An index of refraction algorithm for seawater over temperature, pressure, salinity, density, and wavelength

NASA Astrophysics Data System (ADS)

Millard, R. C.; Seaver, G.

1990-12-01

A 27-term index of refraction algorithm for pure and sea waters has been developed using four experimental data sets of differing accuracies. They cover the range 500-700 nm in wavelength, 0-30°C in temperature, 0-40 psu in salinity, and 0-11,000 db in pressure. The index of refraction algorithm has an accuracy that varies from 0.4 ppm for pure water at atmospheric pressure to 80 ppm at high pressures, but preserves the accuracy of each original data set. This algorithm is a significant improvement over existing descriptions as it is in analytical form with a better and more carefully defined accuracy. A salinometer algorithm with the same uncertainty has been created by numerically inverting the index algorithm using the Newton-Raphson method. The 27-term index algorithm was used to generate a pseudo-data set at the sodium D wavelength (589.26 nm) from which a 6-term densitometer algorithm was constructed. The densitometer algorithm also produces salinity as an intermediate step in the salinity inversion. The densitometer residuals have a standard deviation of 0.049 kg m -3 which is not accurate enough for most oceanographic applications. However, the densitometer algorithm was used to explore the sensitivity of density from this technique to temperature and pressure uncertainties. To achieve a deep ocean densitometer of 0.001 kg m -3 accuracy would require the index of refraction to have an accuracy of 0.3 ppm, the temperature an accuracy of 0.01°C and the pressure 1 db. Our assessment of the currently available index of refraction measurements finds that only the data for fresh water at atmospheric pressure produce an algorithm satisfactory for oceanographic use (density to 0.4 ppm). The data base for the algorithm at higher pressures and various salinities requires an order of magnitude or better improvement in index measurement accuracy before the resultant density accuracy will be comparable to the currently available oceanographic algorithm.

Environmental parameters influence on the dynamics of total and pathogenic Vibrio parahaemolyticus densities in Crassostrea virginica harvested from Mexico's Gulf coast.

PubMed

López-Hernández, Karla M; Pardío-Sedas, Violeta T; Lizárraga-Partida, Leonardo; Williams, José de J; Martínez-Herrera, David; Flores-Primo, Argel; Uscanga-Serrano, Roxana; Rendón-Castro, Karla

2015-02-15

The influence of environmental parameters on the total and pathogenic Vibrio parahaemolyticus seasonal densities in American oysters (Crassostrea virginica) was evaluated for 1 year. Harvesting site A yielded the highest mean densities of V. parahaemolyticus tlh+, tdh+/trh-, tdh-/trh+ and tdh+/trh+ during spring season at 2.57, 1.74, 0.36, and -0.40 log10 MPN/g, respectively, and tdh+/orf8+ during winter season (0.90 log10 MPN/g). V. parahaemolyticus tlh+ densities were associated to salinity (R(2)=0.372, P<0.022), tdh+/trh+ to turbidity (R(2)=0.597, P<0.035), and orf8+ to temperature, salinity, and pH (R(2)=0.964, P<0.001). The exposure to salinity and temperature conditions during winter and spring seasons regulated the dynamics of V. parahaemolyticus harboring potentially pathogenic genotypes within the oyster. The adaptive response of V. parahaemolyticus to seasonal environmental changes may lead to an increase in survival and virulence, threatening the seafood safety and increasing the risk of illness. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of genetic background, salinity, and inoculum size on growth of the ichthyotoxic golden alga (Prymnesium parvum)

USGS Publications Warehouse

Rashel, Rakib H.; Patino, Reynaldo

2017-01-01

Salinity (5–30) effects on golden alga growth were determined at a standard laboratory temperature (22 °C) and one associated with natural blooms (13 °C). Inoculum-size effects were determined over a wide size range (100–100,000 cells ml−1). A strain widely distributed in the USA, UTEX-2797 was the primary study subject but another of limited distribution, UTEX-995 was used to evaluate growth responses in relation to genetic background. Variables examined were exponential growth rate (r), maximum cell density (max-D) and, when inoculum size was held constant (100 cells ml−1), density at onset of exponential growth (early-D). In UTEX-2797, max-D increased as salinity increased from 5 to ∼10–15 and declined thereafter regardless of temperature but r remained generally stable and only declined at salinity of 25–30. In addition, max-D correlated positively with r and early-D, the latter also being numerically highest at salinity of 15. In UTEX-995, max-D and r responded similarly to changes in salinity − they remained stable at salinity of 5–10 and 5–15, respectively, and declined at higher salinity. Also, max-D correlated with r but not early-D. Inoculum size positively and negatively influenced max-D and r, respectively, in both strains and these effects were significant even when the absolute size difference was small (100 versus 1000 cells ml−1). When cultured under similar conditions, UTEX-2797 grew faster and to much higher density than UTEX-995. In conclusion, (1) UTEX-2797’s superior growth performance may explain its relatively wide distribution in the USA, (2) the biphasic growth response of UTEX-2797 to salinity variation, with peak abundance at salinity of 10–15, generally mirrors golden alga abundance-salinity associations in US inland waters, and (3) early cell density – whether artificially manipulated or naturally attained – can influence UTEX-2797 bloom potential.

The role of the Atlantic Water in multidecadal ocean variability in the Nordic and Barents Seas

NASA Astrophysics Data System (ADS)

Yashayaev, Igor; Seidov, Dan

2015-03-01

The focus of this work is on the temporal and spatial variability of the Atlantic Water (AW). We analyze the existing historic hydrographic data from the World Ocean Database to document the long-term variability of the AW throughflow across the Norwegian Sea to the western Barents Sea. Interannual-to-multidecadal variability of water temperature, salinity and density are analyzed along six composite sections crossing the AW flow and coastal currents at six selected locations. The stations are lined up from southwest to northeast - from the northern North Sea (69°N) throughout the Norwegian Sea to the Kola Section in the Barents Sea (33°30‧E). The changing volume and characteristics of the AW throughflow dominate the hydrographic variability on decadal and longer time scales in the studied area. We examine the role of fluctuations of the volume of inflow versus the variable local factors, such as the air-sea interaction and mixing with the fresh coastal and cold Arctic waters, in controlling the long-term regional variability. It is shown that the volume of the AW, passing through the area and affecting the position of the outer edge of the warm and saline core, correlates well with temperature and salinity averaged over the central portions of the studied sections. The coastal flow (mostly associated with the Norwegian Coastal Current flowing over the continental shelf) is largely controlled by seasonal local heat and freshwater impacts. Temperature records at all six lines show a warming trend superimposed on a series of relatively warm and cold periods, which in most cases follow, with a delay of four to five years, the periods of relatively low and high North Atlantic Oscillation (NAO), and the periods of relatively high and low Atlantic Multidecadal Oscillation (AMO), respectively. In general, there is a relatively high correlation between the year-to-year changes of the NAO and AMO indices, which is to some extent reflected in the (delayed) AW temperature fluctuations. It takes about two years for freshening and salinification events and a much shorter time (of about a year or less) for cooling and warming episodes to propagate or spread across the region. This significant difference in the propagation rates of salinity and temperature anomalies is explained by the leading role of horizontal advection in the propagation of salinity anomalies, whereas temperature is also controlled by the competing air-sea interaction along the AW throughflow. Therefore, although a water parcel moves within the flow as a whole, the temperature, salinity and density anomalies split and propagate separately, with the temperature and density signals leading relative to the salinity signal. A new hydrographic index, coastal-to-offshore density step, is introduced to capture variability in the strength of the AW volume transport. This index shows the same cycles of variability as observed in temperature, NAO and AMO but without an obvious trend.

Temperature Data Assimilation with Salinity Corrections: Validation for the NSIPP Ocean Data Assimilation System in the Tropical Pacific Ocean, 1993-1998

NASA Technical Reports Server (NTRS)

Troccoli, Alberto; Rienecker, Michele M.; Keppenne, Christian L.; Johnson, Gregory C.

2003-01-01

The NASA Seasonal-to-Interannual Prediction Project (NSIPP) has developed an Ocean data assimilation system to initialize the quasi-isopycnal ocean model used in our experimental coupled-model forecast system. Initial tests of the system have focused on the assimilation of temperature profiles in an optimal interpolation framework. It is now recognized that correction of temperature only often introduces spurious water masses. The resulting density distribution can be statically unstable and also have a detrimental impact on the velocity distribution. Several simple schemes have been developed to try to correct these deficiencies. Here the salinity field is corrected by using a scheme which assumes that the temperature-salinity relationship of the model background is preserved during the assimilation. The scheme was first introduced for a zlevel model by Troccoli and Haines (1999). A large set of subsurface observations of salinity and temperature is used to cross-validate two data assimilation experiments run for the 6-year period 1993-1998. In these two experiments only subsurface temperature observations are used, but in one case the salinity field is also updated whenever temperature observations are available.

Modifying the baricity of local anesthetics for spinal anesthesia by temperature adjustment: model calculations.

PubMed

Heller, Axel R; Zimmermann, Katrin; Seele, Kristin; Rössel, Thomas; Koch, Thea; Litz, Rainer J

2006-08-01

Although local anesthetics (LAs) are hyperbaric at room temperature, density drops within minutes after administration into the subarachnoid space. LAs become hypobaric and therefore may cranially ascend during spinal anesthesia in an uncontrolled manner. The authors hypothesized that temperature and density of LA solutions have a nonlinear relation that may be described by a polynomial equation, and that conversion of this equation may provide the temperature at which individual LAs are isobaric. Density of cerebrospinal fluid was measured using a vibrating tube densitometer. Temperature-dependent density data were obtained from all LAs commonly used for spinal anesthesia, at least in triplicate at 5 degrees, 20 degrees, 30 degrees, and 37 degrees C. The hypothesis was tested by fitting the obtained data into polynomial mathematical models allowing calculations of substance-specific isobaric temperatures. Cerebrospinal fluid at 37 degrees C had a density of 1.000646 +/- 0.000086 g/ml. Three groups of local anesthetics with similar temperature (T, degrees C)-dependent density (rho) characteristics were identified: articaine and mepivacaine, rho1(T) = 1.008-5.36 E-06 T2 (heavy LAs, isobaric at body temperature); L-bupivacaine, rho2(T) = 1.007-5.46 E-06 T2 (intermediate LA, less hypobaric than saline); bupivacaine, ropivacaine, prilocaine, and lidocaine, rho3(T) = 1.0063-5.0 E-06 T (light LAs, more hypobaric than saline). Isobaric temperatures (degrees C) were as follows: 5 mg/ml bupivacaine, 35.1; 5 mg/ml L-bupivacaine, 37.0; 5 mg/ml ropivacaine, 35.1; 20 mg/ml articaine, 39.4. Sophisticated measurements and mathematic models now allow calculation of the ideal injection temperature of LAs and, thus, even better control of LA distribution within the cerebrospinal fluid. The given formulae allow the adaptation on subpopulations with varying cerebrospinal fluid density.

Morphometric variability of Arctodiaptomus salinus (Copepoda) in the Mediterranean-Black Sea region

PubMed Central

ANUFRIIEVA, Elena V.; SHADRIN, Nickolai V.

2015-01-01

Inter-species variability in morphological traits creates a need to know the range of variability of characteristics in the species for taxonomic and ecological tasks. Copepoda Arctodiaptomus salinus, which inhabits water bodies across Eurasia and North Africa, plays a dominant role in plankton of different water bodies-from fresh to hypersaline. This work assesses the intra- and inter-population morphometric variability of A. salinus in the Mediterranean-Black Sea region and discusses some observed regularities. The variability of linear body parameters and proportions was studied. The impacts of salinity, temperature, and population density on morphological characteristics and their variability can manifest themselves in different ways at the intra- and inter-population levels. A significant effect of salinity, pH and temperature on the body proportions was not found. Their intra-population variability is dependent on temperature and salinity. Sexual dimorphism of A. salinus manifests in different linear parameters, proportions, and their variability. There were no effects of temperature, pH and salinity on the female/male parameter ratio. There were significant differences in the body proportions of males and females in different populations. The influence of temperature, salinity, and population density can be attributed to 80%-90% of intra-population variability of A. salinus. However, these factors can explain less than 40% of inter-population differences. Significant differences in the body proportions of males and females from different populations may suggest that some local populations of A. salinus in the Mediterranean-Black Sea region are in the initial stages of differentiation. PMID:26646569

Study of ocean red tide multi-parameter monitoring technology based on double-wavelength airborne lidar system

NASA Astrophysics Data System (ADS)

Lin, Hong; Wang, Xinming; Liang, Kun

2010-10-01

For monitoring and forecasting of the ocean red tide in real time, a marine environment monitoring technology based on the double-wavelength airborne lidar system is proposed. An airborne lidar is father more efficient than the traditional measure technology by the boat. At the same time, this technology can detect multi-parameter about the ocean red tide by using the double-wavelength lidar.It not only can use the infrared laser to detect the scattering signal under the water and gain the information about the red tise's density and size, but also can use the blue-green laser to detect the Brillouin scattering signal and deduce the temperature and salinity of the seawater.The red tide's density detecting model is firstly established by introducing the concept about the red tide scattering coefficient based on the Mie scattering theory. From the Brillouin scattering theory, the relationship about the blue-green laser's Brillouin scattering frequency shift value and power value with the seawater temperature and salinity is found. Then, the detecting mode1 of the saewater temperature and salinity can be established. The value of the red tide infrared scattering signal is evaluated by the simulation, and therefore the red tide particles' density can be known. At the same time, the blue-green laser's Brillouin scattering frequency shift value and power value are evaluated by simulating, and the temperature and salinity of the seawater can be known. Baed on the multi-parameters, the ocean red tide's growth can be monitored and forecasted.

Effect of hypersaline cooling canals on aquifer salinization

USGS Publications Warehouse

Hughes, Joseph D.; Langevin, Christian D.; Brakefield-Goswami, Linzy

2010-01-01

The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport, and cooling canal geometry on aquifer salinization and movement of the freshwater/saltwater interface. Four different hydraulic conductivity configurations, with values ranging over several orders of magnitude, were evaluated with the model. For all of the conditions evaluated, aquifer salinization was initiated by the formation of dense, hypersaline fingers that descended downward to the bottom of the 30-m thick aquifer. Saline fingers reached the aquifer bottom in times ranging from a few days to approximately 5 years for the lowest hydraulic conductivity case. Aquifer salinization continued after saline fingers reached the aquifer bottom and coalesced by lateral movement away from the site. Model results showed that aquifer salinization was most sensitive to aquifer heterogeneity, but was also sensitive to CCS salinity, temperature, and configuration.

Salinity signature of the Pacific Decadal Oscillation

NASA Astrophysics Data System (ADS)

Overland, James E.; Salo, Sigrid; Adams, Jennifer Miletta

Three sites in the North Pacific have temperature and salinity observations in most months for several years before and after 1977. The Gulf of Alaska station (57°N, 148°W) showed a 2°C warming and a 0.6 freshening in salinity at 10 m depth in the 1980s compared to the 1970s. OWS PAPA (50°N, 145°W) and PAPA line station 7 (49.1°N, 132.4°W) show warming of 0.6°C and 0.9°C, with no major salinity change. The decrease in density and increase in stratification in the Gulf of Alaska after 1977 corresponds primarily to a decrease in salinity in the upper 150 m. We propose that while the Pacific Decadal Oscillation has an east/west character in temperature, the salinity signature will have a NNW/SSE character, similar to the pattern of interannual variability in precipitation.

Decadal Variability of Temperature and Salinity in the Northwest Atlantic Ocean

NASA Astrophysics Data System (ADS)

Mishonov, A. V.; Seidov, D.; Reagan, J. R.; Boyer, T.; Parsons, A. R.

2017-12-01

There are only a few regions in the World Ocean where the density of observations collected over the past 60 years is sufficient for reliable data mapping with spatial resolutions finer than one-degree. The Northwest Atlantic basin is one such regions where a spatial resolution of gridded temperature and salinity fields, comparable to those generated by eddy-resolving numerical models of ocean circulation, has recently becomes available. Using the new high-resolution Northwest Atlantic Regional Climatology, built on quarter-degree and one-tenth-degree resolution fields, we analyzed decadal variability and trends of temperature and salinity over 60 years in the Northwest Atlantic, and two 30-year ocean climates of 1955-1984 and 1985-2012 to evaluate the oceanic climate shift in this region. The 30-year climate shift is demonstrated using an innovative 3-D visualization of temperature and salinity. Spatial and temporal variability of heat accumulation found in previous research of the entire North Atlantic Ocean persists in the Northwest Atlantic Ocean. Salinity changes between two 30-year climates were also computed and are discussed.

High-density genetic map and identification of QTLs for responses to temperature and salinity stresses in the model brown alga Ectocarpus

PubMed Central

Avia, Komlan; Coelho, Susana M.; Montecinos, Gabriel J.; Cormier, Alexandre; Lerck, Fiona; Mauger, Stéphane; Faugeron, Sylvain; Valero, Myriam; Cock, J. Mark; Boudry, Pierre

2017-01-01

Deciphering the genetic architecture of adaptation of brown algae to environmental stresses such as temperature and salinity is of evolutionary as well as of practical interest. The filamentous brown alga Ectocarpus sp. is a model for the brown algae and its genome has been sequenced. As sessile organisms, brown algae need to be capable of resisting the various abiotic stressors that act in the intertidal zone (e.g. osmotic pressure, temperature, salinity, UV radiation) and previous studies have shown that an important proportion of the expressed genes is regulated in response to hyposaline, hypersaline or oxidative stress conditions. Using the double digest RAD sequencing method, we constructed a dense genetic map with 3,588 SNP markers and identified 39 QTLs for growth-related traits and their plasticity under different temperature and salinity conditions (tolerance to high temperature and low salinity). GO enrichment tests within QTL intervals highlighted membrane transport processes such as ion transporters. Our study represents a significant step towards deciphering the genetic basis of adaptation of Ectocarpus sp. to stress conditions and provides a substantial resource to the increasing list of tools generated for the species. PMID:28256542

Salinity transfer in double diffusive convection bounded by two parallel plates

NASA Astrophysics Data System (ADS)

Yang, Yantao; van der Poel, Erwin P.; Ostilla-Monico, Rodolfo; Sun, Chao; Verzicco, Roberto; Grossmann, Siegfried; Lohse, Detlef

2014-11-01

The double diffusive convection (DDC) is the convection flow with the fluid density affected by two different components. In this study we numerically investigate DDC between two parallel plates with no-slip boundary conditions. The top plate has higher salinity and temperature than the lower one. Thus the flow is driven by the salinity difference and stabilised by the temperature difference. Our simulations are compared with the experiments by Hage and Tilgner (Phys. Fluids 22, 076603 (2010)) for several sets of parameters. Reasonable agreement is achieved for the salinity flux and its dependence on the salinity Rayleigh number. For all parameters considered, salt fingers emerge and extend through the entire domain height. The thermal Rayleigh number shows minor influence on the salinity flux although it does affect the Reynolds number. We apply the Grossmann-Lohse theory for Rayleigh-Bénard flow to the current problem without introducing any new coefficients. The theory successfully predicts the salinity flux with respect to the scaling for both the numerical and experimental results.

Impact of Seawater Nonlinearities on Nordic Seas Circulation

NASA Astrophysics Data System (ADS)

Helber, R. W.; Wallcraft, A. J.; Shriver, J. F.

2017-12-01

The Nordic Seas (Greenland, Iceland, and Norwegian Seas) form an ocean basin important for Arctic-mid-latitude climate linkages. Cold fresh water from the Arctic Ocean and warm salty water from the North Atlantic Ocean meet in the Nordic Seas, where a delicate balance between temperature and salinity variability results in deep water formation. Seawater non-linearities are stronger at low temperatures and salinities making high-latitude oceans highly subject to thermbaricity and cabbeling. This presentation highlights and quantifies the impact of seawater non-linearities on the Nordic Seas circulation. We use two layered ocean circulation models, the Hybrid Coordinate Ocean Model (HYOCM) and the Modular Ocean Model version 6 (MOM6), that enable accurate representation of processes along and across density or neutral density surfaces. Different equations-of-state and vertical coordinates are evaluated to clarify the impact of seawater non-linearities. Present Navy systems, however, do not capture some features in the Nrodic Seas vertical structure. For example, observations from the Greenland Sea reveal a subsurface temperature maximum that deepens from approximately 1500 m during 1998 to 1800 m during 2005. We demonstrate that in terms of density, salinity is the largest source of error in Nordic Seas Navy forecasts, regional scale models can represent mesoscale features driven by thermobaricity, vertical coordinates are a critical issue in Nordic Sea circulation modeling.

RELATIONSHIPS BETWEEN HABITAT QUALITY AND DENSITY OF JUVENILE WINTER FLOUNDER

EPA Science Inventory

We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat. The YSI sonde measured temperature, salinity, dissolve...

From convection rolls to finger convection in double-diffusive turbulence

PubMed Central

Verzicco, Roberto; Lohse, Detlef

2016-01-01

Double-diffusive convection (DDC), which is the buoyancy-driven flow with fluid density depending on two scalar components, is ubiquitous in many natural and engineering environments. Of great interests are scalars' transfer rate and flow structures. Here we systematically investigate DDC flow between two horizontal plates, driven by an unstable salinity gradient and stabilized by a temperature gradient. Counterintuitively, when increasing the stabilizing temperature gradient, the salinity flux first increases, even though the velocity monotonically decreases, before it finally breaks down to the purely diffusive value. The enhanced salinity transport is traced back to a transition in the overall flow pattern, namely from large-scale convection rolls to well-organized vertically oriented salt fingers. We also show and explain that the unifying theory of thermal convection originally developed by Grossmann and Lohse for Rayleigh–Bénard convection can be directly applied to DDC flow for a wide range of control parameters (Lewis number and density ratio), including those which cover the common values relevant for ocean flows. PMID:26699474

The evolution of water property in the Mackenzie Bay polynya during Antarctic winter

NASA Astrophysics Data System (ADS)

Xu, Zhixin; Gao, Guoping; Xu, Jianping; Shi, Maochong

2017-10-01

Temperature and salinity profile data, collected by southern elephant seals equipped with autonomous CTD-Satellite Relay Data Loggers (CTD-SRDLs) during the Antarctic wintertime in 2011 and 2012, were used to study the evolution of water property and the resultant formation of the high density water in the Mackenzie Bay polynya (MBP) in front of the Amery Ice Shelf (AIS). In late March the upper 100-200 m layer is characterized by strong halocline and inversion thermocline. The mixed layer keeps deepening up to 250 m by mid-April with potential temperature remaining nearly the surface freezing point and sea surface salinity increasing from 34.00 to 34.21. From then on until mid-May, the whole water column stays isothermally at about -1.90℃ while the surface salinity increases by a further 0.23. Hereafter the temperature increases while salinity decreases along with the increasing depth both by 0.1 order of magnitude vertically. The upper ocean heat content ranging from 120.5 to 2.9 MJ m-2, heat flux with the values of 9.8-287.0 W m-2 loss and the sea ice growth rates of 4.3-11.7 cm d-1 were estimated by using simple 1-D heat and salt budget methods. The MBP exists throughout the whole Antarctic winter (March to October) due to the air-sea-ice interaction, with an average size of about 5.0×103 km2. It can be speculated that the decrease of the salinity of the upper ocean may occur after October each year. The recurring sea-ice production and the associated brine rejection process increase the salinity of the water column in the MBP progressively, resulting in, eventually, the formation of a large body of high density water.

Assessing factors affecting the thermal properties of a passive thermal refuge using three-dimensional hydrodynamic flow and transport modeling

USGS Publications Warehouse

Decker, Jeremy D.; Swain, Eric D.; Stith, Bradley M.; Langtimm, Catherine A.

2013-01-01

Everglades restoration activities may cause changes to temperature and salinity stratification at the Port of the Islands (POI) marina, which could affect its suitability as a cold weather refuge for manatees. To better understand how the Picayune Strand Restoration Project (PSRP) may alter this important resource in Collier County in southwestern Florida, the USGS has developed a three-dimensional hydrodynamic model for the marina and canal system at POI. Empirical data suggest that manatees aggregate at the site during winter because of thermal inversions that provide warmer water near the bottom that appears to only occur in the presence of salinity stratification. To study these phenomena, the environmental fluid dynamics code simulator was used to represent temperature and salinity transport within POI. Boundary inputs were generated using a larger two-dimensional model constructed with the flow and transport in a linked overland-aquifer density-dependent system simulator. Model results for a representative winter period match observed trends in salinity and temperature fluctuations and produce temperature inversions similar to observed values. Modified boundary conditions, representing proposed PSRP alterations, were also tested to examine the possible effect on the salinity stratification and temperature inversion within POI. Results show that during some periods, salinity stratification is reduced resulting in a subsequent reduction in temperature inversion compared with the existing conditions simulation. This may have an effect on POI’s suitability as a passive thermal refuge for manatees and other temperature-sensitive species. Additional testing was completed to determine the important physical relationships affecting POI’s suitability as a refuge.

Refractive-index measurements in freezing sea-ice and sodium chloride brines.

PubMed

Maykut, G A; Light, B

1995-02-20

Sea ice contains numerous pockets of brine and precipitated salts whose size and number distributions change dramatically with temperature. Theoretical treatment of scattering produced by these inclusions requires information on refractive-index differences among the brine, salts, and surrounding ice. Lacking specific data on refractive-index variations in the brine, we carried out laboratory measurements in freezing-equilibrium solutions between -2 and -32 °C. Index values at 589 nm increased from 1.341 to 1.397 over this temperature range, corresponding to salinities of 35 and 240 parts per thousand (ppt). Spectral data were also taken at 50-nm intervals between 400 and 700 nm in nonequilibrium solutions with salinities ranging up to 300 ppt. Spectral gradients increased slightly with salinity but showed no measurable dependence on temperature between +12 and -16 °C. The Lorentz-Lorenz equation, combined with data on density, molar refractivities, and brine composition, yielded temperature-dependent index predictions in excellent agreement with the experimental data. Similar index and density measurements in freezing sodium chloride brines yielded values nearly identical to those in the sea-ice brines. The absence of mirabilite crystals in sodium chloride ice, however, will cause it to have higher transmissivity and lower reflectivity than sea ice above -22 °C.

Fluid inclusion constraints on the genesis of the Puladi muscovite deposit in Gongshan County, Yunnan Province

NASA Astrophysics Data System (ADS)

Yin, Qiong; Liu, Wei

2017-12-01

This paper focuses on beryl mines in the Maji region of Yunnan Province, which are characterized by fluid inclusions. Based on petrography theory, mineralogy, and ore-forming geological conditions, beryl can be divided as CO2 and CO2-H2O inclusions. In addition, the characteristics of inclusions in the coordinate of A/B is summarized. The homogenization temperature of fluid inclusions in the coordinate of A ranges from 250 °C to 397 °C, while the salinity of fluid inclusions ranges from 0.18% to 4.27%. By contrast, the homogenization temperature in the coordinate of B ranges from 210 °C to 340 °C, and the salinity is from 0.22% to 5.11%. The pressure of ore-forming fluid in the coordinate of A/B is approximately 83 MPa with densities of 0.8034 g/m3 and 0.8363 g/m3, which are characteristic of mediumtemperature, low-salinity, and medium-density fluids. Based on Raman spectra and different metallogenic depths, the two types of beryl belong to different metallogenic belts. The beryl deposits in Gongshan are of medium-temperature gas-hydrothermal type.

