumn.

Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

Science.gov (United States)

Li, Jialin; Li, Nan; Li, Fuchao; Zou, Tao; Yu, Shuxian; Wang, Yinchu; Qin, Song; Wang, Guangyi

2014-01-01

The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS). Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones) and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

Directory of Open Access Journals (Sweden)

Jialin Li

Full Text Available The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS. Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

The exchangeable cations in soils flooded with sea water

NARCIS (Netherlands)

Molen, van der W.H.

1958-01-01

The changes in the exchangeable cations of soils flooded with sea-water were extensively studied in the Netherlands after the inundations of 1940, 1945 and 1953. A synopsis of the results was given, both from a theoretical and a practical viewpoint.

Current formulae for ion-exchange tested in the

Oxygen Saturation Surrounding Deep Water Formation Events in the Labrador Sea From Argo-O2 Data

Science.gov (United States)

Wolf, Mitchell K.; Hamme, Roberta C.; Gilbert, Denis; Yashayaev, Igor; Thierry, Virginie

2018-04-01

Deep water formation supplies oxygen-rich water to the deep sea, spreading throughout the ocean by means of the global thermohaline circulation. Models suggest that dissolved gases in newly formed deep water do not come to equilibrium with the atmosphere. However, direct measurements during wintertime convection are scarce, and the controls over the extent of these disequilibria are poorly quantified. Here we show that, when convection reached deeper than 800 m, oxygen in the Labrador Sea was consistently undersaturated at -6.1% to -7.6% at the end of convection. Deeper convection resulted in greater undersaturation, while convection ending later in the year resulted in values closer to equilibrium, from which we produce a predictive relationship. We use dissolved oxygen data from six profiling Argo floats in the Labrador Sea between 2003 and 2016, allowing direct observations of wintertime convection. Three of the six optode oxygen sensors displayed substantial average in situ drift of -3.03 μmol O2 kg-1 yr-1 (-0.94% O2 yr-1), which we corrected to stable deepwater oxygen values from repeat ship surveys. Observations of low oxygen intrusions during restratification and a simple mixing calculation demonstrate that lateral processes act to lower the oxygen inventory of the central Labrador Sea. This suggests that the Labrador Sea is a net sink for atmospheric oxygen, but uncertainties in parameterizing gas exchange limit our ability to quantify the net uptake. Our results constrain the oxygen concentration of newly formed Labrador Sea Water and allow more precise estimates of oxygen utilization and nutrient regeneration in this water mass.

Fate of water pumped from underground and contributions to sea-level rise

Science.gov (United States)

Wada, Yoshihide; Lo, Min-Hui; Yeh, Pat J.-F.; Reager, John T.; Famiglietti, James S.; Wu, Ren-Jie; Tseng, Yu-Heng

2016-08-01

The contributions from terrestrial water sources to sea-level rise, other than ice caps and glaciers, are highly uncertain and heavily debated. Recent assessments indicate that groundwater depletion (GWD) may become the most important positive terrestrial contribution over the next 50 years, probably equal in magnitude to the current contributions from glaciers and ice caps. However, the existing estimates assume that nearly 100% of groundwater extracted eventually ends up in the oceans. Owing to limited knowledge of the pathways and mechanisms governing the ultimate fate of pumped groundwater, the relative fraction of global GWD that contributes to sea-level rise remains unknown. Here, using a coupled climate-hydrological model simulation, we show that only 80% of GWD ends up in the ocean. An increase in runoff to the ocean accounts for roughly two-thirds, whereas the remainder results from the enhanced net flux of precipitation minus evaporation over the ocean, due to increased atmospheric vapour transport from the land to the ocean. The contribution of GWD to global sea-level rise amounted to 0.02 (+/-0.004) mm yr-1 in 1900 and increased to 0.27 (+/-0.04) mm yr-1 in 2000. This indicates that existing studies have substantially overestimated the contribution of GWD to global sea-level rise by a cumulative amount of at least 10 mm during the twentieth century and early twenty-first century. With other terrestrial water contributions included, we estimate the net terrestrial water contribution during the period 1993-2010 to be +0.12 (+/-0.04) mm yr-1, suggesting that the net terrestrial water contribution reported in the IPCC Fifth Assessment Report report is probably overestimated by a factor of three.

Modulation of Sea Ice Melt Onset and Retreat in the Laptev Sea by the Timing of Snow Retreat in the West Siberian Plain

Science.gov (United States)

Crawford, A. D.; Stroeve, J.; Serreze, M. C.; Rajagopalan, B.; Horvath, S.

2017-12-01

As much of the Arctic Ocean transitions to ice-free conditions in summer, efforts have increased to improve seasonal forecasts of not only sea ice extent, but also the timing of melt onset and retreat. This research investigates the potential of regional terrestrial snow retreat in spring as a predictor for subsequent sea ice melt onset and retreat in Arctic seas. One pathway involves earlier snow retreat enhancing atmospheric moisture content, which increases downwelling longwave radiation over sea ice cover downstream. Another pathway involves manipulation of jet stream behavior, which may affect the sea ice pack via both dynamic and thermodynamic processes. Although several possible connections between snow and sea ice regions are identified using a mutual information criterion, the physical mechanisms linking snow retreat and sea ice phenology are most clearly exemplified by variability of snow retreat in the West Siberian Plain impacting melt onset and sea ice retreat in the Laptev Sea. The detrended time series of snow retreat in the West Siberian Plain explains 26% of the detrended variance in Laptev Sea melt onset (29% for sea ice retreat). With modest predictive skill and an average time lag of 53 (88) days between snow retreat and sea ice melt onset (retreat), West Siberian Plains snow retreat is useful for refining seasonal sea ice predictions in the Laptev Sea.

Late Holocene sea ice conditions in Herald Canyon, Chukchi Sea

Science.gov (United States)

Pearce, C.; O'Regan, M.; Rattray, J. E.; Hutchinson, D. K.; Cronin, T. M.; Gemery, L.; Barrientos, N.; Coxall, H.; Smittenberg, R.; Semiletov, I. P.; Jakobsson, M.

2017-12-01

Sea ice in the Arctic Ocean has been in steady decline in recent decades and, based on satellite data, the retreat is most pronounced in the Chukchi and Beaufort seas. Historical observations suggest that the recent changes were unprecedented during the last 150 years, but for a longer time perspective, we rely on the geological record. For this study, we analyzed sediment samples from two piston cores from Herald Canyon in the Chukchi Sea, collected during the 2014 SWERUS-C3 Arctic Ocean Expedition. The Herald Canyon is a local depression across the Chukchi Shelf, and acts as one of the main pathways for Pacific Water to the Arctic Ocean after entering through the narrow and shallow Bering Strait. The study site lies at the modern-day seasonal sea ice minimum edge, and is thus an ideal location for the reconstruction of past sea ice variability. Both sediment cores contain late Holocene deposits characterized by high sediment accumulation rates (100-300 cm/kyr). Core 2-PC1 from the shallow canyon flank (57 m water depth) is 8 meter long and extends back to 4200 cal yrs BP, while the upper 3 meters of Core 4-PC1 from the central canyon (120 mwd) cover the last 3000 years. The chronologies of the cores are based on radiocarbon dates and the 3.6 ka Aniakchak CFE II tephra, which is used as an absolute age marker to calculate the marine radiocarbon reservoir age. Analysis of biomarkers for sea ice and surface water productivity indicate stable sea ice conditions throughout the entire late Holocene, ending with an abrupt increase of phytoplankton sterols in the very top of both sediment sequences. The shift is accompanied by a sudden increase in coarse sediments (> 125 µm) and a minor change in δ13Corg. We interpret this transition in the top sediments as a community turnover in primary producers from sea ice to open water biota. Most importantly, our results indicate that the ongoing rapid ice retreat in the Chukchi Sea of recent decades was unprecedented during the

Laboratory experiments on the transfer dynamics of plutonium from marine sediments to sea water and to marine organisms

International Nuclear Information System (INIS)

Mo, T.; Lowman, F.G.

1975-01-01

The leachability of 239 240 Pu from a fine contaminated calcareous sediment to aerated open sea water and to anoxic sea water was measured. The distribution coefficient for 239 240 Pu from sediment to sea water was 6.1 x 10 -5 for aerated water and 2.6 x 10 -6 for anoxic water. Experiments on the uptake of 239 240 Pu by the clams Donax denticulatus, and Lucina pectinata, were done in aquaria containing kilogram quantities of sediment from the Bravo Crater at Bikini Atoll. The concentration factor for 239 240 Pu by the soft parts of these clams was about 200. All the plutonium taken up in the soft parts was associated with the gill, mantle and siphon. No plutonium was detected in the adductor muscles or hepatopancreas. The smooth surfaces of the shells of the Donax did not show any detectable plutonium, but the rough shell surfaces of the Lucina concentrated plutonium by a factor of 1.10 x 10 4 over that in the sea water. Marine periphyton cultured on glass plates in an aquarium concentrated 239 240 Pu by a factor of about 7 x 10 3 over that in the sea water. (U.S.)