Uncertainties in Climatological Seawater Density Calculations

NASA Astrophysics Data System (ADS)

Dai, Hao; Zhang, Xining

2018-03-01

In most applications, with seawater conductivity, temperature, and pressure data measured in situ by various observation instruments e.g., Conductivity-Temperature-Depth instruments (CTD), the density which has strong ties to ocean dynamics and so on is computed according to equations of state for seawater. This paper, based on density computational formulae in the Thermodynamic Equation of Seawater 2010 (TEOS-10), follows the Guide of the expression of Uncertainty in Measurement (GUM) and assesses the main sources of uncertainties. By virtue of climatological decades-average temperature/Practical Salinity/pressure data sets in the global ocean provided by the National Oceanic and Atmospheric Administration (NOAA), correlation coefficients between uncertainty sources are determined and the combined standard uncertainties uc>(ρ>) in seawater density calculations are evaluated. For grid points in the world ocean with 0.25° resolution, the standard deviations of uc>(ρ>) in vertical profiles cover the magnitude order of 10-4 kg m-3. The uc>(ρ>) means in vertical profiles of the Baltic Sea are about 0.028kg m-3 due to the larger scatter of Absolute Salinity anomaly. The distribution of the uc>(ρ>) means in vertical profiles of the world ocean except for the Baltic Sea, which covers the range of >(0.004,0.01>) kg m-3, is related to the correlation coefficient r>(SA,p>) between Absolute Salinity SA and pressure p. The results in the paper are based on sensors' measuring uncertainties of high accuracy CTD. Larger uncertainties in density calculations may arise if connected with lower sensors' specifications. This work may provide valuable uncertainty information required for reliability considerations of ocean circulation and global climate models.

Deriving Equations of State for Specific Lakes and Inland Seas from Laboratory Measurements

NASA Astrophysics Data System (ADS)

Andrulionis, Natalia; Zavialov, Ivan; Zavialov, Peter; Osadchiev, Alexander; Kolokolova, Alexandra; Alukaeva, Alevtina; Izhitskiy, Alexander; Izhitskaya, Elena

2017-04-01

The equation of state is the dependence of water density on temperature, salinity, and pressure. It is important in many respects, in particular, for numerical modeling of marine systems. The widely used UNESCO equation of state, as well as the more recent and general TEOS-10 equation, are intended for the ocean waters. Hence, they are confined to salinities below 40 ‰ and, even more restrictively, valid only for ionic salt composition characteristic for the ocean. Both conditions do not hold for many lakes. Moreover, significant deviations of the ionic composition from the oceanic one have been documented for coastal zones, especially those exposed to river discharges. Therefore, the objective of this study was to find equations of state for areas or water bodies with non-oceanic ionic salt composition. In order to obtain the required equations, we analyzed water samples obtained in expeditions of 2014-2016 from the Black Sea, the Aral Sea, Lake Issyk-Kul and Caspian Sea. The filtered samples were submitted to high accuracy (up to 0.00001 g/cm3) density measurements in laboratory using the Anton Paar DMA 5000M in the temperature range from 1 to 29°C. The absolute salinity values of the initial samples were obtained through the dry residue method. Further, we diluted the samples by purified deionized water to produce different salinities. To control the accuracy of the dilution process, we used a reference sample of standard IAPSO-certified seawater at 35‰. The density versus salinity and temperature data obtained thereby were then approximated by a best fitting 2-order polynomial surface using the least squares method. This procedure yielded the approximate empirical equations of state for the selected marine areas (the Russian Black Sea shelf) and inland water bodies (the Aral Sea, the Lake Issyk-Kul, the Caspian Sea). The newly derived equations - even the one for the Black Sea shelf - are different from the oceanic equation significantly within the confidence intervals. We also analyzed the salt content in all samples using the ionic chromotography method and the potentiometric titration method and discussed the relations between the ionic composition on the one hand and density on the other.

Horizontal density-gradient effects on simulation of flow and transport in the Potomac Estuary

USGS Publications Warehouse

Schaffranek, Raymond W.; Baltzer, Robert A.; ,

1990-01-01

A two-dimensional, depth-integrated, hydrodynamic/transport model of the Potomac Estuary between Indian Head and Morgantown, Md., has been extended to include treatment of baroclinic forcing due to horizontal density gradients. The finite-difference model numerically integrates equations of mass and momentum conservation in conjunction with a transport equation for heat, salt, and constituent fluxes. Lateral and longitudinal density gradients are determined from salinity distributions computed from the convection-diffusion equation and an equation of state that expresses density as a function of temperature and salinity; thus, the hydrodynamic and transport computations are directly coupled. Horizontal density variations are shown to contribute significantly to momentum fluxes determined in the hydrodynamic computation. These fluxes lead to enchanced tidal pumping, and consequently greater dispersion, as is evidenced by numerical simulations. Density gradient effects on tidal propagation and transport behavior are discussed and demonstrated.

Avicennia germinans (black mangrove) vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico

PubMed Central

Madrid, Eric N.; Armitage, Anna R.; López-Portillo, Jorge

2014-01-01

Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana) had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near-term climate change. PMID:25309570

Avicennia germinans (black mangrove) vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico.

PubMed

Madrid, Eric N; Armitage, Anna R; López-Portillo, Jorge

2014-01-01

Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana) had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near-term climate change.

Effects of salinity and temperature on in vitro cell cycle and proliferation of Perkinsus marinus from Brazil.

PubMed

Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; De Medeiros, Isac Almeida; Da Silva, Patrícia Mirella

2016-04-01

Field and in vitro studies have shown that high salinities and temperatures promote the proliferation and dissemination of Perkinsus marinus in several environments. In Brazil, the parasite infects native oysters Crassostrea gasar and Crassostrea rhizophorae in the Northeast (NE), where the temperature is high throughout the year. Despite the high prevalence of Perkinsus spp. infection in oysters from the NE of Brazil, no mortality events were reported by oyster farmers to date. The present study evaluated the effects of salinity (5, 20 and 35 psu) and temperature (15, 25 and 35 °C) on in vitro proliferation of P. marinus isolated from a host (C. rhizophorae) in Brazil, for a period of up to 15 days and after the return to the control conditions (22 days; recovery). Different cellular parameters (changes of cell phase's composition, cell density, viability and production of reactive oxygen species) were analysed using flow cytometry. The results indicate that the P. marinus isolate was sensitive to the extreme salinities and temperatures analysed. Only the highest temperature caused lasting cell damage under prolonged exposure, impairing P. marinus recovery, which is likely to be associated with oxidative stress. These findings will contribute to the understanding of the dynamics of perkinsiosis in tropical regions.

Effects of Precipitation on Ocean Mixed-Layer Temperature and Salinity as Simulated in a 2-D Coupled Ocean-Cloud Resolving Atmosphere Model

NASA Technical Reports Server (NTRS)

Li, Xiaofan; Sui, C.-H.; Lau, K-M.; Adamec, D.

1999-01-01

A two-dimensional coupled ocean-cloud resolving atmosphere model is used to investigate possible roles of convective scale ocean disturbances induced by atmospheric precipitation on ocean mixed-layer heat and salt budgets. The model couples a cloud resolving model with an embedded mixed layer-ocean circulation model. Five experiment are performed under imposed large-scale atmospheric forcing in terms of vertical velocity derived from the TOGA COARE observations during a selected seven-day period. The dominant variability of mixed-layer temperature and salinity are simulated by the coupled model with imposed large-scale forcing. The mixed-layer temperatures in the coupled experiments with 1-D and 2-D ocean models show similar variations when salinity effects are not included. When salinity effects are included, however, differences in the domain-mean mixed-layer salinity and temperature between coupled experiments with 1-D and 2-D ocean models could be as large as 0.3 PSU and 0.4 C respectively. Without fresh water effects, the nocturnal heat loss over ocean surface causes deep mixed layers and weak cooling rates so that the nocturnal mixed-layer temperatures tend to be horizontally-uniform. The fresh water flux, however, causes shallow mixed layers over convective areas while the nocturnal heat loss causes deep mixed layer over convection-free areas so that the mixed-layer temperatures have large horizontal fluctuations. Furthermore, fresh water flux exhibits larger spatial fluctuations than surface heat flux because heavy rainfall occurs over convective areas embedded in broad non-convective or clear areas, whereas diurnal signals over whole model areas yield high spatial correlation of surface heat flux. As a result, mixed-layer salinities contribute more to the density differences than do mixed-layer temperatures.

Environmental forcing on jellyfish communities in a small temperate estuary.

PubMed

Primo, Ana Lígia; Marques, Sónia C; Falcão, Joana; Crespo, Daniel; Pardal, Miguel A; Azeiteiro, Ulisses M

2012-08-01

The impact of biological, hydrodynamic and large scale climatic variables on the jellyfish community of Mondego estuary was evaluated from 2003 to 2010. Plankton samples were collected at the downstream part of the estuary. Siphonophora Muggiaea atlantica and Diphyes spp. were the main jellyfish species. Jellyfish density was generally higher in summer and since 2005 densities had increased. Summer community analysis pointed out Acartia clausi, estuarine temperature and salinity as the main driven forces for the assemblage's structure. Also, Chl a, estuarine salinity, runoff and SST were identified as the major environmental factors influencing the siphonophores summer interannual variability. Temperature influenced directly and indirectly the community and fluctuation of jellyfish blooms in the Mondego estuary. This study represents a contribution to a better knowledge of the gelatinous plankton communities in small temperate estuaries. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Relationship between Phytoplankton Distribution and Water Column Characteristics in North West European Shelf Sea Waters

PubMed Central

Davidson, Keith; Bolch, Christopher J. S.; Brand, Tim D.; Narayanaswamy, Bhavani E.

2012-01-01

Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the “Ellett Line” cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN∶DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN∶DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of growth at most stations and depths. PMID:22479533

Distribution of Arctic and Pacific copepods and their habitat in the northern Bering Sea and Chukchi Sea

NASA Astrophysics Data System (ADS)

Sasaki, H.; Matsuno, K.; Fujiwara, A.; Onuka, M.; Yamaguchi, A.; Ueno, H.; Watanuki, Y.; Kikuchi, T.

2015-11-01

The advection of warm Pacific water and the reduction of sea-ice extent in the western Arctic Ocean may influence the abundance and distribution of copepods, i.e., a key component in food webs. To understand the factors affecting abundance of copepods in the northern Bering Sea and Chukchi Sea, we constructed habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods, separately, using generalized additive models. Copepods were sampled by NORPAC net. Vertical profiles of density, temperature and salinity in the seawater were measured using CTD, and concentration of chlorophyll a in seawater was measured with a fluorometer. The timing of sea-ice retreat was determined using the satellite image. To quantify the structure of water masses, the magnitude of pycnocline and averaged density, temperature and salinity in upper and bottom layers were scored along three axes using principal component analysis (PCA). The structures of water masses indexed by the scores of PCAs were selected as explanatory variables in the best models. Large Arctic copepods were abundant in the water mass with high salinity water in bottom layer or with cold/low salinity water in upper layer and cold/high salinity water in bottom layer, and small Arctic copepods were abundant in the water mass with warm/saline water in upper layer and cold/high salinity water in bottom layers, while Pacific copepods were abundant in the water mass with warm/saline in upper layer and cold/high salinity water in bottom layer. All copepod groups were abundant in areas with deeper depth. Although chlorophyll a in upper and bottom layers were selected as explanatory variables in the best models, apparent trends were not observed. All copepod groups were abundant where the sea-ice retreated at earlier timing. Our study might indicate potential positive effects of the reduction of sea-ice extent on the distribution of all groups of copepods in the Arctic Ocean.

3D coupled heat and mass transfer processes at the scale of sedimentary basisn

NASA Astrophysics Data System (ADS)

Cacace, M.; Scheck-Wenderoth, M.; Kaiser, B. O.

2014-12-01

We use coupled 3D simulations of fluid, heat, and transport based on a 3D structural model of a complex geological setting, the Northeast German Basin (NEGB). The geological structure of the NEGB is characterized by a relatively thick layer of Permian Zechstein salt, structured in differnet diapirs (up to 5000 m thick) and pillows locally reaching nearly the surface. Salt is thermally more conductive than other sediments, hydraulically impervious but highly solvable. Thus salt structures have first order influence on the temperature distribution, the deep flow regime and the salinity of groundawater bearing aquifers. In addition, the post-Permian sedimentary sequence is vertically subdivided into several aquifers and aquitards. The shallow Quaternary to late Tertiary freshwater aquifer is separated from the underlying Mesozoic saline aquifers by an embedded Tertiary clay enriched aquitard (Rupelian Aquitard). An important feature of this aquitard is that hydraulic connections between the upper and lower aquifers exist in areas where the Rupelian Aquitard is missing (hydrogeological windows). By means of 3D numerical simulations we explore the role of heat conduction, pressure, and density driven groundwater flow as well as fluid viscosity-related and salinity-dependent effects on the resulting flow and temperature fields. Our results suggest that the regional temperature distribution within the basin results from interactions between regional pressure forces and thermal diffusion locally enhanced by thermal conductivity contrasts between the different sedimentary rocks with the highly conductive salt. Buoyancy forces triggered by temperature-dependent fluid density variations affect only locally the internal thermal configuration. Locations, geometry, and wavelengths of convective thermal anomalies are mainly controlled by the permeability field and thickness values of the respective geological layers. Numerical results from 3D thermo-haline numerical simulations suggest that hydrogeological windows act as preferential domains of hydraulic interconnectivity between the different aquifers at depth, and enable vigorous heat and mass transport which causes a mixing of warm and saline groundwater with cold and less saline groundwater within both aquifers.

The formation of thermohaline staircases for large salt concentration differences in double diffusive convection

NASA Astrophysics Data System (ADS)

Yang, Yantao; Verzicco, Roberto; Lohse, Detlef

2016-11-01

In the upper layers of the tropical and subtropical ocean, step-like mean profiles for both temperature and salinity are often observed, a phenomenon referred to as thermohaline staircase. It consists of alternatively stacked mixing layers, and finger layers with sharp gradients in both mean temperature and salinity. It is believed that thermohaline staircases are caused by double diffusive convection (DDC), i.e. the convection flow with fluid density affected by two different scalars. Here we conducted direct numerical simulations of DDC bounded by two parallel plates and aimed to realise the multi-layer state similar to the oceanic thermohaline staircase. We applied an unstable salinity difference and a stable temperature difference across the two plates. We gradually increased the salinity Rayleigh number RaS , i.e. the strength of salinity difference, and fixed the relative strength of temperature difference. When RaS is high enough the flow undergoes a transition from a single finger layer to a triple layer state, where one mixing layer emerges between two finger layers. Such triple layer state is stable up to the turbulent diffusive time scale. The finger-layer height is larger for higher RaS . The dependences of the scalar fluxes on RaS were also investigated. Supported by Dutch FOM Foundation and NWO rpogramme MCEC; Computing resources from SURFSara and PRACE project 2015133124.

Global Modeling of Internal Tides Within an Eddying Ocean General Circulation Model

DTIC Science & Technology

2012-06-01

atmosphere and ocean (Yu and Weller, 2007 ). Salinities in the upper ocean are set by the difference between evaporation and precipitation at the ocean...surface (Yu, 2007 ; Schmitt, 2008). Because the buoyancy (density) of seawater at the ocean surface is con- trolled by temperature and salinity, the...days, these currents mean- der and generate highly energetic meso- scale eddies (Schmitz, 1996a,b; Stammer , 1997), the spinning oceanic dynamical

Evolution of South Atlantic density and chemical stratification across the last deglaciation

PubMed Central

Skinner, Luke C.; Peck, Victoria L.; Kender, Sev; Elderfield, Henry; Waelbroeck, Claire; Hodell, David A.

2016-01-01

Explanations of the glacial–interglacial variations in atmospheric pCO2 invoke a significant role for the deep ocean in the storage of CO2. Deep-ocean density stratification has been proposed as a mechanism to promote the storage of CO2 in the deep ocean during glacial times. A wealth of proxy data supports the presence of a “chemical divide” between intermediate and deep water in the glacial Atlantic Ocean, which indirectly points to an increase in deep-ocean density stratification. However, direct observational evidence of changes in the primary controls of ocean density stratification, i.e., temperature and salinity, remain scarce. Here, we use Mg/Ca-derived seawater temperature and salinity estimates determined from temperature-corrected δ18O measurements on the benthic foraminifer Uvigerina spp. from deep and intermediate water-depth marine sediment cores to reconstruct the changes in density of sub-Antarctic South Atlantic water masses over the last deglaciation (i.e., 22–2 ka before present). We find that a major breakdown in the physical density stratification significantly lags the breakdown of the deep-intermediate chemical divide, as indicated by the chemical tracers of benthic foraminifer δ13C and foraminifer/coral 14C. Our results indicate that chemical destratification likely resulted in the first rise in atmospheric pCO2, whereas the density destratification of the deep South Atlantic lags the second rise in atmospheric pCO2 during the late deglacial period. Our findings emphasize that the physical and chemical destratification of the ocean are not as tightly coupled as generally assumed. PMID:26729858

Evolution of South Atlantic density and chemical stratification across the last deglaciation.

PubMed

Roberts, Jenny; Gottschalk, Julia; Skinner, Luke C; Peck, Victoria L; Kender, Sev; Elderfield, Henry; Waelbroeck, Claire; Vázquez Riveiros, Natalia; Hodell, David A

2016-01-19

Explanations of the glacial-interglacial variations in atmospheric pCO2 invoke a significant role for the deep ocean in the storage of CO2. Deep-ocean density stratification has been proposed as a mechanism to promote the storage of CO2 in the deep ocean during glacial times. A wealth of proxy data supports the presence of a "chemical divide" between intermediate and deep water in the glacial Atlantic Ocean, which indirectly points to an increase in deep-ocean density stratification. However, direct observational evidence of changes in the primary controls of ocean density stratification, i.e., temperature and salinity, remain scarce. Here, we use Mg/Ca-derived seawater temperature and salinity estimates determined from temperature-corrected δ(18)O measurements on the benthic foraminifer Uvigerina spp. from deep and intermediate water-depth marine sediment cores to reconstruct the changes in density of sub-Antarctic South Atlantic water masses over the last deglaciation (i.e., 22-2 ka before present). We find that a major breakdown in the physical density stratification significantly lags the breakdown of the deep-intermediate chemical divide, as indicated by the chemical tracers of benthic foraminifer δ(13)C and foraminifer/coral (14)C. Our results indicate that chemical destratification likely resulted in the first rise in atmospheric pCO2, whereas the density destratification of the deep South Atlantic lags the second rise in atmospheric pCO2 during the late deglacial period. Our findings emphasize that the physical and chemical destratification of the ocean are not as tightly coupled as generally assumed.

Linear and nonlinear effects of temperature and precipitation on ecosystem properties in tidal saline wetlands

USGS Publications Warehouse

Feher, Laura C.; Osland, Michael J.; Griffith, Kereen T.; Grace, James B.; Howard, Rebecca J.; Stagg, Camille L.; Enwright, Nicholas M.; Krauss, Ken W.; Gabler, Christopher A.; Day, Richard H.; Rogers, Kerrylee

2017-01-01

Climate greatly influences the structure and functioning of tidal saline wetland ecosystems. However, there is a need to better quantify the effects of climatic drivers on ecosystem properties, particularly near climate-sensitive ecological transition zones. Here, we used climate- and literature-derived ecological data from tidal saline wetlands to test hypotheses regarding the influence of climatic drivers (i.e., temperature and precipitation regimes) on the following six ecosystem properties: canopy height, biomass, productivity, decomposition, soil carbon density, and soil carbon accumulation. Our analyses quantify and elucidate linear and nonlinear effects of climatic drivers. We quantified positive linear relationships between temperature and above-ground productivity and strong positive nonlinear (sigmoidal) relationships between (1) temperature and above-ground biomass and canopy height and (2) precipitation and canopy height. Near temperature-controlled mangrove range limits, small changes in temperature are expected to trigger comparatively large changes in biomass and canopy height, as mangrove forests grow, expand, and, in some cases, replace salt marshes. However, within these same transition zones, temperature-induced changes in productivity are expected to be comparatively small. Interestingly, despite the significant above-ground height, biomass, and productivity relationships across the tropical–temperate mangrove–marsh transition zone, the relationships between temperature and soil carbon density or soil carbon accumulation were not significant. Our literature review identifies several ecosystem properties and many regions of the world for which there are insufficient data to fully evaluate the influence of climatic drivers, and the identified data gaps can be used by scientists to guide future research. Our analyses indicate that near precipitation-controlled transition zones, small changes in precipitation are expected to trigger comparatively large changes in canopy height. However, there are scant data to evaluate the influence of precipitation on other ecosystem properties. There is a need for more decomposition data across climatic gradients, and to advance understanding of the influence of changes in precipitation and freshwater availability, additional ecological data are needed from tidal saline wetlands in arid climates. Collectively, our results can help scientists and managers better anticipate the linear and nonlinear ecological consequences of climate change for coastal wetlands.

Barrier island community change: What controls it?

NASA Astrophysics Data System (ADS)

Dows, B.; Young, D.; Zinnert, J.

2014-12-01

Conversion from grassland to woody dominated communities has been observed globally. In recent decades, this pattern has been observed in coastal communities along the mid-Atlantic U.S. In coastal environments, a suite of biotic and abiotic factors interact as filters to determine plant community structure and distribution. Microclimatic conditions: soil and air temperature, soil moisture and salinity, and light attenuation under grass cover were measured across a grassland-woody encroachment gradient on a Virginia barrier island; to identify the primary factors that mediate this change. Woody establishment was associated with moderately dense (2200 shoots/m2) grass cover, but reduced at high (> 6200 shoots/ m2) and low (< 1250 shoots/ m2) densities. Moderately dense grass cover reduced light attenuation (82.50 % reduction) to sufficiently reduce soil temperature thereby limiting soil moisture evaporation. However, high grass density reduced light attenuation (98.7 % reduction) enough to inhibit establishment of woody species; whereas low grass density attenuated much less light (48.7 % reduction) which allowed for greater soil moisture evaporation. Soil salinity was dynamic as rainfall, tidal inundation, and sea spray produce spatiotemporal variation throughout the barrier island landscape. The importance of light and temperature were compounded as they also indirectly affect soil salinity via their affects on soil moisture. Determining how these biotic and abiotic factors relate to sea level rise and climate change will improve understanding coastal community response as global changes proceed. Understanding how community shifts affect ecosystem function and their potential to affect adjacent systems will also improve predictive ability of coastal ecosystem responses.

Subduction of a low-salinity water mass around the Xisha Islands in the South China Sea.

PubMed

Huang, Zhida; Zhuang, Wei; Liu, Hailong; Hu, Jianyu

2018-02-15

Based on three climatologically observed temperature and salinity datasets (i.e., GDEM-V3, SCSPOD14 and WOA13), this paper reports a low-salinity (~34.32) water mass in the subsurface-to-intermediate layer around the Xisha Islands in the South China Sea. This water mass mainly subducts from the surface layer into the intermediate layer, characterized by a relatively low potential vorticity tongue extending from the bottom of mixed layer to the thermocline, and accompanied by a thermocline ventilation in spring (especially in April). The potential dynamics are the joint effects of negative wind stress curl, and an anticyclonic eddy triggered by the inherent topographic effect of the Xisha Islands, reflecting that downward vertical motion dominates the subduction. Despite lacking of the homogenous temperature and density, the low-salinity water mass is to some extent similar to the classic mode water and can be regarded as a deformed mode water in the South China Sea.

Seasonal Mixed Layer Heat Budget in the Southeast Tropical Atlantic

NASA Astrophysics Data System (ADS)

Scannell, H. A.; McPhaden, M. J.

2016-12-01

We analyze a mixed layer heat budget at 6ºS, 8ºE from a moored buoy of the Prediction and Research Moored Array in the Atlantic (PIRATA) to better understand the causes of seasonal mixed layer temperature variability in the southeast tropical Atlantic. This region is of interest because it is susceptible to warm biases in coupled global climate models and has historically been poorly sampled. Previous work suggests that thermodynamic changes in both latent heat loss and absorbed solar radiation dominate mixed layer properties away from the equator in the tropical Atlantic, while advection and entrainment are more important near the equator. Changes in mixed layer salinity can also influence temperature through the formation of barrier layers and density gradients. Freshwater flux from the Congo River, migration of the Intertropical Convergence Zone and advection of water masses are considered important contributors to mixed layer salinity variability in our study region. We analyze ocean temperature, salinity and meteorological data beginning in 2013 using mooring, Argo, and satellite platforms to study how seasonal temperature variability in the mixed layer is influenced by air-sea interactions and ocean dynamics.

The density-salinity relation of standard seawater

NASA Astrophysics Data System (ADS)

Schmidt, Hannes; Seitz, Steffen; Hassel, Egon; Wolf, Henning

2018-01-01

The determination of salinity by means of electrical conductivity relies on stable salt proportions in the North Atlantic Ocean, because standard seawater, which is required for salinometer calibration, is produced from water of the North Atlantic. To verify the long-term stability of the standard seawater composition, it was proposed to perform measurements of the standard seawater density. Since the density is sensitive to all salt components, a density measurement can detect any change in the composition. A conversion of the density values to salinity can be performed by means of a density-salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement with an uncertainty of 2 g m-3 is mandatory. We present a new density-salinity relation based on such accurate density measurements. The substitution measurement method used is described and density corrections for uniform isotopic and chemical compositions are reported. The comparison of densities calculated using the new relation with those calculated using the present reference equations of state TEOS-10 suggests that the density accuracy of TEOS-10 (as well as that of EOS-80) has been overestimated, as the accuracy of some of its underlying density measurements had been overestimated. The new density-salinity relation may be used to verify the stable composition of standard seawater by means of routine density measurements.

Temperature Versus Salinity Gradients Below the Ocean Mixed Layer

DTIC Science & Technology

2012-05-03

where salinity controls the depth of the mixed layer are understood to have “barrier” layers [Lukas and Lindstrom , 1991], where the depth of vertically...the horizontal. For example, Rudnick and Martin [2002] have shown that the ocean mixed layer at sub-mesoscales is horizontally well density compensated...Res., 102, 23,063–23,078, doi:10.1029/97JC01443. Barron, C. N., A. B. Kara, P. J. Martin , R. C. Rhodes, and L. F. Smedstad (2006), Formulation

On the relationship between finger width, velocity, and fluxes in thermohaline convection

NASA Astrophysics Data System (ADS)

Sreenivas, K. R.; Singh, O. P.; Srinivasan, J.

2009-02-01

Double-diffusive finger convection occurs in many natural processes. The theories for double-diffusive phenomena that exist at present consider systems with linear stratification in temperature and salinity. The double-diffusive systems with step change in salinity and temperature are, however, not amenable to simple stability analysis. Hence factors that control the width of the finger, velocity, and fluxes in systems that have step change in temperature and salinity have not been understood so far. In this paper we provide new physical insight regarding factors that influence finger convection in two-layer double-diffusive system through two-dimensional numerical simulations. Simulations have been carried out for density stability ratios (Rρ) from 1.5 to 10. For each density stability ratio, the thermal Rayleigh number (RaT) has been systematically varied from 7×103 to 7×108. Results from these simulations show how finger width, velocity, and flux ratios in finger convection are interrelated and the influence of governing parameters such as density stability ratio and the thermal Rayleigh number. The width of the incipient fingers at the time of onset of instability has been shown to vary as RaT-1/3. Velocity in the finger varies as RaT1/3/Rρ. Results from simulation agree with the scale analysis presented in the paper. Our results demonstrate that wide fingers have lower velocities and flux ratios compared to those in narrow fingers. This result contradicts present notions about the relation between finger width and flux ratio. A counterflow heat-exchanger analogy is used in understanding the dependence of flux ratio on finger width and velocity.

Effects of Temperature, Salinity and Fish in Structuring the Macroinvertebrate Community in Shallow Lakes: Implications for Effects of Climate Change

PubMed Central

Brucet, Sandra; Boix, Dani; Nathansen, Louise W.; Quintana, Xavier D.; Jensen, Elisabeth; Balayla, David; Meerhoff, Mariana; Jeppesen, Erik

2012-01-01

Climate warming may lead to changes in the trophic structure and diversity of shallow lakes as a combined effect of increased temperature and salinity and likely increased strength of trophic interactions. We investigated the potential effects of temperature, salinity and fish on the plant-associated macroinvertebrate community by introducing artificial plants in eight comparable shallow brackish lakes located in two climatic regions of contrasting temperature: cold-temperate and Mediterranean. In both regions, lakes covered a salinity gradient from freshwater to oligohaline waters. We undertook day and night-time sampling of macroinvertebrates associated with the artificial plants and fish and free-swimming macroinvertebrate predators within artificial plants and in pelagic areas. Our results showed marked differences in the trophic structure between cold and warm shallow lakes. Plant-associated macroinvertebrates and free-swimming macroinvertebrate predators were more abundant and the communities richer in species in the cold compared to the warm climate, most probably as a result of differences in fish predation pressure. Submerged plants in warm brackish lakes did not seem to counteract the effect of fish predation on macroinvertebrates to the same extent as in temperate freshwater lakes, since small fish were abundant and tended to aggregate within the macrophytes. The richness and abundance of most plant-associated macroinvertebrate taxa decreased with salinity. Despite the lower densities of plant-associated macroinvertebrates in the Mediterranean lakes, periphyton biomass was lower than in cold temperate systems, a fact that was mainly attributed to grazing and disturbance by fish. Our results suggest that, if the current process of warming entails higher chances of shallow lakes becoming warmer and more saline, climatic change may result in a decrease in macroinvertebrate species richness and abundance in shallow lakes. PMID:22393354

Relationships between environmental factors and pathogenic Vibrios in the Northern Gulf of Mexico.

PubMed

Johnson, C N; Flowers, A R; Noriea, N F; Zimmerman, A M; Bowers, J C; DePaola, A; Grimes, D J

2010-11-01

Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

Impacts of the IOD-associated temperature and salinity anomalies on the intermittent equatorial undercurrent anomalies

NASA Astrophysics Data System (ADS)

Li, Junde; Liang, Chujin; Tang, Youmin; Liu, Xiaohui; Lian, Tao; Shen, Zheqi; Li, Xiaojing

2017-11-01

The study of Equatorial Undercurrent (EUC) has attracted a broad attention in recent years due to its strong response and feedback to the Indian Ocean Dipole. In this paper, we first produce a high-quality simulation of three-dimensional temperature, salinity and zonal current simulation from 1982 to 2014, using a high-resolution ocean general circulation model. On this basis, with two sensitivity experiments, we investigate the role of temperature and salinity anomalies in driving and enhancing the EUC during the positive IOD events by examining the variation of the EUC seasonal cycle and diagnosing the zonal momentum budget along the equatorial Indian Ocean. Our results show that during January-March, the EUC can appear along the entire equatorial Indian Ocean in all years, but during August-November, the EUC can appear and reach the eastern Indian Ocean only during the positive IOD events. The zonal momentum budget analysis indicates that the pressure gradient force contributes most to the variation of the eastward acceleration of zonal currents in the subsurface. During the positive IOD events, strong negative subsurface temperature anomalies exist in the eastern Indian Ocean, with negative surface salinity anomalies in the central and eastern Indian Ocean, resulting in a large pressure gradient force to drive EUC during the August-November. Further, the results of two sensitivity experiments indicate that the temperature anomalies significantly impact the pressure gradient force, playing a leading role in driving the EUC, while the surface salinity anomalies can secondarily help to intensify the eastward EUC through increasing the zonal density gradient in the eastern Indian Ocean and impacting the vertical momentum advection in the subsurface.

Salinization in a stratified aquifer induced by heat transfer from well casings

NASA Astrophysics Data System (ADS)

van Lopik, Jan H.; Hartog, Niels; Zaadnoordijk, Willem Jan; Cirkel, D. Gijsbert; Raoof, Amir

2015-12-01

The temperature inside wells used for gas, oil and geothermal energy production, as well as steam injection, is in general significantly higher than the groundwater temperature at shallower depths. While heat loss from these hot wells is known to occur, the extent to which this heat loss may result in density-driven flow and in mixing of surrounding groundwater has not been assessed so far. However, based on the heat and solute effects on density of this arrangement, the induced temperature contrasts in the aquifer due to heat transfer are expected to destabilize the system and result in convection, while existing salt concentration contrasts in an aquifer would act to stabilize the system. To evaluate the degree of impact that may occur under field conditions, free convection in a 50-m-thick aquifer driven by the heat loss from penetrating hot wells was simulated using a 2D axisymmetric SEAWAT model. In particular, the salinization potential of fresh groundwater due to the upward movement of brackish or saline water in a stratified aquifer is studied. To account for a large variety of well applications and configurations, as well as different penetrated aquifer systems, a wide range of well temperatures, from 40 to 100 °C, together with a range of salt concentration (1-35 kg/m3) contrasts were considered. This large temperature difference with the native groundwater (15 °C) required implementation of a non-linear density equation of state in SEAWAT. We show that density-driven groundwater flow results in a considerable salt mass transport (up to 166,000 kg) to the top of the aquifer in the vicinity of the well (radial distance up to 91 m) over a period of 30 years. Sensitivity analysis showed that density-driven groundwater flow and the upward salt transport was particularly enhanced by the increased heat transport from the well into the aquifer by thermal conduction due to increased well casing temperature, thermal conductivity of the soil, as well as decreased porosity values. Enhanced groundwater flow and salt transport was also observed for increased hydraulic conductivity of the aquifer. While advective salt transport was dominant for lower salt concentration contrasts, under higher salt concentration contrasts transport was controlled by dispersive mixing at the fresh-salt water interface between the two separate convection cells in the fresh and salt water layers. The results of this study indicate heat loss from hot well casings can induce density-driven transport and mixing processes in surrounding groundwater. This process should therefore be considered when monitoring for long-term groundwater quality changes near wells through which hot fluids or gases are transported.

Environment of ore deposition in the creede mining district, San Juan Mountains, Colorado: Part V. Epithermal mineralization from fluid mixing in the OH vein

USGS Publications Warehouse

Hayba, D.O.

1997-01-01

Detailed fluid inclusion studies on coarse-grained sphalerite from the OH vein, Creede, Colorado, have shown that the abrupt color changes between growth zones correspond to abrupt changes in the nature of the ore fluids. Within each growth zone, however, the composition of the fluids remained constant. The base of a distinctive orange-brown growth zone marks a sharp increase in both temperature and salinity relative to the preceding yellow-white zone. The orange-brown growth zone can be correlated along much of the vein and is believed to represent a time-stratigraphic interval. Along the vein, temperatures and salinities of fluid inclusions within this interval show a systematic decrease from about 285??C and 11.5 wt percent NaCl equiv near the base of the vein to about 250??C and 8 wt percent NaCl equiv, respectively, near the top of the vein. The iron concentration of this sphalerite growth zone shows a similar pattern, decreasing from about 2.8 to 1.2 mole percent FeS. When plotted on an enthalpy-salinity diagram, the fluid inclusion data define a spatial trend indicating the progressive mixing of deeply circulating hydrothermal brines with overlying, dilute ground waters. The hydrothermal brines entered the OH vein from below at a temperature, salinity, and density of approximately 285??C, 11.5 wt percent NaCl equiv, and 860 kg/m3, respectively, whereas the overlying ground waters appear to have been preheated to roughly 150??C and had an assumed salinity of 0 wt percent and a density of 920 kg/m3. The greater density of the heated ground water promoted mixing with the hydrothermal brine within the open fractures, causing sphalerite deposition. Although there were also episodes of boiling during vein mineralization, boiling appears unimportant for this sphalerite. Isotopic evidence and geochemical modeling studies also indicate that mixing was the depositional mechanism for sphalerite. An important aspect of the mixing hydrology of the Creede system involves an aquitard overlying the OH vein. This low permeability zone restricted the flow of ground water into the vein from above and forced the upwelling hydrothermal fluids to flow laterally along the vein. The mixing environment thus occurred along the interface between a deeply circulating hydrothermal convection cell and a topographically driven shallow ground-water system.

Hydrography and circulation west of Sardinia in June 2014

NASA Astrophysics Data System (ADS)

Knoll, Michaela; Borrione, Ines; Fiekas, Heinz-Volker; Funk, Andreas; Hemming, Michael P.; Kaiser, Jan; Onken, Reiner; Queste, Bastien; Russo, Aniello

2017-11-01

In the frame of the REP14-MED sea trial in June 2014, the hydrography and circulation west of Sardinia, observed by means of gliders, shipborne CTD (conductivity, temperature, depth) instruments, towed devices, and vessel-mounted ADCPs (acoustic doppler current profilers), are presented and compared with previous knowledge. So far, the circulation is not well-known in this area, and the hydrography is subject to long-term changes. Potential temperature, salinity, and potential density ranges as well as core values of the observed water masses were determined. Modified Atlantic Water (MAW), with potential density anomalies below 28.72 kg m-3, showed a salinity minimum of 37.93 at 50 dbar. Levantine Intermediate Water (LIW), with a salinity maximum of about 38.70 at 400 dbar, was observed within a range of 28.72<σΘ/(kg m-3) < 29.10. MAW and LIW showed slightly higher salinities than previous investigations. During the trial, LIW covered the whole area from the Sardinian shelf to 7°15' E. Only north of 40° N was it tied to the continental slope. Within the MAW, a cold and saline anticyclonic eddy was observed in the southern trial area. The strongest variability in temperature and salinity appeared around this eddy, and in the southwestern part of the domain, where unusually low saline surface water entered the area towards the end of the experiment. An anticyclonic eddy of Winter Intermediate Water was recorded moving northward at 0.014 m s-1. Geostrophic currents and water mass transports calculated across zonal and meridional transects showed a good agreement with vessel-mounted ADCP measurements. Within the MAW, northward currents were observed over the shelf and offshore, while a southward transport of about 1.5 Sv occurred over the slope. A net northward transport of 0.38 Sv across the southern transect decreased to zero in the north. Within the LIW, northward transports of 0.6 Sv across the southern transects were mainly observed offshore, and decreased to 0.3 Sv in the north where they were primarily located over the slope. This presentation of the REP14-MED observations helps to further understand the long-term evolution of hydrography and circulation in the Western Mediterranean, where considerable changes occurred after the Eastern Mediterranean Transient and the Western Mediterranean Transition.

Physics in Oceanography.

ERIC Educational Resources Information Center

Charnock, H.

1980-01-01

Described is physical oceanography as analyzed by seven dependent variables, (three components of velocity, the pressure, density, temperature and salinity) as a function of three space variables and time. Topics discussed include the heat balance of the earth, current patterns in the ocean, heat transport, the air-sea interaction, and prospects…

Polar ocean stratification in a cold climate.

PubMed

Sigman, Daniel M; Jaccard, Samuel L; Haug, Gerald H

2004-03-04

The low-latitude ocean is strongly stratified by the warmth of its surface water. As a result, the great volume of the deep ocean has easiest access to the atmosphere through the polar surface ocean. In the modern polar ocean during the winter, the vertical distribution of temperature promotes overturning, with colder water over warmer, while the salinity distribution typically promotes stratification, with fresher water over saltier. However, the sensitivity of seawater density to temperature is reduced as temperature approaches the freezing point, with potential consequences for global ocean circulation under cold climates. Here we present deep-sea records of biogenic opal accumulation and sedimentary nitrogen isotopic composition from the Subarctic North Pacific Ocean and the Southern Ocean. These records indicate that vertical stratification increased in both northern and southern high latitudes 2.7 million years ago, when Northern Hemisphere glaciation intensified in association with global cooling during the late Pliocene epoch. We propose that the cooling caused this increased stratification by weakening the role of temperature in polar ocean density structure so as to reduce its opposition to the stratifying effect of the vertical salinity distribution. The shift towards stratification in the polar ocean 2.7 million years ago may have increased the quantity of carbon dioxide trapped in the abyss, amplifying the global cooling.

The effects of environmental factors on daytime sandeel distribution and abundance on the Dogger Bank

NASA Astrophysics Data System (ADS)

van der Kooij, Jeroen; Scott, Beth E.; Mackinson, Steven

2008-10-01

Spring distribution and abundance of lesser sandeels during the day were linked to zooplankton densities, seabed substrate and various hydrographic factors using small scale empirical data collected in two areas on the Dogger Bank in 2004, 2005 and 2006. The results of a two-step generalized additive model (GAM) suggested that suitable seabed substrate and temperature best explain sandeel distribution (presence/absence) and that sandeel abundance (given presence) was best described by a model that included bottom temperature, difference between surface and bottom temperature and surface salinity. The current study suggests that suitable seabed substrate explains sandeel distribution in the water column. Bottom temperature and surface salinity also played an important role in explaining distribution and abundance, and we speculate that sandeels favour hydrographically dynamic areas. Contrary to our hypothesis sandeels were not strongly associated with areas of high zooplankton density. We speculate that in early spring on the western Dogger Bank plankton is still patchily distributed and that sandeels only emerge from the seabed when feeding conditions near their night-time burrowing habitat are optimal. The results also suggested that when abundance is over a threshold level, the number of sandeel schools increased rather than the schools becoming bigger. This relationship between patchiness and abundance has implications for mortality rates and hence fisheries management.

Geochronology, fluid inclusions and isotopic characteristics of the Chaganbulagen Pb-Zn-Ag deposit, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Li, Tiegang; Wu, Guang; Liu, Jun; Wang, Guorui; Hu, Yanqing; Zhang, Yunfu; Luo, Dafeng; Mao, Zhihao; Xu, Bei

2016-09-01

The large Chaganbulagen Pb-Zn-Ag deposit is located in the Derbugan metallogenic belt of the northern Great Xing'an Range. The vein-style orebodies of the deposit occur in the NWW-trending fault zones. The ore-forming process at the deposit can be divided into three stages: an early quartz-pyrite-arsenopyrite-pyrrhotite-sphalerite-galena-chalcopyrite stage, a middle quartz-carbonate-pyrite-sphalerite-galena-silver-bearing minerals stage, and a late quartz-carbonate-pyrite stage. The sericite sample yielded a 40Ar -39Ar plateau age of 138 ± 1 Ma and an isochron age of 137 ± 3 Ma, and the zircon LA-ICP-MS U-Pb age of monzogranite porphyry was 143 ± 2 Ma, indicating that the ages of mineralization and monzogranite porphyry in the Chaganbulagen deposit should be the Early Cretaceous, and that the mineralization should be slightly later than the intrusion of monzogranite porphyry. There are only liquid inclusions in quartz veins of the Chaganbulagen deposit. Homogenization temperatures, densities, and salinities of the fluid inclusions from the early stage are 261-340 °C, 0.65-0.81 g/cm3, and 0.7-6.3 wt.% NaCl eqv., respectively. Fluid inclusions of the middle stage have homogenization temperatures, densities, and salinities of 209-265 °C, 0.75-0.86 g/cm3, and 0.5-5.7 wt.% NaCl eqv., respectively. For fluid inclusions of the late stage, their homogenization temperatures, densities, and salinities are 173-219 °C, 0.85-0.91 g/cm3, and 0.4-2.7 wt.% NaCl eqv., respectively. The ore-forming fluids of the deposit are generally characterized by moderate temperature and low salinity and density, and belong to an H2O-NaCl ± CO2 ± CH4 system. The δ18Owater values calculated for ore-bearing quartz vary from - 17.9‰ to - 10.8‰, and the δDV-SMOW values from bulk extraction of fluid inclusion waters vary from - 166‰ to - 127‰, suggesting that the ore-forming fluids consist dominantly of meteoric water. The δ34SV-CDT values range from 1.4‰ to 4.1‰. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the ore minerals are in the ranges of 18.302-19.037, 15.473-15.593, and 38.110-38.945, respectively. The data for the S and Pb isotopic systems indicate that the ore-forming metals and sulfur came from Mesozoic magma. The Chaganbulagen deposit is a low-sulfidation epithermal Pb-Zn-Ag deposit, and the temperature decrease is the dominant mechanism for the deposition of ore-forming materials.

LABORATORY EXERCISES IN OCEANOGRAPHY FOR HIGH SCHOOLS.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC.

DESCRIBED ARE LABORATORY EXERCISES IN OCEANOGRAPHY DEVELOPED FOR USE IN HIGH SCHOOLS BY THE SECONDARY SCHOOL TEACHERS IN THE 1967 NATIONAL SCIENCE FOUNDATION (NSF) SUMMER INSTITUTE IN OCEANOGRAPHY AT FLORIDA STATE UNIVERSITY. INCLUDED ARE SUCH ACTIVITIES AS (1) THE MEASUREMENT OF TEMPERATURE, WATER VAPOR, PRESSURE, SALINITY, DENSITY, AND OTHERS,…

Relationships between Environmental Factors and Pathogenic Vibrios in the Northern Gulf of Mexico ▿ †

PubMed Central

Johnson, C. N.; Flowers, A. R.; Noriea, N. F.; Zimmerman, A. M.; Bowers, J. C.; DePaola, A.; Grimes, D. J.

2010-01-01

Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities. PMID:20817802

Detection of temperature distribution via recovering electrical conductivity in MREIT.

PubMed

Oh, Tong In; Kim, Hyung Joong; Jeong, Woo Chul; Chauhan, Munish; Kwon, Oh In; Woo, Eung Je

2013-04-21

In radiofrequency (RF) ablation or hyperthermia, internal temperature measurements and tissue property imaging are important to control their outputs and assess the treatment effect. Recently, magnetic resonance electrical impedance tomography (MREIT), as a non-invasive imaging method of internal conductivity distribution using an MR scanner, has been developed. Its reconstruction algorithm uses measured magnetic flux density induced by injected currents. The MREIT technique has the potential to visualize electrical conductivity of tissue with high spatial resolution and measure relative conductivity variation according to the internal temperature change based on the fact that the electrical conductivity of biological tissues is sensitive to the internal temperature distribution. In this paper, we propose a method to provide a non-invasive alternative to monitor the internal temperature distribution by recovering the electrical conductivity distribution using the MREIT technique. To validate the proposed method, we design a phantom with saline solution and a thin transparency film in a form of a hollow cylinder with holes to create anomalies with different electrical and thermal conductivities controlled by morphological structure. We first prove the temperature maps with respect to spatial and time resolution by solving the thermal conductivity partial differential equation with the real phantom experimental environment. The measured magnetic flux density and the reconstructed conductivity distributions using the phantom experiments were compared to the simulated temperature distribution. The relative temperature variation of two testing objects with respect to the background saline was determined by the relative conductivity contrast ratio (rCCR,%). The relation between the temperature and conductivity measurements using MREIT was approximately linear with better accuracy than 0.22 °C.

Environmental influences on potential recruitment of pink shrimp, Fatlantopenaeus duorarum, from Florida Bay nursery grounds

USGS Publications Warehouse

Browder, Joan A.; Restrepo, V.R.; Rice, J.K.; Robblee, M.B.; Zein-Eldin, Z.

1999-01-01

Two modeling approaches were used to explore the basis for variation in recruitment of pink shrimp, Farfantepenaeus duorarum, to the Tortugas fishing grounds. Emphasis was on development and juvenile densities on the nursery grounds. An exploratory simulation modeling exercise demonstrated large year-to-year variations in recruitment contributions to the Tortugas rink shrimp fishery may occur on some nursery grounds, and production may differ considerably among nursery grounds within the same year, simply on the basis of differences in temperature and salinity. We used a growth and survival model to simulate cumulative harvests from a July-centered cohort of early-settlement-stage postlarvae from two parts of Florida Bay (western Florida Bay and northcentral Florida Bay), using historic temperature and salinity data from these areas. Very large year-to-year differences in simulated cumulative harvests were found for recruits from Whipray Basin. Year-to-year differences in simulated harvests of recruits from Johnson Key Basin were much smaller. In a complementary activity, generalized linear and additive models and intermittent, historic density records were used to develop an uninterrupted multi-year time series of monthly density estimates for juvenile rink shrimp in the Johnson Key Basin. The developed data series was based on relationships of density with environmental variables. The strongest relationship was with sea-surface temperature. Three other environmental variables (rainfall, water level at Everglades National Park Well P35, and mean wind speed) also contributed significantly to explaining variation in juvenile densities. Results of the simulation model and two of the three statistical models yielded similar interannual patterns for Johnson Key Basin. While it is not possible to say that one result validates the other, the concordance of the annual patterns from the two models is supportive of both approaches.

Population ecology of the gulf ribbed mussel across a salinity gradient: recruitment, growth and density

USGS Publications Warehouse

Honig, Aaron; Supan, John; LaPeyre, Megan K.

2015-01-01

Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and promoting productivity. As such, changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences. Recruitment, growth, mortality, population size structure and density of the gulf coast ribbed mussel, Geukensia granosissima, were examined across a salinity gradient in southeastern Louisiana. Data were collected along 100-m transects at interior and edge marsh plots located at duplicate sites in upper (salinity ~4 psu), central (salinity ~8 psu) and lower (salinity ~15 psu) Barataria Bay, Louisiana, U.S.A. Growth, mortality and recruitment were measured in established plots from April through November 2012. Mussel densities were greatest within the middle bay (salinity ~8) regardless of flooding regime, but strongly associated with highest stem densities of Juncus roemerianus vegetation. Mussel recruitment, growth, size and survival were significantly higher at mid and high salinity marsh edge sites as compared to all interior marsh and low salinity sites. The observed patterns of density, growth and mortality in Barataria Bay may reflect detrital food resource availability, host vegetation community distribution along the salinity gradient, salinity tolerance of the mussel, and reduced predation at higher salinity edge sites.

Towards an estimation of water masses formation areas from SMOS-based TS diagrams

NASA Astrophysics Data System (ADS)

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

2014-05-01

Temperature-Salinity (TS) diagrams emphasize the mutual variability of ocean temperature and salinity values, relating them to the corresponding density. Canonically used in oceanography, they provide a means to characterize and trace ocean water masses. In [1], a first attempt to estimate surface-layer TS diagrams based on satellite measurements has been performed, profiting from the recent availability of spaceborne salinity data. In fact, the Soil Moisture and Ocean Salinity (SMOS, [2]) and the Aquarius/SAC-D [3] satellite missions allow to study the dynamical patterns of Sea Surface Salinity (SSS) for the first time on a global scale. In [4], given SMOS and Aquarius salinity estimates, and by also using Sea Surface Temperature (SST) from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA, [5]) effort, experimental satellite-based TS diagrams have been routinely derived for the year 2011. They have been compared with those computed from ARGO-buoys interpolated fields, referring to a customised partition of the global ocean into seven regions, according to the water masses classification of [6]. In [7], moreover, besides using TS diagrams as a diagnostic tool to evaluate the temporal variation of SST and SSS (and their corresponding density) as estimated by satellite measurements, the emphasis was on the interpretation of the geographical deviations with respect to the ARGO baseline (aiming at distinguishing between the SSS retrieval errors and the additional information contained in the satellite data with respect to ARGO). In order to relate these mismatches to identifiable oceanographic structures and processes, additional satellite datasets of ocean currents, evaporation/precipitation fluxes, and wind speed have been super-imposed. Currently, the main focus of the study deals with the exploitation of these TS diagrams as a prognostic tool to derive water masses formation areas. Firstly, following the approach described in [8], the surface density flux (i.e., the change in density induced by surface heat and freshwater fluxes) is computed, characterizing how the buoyancy of a water parcel is being transformed, by increasing or decreasing its density. Afterwards, integrating over a certain time/space and deriving with respect to density, the formation (in Sv) of water masses themselves can be computed, pinpointing the range of SST and SSS in the TS diagrams where a specific water mass is formed. A geographical representation of these points, ultimately, allows to provide a relevant temporal series of the spatial extent of the water masses formation areas (in the specific test zones chosen). This can be then extended over challenging ocean regions, also evaluating the sensitivity of the performances to the datasets used. With this approach, known water masses can be identified and their formation traced in time and space. Longer time series will give further insights by helping to identify inter-annual water mass formation variability and trends in the TS/geographical domains. Future work aims at exploring additional datasets and at connecting the surface information to the vertical structure and to buoyancy-driven ocean circulation processes. References [1] Sabia, R., J. Ballabrera, G. Lagerloef, E. Bayler, M. Talone, Y. Chao, C. Donlon, D. Fernández-Prieto, J. Font, "Derivation of an Experimental Satellite-based T-S Diagram", In Proceedings of IGARSS '12 , Munich, Germany, pp. 5760-5763, 2012. [2] Font, J., A. Camps, A. Borges, M. Martín-Neira, J. Boutin, N. Reul, Y. H. Kerr, A. Hahne, and S. Mecklenburg, "SMOS: The challenging sea surface salinity measurement from space," Proceedings of the IEEE, vol. 98, pp. 649-665, 2010. [3] Le Vine, D.M.; Lagerloef, G.S.E.; Torrusio, S.E.; "Aquarius and Remote Sensing of Sea Surface Salinity from Space," Proceedings of the IEEE , vol.98, no.5, pp.688-703, May 2010, doi: 10.1109/JPROC.2010.2040550. [4] Sabia, R., M. Klockmann, D. Fernández-Prieto, C. Donlon, E. Bayler, J. Font, G. Lagerloef, "Satellite-based T/S Diagrams and Surface Ocean Water Masses", SMOS-Aquarius Science Workshop, Brest, France, April 2013. [5] Donlon, C. J., M. Martin, J. D. Stark, J. Roberts-Jones, E. Fiedler and W. Wimmer, "The Operational Sea Surface Temperature and Sea Ice analysis (OSTIA)", Remote Sensing of the Environment. doi: 10.1016/j.rse.2010.10.017 2011. [6] Emery, W. J., "Water Types and Water Masses", Ocean Circulation, Elsevier science, pp 1556-1567, 2003. [7] Sabia, R., M. Klockmann, C. Donlon, D. Fernández-Prieto, M. Talone, J. Ballabrera, "Satellite-based T-S Diagrams: a prospective diagnostic tool to trace ocean water masses", Living Planet Symposium 2013, Edinburgh, UK, September 2013. [8] Speer, K., E. Tzipermann, "Rates of Water Mass Transformation in the North Atlantic", Journal of Physical Oceanography, 22, 93 - 104, 1992.

Environmental influences on the seasonal distribution of Vibrio parahaemolyticus in the Pacific Northwest of the USA.