Distribution and Diversity of Microbial Eukaryotes in Bathypelagic Waters of the South China Sea.

Science.gov (United States)

Xu, Dapeng; Jiao, Nianzhi; Ren, Rui; Warren, Alan

2017-05-01

Little is known about the biodiversity of microbial eukaryotes in the South China Sea, especially in waters at bathyal depths. Here, we employed SSU rDNA gene sequencing to reveal the diversity and community structure across depth and distance gradients in the South China Sea. Vertically, the highest alpha diversity was found at 75-m depth. The communities of microbial eukaryotes were clustered into shallow-, middle-, and deep-water groups according to the depth from which they were collected, indicating a depth-related diversity and distribution pattern. Rhizaria sequences dominated the microeukaryote community and occurred in all samples except those from less than 50-m deep, being most abundant near the sea floor where they contributed ca. 64-97% and 40-74% of the total sequences and OTUs recovered, respectively. A large portion of rhizarian OTUs has neither a nearest named neighbor nor a nearest neighbor in the GenBank database which indicated the presence of new phylotypes in the South China Sea. Given their overwhelming abundance and richness, further phylogenetic analysis of rhizarians were performed and three new genetic clusters were revealed containing sequences retrieved from the deep waters of the South China Sea. Our results shed light on the diversity and community structure of microbial eukaryotes in this not yet fully explored area. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Strontium-90 and cesium-137 in sea water (from July, 1982, to September, 1982)

International Nuclear Information System (INIS)

1982-01-01

Strontium-90 and cesium-137 in sea water collected at 11 locations across Japan from July to September, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. Sea water was collected at the fixed station where the effect of the terrestrial fresh water from rivers was negligibly small. The sampling was carried out when there was no rainfall for the last few days. The sample solution was prepared and was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.09 to 0.13 pCi/l for Sr-90 and 0.05 to 0.13 pCi/l for Cs-137 in the sea water. (Mori, K.)

Predictability and environmental drivers of chlorophyll fluctuations vary across different time scales and regions of the North Sea

Science.gov (United States)

Blauw, Anouk N.; Benincà, Elisa; Laane, Remi W. P. M.; Greenwood, Naomi; Huisman, Jef

2018-02-01

Phytoplankton concentrations display strong temporal variability at different time scales. Recent advances in automated moorings enable detailed investigation of this variability. In this study, we analyzed phytoplankton fluctuations at four automated mooring stations in the North Sea, which measured phytoplankton abundance (chlorophyll) and several environmental variables at a temporal resolution of 12-30 min for two to nine years. The stations differed in tidal range, water depth and freshwater influence. This allowed comparison of the predictability and environmental drivers of phytoplankton variability across different time scales and geographical regions. We analyzed the time series using wavelet analysis, cross correlations and generalized additive models to quantify the response of chlorophyll fluorescence to various environmental variables (tidal and meteorological variables, salinity, suspended particulate matter, nitrate and sea surface temperature). Hour-to-hour and day-to-day fluctuations in chlorophyll fluorescence were substantial, and mainly driven by sinking and vertical mixing of phytoplankton cells, horizontal transport of different water masses, and non-photochemical quenching of the fluorescence signal. At the macro-tidal stations, these short-term phytoplankton fluctuations were strongly driven by the tides. Along the Dutch coast, variation in salinity associated with the freshwater influence of the river Rhine played an important role, while in the central North Sea variation in weather conditions was a major determinant of phytoplankton variability. At time scales of weeks to months, solar irradiance, nutrient conditions and thermal stratification were the dominant drivers of changes in chlorophyll concentrations. These results show that the dominant drivers of phytoplankton fluctuations differ across marine environments and time scales. Moreover, our findings show that phytoplankton variability on hourly to daily time scales should not be

Temporal variability in SeaWiFS derived apparent optical properties in European seas

Science.gov (United States)

Vantrepotte, V.; Mélin, F.

2010-02-01

The 10-year record of ocean color data provided by the SeaWiFS mission is an important asset for monitoring and research activities conducted on the optically complex European seas. This study makes use of the SeaWiFS data set of normalized water leaving radiances LWN to study the major characteristics of temporal variability associated with optical properties across the entire European domain. Specifically, the time series of LWN and associated band ratios are decomposed into terms representing a fixed seasonal cycle, irregular variations and trends, and the contribution of these components to the total variance is described for the various basins. The diversity of the European waters is fully reflected by the range of results varying with regions and wavelengths. Generally, the Mediterranean and Baltic seas appear as two end-members with, respectively, high and low contributions of the seasonal component to the total variance. The existence of linear trends affecting the satellite products is also explored for each basin. By focusing the analysis on LWN and band ratios, the validity of the results is not limited by the varying levels of uncertainty that characterize derived products such as the concentration of chlorophyll a in optically complex waters. Statistically significant, and in some cases large, trends are detected in the Atlantic Ocean west of the European western shelf, the central North Sea, the English Channel, the Black Sea, the northern Adriatic, and various regions of the Mediterranean Sea and the northern Baltic Sea, revealing changes in the concentrations of optically significant constituents in these regions.

HF Radar Sea-echo from Shallow Water

Directory of Open Access Journals (Sweden)

Josh Kohut

2008-08-01

Full Text Available HF radar systems are widely and routinely used for the measurement of ocean surface currents and waves. Analysis methods presently in use are based on the assumption of infinite water depth, and may therefore be inadequate close to shore where the radar echo is strongest. In this paper, we treat the situation when the radar echo is returned from ocean waves that interact with the ocean floor. Simulations are described which demonstrate the effect of shallow water on radar sea-echo. These are used to investigate limits on the existing theory and to define water depths at which shallow-water effects become significant. The second-order spectral energy increases relative to the first-order as the water depth decreases, resulting in spectral saturation when the waveheight exceeds a limit defined by the radar transmit frequency. This effect is particularly marked for lower radar transmit frequencies. The saturation limit on waveheight is less for shallow water. Shallow water affects second-order spectra (which gives wave information far more than first-order (which gives information on current velocities, the latter being significantly affected only for the lowest radar transmit frequencies for extremely shallow water. We describe analysis of radar echo from shallow water measured by a Rutgers University HF radar system to give ocean wave spectral estimates. Radar-derived wave height, period and direction are compared with simultaneous shallow-water in-situ measurements.

Determination of molybdenum (VI) in sea water with preliminary concentration by the method of ion flotation

International Nuclear Information System (INIS)

Andreeva, I. Yu.; Drapchinskaya, O.L.; Lebedeva, L.I.

1985-01-01

The purpose of this paper is to assess the feasibility of using the method of ion flotation for the concentration of microamounts of molybdenum (VI) during determination in sea water. The ion flotation method is used for the purification of industrial sewage from the ions of nonferrous metals, including molybdenum (VI) with its content of up to 50 mg/liter. A 1.10 -4 M solution of sodium molybdate in 0.1M NaOH was used. The effect of different factors on the ion flotation process of molybdenum (VI) was investigated: pH of the solution, flotation times, concentrations of surface-active substances (SAS), molybdenum (IV), extraneous salts. Data presented show that the ion flotation method in conjunction with the photometric method of determining molybdenum with brompyrogallol red (BPR) and cetylpridinium chloride (CP) (limit of detection 0.02 micrograms/liter) allows the content of molybdenum (VI) in sea water to be established with sufficient reliability and reproducibility

First biological measurements of deep-sea corals from the Red Sea.

Science.gov (United States)

Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with 'deep-sea' and 'cold-water' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

First biological measurements of deep-sea corals from the Red Sea.

KAUST Repository

Roder, Cornelia

2013-10-03

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with \\'deep-sea\\' and \\'cold-water\\' corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.

Isotope analysis of water trapped in fluid inclusions in deep sea corals

Science.gov (United States)

Vonhof, Hubert; Reijmer, John; Feenstra, Eline; Mienis, Furu

2015-04-01

Extant Lophelia pertusa deep sea coral specimens from the Loachev mound region in the North Atlantic Ocean contain water filled fluid inclusions in their skeleton. This fluid inclusion water was extracted with a crushing device, and its hydrogen and oxygen isotope ratios analysed. The resulting data span a wide range of isotope values which are remarkably different from the seawater isotope composition of the sites studied. Comparison with food source isotope signatures suggests that coral inclusion water contains a high, but variable proportion of metabolic water. The isotope composition of the inclusion water appears to vary with the position on the deep see coral reef, and shows a correlation with the stable isotope composition of the coral aragonite. This correlation seems to suggest that growth rate and other ecological factors play an important role in determining the isotope composition of fluids trapped in the coral skeleton, which can potentially be developed as a proxy for non-equilibrium isotope fractionation observed in the aragonite skeleton of many of the common deep sea coral species.