PubMed

Paranjpye, Rohinee N; Nilsson, William B; Liermann, Martin; Hilborn, Elizabeth D; George, Barbara J; Li, Quanlin; Bill, Brian D; Trainer, Vera L; Strom, Mark S; Sandifer, Paul A

2015-12-01

Populations of Vibrio parahaemolyticus in the environment can be influenced by numerous factors. We assessed the correlation of total (tl+) and potentially virulent (tdh+) V. parahaemolyticus in water with three harmful algal bloom (HAB) genera (Pseudo-nitzschia, Alexandrium and Dinophysis), the abundance of diatoms and dinoflagellates, chlorophyll-a and temperature, salinity and macronutrients at five sites in Washington State from 2008-2009. The variability in V. parahaemolyticus density was explained predominantly by strong seasonal trends where maximum densities occurred in June, 2 months prior to the highest seasonal water temperature. In spite of large geographic differences in temperature, salinity and nutrients, there was little evidence of corresponding differences in V. parahaemolyticus density. In addition, there was no evident relationship between V. parahaemolyticus and indices of HAB genera, perhaps due to a lack of significant HAB events during the sampling period. The only nutrient significantly associated with V. parahaemolyticus density after accounting for the seasonal trend was silicate. This negative relationship may be caused by a shift in cell wall structure for some diatom species to a chitinous substrate preferred by V. parahaemolyticus. Results from our study differ from those in other regions corroborating previous findings that environmental factors that trigger vibrio and HAB events may differ depending on geographic locations. Therefore caution should be used when applying results from one region to another. Published by Oxford University Press on behalf of FEMS 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Occurrence of Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus in the Aquacultural Environments of Taiwan.

PubMed

Tey, Yao Hsien; Jong, Koa-Jen; Fen, Shin-Yuan; Wong, Hin-Chung

2015-05-01

The occurrence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern Taiwan was examined by the membrane filtration and colony hybridization method. The halophilic V. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log CFU/g. V. cholerae was found in both the seawater and freshwater ponds but preferentially in freshwater ponds, with a frequency of 72.2% and a mean density of 1.65 log CFU/g. V. vulnificus was identified mainly in seawater ponds, with an isolation frequency of 27.8%. The density of V. parahaemolyticus in seawater ponds was positively related to water temperature (Pearson correlation coefficient, r = 0.555) and negatively related to salinity (r = 2 0.333). The density of V. cholerae in all six ponds was positively related to water temperature (r = 0.342) and negatively related to salinity (r = 2 0.432). Two putatively pathogenic tdh(+) V. parahaemolyticus isolates (1.4% of the samples) and no ctx(+) V. cholerae isolates were identified. The experimental results may facilitate assessments of the risk posed by these pathogenic Vibrio species in Taiwan, where aquaculture provides a large part of the seafood supply.

Temperature and water-quality conditions of the Patuxent River estuary, Maryland, January 1966 through December 1967

USGS Publications Warehouse

Cory, Robert L.; Nauman, Jon W.

1970-01-01

The effect of power plant cooling water in raising natural water temperatures at a location near the power plant on the Patuxent River estuary is clearly evident from thermograph records. Surface temperature at a station 333 m (1,000 ft) downstream from the discharge canal was raised an average of about 4 C, and at times by as much as 8 C. Temperature rises were greatest during the winter. Infrared imagery showed that elevated surface temperatures could be detected about 5.5 km (3 nautical miles) upstream at flood tide. Temperature profiles obtained from airborne radiation equipment revealed a complicated surface temperature pattern and also showed the effects of density differences and wind action on the steam-electric station (S.E.S.) effluent plume. Mean annual salinity for a 5-year period (1963–1967) was highest in 1966, about 12.3 ‰, and lowest in 1967, about 9.9‰. Dissolved oxygen values for 1966–1967 ranged from 3.2 to 15.6 mg/l, and saturation ranged from 55 to 152%. Turbidity levels were inversely related to salinity, with the highest annual, mean of 28 JCU (Jackson Candle Units) occurring in 1967, the lowest salinity year. The extreme tide range was 2.1 m (6.7 ft); mean water levels at the Patuxent Bridge were highest in summer and lowest in winter. Water stages are more affected by wind speed and direction than by flow in the river.

Forward Modeling of Carbonate Proxy Data from Planktonic Foraminifera using Oxygen Isotope Tracers in a Global Ocean Model

NASA Technical Reports Server (NTRS)

Schmidt, Gavin A.

1999-01-01

The distribution and variation of oxygen isotopes in seawater are calculated using the Goddard Institute for Space Studies global ocean model. Simple ecological models are used to estimate the planktonic foraminiferal abundance as a function of depth, column temperature, season, light intensity, and density stratification. These models are combined to forward model isotopic signals recorded in calcareous ocean sediment. The sensitivity of the results to the changes in foraminiferal ecology, secondary calcification, and dissolution are also examined. Simulated present-day isotopic values for ecology relevant for multiple species compare well with core-top data. Hindcasts of sea surface temperature and salinity are made from time series of the modeled carbonate isotope values as the model climate changes. Paleoclimatic inferences from these carbonate isotope records are strongly affected by erroneous assumptions concerning the covariations of temperature, salinity, and delta (sup 18)O(sub w). Habitat-imposed biases are less important, although errors due to temperature-dependent abundances can be significant.

Factors affecting summer distributions of Bering Sea forage fish species: Assessing competing hypotheses

NASA Astrophysics Data System (ADS)

Parker-Stetter, Sandra; Urmy, Samuel; Horne, John; Eisner, Lisa; Farley, Edward

2016-12-01

Hypotheses on the factors affecting forage fish species distributions are often proposed but rarely evaluated using a comprehensive suite of indices. Using 24 predictor indices, we compared competing hypotheses and calculated average models for the distributions of capelin, age-0 Pacific cod, and age-0 pollock in the eastern Bering Sea from 2006 to 2010. Distribution was described using a two stage modeling approach: probability of occurrence ("presence") and density when fish were present. Both local (varying by location and year) and annual (uniform in space but varying by year) indices were evaluated, the latter accounting for the possibility that distributions were random but that overall presence or densities changed with annual conditions. One regional index, distance to the location of preflexion larvae earlier in the year, was evaluated for age-0 pollock. Capelin distributions were best predicted by local indices such as bottom depth, temperature, and salinity. Annual climate (May sea surface temperature (SST), sea ice extent anomaly) and wind (June wind speed cubed) indices were often important for age-0 Pacific cod in addition to local indices (temperature and depth). Surface, midwater, and water column age-0 pollock distributions were best described by a combination of local (depth, temperature, salinity, zooplankton) and annual (May SST, sea ice anomaly, June wind speed cubed) indices. Our results corroborated some of those in previous distribution studies, but suggested that presence and density may also be influenced by other factors. Even though there were common environmental factors that influenced all species' distributions, it is not possible to generalize conditions for forage fish as a group.

Improved characterization of heterogeneous permeability in saline aquifers from transient pressure data during freshwater injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Peter K.; Lee, Jonghyun; Fu, Xiaojing

Managing recharge of freshwater into saline aquifers requires accurate estimation of the heterogeneous permeability field for maximizing injection and recovery efficiency. Here we present a methodology for subsurface characterization in saline aquifers that takes advantage of the density difference between the injected freshwater and the ambient saline groundwater. We combine high-resolution forward modeling of density-driven flow with an efficient Bayesian geostatistical inversion algorithm. In the presence of a density difference between the injected and ambient fluids due to differences in salinity, the pressure field is coupled to the spatial distribution of salinity. This coupling renders the pressure field transient: themore » time evolution of the salinity distribution controls the density distribution which then leads to a time-evolving pressure distribution. We exploit this coupling between pressure and salinity to obtain an improved characterization of the permeability field without multiple pumping tests or additional salinity measurements. We show that the inversion performance improves with an increase in the mixed convection ratio—the relative importance between viscous forces from injection and buoyancy forces from density difference. Thus, our work shows that measuring transient pressure data at multiple sampling points during freshwater injection into saline aquifers can be an effective strategy for aquifer characterization, key to the successful management of aquifer recharge.« less

Improved characterization of heterogeneous permeability in saline aquifers from transient pressure data during freshwater injection

DOE PAGES

Kang, Peter K.; Lee, Jonghyun; Fu, Xiaojing; ...

2017-05-31

Managing recharge of freshwater into saline aquifers requires accurate estimation of the heterogeneous permeability field for maximizing injection and recovery efficiency. Here we present a methodology for subsurface characterization in saline aquifers that takes advantage of the density difference between the injected freshwater and the ambient saline groundwater. We combine high-resolution forward modeling of density-driven flow with an efficient Bayesian geostatistical inversion algorithm. In the presence of a density difference between the injected and ambient fluids due to differences in salinity, the pressure field is coupled to the spatial distribution of salinity. This coupling renders the pressure field transient: themore » time evolution of the salinity distribution controls the density distribution which then leads to a time-evolving pressure distribution. We exploit this coupling between pressure and salinity to obtain an improved characterization of the permeability field without multiple pumping tests or additional salinity measurements. We show that the inversion performance improves with an increase in the mixed convection ratio—the relative importance between viscous forces from injection and buoyancy forces from density difference. Thus, our work shows that measuring transient pressure data at multiple sampling points during freshwater injection into saline aquifers can be an effective strategy for aquifer characterization, key to the successful management of aquifer recharge.« less

From convection rolls to finger convection in double-diffusive turbulence

NASA Astrophysics Data System (ADS)

Yang, Yantao; Verzicco, Roberto; Lohse, Detlef

2015-11-01

The double diffusive convection (DDC), where the fluid density depends on two scalar components with very different molecular diffusivities, is frequently encountered in oceanography, astrophysics, and electrochemistry. In this talk we report a systematic study of vertically bounded DDC for various control parameters. The flow is driven by an unstable salinity difference between two plates and stabilized by a temperature difference. As the relative strength of temperature difference becomes stronger, the flow transits from a state with large-scale convection rolls, which is similar to the Rayleigh-Bénard (RB) flow, to a state with well-organised salt fingers. When the temperature difference increases further, the flow breaks down to a purely conductive state. During this transit the velocity decreases monotonically. Counterintuitively, the salinity transfer can be enhanced when a stabilising temperature field is applied to the system. This happens when convection rolls are replaced by salt fingers. In addition, we show that the Grossmann-Lohse theory originally developed for RB flow can be directly applied to the current problem and accurately predicts the salinity transfer rate for a wide range of control parameters. Supported by Stichting FOM and the National Computing Facilities (NCF), both sponsored by NWO. The simulations were conducted on the Dutch supercomputer Cartesius at SURFsara.

Salinity and temperature tolerance of brown-marbled grouper Epinephelus fuscoguttatus.

PubMed

Cheng, Sha-Yen; Chen, Chih-Sung; Chen, Jiann-Chu

2013-04-01

Grouper have to face varied environmental stressors as a result of drastic changes to water conditions during the storm season. We aimed to test the response of brown-marbled grouper to drastic and gradual changes in temperature and salinity to understand the grouper's basic stress response. The results can improve the culture of grouper. Brown-marbled grouper, Epinephelus fuscoguttatus (6.2 ± 0.8 g) were examined for temperature and salinity tolerances at nine different environmental regimes (10, 20, and 33 ‰ combined with 20, 26 and 32 °C), in which the fish were subjected to both gradual and sudden changes in temperature and salinity. The critical thermal maximum (50 % CTMAX) and the upper incipient lethal temperature (UILT) were in the ranges of 35.9-38.3 and 32.7-36.5 °C, respectively. The critical thermal minimum (50 % CTMIN) and the lower incipient lethal temperature (LILT) were in the ranges of 9.8-12.2 and 14.9-22.3 °C, respectively. The critical salinity maximum (50 % CSMAX) and the upper incipient lethal salinity (UILS) were in the ranges of 67.0-75.5 and 54.2-64.8 ‰, respectively. Fish at temperature of 20 °C and a salinity of 33 ‰ tolerated temperatures as low as 10 °C when the temperature was gradually decreased. Fish acclimated at salinities of 10-33 ‰ and a temperature of 32 °C tolerated salinities of as high as 75-79 ‰. All fish survived from accumulating salinity after acute transfer to 20, 10, 5, and 3 ‰. But all fish died while transferred to 0 ‰. Relationships among the UILT, LILT, 50 % CTMAX, 50 % CTMIN, UILS, 50 % CSMAX, salinity, and temperature were examined. The grouper's temperature and salinity tolerance elevated by increasing acclimation temperature and salinity. On the contrary, the grouper's temperature and salinity tolerance degraded by decreasing acclimation temperature and salinity. The tolerance of temperature and salinity on grouper in gradual changes were higher than in drastic changes.

Monitoring benthic foraminiferal dynamics at Bottsand coastal lagoon (western Baltic Sea)

NASA Astrophysics Data System (ADS)

Schönfeld, Joachim

2018-04-01

Benthic foraminifera from Bottsand coastal lagoon, western Baltic Sea, have been studied since the mid-1960s. They were monitored annually in late autumn since 2003 at the terminal ditch of the lagoon. There were 12 different species recognised, of which three have not been recorded during earlier investigations. Dominant species showed strong interannual fluctuations and a steady increase in population densities over the last decade. Elphidium incertum, a stenohaline species of the Baltic deep water fauna, colonised the Bottsand lagoon in 2016, most likely during a period of salinities >19 units and water temperatures of 18 °C on average in early autumn. The high salinities probably triggered their germination from a propagule bank in the ditch bottom sediment. The new E. incertum population showed densities higher by an order of magnitude than those of the indigenous species. The latter did not decline, revealing that E. incertum used another food source or occupied a different microhabitat. Elphidium incertum survived transient periods of lower salinities in late autumn 2017, though with reduced abundances, and became a regular faunal constituent at the Bottsand lagoon.

The Baltic haline conveyor belt or the overturning circulation and mixing in the Baltic.

PubMed

Döös, Kristofer; Meier, H E Markus; Döscher, Ralf

2004-06-01

A study of the water-mass circulation of the Baltic has been undertaken by making use of a three dimensional Baltic Sea model simulation. The saline water from the North Atlantic is traced through the Danish Sounds into the Baltic where it upwells and mixes with the fresh water inflow from the rivers forming a Baltic haline conveyor belt. The mixing of the saline water from the Great Belt and Oresund with the fresh water is investigated making use of overturning stream functions and Lagrangian trajectories. The overturning stream function was calculated as a function of four different vertical coordinates (depth, salinity, temperature and density) in order to understand the path of the water and where it upwells and mixes. Evidence of a fictive depth overturning cell similar to the Deacon Cell in the Southern Ocean was found in the Baltic proper corresponding to the gyre circulation around Gotland, which vanishes when the overturning stream function is projected on density layers. A Lagrangian trajectory study was performed to obtain a better view of the circulation and mixing of the saline and fresh waters. The residence time of the water masses in the Baltic is calculated to be 26-29 years and the Lagrangian dispersion reaches basin saturation after 5 years.

Warm and Saline Events Embedded in the Meridional Circulation of the Northern North Atlantic

NASA Technical Reports Server (NTRS)

Hakkinen, Sirpa; Rhines, Peter B.; Worthen, Denise L.

2011-01-01

Ocean state estimates from 1958 to 2005 from the Simple Ocean Assimilation System (SODA) system are analyzed to understand circulation between subtropical and subpolar Atlantic and their connection with atmospheric forcing. This analysis shows three periods (1960s, around 1980, and 2000s) with enhanced warm, saline waters reaching high latitudes, alternating with freshwater events originating at high latitudes. It complements surface drifter and altimetry data showing the subtropical -subpolar exchange leading to a significant temperature and salinity increase in the northeast Atlantic after 2001. The warm water limb of the Atlantic meridional overturning cell represented by SODA expanded in density/salinity space during these warm events. Tracer simulations using SODA velocities also show decadal variation of the Gulf Stream waters reaching the subpolar gyre and Nordic seas. The negative phase of the North Atlantic Oscillation index, usually invoked in such variability, fails to predict the warming and salinization in the early 2000s, with salinities not seen since the 1960s. Wind stress curl variability provided a linkage to this subtropical/subpolar gyre exchange as illustrated using an idealized two ]layer circulation model. The ocean response to the modulation of the climatological wind stress curl pattern was found to be such that the northward penetration of subtropical tracers is enhanced when amplitude of the wind stress curl is weaker than normal. In this case both the subtropical and subpolar gyres weaken and the subpolar density surfaces relax; hence, the polar front moves westward, opening an enhanced northward access of the subtropical waters in the eastern boundary current.

Very Mild Hypothermia (35°C) Postischemia Reduces Infarct Volume and Blood/Brain Barrier Breakdown Following tPA Treatment in the Mouse.

PubMed

Cechmanek, Brian K; Tuor, Ursula I; Rushforth, David; Barber, Philip A

2015-12-01

Reperfusion therapies for stroke diminish in effectiveness and safety as time to treatment increases. Hypothermia neuroprotection for stroke is established, but its clinical translation has been hampered by uncertainties regarding optimal temperature and complications associated with moderate hypothermia. Also, hypothermia targeting temperatures of 32-33°C is associated with clinical and logistical problems related to induction and adverse side effects. We hypothesized that ischemic damage and tPA-exacerbated blood/brain barrier (BBB) breakdown produced following 30 minutes of middle cerebral artery occlusion and either 1 hour of saline or tPA infusion would be reduced by treatment with very mild cooling of 1.5°C for 48 hours followed by 24 hours of gradual rewarming. Infarct volume was reduced by 29.6% (p<0.001) and 41.9% (p<0.001) in hypothermic-tPA (Hypo_tPA)-treated and hypothermic-saline (Hypo_Sal)-treated animals compared to normothermic-tPA (Norm_tPA) and saline (Norm_Sal)-treated animals, respectively. Hypothermia also reduced IgG extravasation in tPA-treated, but not saline-treated groups compared to their normothermic controls (p<0.001). The ipsilateral-contralateral changes in optical density for IgG extravasation were 18.4% greater in the Norm_tPA than Norm_Sal (p<0.001) group. The ipsilateral-contralateral changes in optical density for IgG extravasation were reduced by 17.8% (p<0.001) in the Hypo_tPA compared to Norm_tPA group. No significant mean difference in IgG extravasation was seen between Hypo_tPA and Hypo_Sal groups (p>0.05). Very modest hypothermia to reduce the BBB breakdown could improve the availability and safety of reperfusion treatments for stroke.

A descriptive analysis of temporal and spatial patterns of variability in Puget Sound oceanographic properties

Treesearch

Stephanie Moore; Nathan J. Mantua; Jan A. Newton; Mitsuhiro Kawase; Mark J. Warner; Jonathan P. Kellogg

2008-01-01

Temporal and spatial patterns of variability in Puget Sound's oceanographic properties are determined using continuous vertical profile data from two long-term monitoring programs; monthly observations at 16 stations from 1993 to 2002, and biannual observations at 40 stations from 1998 to 2003. Climatological monthly means of temperature, salinity, and density...

The use of SKYLAB in the study of productivity along the eastern shelf waters of the United States

NASA Technical Reports Server (NTRS)

Marshall, H. G.; Bowker, D. E.

1976-01-01

Data sampling from the Rappahannock River and Assateague Island areas are discussed correlating Skylab and ground based measurements. At all sampling stations, information was obtained on composition and density of phytoplankton, total chlorophyll, salinity and water temperature. The results of the water analysis are presented in tables.

A two-dimensional ocean model for long-term climatic simulations: Stability and coupling to atmospheric and sea ice models

NASA Astrophysics Data System (ADS)

Harvey, L. D. Danny

1992-06-01

A two-dimensional (latitude-depth) deep ocean model is presented which is coupled to a sea ice model and an Energy Balance Climate Model (EBCM), the latter having land-sea and surface-air resolution. The processes which occur in the ocean model are thermohaline overturning driven by the horizontal density gradient, shallow wind-driven overturning cells, convective overturning, and vertical and horizontal diffusion of heat and salt. The density field is determined from the temperature and salinity fields using a nonlinear equation of state. Mixed layer salinity is affected by evaporation, precipitation, runoff from continents, and sea ice freezing and melting, as well as by advective, convective, and diffusive exchanges with the deep ocean. The ocean model is first tested in an uncoupled mode, in which hemispherically symmetric mixed layer temperature and salinity, or salinity flux, are specified as upper boundary conditions. An experiment performed with previous models is repeated in which a mixed layer salinity perturbation is introduced in the polar half of one hemisphere after switching from a fixed salinity to a fixed salinity flux boundary condition. For small values of the vertical diffusion coefficient KV, the model undergoes self-sustained oscillations with a period of about 1500 years. With larger values of KV, the model locks into either an asymmetric mode with a single overturning cell spanning both hemispheres, or a symmetric quiescent state with downwelling near the equator, upwelling at high latitudes, and a warm deep ocean (depending on the value of KV). When the ocean model is forced with observed mixed layer temperature and salinity, no oscillations occur. The model successfully simulates the very weak meridional overturning and strong Antarctic Circumpolar Current at the latitudes of the Drake Passage. The coupled EBCM-deep ocean model displays internal oscillations with a period of 3000 years if the ocean fraction is uniform with latitude and KV and the horizontal diffusion coefficient in the mixed layer are not too large. Globally averaged atmospheric temperature changes of 2 K are driven by oscillations in the heat flux into or out of the deep ocean, with the sudden onset of a heat flux out of the deep ocean associated with the rapid onset of thermohaline overturning after a quiescent period, and the sudden onset of a heat flux into the deep ocean associated with the collapse of thermohaline overturning. When the coupled model is run with prescribed parameters (such as land-sea fraction and precipitation) varying with latitude based on observations, the model does not oscillate and produces a reasonable deep ocean temperature field but a completely unrealistic salinity field. Resetting the mixed layer salinity to observations on each time step (equivalent to the "flux correction" method used in atmosphere-ocean general circulation models) is sufficient to give a realistic salinity field throughout the ocean depth, but dramatically alters the flow field and associated heat transport. Although the model is highly idealized, the finding that the maximum perturbation in globally averaged heat flux from the deep ocean to the surface over a 100-year period is 1.4 W m-2 suggests that effect of continuing greenhouse gas increases, which could result in a heating perturbation of 10 W m-2 by the end of the next century, will swamp possible surface heating perturbations due to changes in oceanic circulation. On the other hand, the extreme sensitivity of the oceanic flow field to variations in precipitation and evaporation suggests that it will not be possible to produce accurate projections of regional climatic change in the near term, if at all.

Predicting the variation in Echinogammarus marinus at its southernmost limits under global warming scenarios: can the sex-ratio make a difference?

PubMed

Guerra, Alexandra; Leite, Nuno; Marques, João Carlos; Ford, Alex T; Martins, Irene

2014-01-01

Understanding the environmental parameters that constrain the distribution of a species at its latitudinal extremes is critical for predicting how ecosystems react to climate change. Our first aim was to predict the variation in the amphipod populations of Echinogammarus marinus from the southernmost limit of its distribution under global warming scenarios. Our second aim was to test whether sex-ratio fluctuations - a mechanism frequently displayed by amphipods - respond to the variations in populations under altered climate conditions. To achieve these aims, scenarios were run with a validated model of E. marinus populations. Simulations were divided into: phase I - simulation of the effect of climate change on amphipod populations, and phase II - simulation of the effect of climate change on populations with male and female proportions. In both phases, temperature (T), salinity (S) and temperature and salinity (T-S) were tested. Results showed that E. marinus populations are highly sensitive to increases in temperature (>2 °C), which has adverse effects on amphipod recruitment and growth. Results from the climate change scenarios coupled with the sex-ratio fluctuations depended largely on the degree of female bias within population. Temperature increase of 2 °C had less impact on female-biased populations, particularly when conjugated with increases in salinity. Male-biased populations were highly sensitive to any variation in temperature and/or salinity; these populations exhibited a long-term decline in density. Simulations in which temperature increased more than 4 °C led to a continuous decline in the E. marinus population. According to this work, E. marinus populations at their southernmost limit are vulnerable to global warming. We anticipate that in Europe, temperature increases of 2 °C will incite a withdrawal of the population of 5°N from the amphipod species located at southernmost geographical borders. This effect is discussed in relation to the distribution of E. marinus along the Atlantic coast. © 2013 Elsevier B.V. All rights reserved.

Combining Remote Temperature Sensing with in-Situ Sensing to Track Marine/Freshwater Mixing Dynamics

PubMed Central

McCaul, Margaret; Barland, Jack; Cleary, John; Cahalane, Conor; McCarthy, Tim; Diamond, Dermot

2016-01-01

The ability to track the dynamics of processes in natural water bodies on a global scale, and at a resolution that enables highly localised behaviour to be visualized, is an ideal scenario for understanding how local events can influence the global environment. While advances in in-situ chem/bio-sensing continue to be reported, costs and reliability issues still inhibit the implementation of large-scale deployments. In contrast, physical parameters like surface temperature can be tracked on a global scale using satellite remote sensing, and locally at high resolution via flyovers and drones using multi-spectral imaging. In this study, we show how a much more complete picture of submarine and intertidal groundwater discharge patterns in Kinvara Bay, Galway can be achieved using a fusion of data collected from the Earth Observation satellite (Landsat 8), small aircraft and in-situ sensors. Over the course of the four-day field campaign, over 65,000 in-situ temperatures, salinity and nutrient measurements were collected in parallel with high-resolution thermal imaging from aircraft flyovers. The processed in-situ data show highly correlated patterns between temperature and salinity at the southern end of the bay where freshwater springs can be identified at low tide. Salinity values range from 1 to 2 ppt at the southern end of the bay to 30 ppt at the mouth of the bay, indicating the presence of a freshwater wedge. The data clearly show that temperature differences can be used to track the dynamics of freshwater and seawater mixing in the inner bay region. This outcome suggests that combining the tremendous spatial density and wide geographical reach of remote temperature sensing (using drones, flyovers and satellites) with ground-truthing via appropriately located in-situ sensors (temperature, salinity, chemical, and biological) can produce a much more complete and accurate picture of the water dynamics than each modality used in isolation. PMID:27589770

Combining Remote Temperature Sensing with in-Situ Sensing to Track Marine/Freshwater Mixing Dynamics.

PubMed

McCaul, Margaret; Barland, Jack; Cleary, John; Cahalane, Conor; McCarthy, Tim; Diamond, Dermot

2016-08-31

The ability to track the dynamics of processes in natural water bodies on a global scale, and at a resolution that enables highly localised behaviour to be visualized, is an ideal scenario for understanding how local events can influence the global environment. While advances in in-situ chem/bio-sensing continue to be reported, costs and reliability issues still inhibit the implementation of large-scale deployments. In contrast, physical parameters like surface temperature can be tracked on a global scale using satellite remote sensing, and locally at high resolution via flyovers and drones using multi-spectral imaging. In this study, we show how a much more complete picture of submarine and intertidal groundwater discharge patterns in Kinvara Bay, Galway can be achieved using a fusion of data collected from the Earth Observation satellite (Landsat 8), small aircraft and in-situ sensors. Over the course of the four-day field campaign, over 65,000 in-situ temperatures, salinity and nutrient measurements were collected in parallel with high-resolution thermal imaging from aircraft flyovers. The processed in-situ data show highly correlated patterns between temperature and salinity at the southern end of the bay where freshwater springs can be identified at low tide. Salinity values range from 1 to 2 ppt at the southern end of the bay to 30 ppt at the mouth of the bay, indicating the presence of a freshwater wedge. The data clearly show that temperature differences can be used to track the dynamics of freshwater and seawater mixing in the inner bay region. This outcome suggests that combining the tremendous spatial density and wide geographical reach of remote temperature sensing (using drones, flyovers and satellites) with ground-truthing via appropriately located in-situ sensors (temperature, salinity, chemical, and biological) can produce a much more complete and accurate picture of the water dynamics than each modality used in isolation.