New Observations of the Gulf of Aden Intermediate Water Intrusion into the Red Sea.

Science.gov (United States)

Bower, A.; Abualnaja, Y.

2012-04-01

The three-layer exchange flow between the Red Sea and the Indian Ocean during summer is characterized by a thick, northward intrusion of relatively cold, low-salinity and low in dissolved oxygen (Water (GAIW), sandwiched between two thin layers of outflow water. The flux of GAIW into the Red Sea is important in the heat, freshwater and nutrient budgets of the Red Sea, but the structure and pathways of the intrusion are not well-known due to a paucity of hydrographic and direct velocity observations. A research cruise was executed at the eastern side of the Red Sea during September-October 2011 to conduct the first large-scale survey of the intrusion. This mission is part of a series of expeditions in the Red Sea designed to investigate the seasonal Red Sea circulation. Surprisingly, the GAIW intrusion was observed to stretch nearly the entire length of the Red Sea (~1500 km) as a narrow eastern boundary current with subsurface velocity maximum of 0.1-0.3 m/s in the depth range 50-100 m. The intruding layer is weakly stratified compared to the background, possibly an indication of strong vertical mixing as it flows through the strait. Some GAIW was observed to enter deep channels in a coral reef bank (Farasan Banks) located in the southeastern Red Sea, and to enter the Red Sea interior, the latter possibly due to interactions between the boundary current and mesoscale eddies. The pathways and erosion of the GAIW intrusion will likely have major implications for the spatial distribution of biological productivity.

Short-term variability in halocarbons in relation to phytoplankton pigments in coastal waters of the central eastern Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Roy, R.

The sampling locations, along the Candolim Time-Series Section (CaTS), in coastal waters of the eastern Arabian Sea, are shown in Fig. 1. Water depth at these stations varied between 6 m (G1) and 28 m (G5) whereas samples at G5 were generally collected from a... times. 6 3. Results The short-term variability of halocarbons and pigments has been presented for CaTS station G5, with a brief on hydrography. However, data from stations G1- G4 have been used to derive statistically significant relationships among...

Forecasting Water Waves and Currents: A Space-time Approach

NARCIS (Netherlands)

Ambati, V.R.

2008-01-01

Forecasting water waves and currents in near shore and off shore regions of the seas and oceans is essential to maintain and protect our environment and man made structures. In wave hydrodynamics, waves can be classified as shallow and deep water waves based on its water depth. The mathematical

Sea Levels Online: Sea Level Variations of the United States Derived from National Water Level Observation Network Stations

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water level records are a combination of the fluctuations of the ocean and the vertical land motion at the location of the station. Monthly mean sea level (MSL)...

Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

Science.gov (United States)

Carton, X.; L'Hegaret, P.; Baraille, R.

2012-03-01

By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described. The Red Sea Outflow Water (RSOW) is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relatively barotropic gyres mix it with Indian ocean Central Water. RSOW is also detected along the northeastern coast of Socotra, and fragments of RSOW are found between one and three degrees of latitude north of this island. In the whole Gulf of Aden, the correlation between the deep motions of the floats and the sea-level anomaly measured by altimetry is strong, at regional scale. The finer scale details of the float trajectories are not sampled by altimetry and are often related to the anomalous water masses that the floats encounter. The Persian Gulf Water (PGW) is found in the float profiles near Ras ash Sharbatat (near 57° E, 18° N), again with 36.5 in salinity and about 18-19 °C in temperature. These observations were achieved in winter when the southwestward monsoon currents can advect PGW along the South Arabian coast. Fragments of PGW were also observed in the Arabian Sea between 18 and 20° N and 63 and 65° E in summer, showing that this water mass can escape the Gulf of Oman southeastward, during that season. Kinetic energy distributions of floats with respect to distance or angle share common features between the two regions (Gulf of Aden and Arabian Sea), in particular peaks at 30, 50 and 150 km scales and along the axis of monsoon currents. Hydrological measurements by floats are also influenced by the seasonal variations of PGW and RSOW in these regions.

Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

Directory of Open Access Journals (Sweden)

X. Carton

2012-03-01

Full Text Available By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described.

The Red Sea Outflow Water (RSOW is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relatively barotropic gyres mix it with Indian ocean Central Water. RSOW is also detected along the northeastern coast of Socotra, and fragments of RSOW are found between one and three degrees of latitude north of this island. In the whole Gulf of Aden, the correlation between the deep motions of the floats and the sea-level anomaly measured by altimetry is strong, at regional scale. The finer scale details of the float trajectories are not sampled by altimetry and are often related to the anomalous water masses that the floats encounter.

The Persian Gulf Water (PGW is found in the float profiles near Ras ash Sharbatat (near 57° E, 18° N, again with 36.5 in salinity and about 18–19 °C in temperature. These observations were achieved in winter when the southwestward monsoon currents can advect PGW along the South Arabian coast. Fragments of PGW were also observed in the Arabian Sea between 18 and 20° N and 63 and 65° E in summer, showing that this water mass can escape the Gulf of Oman southeastward, during that season.

Kinetic energy distributions of floats with respect to distance or angle share common features between the two regions (Gulf of Aden and Arabian Sea, in particular peaks at 30, 50 and 150 km scales and along the axis of monsoon currents. Hydrological measurements by floats are also influenced by the seasonal variations of PGW and RSOW in these regions.

THE USE OF SOLAR ENERGY IN THE DESALINATION SEA WATER IN AGRICULTURAL GREENHOUSE

Directory of Open Access Journals (Sweden)

T. Tahri

2015-08-01

Full Text Available The limited resources of fresh water in arid areas like the Middle East and North Africa MENA have led to the use of poor quality water in irrigation agriculture. These can reduce crop yield and environmental damage. Agriculture accounts for 70% of overall consumption in freshwater. Given the evaporation phenomena that occur in arid regions, this figure rises to 90%. This study focuses on the concept of combining the greenhouse with the desalination of seawater This concept is intended for small scale applications in remote areas where only saline water and solar energy are available.  The main objective of this research work is to analyze the production of fresh water using solar energy in the desalination of sea water in the greenhouse. This operating system is in need of thorough study of evaporators, condensers and design of the greenhouse. Desalination, combining the greenhouse to the use of sea water while exploiting the phenomenon of condensation of water vapor in the air, seems to respond positively to the needs of agricultural irrigation.

Millennial-scale variations of late Pleistocene radiolarian assemblages in the Bering Sea related to environments in shallow and deep waters

Science.gov (United States)

Itaki, Takuya; Kim, Sunghan; Rella, Stephan F.; Uchida, Masao; Tada, Ryuji; Khim, Boo-Keun

2012-02-01

A high-resolution record of the radiolarian assemblage from 60 to 10 ka was investigated using a piston core (PC-23A) obtained from the northern slope of the Bering Sea. Faunal changes based on the 29 major radiolarian taxa demonstrated that the surface and deep water conditions in the Bering Sea were related to the orbital and millennial-scale climatic variations known as glacial-interglacial and Dansgaard-Oeschger (D-O) cycles, respectively. During interstadial periods of the D-O cycles, the assemblage was characterized by increases in the high-latitude coastal species Rhizoplegma boreale and the upper-intermediate water species Cycladophora davisiana, while the sea-ice related species Actinomma boreale and A. leptodermum and many deep-water species such as Dictyophimus crisiae and D. hirundo tended to be reduced. This trend was more apparent in two laminated intervals at 15-13.5 and 11.5-11 ka, which were correlated with well-known ice-sheet collapse events that occurred during the last deglaciation: melt-water pulse (MWP)-1A and MWP-1B, respectively. The radiolarian faunal composition in these periods suggests that oceanic conditions were different from today: (1) surface water was affected by increased melt-water discharge from continental ice-sheet, occurring at the same time as an abrupt increase in atmospheric temperature, (2) upper-intermediate water (ca. 200-500 m) was well-ventilated and organic-rich, and (3) lower-intermediate water (ca. 500-1000 m) was oxygen-poor. Conversely, the sea-ice season might have been longer during stadial periods of the D-O cycles and the last glacial maximum (LGM) compared to the interstadial periods and the earliest Holocene. In these colder periods, deep-water species were very abundant, and this corresponded to increases in the oxygen isotope value of benthic foraminifera. Our findings suggest that the oxygen-rich water was present in the lower-intermediate layer resulting from intensified ventilation.

Remote Sensing of Salinity: The Dielectric Constant of Sea Water

Science.gov (United States)

LeVine, David M.; Lang, R.; Utku, C.; Tarkocin, Y.

2011-01-01

Global monitoring of sea surface salinity from space requires an accurate model for the dielectric constant of sea water as a function of salinity and temperature to characterize the emissivity of the surface. Measurements are being made at 1.413 GHz, the center frequency of the Aquarius radiometers, using a resonant cavity and the perturbation method. The cavity is operated in a transmission mode and immersed in a liquid bath to control temperature. Multiple measurements are made at each temperature and salinity. Error budgets indicate a relative accuracy for both real and imaginary parts of the dielectric constant of about 1%.

Red Sea Intermediate Water at the Agulhas Current termination

Science.gov (United States)

Roman, R. E.; Lutjeharms, J. R. E.

2007-08-01

The inter-ocean exchange of water masses at the Agulhas Current termination comes about through the shedding of rings, and this process plays an important role in the global thermohaline circulation. Using several hydrographic sections collected during the ARC (Agulhas Retroflection Cruise), MARE (Mixing of Agulhas Rings Experiment) and WOCE (World Ocean Circulation Experiment), this investigation aims to establish the degree to which Red Sea Intermediate Water (RSIW) is involved in this exchange and at what level of purity. To this end a wide range of hydrographic parameters were used. Upstream from the Agulhas Current retroflection water with clear RSIW origin is shown to move downstream on both the landward and seaward sides of the Agulhas Current with the highest water sample purity or water-mass content exceeding 15%. The least mixed water was found close to the continental shelf. At the retroflection the RSIW purity shows considerable variability that ranges between 5% and 20%. This suggests that RSIW moves down the current in patches of considerably varying degrees of previous mixing. This pattern was also observed in a ring sampled during the ARC experiment. The MARE sections in turn indicate that at times RSIW may be entirely absent in the Agulhas Current. RSIW is therefore shown to travel down the current as discontinuous filaments, and this intermittency is reflected in its presence in Agulhas Rings. From the sections investigated it is therefore clear that any calculation of RSIW fluxes involved in inter-ocean exchange can only be done on the basis of event scales. RSIW not trapped in Agulhas Rings flows east with the Agulhas Return Current.

Seasonal variation in composition and abundance of harmful dinoflagellates in Yemeni waters, southern Red Sea.

Science.gov (United States)

Alkawri, Abdulsalam

2016-11-15

General abundance and species composition of a dinoflagellate community in Yemeni coastal waters of Al Salif (southern Red Sea) were studied with a view to understand the annual variations in particular the toxic species. Dinoflagellates were more abundant among phytoplankton. Thirty five dinoflagellate taxa were identified, among which 12 were reported as potentially toxic species. A significant change in seasonal abundance was recorded with the maximum (2.27∗10 6 cellsl -1 ) in May, and the minimum (2.50∗10 2 cellsl -1 ) recorded in January. Kryptoperidinium foliaceum, which was reported for the first time from the Red Sea, was the most abundant species with a maximum in May 2013 (2.26∗10 6 cellsl -1 ). Spearman's rank correlation analysis indicates that, total harmful dinoflagellate cells, K. foliaceum, Prorocentrum gracile and Prorocentrum micans were significantly correlated with temperature. This study suggests that Yemeni waters should be monitored to investigate harmful species and to identify areas and seasons at higher risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Timing of return from altitude training for optimal sea level performance.

Science.gov (United States)

Chapman, Robert F; Laymon Stickford, Abigail S; Lundby, Carsten; Levine, Benjamin D

2014-04-01

While a number of published studies exist to guide endurance athletes with the best practices regarding implementation of altitude training, a key unanswered question concerns the proper timing of return to sea level prior to major competitions. Evidence reviewed here suggests that, altogether, the deacclimatization responses of hematological, ventilatory, and biomechanical factors with return to sea level likely interact to determine the best timing for competitive performance.

Methane excess in Arctic surface water-triggered by sea ice formation and melting.

Science.gov (United States)

Damm, E; Rudels, B; Schauer, U; Mau, S; Dieckmann, G

2015-11-10

Arctic amplification of global warming has led to increased summer sea ice retreat, which influences gas exchange between the Arctic Ocean and the atmosphere where sea ice previously acted as a physical barrier. Indeed, recently observed enhanced atmospheric methane concentrations in Arctic regions with fractional sea-ice cover point to unexpected feedbacks in cycling of methane. We report on methane excess in sea ice-influenced water masses in the interior Arctic Ocean and provide evidence that sea ice is a potential source. We show that methane release from sea ice into the ocean occurs via brine drainage during freezing and melting i.e. in winter and spring. In summer under a fractional sea ice cover, reduced turbulence restricts gas transfer, then seawater acts as buffer in which methane remains entrained. However, in autumn and winter surface convection initiates pronounced efflux of methane from the ice covered ocean to the atmosphere. Our results demonstrate that sea ice-sourced methane cycles seasonally between sea ice, sea-ice-influenced seawater and the atmosphere, while the deeper ocean remains decoupled. Freshening due to summer sea ice retreat will enhance this decoupling, which restricts the capacity of the deeper Arctic Ocean to act as a sink for this greenhouse gas.

Under Sea Ice phytoplankton bloom detection and contamination in Antarctica

Science.gov (United States)

Zeng, C.; Zeng, T.; Xu, H.

2017-12-01

Previous researches reported compelling sea ice phytoplankton bloom in Arctic, while seldom reports studied about Antarctic. Here, lab experiment showed sea ice increased the visible light albedo of the water leaving radiance. Even a new formed sea ice of 10cm thickness increased water leaving radiance up to 4 times of its original bare water. Given that phytoplankton preferred growing and accumulating under the sea ice with thickness of 10cm-1m, our results showed that the changing rate of OC4 estimated [Chl-a] varied from 0.01-0.5mg/m3 to 0.2-0.3mg/m3, if the water covered by 10cm sea ice. Going further, varying thickness of sea ice modulated the changing rate of estimating [Chl-a] non-linearly, thus current routine OC4 model cannot estimate under sea ice [Chl-a] appropriately. Besides, marginal sea ice zone has a large amount of mixture regions containing sea ice, water and snow, where is favorable for phytoplankton. We applied 6S model to estimate the sea ice/snow contamination on sub-pixel water leaving radiance of 4.25km spatial resolution ocean color products. Results showed that sea ice/snow scale effectiveness overestimated [Chl-a] concentration based on routine band ratio OC4 model, which contamination increased with the rising fraction of sea ice/snow within one pixel. Finally, we analyzed the under sea ice bloom in Antarctica based on the [Chl-a] concentration trends during 21 days after sea ice retreating. Regardless of those overestimation caused by sea ice/snow sub scale contamination, we still did not see significant under sea ice blooms in Antarctica in 2012-2017 compared with Arctic. This research found that Southern Ocean is not favorable for under sea ice blooms and the phytoplankton bloom preferred to occur in at least 3 weeks after sea ice retreating.

First biological measurements of deep-sea corals from the Red Sea

OpenAIRE

C. Roder; M. L. Berumen; J. Bouwmeester; E. Papathanassiou; A. Al-Suwailem; C. R. Voolstra

2013-01-01

It is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with ?deep-sea? and ?cold-water? corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20?C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the ...

Determination of ethylenediaminetetraacetic acid in sea water by solid-phase extraction and high-performance liquid chromatography.

Science.gov (United States)

Kemmei, Tomoko; Kodama, Shuji; Fujishima, Hironori; Yamamoto, Atsushi; Inoue, Yoshinori; Hayakawa, Kazuichi

2012-01-04

The chelating agent EDTA is widely used, and as a result is showing up widely in the aquatic environment. Here we describe a preconcentration procedure for measuring EDTA concentration in sea water samples by HPLC. The procedure consists of forming an Fe(III) complex followed by solid-phase extraction using an activated carbon cartridge. After the preconcentration, EDTA was quantified by HPLC with ultraviolet detection (260 nm). The enrichment permitted the determination of EDTA at concentrations as low as 1 nM. Good recoveries were obtained for both brackish and full-strength sea water with high repeatability (RSD<6%). The method was applied to sea water samples taken from near the mouth of the Oyabe River in Japan. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of SeaWiFS and MODIS time series of inherent optical properties for the Adriatic Sea

Directory of Open Access Journals (Sweden)

F. Mélin

2011-05-01

Full Text Available Time series of inherent optical properties (IOPs derived from SeaWiFS and MODIS are compared for the Adriatic Sea. The IOPs are outputs of the Quasi-Analytical Algorithm and include total absorption a, phytoplankton absorption a_ph, absorption associated with colored detrital material (CDM a_cdm, and particle backscattering coefficient b_bp. The average root-mean square difference Δ computed for log-transformed distributions decreases for $a$ from 0.084 at 412 nm to 0.052 at 490 nm, is higher for a_ph(443 (0.149 than for a_cdm(443 (0.071, and is approximately 0.165 for b_bp at various wavelengths. The SeaWiFS a at 443 and 490 nm, a_ph at 443 nm and b_bp are on average higher than the MODIS counterparts. Statistics show significant variations in space and time. There is an overall increasing gradient for Δ associated with the absorption terms from the open southern and central Adriatic to the northwest part of the basin, and a reversed gradient for the particulate backscattering coefficient. For time series analysis, only a(412 and a_cdm(443 currently present an unbiased continuity bridging the SeaWiFS and MODIS periods for the Adriatic Sea.