Salinity affects behavioral thermoregulation in a marine decapod crustacean

NASA Astrophysics Data System (ADS)

Reiser, Stefan; Mues, Annika; Herrmann, Jens-Peter; Eckhardt, André; Hufnagl, Marc; Temming, Axel

2017-10-01

Thermoregulation in aquatic ectotherms is a complex behavioral pattern that is affected by various biotic and abiotic factors with one being salinity. Especially in coastal and estuarine habitats, altering levels of salinity involve osmoregulatory adjustments that affect total energy budgets and may influence behavioral responses towards temperature. To examine the effect of salinity on behavioral thermoregulation in a marine evertebrate ectotherm, we acclimated juvenile and sub-adult common brown shrimp (Crangon crangon, L.) to salinities of 10, 20 and 30 PSU and investigated their thermal preference in an annular chamber system using the gravitational method for temperature preference determination. Thermal preference of individual brown shrimp was considerably variable and brown shrimp selected a wide range of temperatures in each level of salinity as well as within individual experimental trials. However, salinity significantly affected thermal preference with the shrimp selecting higher temperatures at 10 and 20 PSU when compared to 30 PSU of salinity. Body size had no effect on thermal selection and did not interact with salinity. Temperature preference differed by sex and male shrimp selected significantly higher temperatures at 10 PSU when compared to females. The results show that salinity strongly affects thermal selection in brown shrimp and confirms the strong interrelation of temperature and salinity on seasonal migratory movements that has been previously derived from observations in the field. In the field, however, it remains unclear whether salinity drives thermal selection or whether changes in temperature modify salinity preference.

Stratification at the Earth's largest hyperacidic lake and its consequences

NASA Astrophysics Data System (ADS)

Caudron, Corentin; Campion, Robin; Rouwet, Dmitri; Lecocq, Thomas; Capaccioni, Bruno; Syahbana, Devy; Suparjan; Purwanto, Bambang Heri; Bernard, Alain

2017-02-01

Volcanic lakes provide windows into the interior of volcanoes as they integrate the heat flux discharged by a magma body and condense volcanic gases. Volcanic lake temperatures and geochemical compositions therefore typically serve as warnings for resumed unrest or prior to eruptions. If acidic and hot, these lakes are usually considered to be too convective to allow any stratification within their waters. Kawah Ijen volcano, featuring the largest hyperacidic lake on Earth (volume of 27 million m3), is less homogeneous than previously thought. Hourly temperature measurements reveal the development of a stagnant layer of cold waters (<30 °C), overlying warmer and denser water (generally above 30 °C and density ∼1.083 kg/m3). Examination of 20 yrs of historical records and temporary measurements show a systematic thermal stratification during rainy seasons. The yearly rupture of stratification at the end of the rainy season causes a sudden release of dissolved gases below the cold water layer which appears to generate a lake overturn, i.e. limnic eruption, and a resonance of the lake, i.e. a seiche, highlighting a new hazard for these extreme reservoirs. A minor non-volcanic event, such as a heavy rainfall or an earthquake, may act as a trigger. The density driven overturn requires specific salinity-temperature conditions for the colder and less saline top water layer to sink into the hot saline water. Spectacular degassing occurs when the dissolved gases, progressively stored during the rainy season due to a weakened diffusion of carbon dioxide in the top layer, are suddenly released. These findings challenge the homogenization assumption at acidic lakes and stress the need to develop appropriate monitoring setups.

Double-diffusive convection in geothermal systems: the salton sea, California, geothermal system as a likely candidate

USGS Publications Warehouse

Fournier, R.O.

1990-01-01

Much has been published about double-diffusive convection as a mechanism for explaining variations in composition and temperature within all-liquid natural systems. However, relatively little is known about the applicability of this phenomenon within the heterogeneous rocks of currently active geothermal systems where primary porosity may control fluid flow in some places and fractures may control it in others. The main appeal of double-diffusive convection within hydrothermal systems is-that it is a mechanism that may allow efficient transfer of heat mainly by convection, while at the same time maintaining vertical and lateral salinity gradients. The Salton Sea geothermal system exhibits the following reservoir characteristics: (1) decreasing salinity and temperature from bottom to top and center toward the sides, (2) a very high heat flow from the top of the system that seems to require a major component of convective transfer of heat within the chemically stratified main reservoir, and (3) a relatively uniform density of the reservoir fluid throughout the system at all combinations of subsurface temperature, pressure, and salinity. Double-diffusive convection can account for these characteristics very nicely whereas other previously suggested models appear to account either for the thermal structure or for the salinity variations, but not both. Hydrologists, reservoir engineers, and particularly geochemists should consider the possibility and consequences of double-diffusive convection when formulating models of hydrothermal processes, and of the response of reservoirs to testing and production. ?? 1990.

Salinity and temperature tolerance of an emergent alien species, the Amazon fish Astronotus ocellatus

USGS Publications Warehouse

Gutierrel, Silvia M M; Schofield, Pam; Prodocimo, Viviane

2016-01-01

Astronotus ocellatus (oscar), is native to the Amazon basin and, although it has been introduced to many countries, little is known regarding its tolerances for salinity and temperature. In this report, we provide data on the tolerance of A. ocellatus to abrupt and gradual changes in salinity, its high and low temperature tolerance, and information on how salinity, temperature, and fish size interact to affect survival. Fish were able to survive abrupt transfer to salinities as high as 16 ppt with no mortality. When salinity change was gradual (2 ppt/day), fish in the warm-temperature experiment (28°C) survived longer than fish in the cool-temperature experiment (18°C). Larger fish survived longer than smaller ones at the higher salinities when the temperature was warm, but when the temperature was cool fish size had little effect on survival. In the temperature-tolerance experiments, fish survived from 9 to 41°C for short periods of time. Overall, the species showed a wide range of temperature and salinity tolerance. Thus, in spite of the tropical freshwater origin of this species, physiological stress is not likely to hinder its dispersal to brackish waters, especially when temperatures are warm.

An overview of new insights from satellite salinity missions on oceanography

NASA Astrophysics Data System (ADS)

Reul, Nicolas

2015-04-01

The Soil Moisture and Ocean Salinity (SMOS) mission, launched on 2 November 2009, is the European Space Agency's (ESA) second Earth Explorer Opportunity mission. The scientific objectives of the SMOS mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables describing the Earth's water cycle and having been identified as Essential Climate Variables (ECVs) by the Global Climate Observing System (GCOS). After five years of satellite Sea Surface Salinity (SSS) monitoring from SMOS data, we will present an overview of the scientific highlights these data have brougtht to the oceanographic communities. In particular, we shall review the impact of SMOS SSS and brightness tempeaerture data for the monitoring of: -Mesoscale variability of SSS (and density) in frontal structures, eddies, -Ocean propagative SSS signals (e.g. TIW, planetary waves), -Freshwater flux Monitoring (Evaportaion minus precipitation, river run off), -Large scale SSS anomalies related to climate fluctuations (e.g. ENSO, IOD), -Air-Sea interactions (equatorial upwellings, Tropical cyclone wakes) -Temperature-Salinity dependencies, -Sea Ice thickness, -Tropical Storm and high wind monitoring, -Ocean surface bio-geo chemistry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Wang, Taiping

A three-dimensional coastal ocean model with a tidal turbine module was used in this paper to study the effects of tidal energy extraction on temperature and salinity stratification and density driven two-layer estuarine circulation. Numerical experiments with various turbine array configurations were carried out to investigate the changes in tidally mean temperature, salinity and velocity profiles in an idealized stratified estuary that connects to coastal water through a narrow tidal channel. The model was driven by tides, river inflow and sea surface heat flux. To represent the realistic size of commercial tidal farms, model simulations were conducted based on amore » small percentage of the total number of turbines that would generate the maximum extractable energy in the system. Model results indicated that extraction of tidal energy will increase the vertical mixing and decrease the stratification in the estuary. Extraction of tidal energy has stronger impact on the tidally-averaged salinity, temperature and velocity in the surface layer than the bottom. Energy extraction also weakens the two-layer estuarine circulation, especially during neap tides when tidal mixing the weakest and energy extraction is the smallest. Model results also show that energy generation can be much more efficient with higher hub height with relatively small changes in stratification and two-layer estuarine circulation.« less

Study of the effect of temperature, irradiance and salinity on growth and yessotoxin production by the dinoflagellate Protoceratium reticulatum in culture by using a kinetic and factorial approach.

PubMed

Paz, Beatriz; Vázquez, José A; Riobó, Pilar; Franco, José M

2006-10-01

A complete first order orthogonal plan was used to optimize the growth and the production of yessotoxin (YTX) by the dinoflagellate Protoceratium reticulatum in culture by controlling salinity, temperature and irradiance. Initially, an approach to the kinetic data of cellular density and YTX production for each one of the experimental design conditions was performed. The P. reticulatum growth and YTX production were fitted to logistical equations and to a first-order kinetic model, respectively. The parameters obtained from this adjustment were used as dependent variables for the formulation of the empirical equations of the factorial design tested. The results showed that in practically all the cases for both, P. reticulatum growth and YTX production, irradiance is the primary independent variable and has a positive effect in the range 50-90 micromol photons m(-2) s(-1). Additionally, in certain specific cases, temperature reveals significant positive effects when maintained between 15 and 23 degrees C and salinity in the range of 20-34 displays negative effects. Despite the narrow ranges used in the work, results showed the suitability of factorial analysis to evaluate the optimal conditions for growth and yessotoxin production by the dinoflagellate P. reticulatum.

Addition of simultaneous heat and solute transport and variable fluid viscosity to SEAWAT

USGS Publications Warehouse

Thorne, D.; Langevin, C.D.; Sukop, M.C.

2006-01-01

SEAWAT is a finite-difference computer code designed to simulate coupled variable-density ground water flow and solute transport. This paper describes a new version of SEAWAT that adds the ability to simultaneously model energy and solute transport. This is necessary for simulating the transport of heat and salinity in coastal aquifers for example. This work extends the equation of state for fluid density to vary as a function of temperature and/or solute concentration. The program has also been modified to represent the effects of variable fluid viscosity as a function of temperature and/or concentration. The viscosity mechanism is verified against an analytical solution, and a test of temperature-dependent viscosity is provided. Finally, the classic Henry-Hilleke problem is solved with the new code. ?? 2006 Elsevier Ltd. All rights reserved.

Properties, formation, and dissipation of the North Pacific Eastern Subtropical Mode Water and its impact on interannual spiciness anomalies

NASA Astrophysics Data System (ADS)

Katsura, Shota

2018-03-01

The properties, formation, and dissipation of the North Pacific Eastern Subtropical Mode Water (ESTMW), their interannual variability, and impact on spiciness anomalies in the upper permanent pycnocline were investigated using Argo profiling float data in 2005-2015. The core temperature and salinity of ESTMWs were horizontally compensated to a constant density, and core potential density concentrates in a range of 24.5-25.2 kg m-3 with two distinct peaks. ESTMWs showed different spatial distribution and persistence for its core potential density. Denser ESTMWs with a potential density of 24.9-25.2 kg m-3 were formed in winter mixed layer depth maximum centered at 30°N, 140°W and lighter ESTMWs of 24.5-24.9 kg m-3 were formed south and east of it. After formation through shoaling of the winter mixed layer, the former persisted until the following autumn and a small part of it subducted in winter, while the latter dissipated in summer. The formation region of ESTMW corresponded to the summer sea surface density maximum resulting from its poleward sea surface salinity front. Sea surface density maximum maintains weak stratification during summer, preconditioning the deepening of the winter mixed layer and hence the formation of ESTMWs. A relationship between the ESTMW formation region and the summer sea surface density maximum was also found in the North Atlantic and the South Pacific, implying the importance of sea surface salinity fronts and the associated summer sea surface density maximum to ESTMW formation. Interannual variations of ESTMW reflected that of the winter mixed layer in its formation region, and the thickness of ESTMW was related to the Pacific decadal oscillation. ESTMW contributed to the occurrence of spice injection and affected spiciness anomalies in the upper permanent pycnocline through its formation and dissipation.

Effects of temperature and salinity on survival, growth and DNA methylation of juvenile Pacific abalone, Haliotis discus hannai Ino

NASA Astrophysics Data System (ADS)

Kong, Ning; Liu, Xiao; Li, Junyuan; Mu, Wendan; Lian, Jianwu; Xue, Yanjie; Li, Qi

2017-09-01

Temperature and salinity are two of the most potent abiotic factors influencing marine mollusks. In this study, we investigated the individual and combined effects of temperature and salinity on the survival and growth of juvenile Pacific abalone, Haliotis discus hannai Ino, and also examined the DNA methylation alteration that may underpin the phenotypic variation of abalone exposed to different rearing conditions. The single-factor data showed that the suitable ranges of temperature and salinity were 16-28°C at a constant salinity of 32, and 24-40 at a constant temperature of 20°C, respectively. The two-factor data indicated that both survival and growth were significantly affected by temperature, salinity and their interaction. The optimal temperature-salinity combination for juveniles was 23-25°C and 30-36. To explore environment-induced DNA methylation alteration, the methylation-sensitive amplified polymorphism (MSAP) technique was used to analyze the genomic methylation profiles of abalone reared in optimal and adverse conditions. Neither temperature nor salinity induced evident changes in the global methylation level, but 67 and 63 differentially methylated loci were identified in temperature and salinity treatments, respectively. The between-group eigen analysis also showed that both temperature and salinity could induce epigenetic differentiation in H. discus hannai Ino. The results of our study provide optimal rearing conditions for juvenile H. discus hannai Ino, and represent the first step toward revealing the epigenetic regulatory mechanism of abalone in response to thermal and salt stresses.

Interaction of lateral baroclinic forcing and turbulence in an estuary

USGS Publications Warehouse

Lacy, J.R.; Stacey, M.T.; Burau, J.R.; Monismith, Stephen G.

2003-01-01

Observations of density and velocity in a channel in northern San Francisco Bay show that the onset of vertical density stratification during flood tides is controlled by the balance between the cross-channel baroclinic pressure gradient and vertical mixing due to turbulence. Profiles of velocity, salinity, temperature, and suspended sediment concentration were measured in transects across Suisun Cutoff, in northern San Francisco Bay, on two days over the 12.5-hour tidal cycle. During flood tides an axial density front developed between fresher water flowing from the shallows of Grizzly Bay into the northern side of Suisun Cutoff and saltier water flowing up the channel. North of the front, transverse currents were driven by the lateral salinity gradient, with a top-to-bottom velocity difference greater than 30 cm/s. South of the front, the secondary circulation was weak, and along-channel velocities were greater than to the north. The gradient Richardson number shows that stratification was stable north of the front, while the water column was turbulently mixed south of the front. Time-series measurements of velocity and salinity demonstrate that the front develops during each tidal cycle. In estuaries, longitudinal dynamics predict less stratification during flood than ebb tides. These data show that stratification can develop during flood tides due to a lateral baroclinic pressure gradient in estuaries with complex bathymetry.

Density and distribution of water boatmen and brine shrimp at a major shorebird wintering area in Puerto Rico

USGS Publications Warehouse

Tripp, K.J.; Collazo, J.A.

2003-01-01

The Cabo Rojo salt flats are an important wintering area for migratory shorebirds. Their quality is intimately related to prey availability, as prey are needed to meet energetic requirements. Understanding prey dynamics is, therefore, a key element of shorebird conservation plans. To this end, we monitored the density and distribution of water-boatmen (Trichocorixa spp.) and brine shrimp (Artemia spp.) in relation to water salinity from September to November of 1994 and 1995. Salinity ranged from 4 to 292 ppt, and gradients were related to hydrological alterations (e.g., salt extraction) and connection to the ocean. Brine shrimp were restricted to areas of highest salinity (??? 106 ppt), whereas water-boatmen to areas of lowest salinity ( 100 ppt. Lowering water salinity did not result in osmolal related mortality. Results underscored the sensitivity of water boatmen to high salinity, particularly when the difference in salinity between the 'source' and 'destination' localities widened. Water boatmen density increased in one lagoon as salinity decreased from 65 to 47 ppt. On the basis of our experiments, local adult survivorship improved and immigration and subsequent survival of adults, if any, was not hindered. The density of nymphs also suggested that hatching occurred concurrently. The foraging value of the salt flats can be enhanced by maintaining salinity at < 65 ppt in selected management units and minimizing differences in salinity concentrations among them.

The effects of heated and room-temperature abdominal lavage solutions on core body temperature in dogs undergoing celiotomy.

PubMed

Nawrocki, Michael A; McLaughlin, Ron; Hendrix, P K

2005-01-01

To document the magnitude of temperature elevation obtained with heated lavage solutions during abdominal lavage, 18 dogs were lavaged with sterile isotonic saline intraoperatively (i.e., during a celiotomy). In nine dogs, room-temperature saline was used. In the remaining nine dogs, saline heated to 43+/-2 degrees C (110+/-4 degrees F) was used. Esophageal, rectal, and tympanic temperatures were recorded every 60 seconds for 15 minutes after initiation of the lavage. Temperature levels decreased in dogs lavaged with room-temperature saline. Temperature levels increased significantly in dogs lavaged with heated saline after 2 to 6 minutes of lavage, and temperatures continued to increase throughout the 15-minute lavage period.

Strength and Permeability Evolution of Compressed Bentonite in Response to Salinity and Temperature Changes

NASA Astrophysics Data System (ADS)

Winnard, B. R.; Mitchell, T. M.; Browning, J.; Cuss, R. J.; Norris, S.; Meredith, P. G.

2017-12-01

Deep geological repositories are the preferred solution to dispose of radioactive waste; design concepts for these disposal facilities include compacted, saturated bentonite as a buffer between waste canister and host rock. Bentonite is favoured for its high swelling capacity, low permeability, and radionuclide retention properties. However, its thermo-hydro-mechanical tolerances must be thoroughly tested to ensure adequate long term performance. Climate variations are likely to induce periods of permafrost, and consequently, changes in groundwater salinity at depth. We performed laboratory experiments investigating effects of temperature and salinity change on uniaxial compressive strength (UCS), and permeability of compacted MX-80 bentonite cylinders. These specimens (moisture content = 22.9±0.1%, dry density = 1.66±0.02 g.cm-3) were compacted with deionised water, and a range of wt% NaCl, CaCl2, or KCl, to compare the effects of compaction fluid. Samples of compressed bentonite were cooled to -20 °C, and heated to 90 ºC, a possible temperature forecast for a repository dependent on factors such as geographical location, waste type, and facility design. Tests were all performed at room temperature, however in situ temperature tests are planned. The UCS of samples that experienced freeze thaw, and 40 ºC treatment failed at 6.5 MPa, with 4% strain, maintaining the same values as untreated bentonite compacted with deionised water. Samples compacted with saline solutions also yielded similar strengths, of 7 MPa, and failed at 4%. However, the 90 ºC, regardless of compaction fluid, failed at 15-18 MPa, at just 2% strain. In all experiments, the spread of strain accommodated varied inconsistently, however, peak stress was uniform. Further experiments into heterogeneity are needed to understand the responsible mechanisms. To obtain permeability, we utilised the pore pressure oscillation (PPO) technique with argon as the pore fluid. We also tested water as the pore fluid to assess the contribution of montmorillonite swelling and compare argon and water permeability. There is potential for salinity to markedly affect permeability, as electrolytes can initiate cation-exchange reactions. Permeability and strength are both key parameters to assess the long term safety of a geological disposal facility.

Multimodel inference to quantify the relative importance of abiotic factors in the population dynamics of marine zooplankton

NASA Astrophysics Data System (ADS)

Everaert, Gert; Deschutter, Yana; De Troch, Marleen; Janssen, Colin R.; De Schamphelaere, Karel

2018-05-01

The effect of multiple stressors on marine ecosystems remains poorly understood and most of the knowledge available is related to phytoplankton. To partly address this knowledge gap, we tested if combining multimodel inference with generalized additive modelling could quantify the relative contribution of environmental variables on the population dynamics of a zooplankton species in the Belgian part of the North Sea. Hence, we have quantified the relative contribution of oceanographic variables (e.g. water temperature, salinity, nutrient concentrations, and chlorophyll a concentrations) and anthropogenic chemicals (i.e. polychlorinated biphenyls) to the density of Acartia clausi. We found that models with water temperature and chlorophyll a concentration explained ca. 73% of the population density of the marine copepod. Multimodel inference in combination with regression-based models are a generic way to disentangle and quantify multiple stressor-induced changes in marine ecosystems. Future-oriented simulations of copepod densities suggested increased copepod densities under predicted environmental changes.

Influence of physico-chemical properties on the abundance of a few economically important juvenile fin-fishes of Vellar estuary.

PubMed

Brinda, S; Bragadeeswaran, S

2005-01-01

Studies on the economically important juvenile fin-fishes such as Elops machnata, Chanos chanos, Lates calcarifer, Epinephelus sp., Sillago sihama, Etroplus suratensis, Mugil cephalus, Liza parsia and Liza tade with relation to the hydrographical parameters as rainfall, temperature, salinity, dissolved oxygen and pH of Vellar estuary during September 2001 to August 2002. The simple correlation co-efficient showed positive significance against juvenile density with water temperature and dissolved oxygen. The influence of hydrographical parameters to the fin-fishes and its abundance is discussed.

Monitoring Bloom Dynamics of a Common Coastal Bioluminescent Ctenophore

DTIC Science & Technology

2008-01-01

profound impacts on coastal ecosystems. Although the causes of jellyfish blooms are not well understood, correlations have been made between...changes in jellyfish density and changes in physical factors, such as temperature and salinity, and biological factors, such as prey abundance and...Current sampling methods for jellyfish populations are done with net collections by hand at stations weekly, monthly, or seasonally. These time scales

Assimilation of temperature and salinity profile data in the Norwegian Climate Prediction Model

NASA Astrophysics Data System (ADS)

Wang, Yiguo; Counillon, Francois; Bertino, Laurent; Bethke, Ingo; Keenlyside, Noel

2016-04-01

Assimilating temperature and salinity profile data is promising to constrain the ocean component of Earth system models for the purpose of seasonal-to-dedacal climate predictions. However, assimilating temperature and salinity profiles that are measured in standard depth coordinate (z-coordinate) into isopycnic coordinate ocean models that are discretised by water densities is challenging. Prior studies (Thacker and Esenkov, 2002; Xie and Zhu, 2010) suggested that converting observations to the model coordinate (i.e. innovations in isopycnic coordinate) performs better than interpolating model state to observation coordinate (i.e. innovations in z-coordinate). This problem is revisited here with the Norwegian Climate Prediction Model, which applies the ensemble Kalman filter (EnKF) into the ocean isopycnic model (MICOM) of the Norwegian Earth System Model. We perform Observing System Simulation Experiments (OSSEs) to compare two schemes (the EnKF-z and EnKF-ρ). In OSSEs, the truth is set to the EN4 objective analyses and observations are perturbations of the truth with white noises. Unlike in previous studies, it is found that EnKF-z outperforms EnKF-ρ for different observed vertical resolution, inhomogeneous sampling (e.g. upper 1000 meter observations only), or lack of salinity measurements. That is mostly because the operator converting observations into isopycnic coordinate is strongly non-linear. We also study the horizontal localisation radius at certain arbitrary grid points. Finally, we perform the EnKF-z with the chosen localisation radius in a realistic framework with NorCPM over a 5-year analysis period. The analysis is validated by different independent datasets.

Effects of temperature and salinity on survival rate of cultured corals and photosynthetic efficiency of zooxanthellae in coral tissues

NASA Astrophysics Data System (ADS)

Kuanui, Pataporn; Chavanich, Suchana; Viyakarn, Voranop; Omori, Makoto; Lin, Chiahsin

2015-06-01

This study investigated the effects of temperature and salinity on growth, survival, and photosynthetic efficiency of three coral species, namely, Pocillopora damicornis, Acropora millepora and Platygyra sinensis of different ages (6 and 18 months old). The experimental corals were cultivated via sexual propagation. Colonies were exposed to 5 different temperatures (18, 23, 28, 33, and 38°C) and 5 different salinities (22, 27, 32, 37, and 42 psu). Results showed that temperature significantly affected photosynthetic efficiency (Fv/Fm) (p < 0.05) compared to salinity. The maximum quantum yield of corals decreased ranging from 5% to 100% when these corals were exposed to different temperatures and salinities. Temperature also significantly affected coral growth and survival. However, corals exposed to changes in salinity showed higher survivorship than those exposed to changes in temperature. Results in this study also showed that corals of different ages and of different species did not display the same physiological responses to changes in environmental conditions. Thus, the ability of corals to tolerate salinity and temperature stresses depends on several factors.

The Role of Snow Thickness over Arctic Winter Sea Ice in the Survival and Dispersal of Brine-Derived Microbes

NASA Astrophysics Data System (ADS)

Deming, J. W.; Ewert, M.; Bowman, J. S.

2013-12-01

The brines of polar winter sea ice are inhabited by significant densities of microbes (Bacteria and Archaea) that experience a range of extreme conditions depending on location in, and age of, the ice. Newly formed sea ice in winter expels microbes (and organic exudates) onto the surface of the ice, where they can be wicked into frost flowers or into freshly deposited snow, resulting in populations at the ice-air and air-snow interfaces characterized by even more extreme conditions. The influence of snow thickness over the ice on the fate of these microbes, and their potential for dispersal or mediation of exchanges with other components of the ice-snow system, is not well known. Examination of in situ temperature data from the Mass Balance Observatory (MBO) offshore of Barrow, Alaska, during the winter of 2011 allowed recognition of an hierarchy of fluctuation regimes in temperature and (by calculation) brine salinity, where the most stable conditions were encountered within the sea ice and the least stable highest in the snow cover, where temperature fluctuations were significantly more energetic as determined by an analysis of power spectral density. A prior analysis of snow thickness near the MBO had already revealed significant ablation events, potentially associated with bacterial mortality, that would have exposed the saline (microbe-rich) snow layer to wind-based dispersal. To better understand the survival of marine bacteria under these dynamic and extreme conditions, we conducted laboratory experiments with Arctic bacterial isolates, subjecting them to simulations of the freezing regimes documented at the MBS. The impact of the fluctuation regime was shown to be species-specific, with the organism of narrower temperature and salinity growth ranges suffering 30-50% mortality (which could be partially relieved by providing protection against salt-shock). This isolate, the psychrophilic marine bacterium Colwellia psychrerythraea strain 34H (temperature range of -12 to 18°C, salinity range of 20 to 50), was originally isolated from Arctic marine sediments. The other isolate, the psychrotolerant and extremely halophilic bacterium Psychrobacter sp. strain 7E (temperature range of -1 [possibly lower] to 25°C, salinity range of 32 to 125), not only survived the most extreme conditions but demonstrated a potentially effective dispersal strategy of cell fragmentation and miniaturization (resulting in higher cell numbers). This extremophile was isolated from upper winter sea-ice brine in the Beaufort Sea. Bacterial survival and dispersal from sea-ice brines in Arctic winter thus appears to depend on the nature of the organisms involved and on the thickness of snow cover, which determines how dynamic and extreme are the exposure conditions. The observed species-specific reactions to extreme and fluctuating conditions may help to explain the different structures of microbial communities inhabiting the range of environments defined by the ice-snow system and provide model organisms and research directions for future work to evaluate potential activity or exchanges with other components of the system.