Spectrochemical method of uranium determination in sea water

International Nuclear Information System (INIS)

Koval'chuk, L.I.; Koryukova, V.P.; Andrianov, A.M.

1979-01-01

A spectrochemical method of uranium determination in sea water is reported. The method involves the use of hydrated titanium oxide as a concentrator and a substrate for the analysis. The uranium-containing concentrate mixed with carbon powder (1:1) is burned in the alternating current ark (i=15 A) and the spectra are recorded by a diffraction spectrometer. The analytical line of uranium is 2865.14 A. The variation coefficient is 12%

Sea ice draft in the Weddell Sea, measured by upward looking sonars

Directory of Open Access Journals (Sweden)

A. Behrendt

2013-06-01

Full Text Available The presented database contains time-referenced sea ice draft values from upward looking sonar (ULS measurements in the Weddell Sea, Antarctica. The sea ice draft data can be used to infer the thickness of the ice. They were collected during the period 1990–2008. In total, the database includes measurements from 13 locations in the Weddell Sea and was generated from more than 3.7 million measurements of sea ice draft. The files contain uncorrected raw drafts, corrected drafts and the basic parameters measured by the ULS. The measurement principle, the data processing procedure and the quality control are described in detail. To account for the unknown speed of sound in the water column above the ULS, two correction methods were applied to the draft data. The first method is based on defining a reference level from the identification of open water leads. The second method uses a model of sound speed in the oceanic mixed layer and is applied to ice draft in austral winter. Both methods are discussed and their accuracy is estimated. Finally, selected results of the processing are presented. The data can be downloaded from doi:10.1594/PANGAEA.785565.

Influence of sea squirt (Halocynthia roretzi) aquaculture on benthic-pelagic coupling in coastal waters: A study of the South Sea in Korea

Science.gov (United States)

Lee, Jae Seong; Kim, Sung-Han; Kim, Yong-Tae; Hong, Sok Jin; Han, Jeong Hee; Hyun, Jung-Ho; Shin, Kyung-Hoon

2012-03-01

The influence of sea squirt aquaculture on benthic-pelagic coupling was evaluated in semi-enclosed Korean coastal waters with an in situ benthic chamber and results show for the first time that suspended sea squirt cultures play an important role in benthic-pelagic coupling in the coastal zone. Measurements of primary production, vertical particulate fluxes, and benthic fluxes were made at two stations, a sea squirt (Halocynthia roretzi) farm (SSF) and an area of organic-matter-enriched sediment in Jinhae Bay. The vertical material fluxes of organic carbon, nitrogen, and biogenic silicate (BSi) were significantly higher at SSF than in Jinhae Bay, indicating massive biodeposits in the surface sediments at SSF. The organic carbon oxidation rates (Cox) were estimated after correction for CaCO3 dissolution. The average Cox at SSF (204 mmol C m-2 d-1) was significantly higher than that in the organic-enriched Jinhae Bay sediment (77 mmol C m-2 d-1). The organic carbon burial fluxes were determined using vertical profiles of organic carbon of up to 30 cm and the sedimentation rate calculated from the excess 210Pb distribution. At both stations, ˜95% of the settled organic carbon was oxidized and only ˜5% was buried in the deep sediment layer. The benthic fluxes of dissolved inorganic nitrogen and phosphate at SSF were 2-12 times higher than in Jinhae Bay, corresponding to 85%, and 270%, respectively, of the requirements for primary production.

Origin and pathways of Winter Intermediate Water in the Northwestern Mediterranean Sea using observations and numerical simulation

Science.gov (United States)

Juza, Mélanie; Renault, Lionel; Ruiz, Simon; Tintoré, Joaquin

2013-12-01

The study of water masses worldwide (their formation, spreading, mixing, and impact on general circulation) is essential for a better understanding of the ocean circulation and variability. In this paper, the formation and main pathways of Winter Intermediate Water (WIW) in the Northwestern Mediterranean Sea (NWMED) are investigated during the winter-spring 2011 using observations and numerical simulation. The main results show that the WIW, formed along the continental shelves of the Gulf of Lion and Balearic Sea, circulates southward following five preferential pathways depending on the WIW formation site location and the oceanic conditions. WIW joins the northeastern part of the Balearic Sea, or flows along the continental shelves until joining the Balearic Current (maximum of 0.33 Sv in early-April) or further south until the Ibiza Channel entrance. Two additional trajectories, contributing to water mass exchanges with the southern part of the Western Mediterranean Sea, bring the WIW through the Ibiza and Mallorca Channels (maxima of 0.26 Sv in late-March and 0.1 Sv in early-April, respectively). The circulation of WIW over the NWMED at 50-200 m depth, its mixing and spreading over the Western Mediterranean Sea (reaching the south of the Balearic Islands, the Algero-Provencal basin, the Ligurian and the Alboran Seas) suggest that the WIW may have an impact on the ocean circulation by eddy blocking effect, exchange of water masses between north and south subbasins of Western Mediterranean Sea through the Ibiza Channel or modification of the ocean stratification.

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

Science.gov (United States)

Jain, Vineet; Shankar, D.; Vinayachandran, P. N.; Kankonkar, A.; Chatterjee, Abhisek; Amol, P.; Almeida, A. M.; Michael, G. S.; Mukherjee, A.; Chatterjee, Meenakshi; Fernandes, R.; Luis, R.; Kamble, Amol; Hegde, A. K.; Chatterjee, Siddhartha; Das, Umasankar; Neema, C. P.

2017-05-01

The high-salinity water masses that originate in the North Indian Ocean are Arabian Sea High-Salinity Water (ASHSW), Persian Gulf Water (PGW), and Red Sea Water (RSW). Among them, only ASHSW has been shown to exist in the Bay of Bengal. We use CTD data from recent cruises to show that PGW and RSW also exist in the bay. The presence of RSW is marked by a deviation of the salinity vertical profile from a fitted curve at depths ranging from 500 to 1000 m; this deviation, though small (of the order of 0.005 psu and therefore comparable to the CTD accuracy of 0.003 psu), is an order of magnitude larger than the 0.0003 psu fluctuations associated with the background turbulence or instrument noise in this depth regime, allowing us to infer the existence of RSW throughout the bay. PGW is marked by the presence of a salinity maximum at 200-450 m; in the southwestern bay, PGW can be distinguished from the salinity maximum due to ASHSW because of the intervening Arabian Sea Salinity Minimum. This salinity minimum and the maximum associated with ASHSW disappear east and north of the south-central bay (85°E, 8°N) owing to mixing between the fresher surface waters that are native to the bay (Bay of Bengal Water or BBW) with the high-salinity ASHSW. Hence, ASHSW is not seen as a distinct water mass in the northern and eastern bay and the maximum salinity over most of the bay is associated with PGW. The surface water over most of the bay is therefore a mixture of ASHSW and the low-salinity BBW. As a corollary, we can also infer that the weak oxygen peak seen within the oxygen-minimum zone in the bay at a depth of 250-400 m is associated with PGW. The hydrographic data also show that these three high-salinity water masses are advected into the bay by the Summer Monsoon Current, which is seen to be a deep current extending to 1000 m. These deep currents extend into the northern bay as well, providing a mechanism for spreading ASHSW, PGW, and RSW throughout the bay.

The diet and feeding ecology of Conger conger (L. 1758 in the deep waters of the Eastern Ionian Sea

Directory of Open Access Journals (Sweden)

A. ANASTASOPOULOU

2013-06-01

Full Text Available The diet of the European conger eel Conger conger was investigated for the first time in the Eastern Mediterranean. Fish dominated the European conger eel diet in the deep waters of E. Ionian Sea. All other prey taxa were identified as accidental preys. However, intestine analysis showed that Natantia, Brachyura and Cephalopoda might have a more important contribution in the diet of the species. C. conger exhibited a benthopelagic feeding behavior as it preyed upon both demersal and mesopelagic taxa. The high vacuity index and the low stomach and intestine fullness indicated that the feeding intensity of the species in the deep waters of Eastern Ionian Sea was quite low. C. conger feeding strategy was characterised by specialisation in various resource items. A between-phenotype contribution to niche width was observed for some prey categories. European Conger eel feeding specialisation seemed to be an adaptation to a food-scarce environment, as typified in deep-water habitats

Primary tasks of environmental improvement of the Aral Sea region

International Nuclear Information System (INIS)

Tauipbaev, S.T.; Turebaev, Sh.Kh.; Kusherbaev, A.E.

1997-01-01

Main reasons of environmental crisis in Aral Sea region are analyzed. Primary tasks of its environmental improvement are planed: - creation of conditions of guarantee ensuring (by territory and time) for all water consumers of water resources of the Syr-Dariya and Amu Dariya rivers at the expense of increase of water system efficiency and organization of Water Union of Basin Countries; - acceptance of regional measures on good quality water supply for the Aral Sea region population, mainly at expense of underground water use; -fulfillment of primary measures for Aral Sea save, envisaging building of land dam separating the Small Aral: - solution of unemployment problem by capacity of strengthening of farm economy and rebirth of native business

Bio-engineering in the Baltic Sea

DEFF Research Database (Denmark)

Zandersen, Marianne

2011-01-01

Bio-engineering in the Baltic Sea – value of water quality improvements & risk perceptions Dr. Marianne Zandersen1 Department of Environmental Science, Aarhus University Abstract The Baltic Sea is heavily eutrofied and the trend has gone from bad to worse. The hypoxic zone has increased about 4...... of the water column to the bottom waters/deepwater. The expected effects include a slowing down of the sediment release from the bottom and improvement of the possibilities for aerobic bacterial decomposition and over time for the establishment of fauna. The projects test a bio-engineered approach to speeding...

Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

Science.gov (United States)

Wang, P.; Linker, L.; Wang, H.; Bhatt, G.; Yactayo, G.; Hinson, K.; Tian, R.

2017-08-01

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

Southern Dobrogea coastal potable water sources and Upper Quaternary Black Sea level changes

Science.gov (United States)

Caraivan, Glicherie; Stefanescu, Diana

2013-04-01

Southern Dobrogea is a typical geologic platform unit, placed in the south-eastern part of Romania, with a Pre-Cambrian crystalline basement and a Paleozoic - Quaternary sedimentary cover. It is bordered to the north by the Capidava - Ovidiu fault and by the Black Sea to the east. A regional WNW - ESE and NNE - SSW fault system divides the Southern Dobrogea structure in several tectonic blocks. Four drinking water sources have been identified: surface water, phreatic water, medium depth Sarmatian aquifer, and deep Upper Jurassic - Lower Cretaceous aquifer. Surface water sources are represented by several springs emerged from the base of the loess cliff, and a few small rivers, barred by coastal beaches. The phreatic aquifer develops at the base of the loess deposits, on the impervious red clay, overlapping the Sarmatian limestones. The medium depth aquifer is located in the altered and karstified Sarmatian limestones, and discharges into the Black Sea. The Sarmatian aquifer is unconfined where covered by silty loess deposits, and locally confined, where capped by clayey loess deposits. The aquifer is supplied from the Pre-Balkan Plateau. The Deep Upper Jurassic - Lower Cretaceous aquifer, located in the limestone and dolomite deposits, is generally confined and affected by the regional WNW - ESE and NNE - SSW fault system. In the south-eastern Dobrogea, the deep aquifer complex is separated from the Sarmatian aquifer by a Senonian aquitard (chalk and marls). The natural boundary of the Upper Jurassic - Lower Cretaceous aquifer is the Capidava - Ovidiu Fault. The piezometric heads show that the Upper Jurassic - Lower Cretaceous aquifer is supplied from the Bulgarian territory, where the Upper Jurassic deposits crop out. The aquifer discharges into the Black Sea to the east and into Lake Siutghiol to the northeast. The cyclic Upper Quaternary climate changes induced drastic remodeling of the Black Sea level and the corresponding shorelines. During the Last Glacial

Sea-water/groundwater interactions along a small catchment of the European Atlantic coast

International Nuclear Information System (INIS)

Einsiedl, Florian

2012-01-01

The geochemistry and isotopic composition of a karstic coastal aquifer in western Ireland has shed light on the effect of sea-water/groundwater interactions on the water quality of Ireland’s Atlantic coastal zone. The use of stable isotope data from the IAEA precipitation station in Valentia, located in SW Ireland has facilitated the characterization of groundwater recharge conditions in the western part of Ireland and suggests that groundwater is mostly replenished by the isotopically light winter precipitation. The dissolved SO 4 2- in the karstic groundwater that was collected during baseflow conditions with δ 34 S values between 4.6‰ and 18‰ may be composed of S stemming from three principal sources: SO 4 2- derived from precipitation which is composed of both sea-spray S (δ 34 S: 20‰) and an isotopically light anthropogenic source (δ 34 S: 1–5‰), SO 4 2- stemming from animal slurries (δ 34 S: ∼5‰), and intruding sea-water SO 4 2- (δ 34 S: 20.2‰). The isotopic composition of δ 18 O in dissolved groundwater SO 4 2- collected during baseflow conditions is interpreted as reflecting sea-water intrusion to the karstic coastal groundwater system. The highest δ 18 O values in dissolved groundwater SO 4 2- were in samples collected near the coast (4.8 ± 0.4‰) and the lowest (2 ± 0.5‰) were collected further inland. The δ 15 N and δ 18 O values of groundwater NO 3 - were between 3.4‰ and 11.4‰ and approximately 7.7‰, respectively, and reflect geochemical conditions in the aquifer that do not promote attenuation of NO 3 - through denitrification. As a result N loading to Kinvara Bay that is controlled by submarine groundwater discharge (SGD) was calculated as 5 tons/day on average compared to an estimated N-input that derives from precipitation of approximately 2.5 tons/a. SGD into the bay may result in near coastal sea-water quality changes. These results represent one of the first studies addressing the effect of groundwater

Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

OpenAIRE

Carton, X.; L'Hegaret, P.; Baraille, R.

2012-01-01

By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described.

The Red Sea Outflow Water (RSOW) is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relative...

The Influence of Wind and Basin Eddies in Controlling Sea Level Variations in the Coastal Red Sea

KAUST Repository

Abualnaja, Yasser

2015-04-01

Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. Roughly half of the coastal sea level variance in central Red Sea is due to elevation changes in an \\'intermediate\\' frequency band, with periods between 2 days and 1 month. We examined the sea level signal in this band using the data from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters between 20.1 and 23.5 oN. We find that the intermediate-band sea level variations are strongly correlated with the local wind stress measured at a meteorological buoy. The maximum pressure-wind correlation occurs at wind direction closely aligned with the alongshore orientation and at a lag (wind leading) of 45 hr, which is consistent with the expected response of the coastal sea level to local wind forcing. However, less than half of the sea level variance in the intermediate band is related, through linear correlation, with local wind forcing. Our analysis indicates that the residual coastal sea level signal, not associated with wind forcing, is largely driven remotely by the passage of mesoscale eddies, revealed by satellite altimeter-derived sea level anomaly fields of the central Red Sea. These eddy-driven coastal sea level changes occur on time scales of 10-30 days. They span a range of 0.5 m, and thus constitute an import component of the sea level signal in the coastal Red Sea.

The Influence of Wind and Basin Eddies in Controlling Sea Level Variations in the Coastal Red Sea

KAUST Repository

Abualnaja, Yasser; Churchill, James H.; Nellayaputhenpeedika, Mohammedali; Limeburner, Richard

2015-01-01

Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. Roughly half of the coastal sea level variance in central Red Sea is due to elevation changes in an 'intermediate' frequency band, with periods between 2 days and 1 month. We examined the sea level signal in this band using the data from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters between 20.1 and 23.5 oN. We find that the intermediate-band sea level variations are strongly correlated with the local wind stress measured at a meteorological buoy. The maximum pressure-wind correlation occurs at wind direction closely aligned with the alongshore orientation and at a lag (wind leading) of 45 hr, which is consistent with the expected response of the coastal sea level to local wind forcing. However, less than half of the sea level variance in the intermediate band is related, through linear correlation, with local wind forcing. Our analysis indicates that the residual coastal sea level signal, not associated with wind forcing, is largely driven remotely by the passage of mesoscale eddies, revealed by satellite altimeter-derived sea level anomaly fields of the central Red Sea. These eddy-driven coastal sea level changes occur on time scales of 10-30 days. They span a range of 0.5 m, and thus constitute an import component of the sea level signal in the coastal Red Sea.