A global algorithm for estimating Absolute Salinity

NASA Astrophysics Data System (ADS)

McDougall, T. J.; Jackett, D. R.; Millero, F. J.; Pawlowicz, R.; Barker, P. M.

2012-12-01

The International Thermodynamic Equation of Seawater - 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density) than does Practical Salinity. When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg-1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p) in the world ocean. To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally).

Development, Testing, and Application of a Coupled Hydrodynamic Surface-Water/Groundwater Model (FTLOADDS) with Heat and Salinity Transport in the Ten Thousand Islands/Picayune Strand Restoration Project Area, Florida

USGS Publications Warehouse

Swain, Eric D.; Decker, Jeremy D.

2009-01-01

A numerical model application was developed for the coastal area inland of the Ten Thousand Islands (TTI) in southwestern Florida using the Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) model. This model couples a two-dimensional dynamic surface-water model with a three-dimensional groundwater model, and has been applied to several locations in southern Florida. The model application solves equations for salt transport in groundwater and surface water, and also simulates surface-water temperature using a newly enhanced heat transport algorithm. One of the purposes of the TTI application is to simulate hydrologic factors that relate to habitat suitability for the West Indian Manatee. Both salinity and temperature have been shown to be important factors for manatee survival. The inland area of the TTI domain is the location of the Picayune Strand Restoration Project, which is designed to restore predevelopment hydrology through the filling and plugging of canals, construction of spreader channels, and the construction of levees and pump stations. The effects of these changes are simulated to determine their effects on manatee habitat. The TTI application utilizes a large amount of input data for both surface-water and groundwater flow simulations. These data include topography, frictional resistance, atmospheric data including rainfall and air temperature, aquifer properties, and boundary conditions for tidal levels, inflows, groundwater heads, and salinities. Calibration was achieved by adjusting the parameters having the largest uncertainty: surface-water inflows, the surface-water transport dispersion coefficient, and evapotranspiration. A sensitivity analysis did not indicate that further parameter changes would yield an overall improvement in simulation results. The agreement between field data from GPS-tracked manatees and TTI application results demonstrates that the model can predict the salinity and temperature fluctuations which affect manatee behavior. Comparison of the existing conditions simulation with the simulation incorporating restoration changes indicated that the restoration would increase the period of inundation for most of the coastal wetlands. Generally, surface-water salinity was lowered by restoration changes in most of the wetlands areas, especially during the early dry season. However, the opposite pattern was observed in the primary canal habitat for manatees, namely, the Port of the Islands. Salinities at this location tended to be moderately elevated during the dry season, and unchanged during the wet season. Water temperatures were in close agreement between the existing conditions and restoration simulations, although minimum temperatures at the Port of the Islands were slightly higher in the restoration simulation as a result of the additional surface-water ponding and warming that occurs in adjacent wetlands. The TTI application output was used to generate salinity and temperature time series for comparison to manatee field tracking data and an individually-based manatee-behavior model. Overlaying field data with salinity and temperature results from the TTI application reflects the effect of warm water availability and the periodic need for low-salinity drinking water on manatee movements. The manatee-behavior model uses the TTI application data at specific model nodes along the main manatee travel corridors to determine manatee migration patterns. The differences between the existing conditions and restoration scenarios can then be compared for manatee refugia. The TTI application can be used to test a variety of hydrologic conditions and their effect on important criteria.

Deep Bering Sea Circulation and Variability, 2001-2016, From Argo Data

NASA Astrophysics Data System (ADS)

Johnson, Gregory C.; Stabeno, Phyllis J.

2017-12-01

The mean structure, seasonal cycle, and interannual variability of temperature and salinity are analyzed in the deep Bering Sea basin using Argo profile data collected from 2001 to 2016. Gyre transports are estimated using geostrophic stream function maps of Argo profile data referenced to a 1,000 dbar nondivergent absolute velocity stream function mapped from Argo parking pressure displacement data. Relatively warm and salty water from the North Pacific enters the basin through the Near Strait and passages between Aleutian Islands to the east. This water then flows in a cyclonic (counterclockwise) direction around the region, cooling (and freshening) along its path. Aleutian North Slope Current transports from 0 to 1,890 dbar are estimated at 3-6 Sverdrups (1 Sv = 106 m3 s-1) eastward, feeding into the northwestward Bering Slope Current with transports of mostly 5-6 Sv. The Kamchatka Current has transports of ˜6 Sv north of Shirshov Ridge, increasing to 14-16 Sv south of the ridge, where it is augmented by westward flow from Near Strait. Temperature exhibits strong interannual variations in the upper ocean, with warm periods in 2004-2005 and 2015-2016, and cold periods around 2009 and 2012. In contrast, upper ocean salinity generally decreases from 2001 to 2016. As a result of this salinity decrease, the density of the subsurface temperature minimum decreased over this time period, despite more interannual variability in the minimum temperature value. The subsurface temperature maximum also exhibits interannual variability, but with values generally warmer than those previously reported for the 1970s and 1980s.

Increased temperatures combined with lowered salinities differentially impact oyster size class growth and mortality

USGS Publications Warehouse

LaPeyre, Megan K.; Rybovich, Molly; Hall, Steven G.; La Peyre, Jerome F.

2016-01-01

Changes in the timing and interaction of seasonal high temperatures and low salinities as predicted by climate change models could dramatically alter oyster population dynamics. Little is known explicitly about how low salinity and high temperature combinations affect spat (<25mm), seed (25–75mm), andmarket (>75mm) oyster growth and mortality. Using field and laboratory studies, this project quantified the combined effects of extremely low salinities (<5) and high temperatures (>30°C) on growth and survival of spat, seed, andmarket-sized oysters. In 2012 and 2013, hatchery-produced oysters were placed in open and closed cages at three sites in Breton Sound, LA, along a salinity gradient that typically ranged from 5 to 20. Growth and mortality were recorded monthly. Regardless of size class, oysters at the lowest salinity site (annualmean = 4.8) experienced significantly highermortality and lower growth than oysters located in higher salinity sites (annual means = 11.1 and 13.0, respectively); furthermore, all oysters in open cages at the two higher salinity sites experienced higher mortality than in closed cages, likely due to predation. To explicitly examine oyster responses to extreme low salinity and high temperature combinations, a series of laboratory studies were conducted. Oysters were placed in 18 tanks in a fully crossed temperature (25°C, 32°C) by salinity (1, 5, and 15) study with three replicates, and repeated at least twice for each oyster size class. Regardless of temperature, seed and market oysters held in low salinity tanks (salinity 1) experienced 100% mortality within 7 days. In contrast, at salinity 5, temperature significantly affected mortality; oysters in all size classes experienced greater than 50%mortality at 32°C and less than 40%mortality at 25°C. At the highest salinity tested (15), only market-sized oysters held at 32°C experienced significant mortality (>60%). These studies demonstrate that high water temperatures (>30°C) and low salinities (<5) negatively impact oyster growth and survival differentially and that high temperatures alone may negatively impact market-sized oysters. It is critical to understand the potential impacts of climate and anthropogenic changes on oyster resources to better adapt and manage for long-term sustainability.

Influence of temperature and conductivity on the life-history characteristics of a pampean strain of Brachionus plicatilis.

PubMed

Ferrando, Noelia S; Claps, María C; Benítez, Hernán H; Gabellone, Néstor A

2018-05-14

In the present work, we provide the first approach about the life-history of Brachionus plicatilis in South America. We tested with laboratory experiments the response of the pampean strain of B. plicatilis for two of its main stressors (conductivity and temperature). We evaluated the effects of eight conductivity values from 1 to 17 mS.cm-1 and two temperatures (15 and 25 °C) to compare its abundance with those obtained in the pampean lotic and lentic environments, where this rotifer is frequent or dominant. The results demonstrated that the increase in population-growth rate and the peak of abundance occurred at the highest temperature and at medium conductivity. Minimum values were obtained at the lowest temperature and conductivities analyzed, but the final density attained was nevertheless similar to those recorded in the pampean environments at the optimum conductivity and during the spring and summer seasons. Males, mictic females, and resting eggs were observed at the minimum and maximum conductivities, revealing the strategy of this species for maintaining dominance in environments with fluctuating salinity. The experiments also indicated the possible behavior of this relevant member of the zooplankton community within a scenario of increasing temperature and salinity related to the climate changes occurring in the pampean region.

Investigation of a fiber optic surface plasmon spectroscopy in conjunction with conductivity as an in situ method for simultaneously monitoring changes in dissolved organic carbon and salinity in coastal waters.

PubMed

Kim, Yoon-Chang; Cramer, Jeffrey A; Booksh, Karl S

2011-10-21

A combination surface plasmon resonance (SPR) and conductivity sensor array was developed and implemented to demonstrate the ability to differentiate among changes in dissolved organic carbon (DOC) and salinity in coastal water. The array is capable of achieving sufficient spatial and temporal data density to better understand the cycling and fate of terrestrial DOC in coastal areas. DOC is the second largest source of bioreactive carbon in the environment and plays a key role in mediating microbial activity and generation of atmospheric CO(2). In the coastal areas, the salinity is also an important property in many applications, such as leak detection for landfill liners, saltwater intrusion to drinking water, marine environment monitoring, and seasonal climate prediction. Conductivity sensors are the industry standard for determining salinity in ocean systems. However, both conductivity and refractive index sensors, such as SPR spectroscopy based sensors, respond to salinity and DOC levels. To demonstrate the capability of the SPR sensor and a conductivity sensor to collect complimentary data useful in discrimination of salinity and DOC in coastal zone water, conductivity, SPR, and temperature data were collected during passage from the Juan de Fuca ridge area returning to the University of Washington docks.

High Temperature and Salinity Enhance Soil Nitrogen Mineralization in a Tidal Freshwater Marsh

PubMed Central

Gao, Haifeng; Bai, Junhong; He, Xinhua; Zhao, Qingqing; Lu, Qiongqiong; Wang, Junjing

2014-01-01

Soil nitrogen (N) mineralization in wetlands is sensitive to various environmental factors. To compare the effects of salinity and temperature on N mineralization, wetland soils from a tidal freshwater marsh locating in the Yellow River Delta was incubated over a 48-d anaerobic incubation period under four salinity concentrations (0, 10, 20 and 35‰) and four temperature levels (10, 20, 30 and 40°C). The results suggested that accumulated ammonium nitrogen (NH4 +-N) increased with increasing incubation time under all salinity concentrations. Higher temperatures and salinities significantly enhanced soil N mineralization except for a short-term (≈10 days) inhibiting effect found under 35‰ salinity. The incubation time, temperature, salinity and their interactions exhibited significant effects on N mineralization (P<0.001) except the interactive effect of salinity and temperature (P>0.05), while temperature exhibited the greatest effect (P<0.001). Meanwhile, N mineralization processes were simulated using both an effective accumulated temperature model and a one-pool model. Both models fit well with the simulation of soil N mineralization process in the coastal freshwater wetlands under a range of 30 to 40°C (R2 = 0.88–0.99, P<0.01). Our results indicated that an enhanced NH4 +-N release with increasing temperature and salinity deriving from the projected global warming could have profound effects on nutrient cycling in coastal wetland ecosystems. PMID:24733366

Use of fiber-optic DTS to investigate physical processes in thermohaline environments

NASA Astrophysics Data System (ADS)

Suarez, F. I.; Sarabia, A.; Silva, C.

2014-12-01

Salt-gradient solar ponds are artificial thermohaline environments that collect and store thermal energy for long time-periods. A solar pond consists of three distinctive zones: the upper convective zone, which is a thin layer of cooler, less salty water; the non-convective zone that has gradients in temperature and salinity; and the lower convective zone, a layer of high salinity brine where temperatures are the highest. The solar radiation that penetrates the upper layers of the pond reaches the lower convective zone and heats the high salinity brine, which does not rise beyond the lower convective zone because the effect of salinity on density is greater than the effect of temperature. The sediments beneath the pond are also heated due to the temperature increase in the lower convective zone, providing an additional volume for energy storage. To study the different physical processes occurring within a solar pond and its surroundings, we deployed a helicoidally wrapped distributed-temperature-sensing (DTS) system in a small-scale solar pond (1-m deep, 2.5-m long and 1.5-m width). In this installation, the pond is surrounded by a sandy soil that serves as an additional energy storage volume. The thermal profile is observed at a spatial sampling resolution of 1.1 cm (spatial resolution of 2.2. cm), a temporal resolution ranging from 15 s to 5 min, and a thermal resolution ranging from 0.05 to 0.5°C. These resolutions allow closing the energy balance and inferring physical processes such as double-diffusive convection, solar radiation absorption, and heat conduction through the sediments or through the non-convective zone. Independent thermal measurements are also being made to evaluate strengths and limitations of DTS systems in thermohaline environments, and to assess different calibration algorithms that have been proposed in the past.

Studies on the Time Course of Salinity and Temperature Adaptation in the Commercial Brown Shrimp Penaeus aztecus Ives.

DTIC Science & Technology

1977-09-01

Effect of temperature background 52 Effect of salinity and temperature change 53 Blood Osmoregulation During the Time Course of Adaptation... Osmoregulators Osmotic concentration Salinity Serum Standard metabolism Weight specific metabolic rate APPENDIX B: Tables I-IX. Mean... Effect of salinity and temperature change on the blood osmoregulation of Penaeus aztecus in relation to the isosmotic line 153 81

The interaction between sea ice and salinity-dominated ocean circulation: implications for halocline stability and rapid changes of sea ice cover

NASA Astrophysics Data System (ADS)

Jensen, Mari F.; Nilsson, Johan; Nisancioglu, Kerim H.

2016-11-01

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. In this study, we develop a simple conceptual model to examine how interactions between sea ice and oceanic heat and freshwater transports affect the stability of an upper-ocean halocline in a semi-enclosed basin. The model represents a sea ice covered and salinity stratified Nordic Seas, and consists of a sea ice component and a two-layer ocean. The sea ice thickness depends on the atmospheric energy fluxes as well as the ocean heat flux. We introduce a thickness-dependent sea ice export. Whether sea ice stabilizes or destabilizes against a freshwater perturbation is shown to depend on the representation of the diapycnal flow. In a system where the diapycnal flow increases with density differences, the sea ice acts as a positive feedback on a freshwater perturbation. If the diapycnal flow decreases with density differences, the sea ice acts as a negative feedback. However, both representations lead to a circulation that breaks down when the freshwater input at the surface is small. As a consequence, we get rapid changes in sea ice. In addition to low freshwater forcing, increasing deep-ocean temperatures promote instability and the disappearance of sea ice. Generally, the unstable state is reached before the vertical density difference disappears, and the temperature of the deep ocean do not need to increase as much as previously thought to provoke abrupt changes in sea ice.

Step-changes in the physical, chemical and biological characteristics of the Gulf of Maine, as documented by the GNATS time series

USGS Publications Warehouse

Balch, William M.; Drapeau, D.T.; Bowler, B.C.; Huntington, Thomas G.

2012-01-01

We identify step-changes in the physical, chemical and biological characteristics of the Gulf of Maine (GoM) using the Gulf of Maine North Atlantic Time Series (GNATS), a series of oceanographic measurements obtained between September 1998 and December 2010 along a transect in the GoM running from Portland, ME, to Yarmouth, NS. GNATS sampled a period of extremes in precipitation and river discharge (4 of the 8 wettest years of the last century occurred between 2005 and 2010). Coincident with increased precipitation, we observed the following shifts: (1) decreased salinity and density within the surface waters of the western GoM; (2) both reduced temperature and vertical temperature gradients in the upper 50 m; (3) increased colored dissolved organic matter (CDOM) concentrations and particle scattering in the western GoM; (4) increased concentrations of nitrate and phosphate across all but the eastern GoM; (5) increased silicate, particularly in the western GoM, with a sharp increase in the ratio of silicate to dissolved inorganic nitrogen; (6) sharply decreased carbon fixation by phytoplankton; (7) moderately decreased chlorophyll, particulate organic carbon (POC) and particulate inorganic carbon (PIC) in the central GoM and (8) decreased POC- and PIC-specific growth rates. Gulf-wide anomaly analyses suggest that (1) the surface density changes were predominantly driven by temperature, (2) dissolved nutrients, as well as POC/PON, varied in Redfield ratios and (3) anomalies for salinity, density, CDOM, particle backscattering and silicate were significantly correlated with river discharge. Precipitation and river discharge appear to be playing a critical role in controlling the long-term productivity of the Gulf of Maine by supplying CDOM and detrital material, which ultimately competes with phytoplankton for light absorption.

Analyzing the propagation behavior of scintillation index and bit error rate of a partially coherent flat-topped laser beam in oceanic turbulence.

PubMed

Yousefi, Masoud; Golmohammady, Shole; Mashal, Ahmad; Kashani, Fatemeh Dabbagh

2015-11-01

In this paper, on the basis of the extended Huygens-Fresnel principle, a semianalytical expression for describing on-axis scintillation index of a partially coherent flat-topped (PCFT) laser beam of weak to moderate oceanic turbulence is derived; consequently, by using the log-normal intensity probability density function, the bit error rate (BER) is evaluated. The effects of source factors (such as wavelength, order of flatness, and beam width) and turbulent ocean parameters (such as Kolmogorov microscale, relative strengths of temperature and salinity fluctuations, rate of dissipation of the mean squared temperature, and rate of dissipation of the turbulent kinetic energy per unit mass of fluid) on propagation behavior of scintillation index, and, hence, on BER, are studied in detail. Results indicate that, in comparison with a Gaussian beam, a PCFT laser beam with a higher order of flatness is found to have lower scintillations. In addition, the scintillation index and BER are most affected when salinity fluctuations in the ocean dominate temperature fluctuations.

3D Dynamics of the Near-Surface Layer of the Ocean in the Presence of Freshwater Influx

NASA Astrophysics Data System (ADS)

Dean, C.; Soloviev, A.

2015-12-01

Freshwater inflow due to convective rains or river runoff produces lenses of freshened water in the near surface layer of the ocean. These lenses are localized in space and typically involve both salinity and temperature anomalies. Due to significant density anomalies, strong pressure gradients develop, which result in lateral spreading of freshwater lenses in a form resembling gravity currents. Gravity currents inherently involve three-dimensional dynamics. The gravity current head can include the Kelvin-Helmholtz billows with vertical density inversions. In this work, we have conducted a series of numerical experiments using computational fluid dynamics tools. These numerical simulations were designed to elucidate the relationship between vertical mixing and horizontal advection of salinity under various environmental conditions and potential impact on the pollution transport including oil spills. The near-surface data from the field experiments in the Gulf of Mexico during the SCOPE experiment were available for validation of numerical simulations. In particular, we observed a freshwater layer within a few-meter depth range and, in some cases, a density inversion at the edge of the freshwater lens, which is consistent with the results of numerical simulations. In conclusion, we discuss applicability of these results to the interpretation of Aquarius and SMOS sea surface salinity satellite measurements. The results of this study indicate that 3D dynamics of the near-surface layer of the ocean are essential in the presence of freshwater inflow.

Heat and salt budgets over the Gulf Stream North Wall during LatMix survey in winter 2012.

NASA Astrophysics Data System (ADS)

Sanchez-Rios, A.; Shearman, R. K.; D'Asaro, E. A.; Lee, C.; Gula, J.; Klymak, J. M.

2016-02-01

As part of the ONR-sponsored LatMix Experiment, ship-based and glider-based observations following a Lagrangian float are used to examine the evolution of temperature, salinity and density along the Gulf Stream north wall in wintertime. Satellite observations during the survey and the in-situ measurements showed the presence of submesoscale (<10 km) features along the front. Models have successfully reproduced similar features, but observations are lacking, particularly at the small scales needed to understand their role in the transport of heat and salt across the front and out of the mixed layer. Calculating the trend in time at each depth and cross-front location we found an increase of heat and salinity in regions where the strongest cross-front gradients of velocity were observed at the mixed layer and around 150m depth, these changes are density compensated and suggest isopycnal mixing and a connection between the mixed layer and subsurface layers. The large Rossby number (Ro>1) calculated for this regions corroborates the possibility of submesoscale dynamics. Using a heat and salinity budget, we show that surface forcing, entrainment from below and advection by the mean flow velocities are not sufficient to explain the observed rate of change of heat and salinity in the mixed layer. Although confidence estimates prevent an accurate flux divergence calculation, Reynold flux estimates are consistent with a cross-frontal exchange that can reproduce the observed temporal trends.

Ecology and Population Dynamics of Juvenile Dungeness Crab in Grays Harbor Estuary and Adjacent Nearshore Waters of the Southern Washington Coast

DTIC Science & Technology

1989-10-01

77 5.1.2 Models of environmental and density- dependent recruitment ................................................ 80 5.2 Other Population...juvenile Dungeness crabs and flatfish ........................................ 17 Figure 1.6. Seasonal change in bottom temperature and bottom salinity ...to 2+ ............. 120 Figure 6.14. Size dependence of relative size increments per molt (expressed as a fraction of premolt size), as obtained from

Structure and Dynamics of the Thermohaline Staircases in the Beaufort Gyre

DTIC Science & Technology

2007-09-01

diffusive layering created by heating a salt gradient from below, after Figure 6 (Kelley 2003) A is the first quasi - stationary interface. B is the...sources Crapper (1975), Turner (1965), and Newell (1984) from Kelley (1990). The solid line is the empirical fit....12 Figure 11. Schematic of Ice...Salinity, Potential Temperature and Density plots show thermohaline xi step characteristics. b) Sound velocity profiles showing the step data

Numerical experiments with a wind- and buoyancy-driven two-and-a-half-layer upper ocean model

NASA Astrophysics Data System (ADS)

Cherniawsky, J. Y.; Yuen, C. W.; Lin, C. A.; Mysak, L. A.

1990-09-01

We describe numerical experiments with a limited domain (15°-67°N, 65° west to east) coarse-resolution two-and-a-half-layer upper ocean model. The model consists of two active variable density layers: a Niiler and Kraus (1977) type mixed layer and a pycnocline layer, which overlays a semipassive deep ocean. The mixed layer is forced with a cosine wind stress and Haney type heat and precipitation-evaporation fluxes, which were derived from zonally averaged climatological (Levitus, 1982) surface temperatures and salinities for the North Atlantic. The second layer is forced from below with (1) Newtonian cooling to climatological temperatures and salinities at the lower boundary, (2) convective adjustment, which occurs whenever the density of the second layer is unstable with respect to climatology, and (3) mass entrainment in areas of strong upwelling, when the deep ocean ventilates through the bottom surface. The sensitivity of this model to changes in its internal (mixed layer) and external (e.g., a Newtonian coupling coefficient) parameters is investigated and compared to the results from a control experiment. We find that the model is not overly sensitive to changes in most of the parameters that were tested, albeit these results may depend to some extent on the choice of the control experiment.

Pumping bottom water to prevent Korean red tide damage caused by Cochlodinium polykrikoides Margalef.

PubMed

Cho, Eun Seob; Moon, Seong Yong; Shu, Young Sang; Hwang, Jae Dong; Youn, Seok Hyun

2015-09-01

Cochlodinium polykrikoides Margalef produces annual massive blooms in Korean coastal waters which cause great damage to aquaculture and fisheries. Although various methods have been developed to remove the red tide of C. polykrikoides, release of yellow loess has been regarded as the most desirable technique for mitigation for over 10 years. Each August, strong irradiation generates water column stratification separating warm surface from colder bottom waters. Water from a distance of 0 (St. 1), 5 (St. 2), 10 (St. 3), and 15 m (St. 4) was pumped by running a pump for 0, 10, 30 and 90 min and characterized water temperature, salinity collected, suspended solids, Chl-a, and phytoplankton including C. polykrikoides. After running for 30 min, was temperature and salinity in surface water was similar to those of bottom water, and water column stratification completely reversed after 90 min. Likewise, suspended solids, Chl-a, and total phytoplankton cell density decreased after 30 min, but C. polykrikoides did not show strong removal because of low cell density during sampling. However, the number of C. polykrikoides was significantly diluted (80%) after 90 min. These results suggested that pumping device was as an environmentally-friendly method convenient to be install in fish cages and effective to remove C. polykrikoides stratified water column conditions.

Pearl Harbor Biological Survey

DTIC Science & Technology

1974-08-30

properties, uses, and driving mechanisms affecting the harbor is given. The methods of obtaining current data, salinity profiles, and temperature... salinities were used for each calibration In order to check the salinity computation mechanism of the Instrument. Temperature calibrations were...Water Temperature Contours for Navy Thermal Discharges 3.2-23 3.2-7. General Layout of Pearl Harbor Showing Mean Monthly Salinity (3L) Variation

Salinity and Temperature Tolerance of the Nemertean Worm Carcinonemertes errans, an Egg Predator of the Dungeness Crab.

PubMed

Dunn, Paul H; Young, Craig M

2015-04-01

Estuaries can be harsh habitats for the marine animals that enter them, but they may also provide these species with sub-saline refuges from their parasites. The nemertean egg predator Carcinonemertes errans is known to occur less frequently and in smaller numbers on its host, the Dungeness crab Metacarcinus magister, when the hosts are found within estuaries. We examined the temperature and salinity tolerances of C. errans to determine if this observed distribution represents a true salinity refuge. We monitored the survival of juvenile and larval worms exposed to ecologically relevant salinities (5-30) and temperatures (8-20 °C) over the course of several days under laboratory conditions. Juvenile worms were unaffected by the experimental temperature levels and exhibited robustness to salinity treatments 25 and 30. However, significant mortality was seen at salinity treatments 20 and below. Larvae were less tolerant than juveniles to lowered salinity and were also somewhat more susceptible to the higher temperatures tested. Given that the Dungeness crab can tolerate forays into mesohaline (salinity 5-18) waters for several days at a time, our findings suggest that salinity gradients play an important role in creating a parasite refuge for this species within the estuaries of the Pacific Northwest. © 2015 Marine Biological Laboratory.

Effects of acute changes in salinity and temperature on routine metabolism and nitrogen excretion in gambusia (Gambusia affinis) and zebrafish (Danio rerio).

PubMed

Uliano, E; Cataldi, M; Carella, F; Migliaccio, O; Iaccarino, D; Agnisola, C

2010-11-01

Acute stress may affect metabolism and nitrogen excretion as part of the adaptive response that allows animals to face adverse environmental changes. In the present paper the acute effects of different salinities and temperatures on routine metabolism, spontaneous activity and excretion of ammonia and urea were studied in two freshwater fish: gambusia, Gambusia affinis and zebrafish, Danio rerio, acclimated to 27 degrees C. The effects on gill morphology were also evaluated. Five salinities (0 per thousand, 10 per thousand, 20 per thousand, 30 per thousand and 35 per thousand) were tested in gambusia, while four salinities were used in zebrafish (0 per thousand, 10 per thousand, 20 per thousand and 25 per thousand). Each salinity acute stress was tested alone or in combination with an acute temperature reduction to 20 degrees C. In gambusia, both salinity and temperature acute stress strongly stimulated urea excretion. Routine oxygen consumption was barely affected by acute salinity or temperature stress, and was reduced by the combined effects of temperature and high salinity. Gills maintained their structural integrity in all stressing conditions; hyperplasia and hypertrophy of mitochondria-rich cells were observed. In zebrafish, temperature and salinity acute changes, both alone and in combination, scarcely affected any parameter tested. The major effect observed was a reduction of nitrogen excretion at 20 degrees C-25 per thousand; under these extreme conditions a significant structural disruption of gills was observed. These results confirm the high tolerance to acute salinity and temperature stress in gambusia, and demonstrate the involvement of urea excretion modulation in the stress response in this species. Copyright 2010 Elsevier Inc. All rights reserved.