WATER TEMPERATURE and other data from STARK in the Mediterranean Sea from 1992-01-07 to 1992-01-31 (NODC Accession 9200044)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession were collected in Mediterranean Sea from ship STARK between January 7, 1992 and January 31, 1992. The real time data of water temperature...

EXPERIENCE OF SEA WATER HYPERTONIC SOLUTION APPLICATION FOR TOPICAL TREATMENT OF CHRONIC TONSILLITIS

Directory of Open Access Journals (Sweden)

E.P. Karpova

2006-01-01

Full Text Available The study examined the effectiveness of sea water hypertonic solution (Aqua Maris troath and oral cavity spray, Jadran, Croatia medication to treat chronic tonsillitis of the compensated form on 84 children aged between 5 and 15. All children had their tonsil lacunae rinsed in a day № 6–8. 64 children had them rinsed with the sea water hypertonic solution (main group, while 20 children had them rinsed with the nitrofural solution (comparison group. Treatment effectiveness was determined according to dynamics of main symptoms (odynophagia, dysphagia, hyperemia and mucosa infiltration of pillars of the fauces, as well as the degree of tonsil bacterial number before and after treatment (by the 14th day. The dynamic analysis of subjective data during treatment revealed more significant and positive changes among the children of the main group if compared with patients from the comparison group. After treatment the researchers noticed reduction of tonsil bacterial number among 90,62% of children from the main group, whereas this rate made up 60% in the comparison group. Acquired data allowed recommending this medication for the multimodality therapy of infant adenoid disease.Key words: chronic tonsillitis, treatment, children, sea water hypertonic solution.

Violent storms within the sea: Dense water formation episodes in the Mediterranean.

Science.gov (United States)

Salat, J.

2009-09-01

The Mediterranean is a semi enclosed basin which receives surface water from the Atlantic Ocean. Most of this water is returned into the Ocean with higher density, spreading at more than 1000 m depth (the rest is transported by the atmosphere and the rivers to the Ocean surface). In terms of water budget, the Mediterranean is considered an evaporation basin, but the loss of water is neither the only process that increases the water density nor it is a steady or uniform process. The factors affecting the water density, temperature and salinity, are driven by mass and heat exchanges with the atmosphere. Those exchanges may be by direct contact or mediated by the land. Therefore, changes in water density depend on the water circulation and local weather conditions, both with seasonal and geographical constraints. As the compressibility of water is very low, stratification is expected and horizontal motion is the predominant in the sea interior. Among the few processes that may introduce a vertical component in the water motion are surface heat loss or evaporation that increase the surface water density triggering convective cells. Such processes will be enhanced by surface cooling or by dry continental winds, and counterbalanced by rain, river runoff, solar heating and condensation. Therefore dense water formation are more likely to occur when sea surface temperature is higher than the surface air temperature. There are several scales of convective motions in the ocean, starting from the formation of the surface mixed layer during summer, by night cooling, breezes, and occasional wind storms. During autumn and winter, the vertical scale of the mixing is increasing by steps, through wind storms and progressive cooling, to easily reach the bottom over the continental shelves, typically not deeper than 150 m. However, as the Gibraltar sill is relatively shallow (~350 m) in relation to the average Mediterranean basin (2000-3000 m), the stratification of the deeper layers

Mantle helium in the Red Sea brines

International Nuclear Information System (INIS)

Lupton, J.E.; Weiss, R.F.; Craig, H.

1977-01-01

It is stated that He isotope studies of terrestrial samples have shown the existence of two He components that are clearly distinct from atmospheric He. These are termed 'crustal' He and 'mantle' He; the latter was discovered as 'excess 3 He' in deep ocean water and attributed to a flux of primordial He from the mantle. Studies of the 3 He/ 4 He ratio in deep Pacific water and in He trapped in submarine basalt glasses showed that this 'mantle' component is characterised by ratios about ten times the atmospheric ratio and 100 times the ratio in 'crustal' He. Basalt glasses from other deep sea waters also showed similar ratios, and it is indicated that 'mantle' He in areas in which new lithosphere is being formed has a unique and uniform isotopic signature. Measurements of He and Ne are here reported that reveal additional information on the origin of Red Sea brines and their relationship to the Red Sea rifts. (U.K.)

Movement of Water Across Passages Connecting Philippine Inland Sea Basins

Directory of Open Access Journals (Sweden)

Lambert Anthony B Meñez

2006-12-01

Full Text Available Advection of Pacific water to the inland seas is through a number of straits bordering the archipelago. Movement of water was demonstrated by temperature-salinity diagrams plotted for a number of stations situated along the various passages. As water from the Pacific flowed through the straits its characteristic T-S profile was modified as it mixed with waters of different properties. This was best seen along the San Bernardino-Verde Island transect where strong surface flow during the NE monsoon resulted in separation of profiles at the surface indicating dilution as water moved away from the source. For deeper water, the erosion of the subsurface salinity minimum and maximum representing the core of the intermediate waters showed transport. These waters were restricted by shallow sill along the eastern coast of the country and limited to a depth of 441m by the sill across the Mindoro Strait.

Nature of the Jurassic Magnetic Quiet Zone revealed by the sea-surface, mid-water, and near-source magnetic sensor data in the western Pacific.

Science.gov (United States)

Tominaga, M.; Tivey, M.; Sager, W. W.

2015-12-01

The nature of the Jurassic Quiet Zone (JQZ) has been a long-standing debate in understanding Earth's geomagnetic field history and behavior. We present a coherent and likely globally significant marine magnetic reversal record for the JQZ by constructing a correlation of new and previously acquired magnetic anomaly profiles in the western Pacific. We obtained a high-resolution marine magnetic anomaly record using sea surface, mid-water (3-km level deep-towed), and near-bottom (Autonomous Underwater Vehicle (AUV)) profiles that targeted a spreading corridor in the Hawaiian lineation in 2011 (TN272 on R/V Thompson) and 2014 (SKQ2014S2 on R/V Sikuliaq). To extract crustal magnetic signals, the sea surface and mid-water magnetic data were corrected for ship-to-sensor offset, the diurnal effect, and the present-day ambient geomagnetic field. Mid-water data were upward continued to a constant 3 km level plane and to the sea surface. Near-bottom data were calibrated to remove the induced magnetic field by AUV Sentry, then corrected for IGRF and diurnal variations. We used these near-source data as an anchor for correlations with the sea surface and mid-water level data because of the AUV's superb inertial navigation and hydrodynamically stable, quiet platform environment. Our sea surface anomaly correlation with the previously established Japanese lineation sequence shows (i) an excellent correlation of anomaly shapes from M29 to M42; (ii) a remarkable similarity in anomaly amplitude envelope, which decreases back in time from M19 to M38, with a minimum at M41, then increases back in time from M42; and (iii) refined locations of pre-M25 lineations in the Hawaiian lineation set. Moreover, short-wavelength anomalies from the mid-water and near-bottom profiles show a strong similarity in the M37/M38 polarity attributes found both in the magnetostratigraphic and marine magnetic records, implying that rapid magnetic reversals were occurring at that time. The average reversal

WATER TEMPERATURE and other data from PAUL in the Caribbean Sea from 1991-03-16 to 1991-03-24 (NODC Accession 9100075)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession were collected in Carribbean Sea from Ship Paul between March 16, 1991 to March 24, 1991. The real time data of water temperature at...

Chromatographic determination of the rate and extent of absorption of air pollutants by sea water

International Nuclear Information System (INIS)

Nikolakaki, S.; Vassilakos, C.; Katsanos, N.A.

1994-01-01

A simple chromatographic method is developed to determine the rate constant for expulsion of an air pollutant from water or its diffusion parameter in the liquid, the rate constant for chemical reaction of the pollutant with water, its mass transfer coefficient in the liquid, and the partition coefficient between liquid water and air. From these physicochemical parameters, the absorption rate by sea water and, therefore, the depletion rate of a polluting substance from the air can be calculated, together with the equilibrium state of this absorption. The method has been applied to nitrogen dioxide being absorbed by triple-distilled water and by sea water, at various temperatures. From the temperature variation of the reaction rate constant and of the partition coefficient, the activation energy for the reaction and the differential heat of solution were determined. (orig.)

The Baltic Sea as a time machine for the future coastal ocean

DEFF Research Database (Denmark)

Reusch, Thorsten B. H.; Dierking, Jan; Andersson, Helen C.