Toxicity of antifouling biocides to the intertidal harpacticoid copepod Tigriopus japonicus (Crustacea, Copepoda): effects of temperature and salinity.

PubMed

Kwok, K W H; Leung, K M Y

2005-01-01

Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 x 3 x 4 factorial design (i.e. two temperatures: 25 and 35 degrees C; three salinities: 15.0 per thousand, 34.5 per thousand and 45.0 per thousand; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96 h-LC50s of Cu and TBT were 1024 and 0.149 microg l(-1) respectively (at 25 degrees C; 34.5 per thousand) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using 'concentration' as the covariate and both 'temperature' and 'salinity' as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle.

Hydrodynamic and suspended-solids concentration measurements in Suisun Bay, California, 1995

USGS Publications Warehouse

Cuetara, Jay I.; Burau, Jon R.; Schoellhamer, David H.

2001-01-01

Sea level, current velocity, water temperature, salinity (computed from conductivity and temperature), and suspended-solids data collected in Suisun Bay, California, from May 30, 1995, through October 27, 1995, by the U.S. Geological Survey are documented in this report. Data were collected concurrently at 21 sites. Various parameters were measured at each site. Velocity-profile data were collected at 6 sites, single-point velocity measurements were made at 9 sites, salinity data were collected at 20 sites, and suspended-solids concentrations were measured at 10 sites. Sea-level and velocity data are presented in three forms; harmonic analysis results; time-series plots (sea level, current speed, and current direction versus time); and time-series plots of low-pass-filtered time series. Temperature, salinity, and suspended-solids data are presented as plots of raw and low-pass-filtered time series.The velocity and salinity data presented in this report document a period when the residual current patterns and salt field were transitioning from a freshwater-inflow-dominated condition towards a quasi steady-state summer condition when density-driven circulation and tidal nonlinearities became relatively more important as long-term transport mechanisms. Sacramento-San Joaquin River Delta outflow was high prior to and during this study, so the tidally averaged salinities were abnormally low for this time of year. For example, the tidally averaged salinities varied from 0-12 at Martinez, the western border of Suisun Bay, to a maximum of 2 at Mallard Island, the eastern border of Suisun Bay. Even though salinities increased overall in Suisun Bay during the study period, the near-bed residual currents primarily were directed seaward. Therefore, salinity intrusion through Suisun Bay towards the Delta primarily was accomplished in the absence of the tidally averaged, two-layer flow known as gravitational circulation where, by definition, the net currents are landward at the bed. The Folsom Dam spillway gate failure on July 17, 1995, was analyzed to determine the effect on the hydrodynamics of Suisun Bay. The peak flow of the American River reached roughly 1,000 cubic meters per second as a result of the failure, which is relatively small. This was roughly 15 percent of the approximate 7,000 cubic meters per second tidal flows that occur daily in Suisun Bay and was likely attenuated greatly. Based on analysis of tidally averaged near-bed salinity and depth-averaged currents after the failure, the effect was essentially nonexistent and is indistinguishable from the natural variability.

Elevated temperature enhances normal early embryonic development in the coral Platygyra acuta under low salinity conditions

NASA Astrophysics Data System (ADS)

Chui, Apple Pui Yi; Ang, Put

2015-06-01

To better understand the possible consequences of climate change on reef building scleractinian corals in a marginal environment, laboratory experiments were conducted to examine the interactive effects of changes in salinity and temperature on percent fertilization success and early embryonic development of the coral Platygyra acuta. In the present study, a salinity of 24 psu (ambient 32 psu) reduced fertilization success by 60 %. Normal embryonic development was reduced by >80 % at 26 psu (ambient 33 psu) with 100 % abnormal development at 22 psu under ambient temperature. Elevated temperature (+3 °C) above the ambient spawning temperature did not show any negative effects on fertilization success. However, there was a trend for more abnormal embryos to develop at elevated temperature in the 2 d of the spawning event. The interactive effects between salinity and temperature are statistically significant only on normal embryonic development of P. acuta, but not on its fertilization success. Salinity was revealed to be the main factor affecting both fertilization success and normal embryonic development. Interestingly, the much lower fertilization success (76 %) observed in the second day of spawning (Trial 2) under ambient temperature recovered to 99 % success under elevated (+3 °C) temperature conditions. Moreover, elevated temperature enhanced normal early embryonic development under lowered salinity (26 psu). This antagonistic interactive effect was consistently observed in two successive nights of spawning. Overall, our results indicate that, in terms of its fertilization success and embryonic development, P. acuta is the most tolerant coral species to reduced salinity thus far reported in the literature. Elevated temperature, at least that within the tolerable range of the corals, could apparently alleviate the potential negative effects from salinity stresses. This mitigating role of elevated temperature appears not to have been reported on corals before.

The effects of salinity and temperature shock on Kappaphycus alvarezii seaweed spores release

NASA Astrophysics Data System (ADS)

Harwinda, F. K.; Satyantini, W. H.; Masithah, E. W.

2018-04-01

One of the reproductive aspects of development step that is considered as the solution of this issue is seaweed sporulation technique through which is induced through salinity and temperature shock. This study aims to determine the effect of combination and interaction of salinity and temperature shock on the release of K. alvarezii spores in order to produce superior seeds. This research was conducted using Complete Randomized Design Factorial which consists of nine combinations of treatments and three replications. The used treatment in this study is the combination of different environmental factors such as salinity shock and temperature shock. The data were analyzed using ANOVA (Analysis of Variance) followed by Duncan Multiple Range Test. The results showed that salinity (31 ppt, 33 ppt, and 35 ppt) and temperature (30°C, 32°C, and 34°C). shock affected the osmoregulation system and the release of K. alvarezii spores. The salinity shock and temperature shock had interaction with K. alvarezii spore release on the sixth and seventh day with the best treatment at 32°C temperature and 31 ppt salinity and released 5413 cells/ml spores on the seventh day.

Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

USGS Publications Warehouse

Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

2017-01-01

The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

Impact of Variable-Density Flow on the Value-of-Information from Pressure and Concentration Data for Saline Aquifer Characterization

NASA Astrophysics Data System (ADS)

Yoon, S.; Williams, J. R.; Juanes, R.; Kang, P. K.

2017-12-01

Managed aquifer recharge (MAR) is becoming an important solution for ensuring sustainable water resources and mitigating saline water intrusion in coastal aquifers. Accurate estimates of hydrogeological parameters in subsurface flow and solute transport models are critical for making predictions and managing aquifer systems. In the presence of a density difference between the injected freshwater and ambient saline groundwater, the pressure field is coupled to the spatial distribution of salinity distribution, and therefore experiences transient changes. The variable-density effects can be quantified by a mixed convection ratio between two characteristic types of convection: free convection due to density contrast, and forced convection due to a hydraulic gradient. We analyze the variable-density effects on the value-of-information of pressure and concentration data for saline aquifer characterization. An ensemble Kalman filter is used to estimate permeability fields by assimilating the data, and the performance of the estimation is analyzed in terms of the accuracy and the uncertainty of estimated permeability fields and the predictability of arrival times of breakthrough curves in a realistic push-pull setting. This study demonstrates that: 1. Injecting fluids with the velocity that balances the two characteristic convections maximizes the value of data for saline aquifer characterization; 2. The variable-density effects on the value of data for the inverse estimation decrease as the permeability heterogeneity increases; 3. The advantage of joint inversion of pressure and concentration data decreases as the coupling effects between flow and transport increase.

Measurements of the dielectric properties of sea water at 1.43 GHz

NASA Technical Reports Server (NTRS)

Ho, W. W.; Love, A. W.; Vanmelle, M. J.

1974-01-01

Salinity and temperature of water surfaces of estuaries and bay regions are determined to accuracies of 1 ppt salinity and 0.3 kelvin surface temperature. L-band and S-band radiometers are used in combination as brightness temperature detectors. The determination of the brightness temperature versus salinity, with the water surface temperature as a parameter for 1.4 GHz, is performed with a capillary tube inserted into a resonance cavity. Detailed analysis of the results indicates that the measured values are accurate to better than 0.2 percent in the electric property epsilon' and 0.4 percent in epsilon''. The calculated brightness temperature as a function of temperature and salinity is better than 0.2 kelvin. Thus it is possible to reduce the measured data obtained with the two-frequency radiometer system with 1 ppt accuracy to values in the salinity range 5 to 40 ppt.

Effects of Seawater Salinity and Temperature on Growth and Pigment Contents in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta)

PubMed Central

Ding, Lanping; Ma, Yuanyuan; Huang, Bingxin; Chen, Shanwen

2013-01-01

This study simulated outdoor environmental living conditions and observed the growth rates and changes of several photosynthetic pigments (Chl a, Car, PE, and PC) in Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta) by setting up different ranges of salinity (25, 30, 35, 40, 45, and 50) and temperature (15, 20, 25, and 30°C). At conditions of culture, the results are as follows. (1) Changes in salinity and temperature have significant effects on the growth of H. cervicornis. The growth rates first increase then decrease as the temperature increases, while growth tends to decline as salinity increases. The optimum salinity and temperature conditions for growth are 25 and 25°C, respectively. (2) Salinity and temperature have significant or extremely significant effects on photosynthetic pigments (Chl a, Car, PE, and PC) in H. cervicornis. The results of this study are advantageous to ensure propagation and economic development of this species in the southern sea area of China. PMID:24350276

A microstructural study of the degradation and calcium release from hydroxyapatite-calcium oxide ceramics made by infiltration.

PubMed

Zhang, Qinghao; Schmelzer, Eva; Gerlach, Jörg C; Nettleship, Ian

2017-04-01

Hydroxyapatite pellets, partially densified in a low-temperature heat treatment, were infiltrated with calcium nitrate solution followed by in-situ precipitation of Ca(OH) 2 and CaCO 3 . The infiltrated bodies were then densified to high relative density and the calcium carbonate transformed to calcium oxide during sintering and resulted in biphasic hydroxyapatite-CaO ceramics. This work investigated the influence of the infiltration on surface morphology, weight change, and microstructural-level degradation caused by exposure to saline at pH=7.4 and a temperature of 20°C. The CaO rendered the materials more susceptible to degradation, and released calcium into the saline faster than single phase, calcium deficient hydroxyapatite (HA) that were used as a control. In consequence, these ceramics could be used to release calcium into the culture microenvironments of bone tissue or bone marrow cells next to a scaffold surface. Copyright © 2016 Elsevier B.V. All rights reserved.

Global warming-induced upper-ocean freshening and the intensification of super typhoons

PubMed Central

Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby; Emanuel, Kerry A.

2016-01-01

Super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards globally. The violent winds of these storms induce deep mixing of the upper ocean, resulting in strong sea surface cooling and making STYs highly sensitive to ocean density stratification. Although a few studies examined the potential impacts of changes in ocean thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper ocean, caused by greater rainfall in places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper ocean. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ∼53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of ocean temperature changes. PMID:27886199

Global warming-induced upper-ocean freshening and the intensification of super typhoons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby

Here, super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards globally. The violent winds of these storms induce deep mixing of the upper ocean, resulting in strong sea surface cooling and making STYs highly sensitive to ocean density stratification. Although a few studies examined the potential impacts of changes in ocean thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper ocean, caused by greater rainfall inmore » places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper ocean. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ~53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of ocean temperature changes.« less

Global warming-induced upper-ocean freshening and the intensification of super typhoons.

PubMed

Balaguru, Karthik; Foltz, Gregory R; Leung, L Ruby; Emanuel, Kerry A

2016-11-25

Super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards globally. The violent winds of these storms induce deep mixing of the upper ocean, resulting in strong sea surface cooling and making STYs highly sensitive to ocean density stratification. Although a few studies examined the potential impacts of changes in ocean thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper ocean, caused by greater rainfall in places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper ocean. We further demonstrate that the strengthening effect of this freshening over the period 1961-2008 is ∼53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of ocean temperature changes.

Global warming-induced upper-ocean freshening and the intensification of super typhoons

DOE PAGES

Balaguru, Karthik; Foltz, Gregory R.; Leung, L. Ruby; ...

2016-11-25

Here, super typhoons (STYs), intense tropical cyclones of the western North Pacific, rank among the most destructive natural hazards globally. The violent winds of these storms induce deep mixing of the upper ocean, resulting in strong sea surface cooling and making STYs highly sensitive to ocean density stratification. Although a few studies examined the potential impacts of changes in ocean thermal structure on future tropical cyclones, they did not take into account changes in near-surface salinity. Here, using a combination of observations and coupled climate model simulations, we show that freshening of the upper ocean, caused by greater rainfall inmore » places where typhoons form, tends to intensify STYs by reducing their ability to cool the upper ocean. We further demonstrate that the strengthening effect of this freshening over the period 1961–2008 is ~53% stronger than the suppressive effect of temperature, whereas under twenty-first century projections, the positive effect of salinity is about half of the negative effect of ocean temperature changes.« less

Effect of temperature and salinity on phosphate sorption on marine sediments.

PubMed

Zhang, Jia-Zhong; Huang, Xiao-Lan

2011-08-15

Our previous studies on the phosphate sorption on sediments in Florida Bay at 25 °C in salinity 36 seawater revealed that the sorption capacity varies considerably within the bay but can be attributed to the content of sedimentary P and Fe. It is known that both temperature and salinity influence the sorption process and their natural variations are the greatest in estuaries. To provide useful sorption parameters for modeling phosphate cycle in Florida Bay, a systematic study was carried out to quantify the effects of salinity and temperature on phosphate sorption on sediments. For a given sample, the zero equilibrium phosphate concentration and the distribution coefficient were measured over a range of salinity (2-72) and temperature (15-35 °C) conditions. Such a suite of experiments with combinations of different temperature and salinity were performed for 14 selected stations that cover a range of sediment characteristics and geographic locations of the bay. Phosphate sorption was found to increase with increasing temperature or decreasing salinity and their effects depended upon sediment's exchangeable P content. This study provided the first estimate of the phosphate sorption parameters as a function of salinity and temperature in marine sediments. Incorporation of these parameters in water quality models will enable them to predict the effect of increasing freshwater input, as proposed by the Comprehensive Everglades Restoration Plan, on the seasonal cycle of phosphate in Florida Bay.

Survival, growth and reproduction of non-indigenous Nile tilapia, Oreochromis niloticus (Linnaeus 1758). I. Physiological capabilities in various temperatures and salinities

USGS Publications Warehouse

Schofield, Pamela J.; Peterson, Mark S.; Lowe, Michael R.; Brown-Peterson, Nancy J.; Slack, William T.

2011-01-01

The physiological tolerances of non-native fishes is an integral component of assessing potential invasive risk. Salinity and temperature are environmental variables that limit the spread of many non-native fishes. We hypothesised that combinations of temperature and salinity will interact to affect survival, growth, and reproduction of Nile tilapia, Oreochromis niloticus, introduced into Mississippi, USA. Tilapia withstood acute transfer from fresh water up to a salinity of 20 and survived gradual transfer up to 60 at typical summertime (30°C) temperatures. However, cold temperature (14°C) reduced survival of fish in saline waters ≥10 and increased the incidence of disease in freshwater controls. Although fish were able to equilibrate to saline waters in warm temperatures, reproductive parameters were reduced at salinities ≥30. These integrated responses suggest that Nile tilapia can invade coastal areas beyond their point of introduction. However, successful invasion is subject to two caveats: (1) wintertime survival depends on finding thermal refugia, and (2) reproduction is hampered in regions where salinities are ≥30. These data are vital to predicting the invasion of non-native fishes into coastal watersheds. This is particularly important given the predicted changes in coastal landscapes due to global climate change and sea-level rise.

Interpretation of time series (salinity and temperature) layers in North Atlantic from 1950 to 2011

NASA Astrophysics Data System (ADS)

Rubchenia, A.; Popov, A.; Fedorova, A.; Lebedev, N.

2012-04-01

On the basis of long period data series (1950-2011) form various sources (National Oceanographic Data Center (NOAD) (www.nodc.noaa.gov), WOD09 database and data from ARGO project) 10 boxes in North Atlantic were selected. Location of boxes was determined by circulation pattern in North Atlantic and Euro-Arctic Seas. For further analysis two "seasons" was selected: "cold season" (October-May) and "warm season" (June-September). Data verification was made. Analysis of data series clearly show the "Great Salinity Anomaly" (so-called GSA) in 1960-70th, 1980th and 1990th. Trends of salinity and temperature data series were calculated. Spectral analysis allow us to calculate periodicity from 2 to 22 years. Boxes situated in regions with Arctic waters have singularity showed through domination of high frequency oscillation during propagation to South. In Fram Strait salinity fluctuates with periods 9..11 and 20 years, the same period was calculated using temperature data series. In Denmark Strait there are oscillations of temperature with specific period from 4 to 7 years. Range of variability vary. For salinity it is 0.4..4.6 psu, for temperature it is 0.04..5.5C. In salinity data series from boxes with surface Arctic waters noticed clear minimums connected with GSAs. Trends in Denmark Strait and Fram strait in the end of 2000th are negative at different levels. Since 1975 to 2001 salinity near the southern part of Greenland was increased, since 2001 - decreased. But temperature was raised from 0.04 in 1989 to 5.59 in 2010. Thermohaline characteristics of water masses which has Atlantic origin oscillated with period near 20 years. Salinity near Newfoundland was decreased since 2005. In Farrero-Shetland straits salinity trend is positive since at 100m level, Salinity rising from 1970th to 2006 is about 0.3 psu were noticed. Oscillations with period 2..4 years is weak. But at 800m layer salinity oscillations are different, since 1990 there is not significant oscillations at all. Temperature trend at this level is negative since 1950th. Salinity at 100-300 level at Station M area described with negative trend since 1960 to 1993, in both "seasons". Next, up to 2010 salinity is increasing, but in 2011 salinity dramatically decreased. Main oscillations have periods 2..3 years, 4..5 years and 20 years. At 800m level oscillations are very weak. Temperature is increased since 1995 in surface layer and since 2002 in deeper levels. At all levels temperature dramatically decreased after 2010. In central part of Greenland Sea ("Cupola area") dominated oscillations with period 4 years (1950-60th), 5..7 years (1970th) and 9 years (after 1979). In "cold season" oscillation with 11 years traced. Salinity trend is positive at all levels during last 10-15 years. Salinity and temperature were increased at 800m level up to 2006. It could lead to termination of deep water formation. Since 2006 temperature decreased, especially in "cold season". Salinity trend in West Spitsbergen Current is positive since 1996 at surface and sine 1978 at deeper levels. Temperature was increased since 1965 to 2006 in surface layer, but since 2006 in "warm season" temperature is decreasing at all layers. Main oscillations is 4..5 years, 6..7 years and 9..11 years.

Distribution of hydro-biological parameters in coastal waters off Rushikulya Estuary, East Coast of India: a premonsoon case study.

PubMed

Baliarsingh, S K; Srichandan, S; Naik, S; Sahu, K C; Lotliker, Aneesh A; Kumar, T S

2013-08-15

The hydro-biological parameters of coastal waters off Rushikulya estuary was investigated during premonsoon 2011. Important hydro-biological parameters such as water temperature, salinity, pH, DO, NO2, NO3, NH4, PO4, SiO4, TSM, Chl-a, phytoplankton and zooplankton were measured during the present study. Temperature established a strong positive correlation with salinity and pH during the present study. Chl-a found in positive relation with NO3, SiO, and TSM. Analysis of variance revealed significant monthly variation in pH, salinity and TSM. Significant station wise variation was observed in DO and most of the nutrients i.e., NO3, NH4, PO4, SiO4. A total of 119 species of phytoplankton were identified of which 84 species are of diatoms, 22 species of dinoflagellates, 7 species of green algae, 5 species of cyanobacteria (blue green algae) and 1 species of cocolithophore. Phytoplankton abundance varied between 25543 (Nos. L(-1)) and 36309 (Nos. L(-1)). Diatoms dominated the phytoplankton community followed by dinoflagellates in all the months. Diatoms contributed to 82-89% of the total phytoplankton population density whereas dinoflagellates contributed to 6-12%. The regression between Chl-a and phytoplankton abundance resulted with weak relation (R(2) = 0.042). Zooplankton fauna composed of 134 species of holoplankton and 20 types of meroplankton were encountered during the study period. Zooplankton population dominated by copepod during all months and accounted for 74 to 85% to the total zooplankton. The population density ranged from 6959 to 35869 Nos./10 m(3). Analysis of variance explained no significant variation in total zooplankton abundance and also for different groups of zooplankton.

Value of Bulk Heat Flux Parameterizations for Ocean SST Prediction

DTIC Science & Technology

2008-03-01

Generalized Digital Environmental Model ( GDEM ) climatology (NAVO- CEANO, 2003). The density difference values were chosen so that the layers tend to...Monthly mean temperature and salinity from the GDEM climatology in August are used to initialize the model. There is a relaxation to monthly mean SSS...and European Remote Sensing Satellite (ERS) data are used in ERA-40. The SST/Ice data set produced by the Hadley Centre and National Oceanic and

Value of Bulk Heat Flux Parameterizations for Ocean SST Prediction

DTIC Science & Technology

2008-01-01

Digital Environmental Model ( GDEM ) climatology (NAVO- CEANO, 2003). The density difference values were chosen so that the layers tend to become...Monthly mean temperature and salinity from the GDEM climatology in August are used to initialize the model. There is a relaxation to monthly mean...retrievals were used. In addition. Special Sensor Microwave Imager (SSM/1) and European Remote Sensing Satellite (ERS) data are used in ERA-40. The SST/Ice

Variability of Total and Pathogenic Vibrio parahaemolyticus Densities in Northern Gulf of Mexico Water and Oysters▿

PubMed Central

Zimmerman, A. M.; DePaola, A.; Bowers, J. C.; Krantz, J. A.; Nordstrom, J. L.; Johnson, C. N.; Grimes, D. J.

2007-01-01

Vibrio parahaemolyticus is indigenous to coastal environments and a frequent cause of seafood-borne gastroenteritis in the United States, primarily due to raw-oyster consumption. Previous seasonal-cycle studies of V. parahaemolyticus have identified water temperature as the strongest environmental predictor. Salinity has also been identified, although it is evident that its effect on annual variation is not as pronounced. The effects of other environmental factors, both with respect to the seasonal cycle and intraseasonal variation, are uncertain. This study investigated intraseasonal variations of densities of total and pathogenic V. parahaemolyticus organisms in oysters and overlying waters during the summer of 2004 at two sites in the northern Gulf of Mexico. Regression analyses indicated significant associations (P < 0.001) between total V. parahaemolyticus densities and salinity, as well as turbidity in water and in oysters at the Mississippi site but not at the Alabama site. Pathogenic V. parahaemolyticus organisms in Mississippi oyster and water samples were detected in 56% (9 out of 16) and 78% (43 out of 55) of samples, respectively. In contrast, 44% (7 out of 16) of oyster samples and 30% (14 out of 47) of water samples from Alabama were positive. At both sites, there was greater sample-to-sample variability in pathogenic V. parahaemolyticus densities than in total V. parahaemolyticus densities. These data suggest that, although total V. parahaemolyticus densities may be very informative, there is greater uncertainty when total V. parahaemolyticus densities are used to predict the risk of infection by pathogenic V. parahaemolyticus than previously recognized. PMID:17921270

Variability of total and pathogenic Vibrio parahaemolyticus densities in northern Gulf of Mexico water and oysters.

PubMed

Zimmerman, A M; DePaola, A; Bowers, J C; Krantz, J A; Nordstrom, J L; Johnson, C N; Grimes, D J

2007-12-01

Vibrio parahaemolyticus is indigenous to coastal environments and a frequent cause of seafood-borne gastroenteritis in the United States, primarily due to raw-oyster consumption. Previous seasonal-cycle studies of V. parahaemolyticus have identified water temperature as the strongest environmental predictor. Salinity has also been identified, although it is evident that its effect on annual variation is not as pronounced. The effects of other environmental factors, both with respect to the seasonal cycle and intraseasonal variation, are uncertain. This study investigated intraseasonal variations of densities of total and pathogenic V. parahaemolyticus organisms in oysters and overlying waters during the summer of 2004 at two sites in the northern Gulf of Mexico. Regression analyses indicated significant associations (P < 0.001) between total V. parahaemolyticus densities and salinity, as well as turbidity in water and in oysters at the Mississippi site but not at the Alabama site. Pathogenic V. parahaemolyticus organisms in Mississippi oyster and water samples were detected in 56% (9 out of 16) and 78% (43 out of 55) of samples, respectively. In contrast, 44% (7 out of 16) of oyster samples and 30% (14 out of 47) of water samples from Alabama were positive. At both sites, there was greater sample-to-sample variability in pathogenic V. parahaemolyticus densities than in total V. parahaemolyticus densities. These data suggest that, although total V. parahaemolyticus densities may be very informative, there is greater uncertainty when total V. parahaemolyticus densities are used to predict the risk of infection by pathogenic V. parahaemolyticus than previously recognized.

Effects of hydrologic connectivity on aquatic macroinvertebrate assemblages in different marsh types

USGS Publications Warehouse

Kang, Sung-Ryong; King, Sammy L.

2013-01-01

Hydrologic connectivity can be an important driver of aquatic macroinvertebrate assemblages. Its effects on aquatic macroinvertebrate assemblages in coastal marshes, however, are relatively poorly studied. We evaluated the effects of lateral hydrologic connectivity (permanently connected ponds: PCPs; temporary connected ponds: TCPs), and other environmental variables on aquatic macroinvertebrate assemblages and functional feeding groups (FFGs) in freshwater, brackish, and saline marshes in Louisiana, USA. We hypothesized that (1) aquatic macroinvertebrate assemblages in PCPs would have higher assemblage metric values (density, biomass, Shannon-Wiener diversity) than TCPs and (2) the density and proportional abundance of certain FFGs (i.e. scrapers, shredders, and collectors) would be greater in freshwater marsh than brackish and saline marshes. The data in our study only partially supported our first hypothesis: while freshwater marsh PCPs had higher density and biomass than TCPs, assemblage metric values in saline TCPs were greater than saline PCPs. In freshwater TCPs, long duration of isolation limited access of macroinvertebrates from adjacent water bodies, which may have reduced assemblage metric values. However, the relatively short duration of isolation in saline TCPs provided more stable or similar habitat conditions, facilitating higher assemblage metric values. As predicted by our second hypothesis, freshwater PCPs and TCPs supported a greater density of scrapers, shredders, and collectors than brackish and saline ponds. Aquatic macroinvertebrate assemblages seem to be structured by individual taxa responses to salinity as well as pond habitat attributes.

Salinity effect on the maximal growth temperature of some bacteria isolated from marine enviroments.