2018-01-01

Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use...... transcending its complex multistate policy setting, with integrated management of watershed and sea. The Baltic Sea also demonstrates how rapidly progressing global pressures, particularly warming of Baltic waters and the surrounding catchment area, can offset the efficacy of current management approaches...... of multistressor disturbance and ecosystem deterioration and early implementation of cross-border environmental management to address these problems. The Baltic Sea also stands out in providing a strong scientific foundation and accessibility to long-term data series that provide a unique opportunity to assess...

Abrupt changes of intermediate water properties on the northeastern slope of the Bering Sea during the last glacial and deglacial period

Science.gov (United States)

Rella, Stephan F.; Tada, Ryuji; Nagashima, Kana; Ikehara, Minoru; Itaki, Takuya; Ohkushi, Ken'ichi; Sakamoto, Tatsuhiko; Harada, Naomi; Uchida, Masao

2012-09-01

Millennial-scale variability in the behavior of North Pacific Intermediate Water during the last glacial and deglacial period, and its association with Dansgaard-Oeschger (D-O) cycles and Heinrich events, are examined based on benthic foraminiferal oxygen and carbon isotopes (δ18Obf and δ13Cbf) and %CaCO3 using a sediment core recovered from the northeastern slope of the Bering Sea. A suite of positive δ18Obf excursions at intermediate depths of the Bering Sea, which seem at least in part associated with increases in the δ18Obf gradients between the Bering and Okhotsk Seas, suggest the Bering Sea as a proximate source of intermediate water during several severe stadial episodes in the last glacial and deglacial period. Absence of such δ18Obf gradients during periods of high surface productivity in the Bering and Okhotsk Seas, which we correlate to D-O interstadials, suggests a reduction in intermediate water production in the Bering Sea and subsequent introduction of nutrient-rich deep waters from the North Pacific into intermediate depths of the Bering Sea. We argue that a reorganization of atmospheric circulation in the high-latitude North Pacific during severe cold episodes in the last glacial and deglacial period created favorable conditions for brine rejection in the northeastern Bering Sea. The resulting salinity increase in the cold surface waters could have initiated intermediate (and deep) water formation that spread out to the North Pacific.

[Monitoring "green tide" in the Yellow Sea and the East China Sea using multi-temporal and multi-source remote sensing images].

Science.gov (United States)

Xing, Qian-Guo; Zheng, Xiang-Yang; Shi, Ping; Hao, Jia-Jia; Yu, Ding-Feng; Liang, Shou-Zhen; Liu, Dong-Yan; Zhang, Yuan-Zhi

2011-06-01

Landsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectrora-diometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixing behavior, and satellite images with finer spatical resolution are more effective in detection of macro-algae patches. Macro-algae patches were detected by the Landsat images for the first time at the Sheyang estuary where is dominated by very turbid waters. The MODIS images showed that the macro-algae from the turbid waters near the Northern Jiangsu Shoal drifted southwardly in the early of May and affected the East China Sea waters; with the strengthening east-asian Summer Monsoon, macro-algae patches mainly drifted in a northward path which was mostly observed at the Yellow Sea. Macro-algae patches were also found to drift eastwardly towards the Korea Peninsular, which are supposed to be driven by the sea surface wind.

Combined effects of sea water acidification and copper exposure on the symbiont-bearing foraminifer Amphistegina gibbosa

Science.gov (United States)

Marques, Joseane Aparecida; de Barros Marangoni, Laura Fernandes; Bianchini, Adalto

2017-06-01

Coral reefs are threatened by global and local stressors such as ocean acidification and trace metal contamination. Reliable early warning monitoring tools are needed to assess and monitor coral reef health. Symbiont-bearing foraminifers ( Amphistegina gibbosa) were kept under ambient conditions (no sea water acidification and no copper addition) or exposed to combinations of different levels of sea water pH (8.1, 7.8, 7.5 and 7.2) and environmentally relevant concentrations of dissolved copper (measured: 1.0, 1.6, 2.3 and 3.2 µg L-1) in a mesocosm system. After 10- and 25-d exposure, foraminifers were analyzed for holobiont Ca2+-ATPase activity, bleaching, growth and mortality. Enzyme activity was inhibited in foraminifers exposed to pH 7.2 and 3.2 µg L-1 Cu for 25 d. Bleaching frequency was also higher at pH 7.2 combined with copper addition. There was no significant effect of sea water acidification and copper addition on mortality. However, test size was smaller in foraminifers exposed to copper, with a positive interactive effect of sea water acidification. These findings can be explained by the higher availability of free copper ions at lower water pH. This condition would increase Cu competition with Ca2+ for the binding sites on the organism, thus inhibiting Ca2+-ATPase activity and affecting the organism's overall fitness. Findings reported here suggest that key processes in A. gibbosa, such as calcification and photosynthesis, are affected by the combined effect of global (sea water acidification) and local (copper contamination) stressors. Considering the experimental conditions employed (mesocosm system, possible ocean acidification scenarios, low copper concentrations, biomarkers of ecological relevance and chronic exposure), our findings support the use of foraminifera and biomarkers analyzed in the present study as reliable tools to detect and monitor the ecological impacts of multiple stressors in coral reef environments.

THE GEOPOLITICAL DIMENSION OF ENVIRONMENTAL QUALITY. WATERS AND CONFLICT IN THE ARAL SEA BASIN

Directory of Open Access Journals (Sweden)

Stefano Piastra

2009-07-01

Full Text Available In the last decades the Aral Sea, located in Central Asia on the boundary between Kazakhstan and Uzbekistan, experienced a dramatic shrinking, divulged even in newspapers and magazines. Such an ecological catastrophe, renamed the “Aral Sea Crisis”, was triggered by the artificial diversion of the rivers of the basin during the Soviet period, in order to irrigate new cotton fields. Nowadays, notwithstanding the fulfilment of several environmental restoration projects and a wide scientific literature about the process, the general balance about the water body, in particular its Uzbek side, is still critical. This paper, after a synthesis concerning the causes and the consequences of the ecological disaster, analyses the geopolitical implications connected to the deterioration of the environmental quality in the region and to water management in Post-Soviet Central Asia, underlining, in the case of the Aral Sea Basin, the criticities linked to its fast transition from an internal basin to an international one. Finally, Central Asian water-related old programs and future scenarios are discussed.

Radar and infrared remote sensing of terrain, water resources, arctic sea ice, and agriculture

Science.gov (United States)

Biggs, A. W.

1983-01-01

Radar range measurements, basic waveforms of radar systems, and radar displays are initially described. These are followed by backscatter from several types of terrain and vegetation as a function of frequency and grazing angle. Analytical models for this backscatter include the facet models of radar return, with range-angle, velocity-range, velocity-angle, range, velocity, and angular only discriminations. Several side-looking airborne radar geometries are presented. Radar images of Arctic sea ice, fresh water lake ice, cloud-covered terrain, and related areas are presented to identify applications of radar imagery. Volume scatter models are applied to radar imagery from alpine snowfields. Short pulse ice thickness radar for subsurface probes is discussed in fresh-water ice and sea ice detection. Infrared scanners, including multispectral, are described. Diffusion of cold water into a river, Arctic sea ice, power plant discharges, volcanic heat, and related areas are presented in thermal imagery. Multispectral radar and infrared imagery are discussed, with comparisons of photographic, infrared, and radar imagery of the same terrain or subjects.

Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

Science.gov (United States)

Eelsalu, Maris; Soomere, Tarmo

2016-04-01

The risks and damages associated with coastal flooding that are naturally associated with an increase in the magnitude of extreme storm surges are one of the largest concerns of countries with extensive low-lying nearshore areas. The relevant risks are even more contrast for semi-enclosed water bodies such as the Baltic Sea where subtidal (weekly-scale) variations in the water volume of the sea substantially contribute to the water level and lead to large spreading of projections of future extreme water levels. We explore the options for using large ensembles of projections to more reliably evaluate return periods of extreme water levels. Single projections of the ensemble are constructed by means of fitting several sets of block maxima with various extreme value distributions. The ensemble is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. A hindcast by the Rossby Centre Ocean model is sampled with a resolution of 6 h and a similar hindcast by the circulation model NEMO with a resolution of 1 h. As the annual maxima of water levels in the Baltic Sea are not always uncorrelated, we employ maxima for calendar years and for stormy seasons. As the shape parameter of the Generalised Extreme Value distribution changes its sign and substantially varies in magnitude along the eastern coast of the Baltic Sea, the use of a single distribution for the entire coast is inappropriate. The ensemble involves projections based on the Generalised Extreme Value, Gumbel and Weibull distributions. The parameters of these distributions are evaluated using three different ways: maximum likelihood method and method of moments based on both biased and unbiased estimates. The total number of projections in the ensemble is 40. As some of the resulting estimates contain limited additional information, the members of pairs of projections that are highly correlated are assigned weights 0.6. A comparison of the ensemble-based projection of