PubMed

Stanley, S O; Morita, R Y

1968-01-01

Salinity of the growth medium was found to have a marked effect on the maximal growth temperature of four bacteria isolated from marine sources. Vibrio marinus MP-1 had a maximal growth temperature of 21.2 C at a salinity of 35% and a maximal growth temperature of 10.5 C at a salinity of 7%, the lowest salinity at which it would grow. This effect was shown to be due to the presence of various cations in the medium. The order of effectiveness of cations in restoring the normal maximal growth temperature, when added to dilute seawater, was Na(+) > Li(+) > Mg(++) > K(+) > Rb(+) > NH(4) (+). The anions tested, with the exception of SO(4)=, had no marked effect on the maximal growth temperature response. In a completely defined medium, the highest maximal growth temperature was 20.0 C at 0.40 m NaCl. A decrease in the maximal growth temperature was observed at both low and high concentrations of NaCl.

Sea-surface temperature and salinity mapping from remote microwave radiometric measurements of brightness temperature

NASA Technical Reports Server (NTRS)

Hans-Juergen, C. B.; Kendall, B. M.; Fedors, J. C.

1977-01-01

A technique to measure remotely sea surface temperature and salinity was demonstrated with a dual frequency microwave radiometer system. Accuracies in temperature of 1 C and in salinity of part thousand for salinity greater than 5 parts per thousand were attained after correcting for the influence of extraterrestrial background radiation, atmospheric radiation and attenuation, sea-surface roughness, and antenna beamwidth. The radiometers, operating at 1.43 and 2.65 GHz, comprise a third-generation system using null balancing and feedback noise injection. Flight measurements from an aircraft at an altitude of 1.4 km over the lower Chesapeake Bay and coastal areas of the Atlantic Ocean resulted in contour maps of sea-surface temperature and salinity with a spatial resolution of 0.5 km.

Flow convergence caused by a salinity minimum in a tidal channel

USGS Publications Warehouse

Warner, John C.; Schoellhamer, David H.; Burau, Jon R.; Schladow, S. Geoffrey

2006-01-01

Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of tidal channels can create a local reversal (change in sign) of the density gradient. This can occur due to a difference in the phase of tidal currents in each channel. In San Francisco Bay, the phasing of the currents at the junction of Mare Island Strait and Carquinez Strait produces a local salinity minimum in Mare Island Strait. At the location of a local salinity minimum the longitudinal density gradient reverses direction. This paper presents four numerical models that were used to investigate the circulation caused by the salinity minimum: (1) A simple one-dimensional (1D) finite difference model demonstrates that a local salinity minimum is advected into Mare Island Strait from the junction with Carquinez Strait during flood tide. (2) A three-dimensional (3D) hydrodynamic finite element model is used to compute the tidally averaged circulation in a channel that contains a salinity minimum (a change in the sign of the longitudinal density gradient) and compares that to a channel that contains a longitudinal density gradient in a constant direction. The tidally averaged circulation produced by the salinity minimum is characterized by converging flow at the bed and diverging flow at the surface, whereas the circulation produced by the constant direction gradient is characterized by converging flow at the bed and downstream surface currents. These velocity fields are used to drive both a particle tracking and a sediment transport model. (3) A particle tracking model demonstrates a 30 percent increase in the residence time of neutrally buoyant particles transported through the salinity minimum, as compared to transport through a constant direction density gradient. (4) A sediment transport model demonstrates increased deposition at the near-bed null point of the salinity minimum, as compared to the constant direction gradient null point. These results are corroborated by historically noted large sedimentation rates and a local maximum of selenium accumulation in clams at the null point in Mare Island Strait.

Correlation between environmental factors and prevalence of Vibrio parahaemolyticus in oysters harvested in the southern coastal area of Sao Paulo State, Brazil.

PubMed

Sobrinho, Paulo de Souza Costa; Destro, Maria T; Franco, Bernadette D G M; Landgraf, Mariza

2010-02-01

The presence of Vibrio parahaemolyticus in 123 oyster samples collected from an estuary on the southern coast of Sao Paulo state, Brazil, was investigated. Of the 123 samples, 99.2% were positive with densities ranging from < 3 to 10(5) most probable number (MPN)/g. Densities correlated significantly with water temperature (r = 0.48; P < 0.001) but not with salinity (r = -0.09; P = 0.34). The effect of harvest site on counts was not significant (P > 0.05). These data provide information for the assessment of exposure of V. parahaemolyticus in oysters at harvest.

Last Glacial Maximum Salinity Reconstruction

NASA Astrophysics Data System (ADS)

Homola, K.; Spivack, A. J.

2016-12-01

It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were determined experimentally. We compare the high precision salinity profiles determined using our new method to profiles determined from the traditional chloride titrations of parallel samples. Our technique provides a more accurate reconstruction of past salinity, informing questions of water mass composition and distribution during the LGM.

Spatial variability of the Arctic Ocean's double-diffusive staircase

NASA Astrophysics Data System (ADS)

Shibley, N. C.; Timmermans, M.-L.; Carpenter, J. R.; Toole, J. M.

2017-02-01

The Arctic Ocean thermohaline stratification frequently exhibits a staircase structure overlying the Atlantic Water Layer that can be attributed to the diffusive form of double-diffusive convection. The staircase consists of multiple layers of O(1) m in thickness separated by sharp interfaces, across which temperature and salinity change abruptly. Through a detailed analysis of Ice-Tethered Profiler measurements from 2004 to 2013, the double-diffusive staircase structure is characterized across the entire Arctic Ocean. We demonstrate how the large-scale Arctic Ocean circulation influences the small-scale staircase properties. These staircase properties (layer thicknesses and temperature and salinity jumps across interfaces) are examined in relation to a bulk vertical density ratio spanning the staircase stratification. We show that the Lomonosov Ridge serves as an approximate boundary between regions of low density ratio (approximately 3-4) on the Eurasian side and higher density ratio (approximately 6-7) on the Canadian side. We find that the Eurasian Basin staircase is characterized by fewer, thinner layers than that in the Canadian Basin, although the margins of all basins are characterized by relatively thin layers and the absence of a well-defined staircase. A double-diffusive 4/3 flux law parametrization is used to estimate vertical heat fluxes in the Canadian Basin to be O(0.1) W m-2. It is shown that the 4/3 flux law may not be an appropriate representation of heat fluxes through the Eurasian Basin staircase. Here molecular heat fluxes are estimated to be between O(0.01) and O(0.1) W m-2. However, many uncertainties remain about the exact nature of these fluxes.

The interplay of evolved seawater and magmatic-hydrothermal fluids in the 3.24 Ga panorama volcanic-hosted massive sulfide hydrothermal system, North Pilbara Craton, Western Australia

USGS Publications Warehouse

Drieberg, Susan L.; Hagemann, Steffen G.; Huston, David L.; Landis, Gary; Ryan, Chris G.; Van Achterbergh, Esmé; Vennemann, Torsten

2013-01-01

The ~3240 Ma Panorama volcanic-hosted massive sulfide (VHMS) district is unusual for its high degree of exposure and low degree of postdepositional modification. In addition to typical seafloor VHMS deposits, this district contains greisen- and vein-hosted Mo-Cu-Zn-Sn mineral occurrences that are contemporaneous with VHMS orebodies and are hosted by the Strelley granite complex, which also drove VHMS circulation. Hence the Panorama district is a natural laboratory to investigate the role of magmatic-hydrothermal fluids in VHMS hydrothermal systems. Regional and proximal high-temperature alteration zones in volcanic rocks underlying the VHMS deposits are dominated by chlorite-quartz ± albite assemblages, with lesser low-temperature sericite-quartz ± K-feldspar assemblages. These assemblages are typical of VHMS hydrothermal systems. In contrast, the alteration assemblages associated with granite-hosted greisens and veins include quartz-topaz-muscovite-fluorite and quartz-muscovite (sericite)-chlorite-ankerite. These vein systems generally do not extend into the overlying volcanic pile. Fluid inclusion and stable isotope studies suggest that the greisens were produced by high-temperature (~590°C), high-salinity (38–56 wt % NaCl equiv) fluids with high densities (>1.3 g/cm3) and high δ18O (9.3 ± 0.6‰). These fluids are compatible with the measured characteristics of magmatic fluids evolved from the Strelley granite complex. In contrast, fluids in the volcanic pile (including the VHMS ore-forming fluids) were of lower temperature (90°–270°C), lower salinity (5.0–11.2 wt % NaCl equiv), with lower densities (0.88–1.01 g/cm3) and lower δ18O (−0.8 ± 2.6‰). These fluids are compatible with evolved Paleoarchean seawater. Fluids that formed the quartz-chalcopyrite-sphalerite-cassiterite veins, which are present within the granite complex near the contact with the volcanic pile, were intermediate in temperature and isotopic composition between the greisen and volcanic pile fluids (T = 240°–315°C; δ18O = 4.3 ± 1.5‰) and are interpreted to indicate mixing between the two end-member fluids. Evidence of mixing between evolved seawater and magmatic-hydrothermal fluid within the granite complex, together with the lack of evidence for a magmatic component in fluids from the volcanic pile, suggest partitioning of magmatic-hydrothermal from evolved seawater hydrothermal systems in the Panorama VHMS system. This separation is interpreted to result from either the swamping of a relatively small magmatic-hydro-thermal system by evolved seawater or density contrasts precluding movement of magmatic-hydrothermal fluids into the volcanic pile. Variability in the salinity of fluids in the volcanic pile, combined with evidence for mixing of low- and high-salinity fluids in the massive sulfide lens, is interpreted to indicate that phase separation occurred within the Panorama hydrothermal system. Although we consider this phase separation to have most likely occurred at depth within the system, as has been documented in modern VHMS systems, the data do not allow the location of the inferred phase separation to be determined.

Maximizing the value of pressure data in saline aquifer characterization

NASA Astrophysics Data System (ADS)

Yoon, Seonkyoo; Williams, John R.; Juanes, Ruben; Kang, Peter K.

2017-11-01

The injection and storage of freshwater in saline aquifers for the purpose of managed aquifer recharge is an important technology that can help ensure sustainable water resources. As a result of the density difference between the injected freshwater and ambient saline groundwater, the pressure field is coupled to the spatial salinity distribution, and therefore experiences transient changes. The effect of variable density can be quantified by the mixed convection ratio, which is a ratio between the strength of two convection processes: free convection due to the density differences and forced convection due to hydraulic gradients. We combine a density-dependent flow and transport simulator with an ensemble Kalman filter (EnKF) to analyze the effects of freshwater injection rates on the value-of-information of transient pressure data for saline aquifer characterization. The EnKF is applied to sequentially estimate heterogeneous aquifer permeability fields using real-time pressure data. The performance of the permeability estimation is analyzed in terms of the accuracy and the uncertainty of the estimated permeability fields as well as the predictability of breakthrough curve arrival times in a realistic push-pull setting. This study demonstrates that injecting fluids at a rate that balances the two characteristic convections can maximize the value of pressure data for saline aquifer characterization.

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest) Crangonid Shrimp

DTIC Science & Technology

1989-12-01

temperature affected survival at different shelter has been suggested as an important salinities and salinity affected survival at mechanism of nutrient...10 Salinity . . . . .. . . . . .. . . . .. . .. . .. . .. .. . .. .. .. .. . .. . . .. . .. . . . . .. . . . 11 Temperature- Salinity ...members of the tribe Caridca by four features Order .................... Decapoda (Figure 3); (1)-the rostrum is very short, Suborder

Oscillating Adriatic temperature and salinity regimes mapped using the Self-Organizing Maps method

NASA Astrophysics Data System (ADS)

Matić, Frano; Kovač, Žarko; Vilibić, Ivica; Mihanović, Hrvoje; Morović, Mira; Grbec, Branka; Leder, Nenad; Džoić, Tomislav

2017-01-01

This paper aims to document salinity and temperature regimes in the middle and south Adriatic Sea by applying the Self-Organizing Maps (SOM) method to the available long-term temperature and salinity series. The data were collected on a seasonal basis between 1963 and 2011 in two dense water collecting depressions, Jabuka Pit and Southern Adriatic Pit, and over the Palagruža Sill. Seasonality was removed prior to the analyses. Salinity regimes have been found to oscillate rapidly between low-salinity and high-salinity SOM solutions, ascribed to the advection of Western and Eastern Mediterranean waters, respectively. Transient salinity regimes normally lasted less than a season, while temperature transient regimes lasted longer. Salinity regimes prolonged their duration after the major basin-wide event, the Eastern Mediterranean Transient, in the early 1990s. A qualitative relationship between high-salinity regimes and dense water formation and dynamics has been documented. The SOM-based analyses have a large capacity for classifying the oscillating ocean regimes in a basin, which, in the case of the Adriatic Sea, beside climate forcing, is an important driver of biogeochemical changes that impacts trophic relations, appearance and abundance of alien organisms, and fisheries, etc.

Estimation of Geotropic Currents in the Bay of Bengal using In-situ Observations.

NASA Astrophysics Data System (ADS)

T, V. R.

2014-12-01

Geostraphic Currents (GCs) can be estimated from temperature and salinity observations. In this study an attempt has been made to compute GC using temperature and salinity observations from Expendable Bathy Thermograph (XBT) and CTD over Bay of Bengal (BoB). Although in recent time we have Argo observations but it is for a limited period and coarse temporal resolutions. In BoB Bengal, where not enough simultaneous hydrographic temperature and salinity data are available with reasonable spatial resolution (~one degree spatial resolution) and for a longer period. To overcome the limitations of GC computed from XBT profiles, temperature-salinity relationships were used from simultaneous temperature and salinity observations. We have demonstrated that GCs can be computed with an accuracy of less than 8.5 cm/s (root mean square error) at the surface with respect to temperature from XBT and salinity from climatological record. This error reduces with increasing depth. Finally, we demonstrated the application of this approach to study the temporal variation of the GCs during 1992 to 2012 along an XBT transect.

Density currents in the Chicago River: Characterization, effects on water quality, and potential sources

USGS Publications Warehouse

Jackson, P. Ryan; Garcia, Carlos M.; Oberg, Kevin A.; Johnson, Kevin K.; Garcia, Marcelo H.

2008-01-01

Bidirectional flows in a river system can occur under stratified flow conditions and in addition to creating significant errors in discharge estimates, the upstream propagating currents are capable of transporting contaminants and affecting water quality. Detailed field observations of bidirectional flows were made in the Chicago River in Chicago, Illinois in the winter of 2005-06. Using multiple acoustic Doppler current profilers simultaneously with a water-quality profiler, the formation of upstream propagating density currents within the Chicago River both as an underflow and an overflow was observed on three occasions. Density differences driving the flow primarily arise from salinity differences between intersecting branches of the Chicago River, whereas water temperature is secondary in the creation of these currents. Deicing salts appear to be the primary source of salinity in the North Branch of the Chicago River, entering the waterway through direct runoff and effluent from a wastewater-treatment plant in a large metropolitan area primarily served by combined sewers. Water-quality assessments of the Chicago River may underestimate (or overestimate) the impairment of the river because standard water-quality monitoring practices do not account for density-driven underflows (or overflows). Chloride concentrations near the riverbed can significantly exceed concentrations at the river surface during underflows indicating that full-depth parameter profiles are necessary for accurate water-quality assessments in urban environments where application of deicing salt is common.

Infrared thermal remote sensing for soil salinity assessment on landscape scale

NASA Astrophysics Data System (ADS)

Ivushkin, Konstantin; Bartholomeus, Harm; Bregt, Arnold K.; Pulatov, Alim; Bui, Elisabeth N.; Wilford, John

2017-04-01

Soil salinity is considered as one of the most severe land degradation aspects. An increased soil salt level inhibits growth and development of crops. Therefore, up to date soil salinity information is vital for appropriate management practices and reclamation strategies. This information is required at increasing spatial and temporal resolution for appropriate management adaptations. Conventional soil sampling and associated laboratory analyses are slow, expensive, and often cannot deliver the temporal and spatial resolution required. The change of canopy temperature is one of the stress indicators in plants. Its behaviour in response to salt stress on individual plant level is well studied in laboratory and greenhouse experiments, but its potential for landscape scale studies using remote sensing techniques is not investigated yet. In our study, possibilities of satellite thermography for landscape scale soil salinity assessment of cropped areas were studied. The performance of satellite thermography is compared with other approaches that have been used before, like Normalised Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). The study areas were Syrdarya province of Uzbekistan and four study areas in four Australian states namely, Western Australia, South Australia, Queensland and New South Wales. The diversity of the study areas allowed us to analyse behaviour of canopy temperature of different crops (wheat, cotton, barley) and different agriculture practices (rain fed and irrigated). MODIS and Landsat TM multiannual satellite images were used to measure canopy temperature. As ground truth for Uzbekistan study area we used a provincial soil salinity map. For the Australian study areas we used the EC map for the whole country. ANOVA was used to analyse relations between the soil salinity maps and canopy temperature, NDVI, EVI. Time series graphs were created to analyse the dynamics of the indicators during the growing season. The results showed significant relations between the soil salinity maps and canopy temperature. The amplitude of canopy temperature difference between salinity classes varies for different crops, but the trend of temperature increase under increased salinity is present in all cases. The calculated F-values were higher for canopy temperature than for all other compared indicators. The vegetation indices also showed significant differences, but F-values were lower compared to canopy temperature. Also the visual comparison of the soil salinity map and the canopy temperature map show similar spatial patterns. The NDVI and EVI maps look more random and noisy and patterns are less pronounced than for the canopy temperature map. The strongest relation between the soil salinity map and canopy temperature was usually observed at the end of a dry season and in the period of maximum crop development. Satellite thermography appeared to be a valuable approach to detect soil salinity under agricultural crops at landscape scale.

Continuous salinity and temperature data from san francisco estuary, 19822002: Trends and the salinity-freshwater inflow relationship

USGS Publications Warehouse

Shellenbarger, G.G.; Schoellhamer, D.H.

2011-01-01

The U.S. Geological Survey and other federal and state agencies have been collecting continuous temperature and salinity data, two critical estuarine habitat variables, throughout San Francisco estuary for over two decades. Although this dynamic, highly variable system has been well studied, many questions remain relating to the effects of freshwater inflow and other physical and biological linkages. This study examines up to 20 years of publically available, continuous temperature and salinity data from 10 different San Francisco Bay stations to identify trends in temperature and salinity and quantify the salinityfreshwater inflow relationship. Several trends in the salinity and temperature records were identified, although the high degree of daily and interannual variability confounds the analysis. In addition, freshwater inflow to the estuary has a range of effects on salinity from -0.0020 to -0.0096 (m3 s-1) -1 discharge, depending on location in the estuary and the timescale of analyzed data. Finally, we documented that changes in freshwater inflow to the estuary that are within the range of typical management actions can affect bay-wide salinities by 0.61.4. This study reinforces the idea that multidecadal records are needed to identify trends from decadal changes in water management and climate and, therefore, are extremely valuable. ?? 2011 Coastal Education & Research Foundation.

Geomorphic modeling of macro-tidal embayment with extensive tidal flats: Skagit Bay, Washington

DTIC Science & Technology

2012-09-30

integrated Delft3D-MOR submodel. Measured river discharge, predicted tides, bathymetry, wind , and density-driven flow were incorporated into the model...supplied with sediment initially. Water temperature and salinity at the tidal boundary were adapted from (Moore et al., 2008). Wind forcing was...tide range varied from 2.4 m at Deception Pass to 3.5 m at Crescent Harbor. Because observations have indicated that wind -generated waves may be

Effective Elastic and Neutron Capture Cross Section Calculations Corresponding to Simulated Fluid Properties from CO2 Push-Pull Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chugunov, Nikita; Altundas, Bilgin

The submission contains a .xls files consisting of 10 excel sheets, which contain combined list of pressure, saturation, salinity, temperature profiles from the simulation of CO2 push-pull using Brady reservoir model and the corresponding effective compressional and shear velocity, bulk density, and fluid and time-lapse neutron capture cross section profiles of rock at times 0 day (baseline) through 14 days. First 9 sheets (each named after the corresponding CO2 push-pull simulation time) contains simulated pressure, saturation, temperature, salinity profiles and the corresponding effective elastic and neutron capture cross section profiles of rock matrix at the time of CO2 injection. Eachmore » sheet contains two sets of effective compressional velocity profiles of the rock, one based on Gassmann and the other based on Patchy saturation model. Effective neutron capture cross section calculations are done using a proprietary neutron cross-section simulator (SNUPAR) whereas for the thermodynamic properties of CO2 and bulk density of rock matrix filled with fluid, a standalone fluid substitution tool by Schlumberger is used. Last sheet in the file contains the bulk modulus of solid rock, which is inverted from the rock properties (porosity, sound speed etc) based on Gassmann model. Bulk modulus of solid rock in turn is used in the fluid substitution.« less

Plasma osmolality and oxygen consumption of perch Perca fluviatilis in response to different salinities and temperatures.

PubMed

Christensen, E A F; Svendsen, M B S; Steffensen, J F

2017-03-01

The present study determined the blood plasma osmolality and oxygen consumption of the perch Perca fluviatilis at different salinities (0, 10 and 15) and temperatures (5, 10 and 20° C). Blood plasma osmolality increased with salinity at all temperatures. Standard metabolic rate (SMR) increased with salinity at 10 and 20° C. Maximum metabolic rate (MMR) and aerobic scope was lowest at salinity of 15 at 5° C, yet at 20° C, they were lowest at a salinity of 0. A cost of osmoregulation (SMR at a salinity of 0 and 15 compared with SMR at a salinity of 10) could only be detected at a salinity of 15 at 20° C, where it was 28%. The results show that P. fluviatilis have capacity to osmoregulate in hyper-osmotic environments. This contradicts previous studies and indicates intraspecific variability in osmoregulatory capabilities among P. fluviatilis populations or habitat origins. An apparent cost of osmoregulation (28%) at a salinity of 15 at 20° C indicates that the cost of osmoregulation in P. fluviatilis increases with temperature under hyperosmotic conditions and a power analysis showed that the cost of osmoregulation could be lower than 12·5% under other environmental conditions. The effect of salinity on MMR is possibly due to a reduction in gill permeability, initiated to reduce osmotic stress. An interaction between salinity and temperature on aerobic scope shows that high salinity habitats are energetically beneficial during warm periods (summer), whereas low salinity habitats are energetically beneficial during cold periods (winter). It is suggested, therefore, that the seasonal migrations of P. fluviatilis between brackish and fresh water is to select an environment that is optimal for metabolism and aerobic scope. © 2016 The Fisheries Society of the British Isles.

Improving Hurricane Heat Content Estimates From Satellite Altimeter Data

NASA Astrophysics Data System (ADS)

de Matthaeis, P.; Jacob, S.; Roubert, L. M.; Shay, N.; Black, P.

2007-12-01

Hurricanes are amongst the most destructive natural disasters known to mankind. The primary energy source driving these storms is the latent heat release due to the condensation of water vapor, which ultimately comes from the ocean. While the Sea Surface Temperature (SST) has a direct correlation with wind speeds, the oceanic heat content is dependent on the upper ocean vertical structure. Understanding the impact of these factors in the mutual interaction of hurricane-ocean is critical to more accurately forecasting intensity change in land-falling hurricanes. Use of hurricane heat content derived from the satellite radar altimeter measurements of sea surface height has been shown to improve intensity prediction. The general approach of estimating ocean heat content uses a two-layer model representing the ocean with its anomalies derived from altimeter data. Although these estimates compare reasonably well with in-situ measurements, they are generally about 10% under-biased. Additionally, recent studies show that the comparisons are less than satisfactory in the Western North Pacific. Therefore, our objective is to develop a methodology to more accurately represent the upper ocean structure using in-situ data. As part of a NOAA/ USWRP sponsored research, upper ocean observations were acquired in the Gulf of Mexico during the summers of 1999 and 2000. Overall, 260 expendable profilers (XCTD, XBT and XCP) acquired vertical temperature structure in the high heat content regions corresponding to the Loop Current and Warm Core Eddies. Using the temperature and salinity data from the XCTDs, first the Temperature-Salinity relationships in the Loop Current Water and Gulf Common water are derived based on the depth of the 26° C isotherm. These derived T-S relationships compare well with those inferred from climatology. By means of these relationships, estimated salinity values corresponding to the XBT and XCP temperature measurements are calculated, and used to derive continuous profiles of density. Ocean heat content is then estimated from these profiles, and compared to that derived from altimeter data, showing - as mentioned earlier - a consistent bias. Using a procedure that conserves density in the vertical, these density profiles are discretized into five isopycnic layers representative of the upper ocean in the Gulf of Mexico. Statistical correlations are then derived between the altimetric sea surface height anomalies and the thickness of these layers in the region. Using these correlations, a higher resolution upper ocean structure is derived from the altimeter data. Withholding observations from one snapshot of data in the correlations, and comparing the estimated ocean heat content with in-situ values, will allow us to quantify errors in this approach. This methodology will then be extended to the Western Pacific using Argo data, and results will be presented.

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest). Dungeness Crab.

DTIC Science & Technology

1986-08-01

variety of factors crab eggs has been linked to increased including depth, latitude, tempera- egg mortality because of mechanical ture, salinity and...time. crabs seem less dependent on epibenthic cover and can be found over more exposed substrates. Most crabs Temperature- Salinity Interactions remain...13 Salinity . .. ....... ........................................ 14 Temperature- Salinity Interactions. .. .... ....... ....... 14

Fluctuations in the meiofauna of the Aufwuchs community in a brackish-water lagoon

NASA Astrophysics Data System (ADS)

Little, Colin

1986-08-01

The organization of the Aufwuchs community in a brackish-water lagoon (Swanpool, Falmouth, U.K.) is described. Changes in the population densities of encrusting bryozoans and mobile meiofauna are described for a period of 3 years. Most meiofaunal species reached peak densities in the spring (January-March). These included tardigrades ( Macrobiotus sp.), oligochaetes ( Nais elinguis, Chaetogaster diaphanus), the harpacticoid copepod Schizopera clandestina, ostracods, the nematodes Dichromadora geophila and Theristus spp., and possibly the nematodes Chromadorina germanica and Atrochromadora microlaima. Other meiofaunal populations peaked in summer (July-September), and these included the chironomid Chironomus salinarius, the harpacticoid copepod Nitocra spinipes and the nematode Adoncholaimus thalassophygas. Two further species, the mite Halacarus balticus and the nematode Aphelencoides sp., showed irregular bursts in numbers. It is concluded that the spring-peaking species increased in numbers dependent upon the growth of the Aufwuchs, and particularly of the surface film of diatoms, while the summer-peaking species may have been controlled more by limiting values of salinity and temperature. These conclusions are contrasted with the general view of salinity as the over-riding factor in brackish-water ecosystems.

Release of cell-free ice nuclei from Halomonas elongata expressing the ice nucleation gene inaZ of Pseudomonas syringae.

PubMed

Tegos, G; Vargas, C; Perysinakis, A; Koukkou, A I; Christogianni, A; Nieto, J J; Ventosa, A; Drainas, C

2000-11-01

Release of ice nuclei in the growth medium of recombinant Halomonas elongata cells expressing the inaZ gene of Pseudomonas syringae was studied in an attempt to produce cell-free active ice nuclei for biotechnological applications. Cell-free ice nuclei were not retained by cellulose acetate filters of 0.2 microm pore size. Highest activity of cell-free ice nuclei was obtained when cells were grown in low salinity (0.5-5% NaCl, w/v). Freezing temperature threshold, estimated to be below -7 degrees C indicating class C nuclei, was not affected by medium salinity. Their density, as estimated by Percoll density centrifugation, was 1.018 +/- 0.002 gml(-1) and they were found to be free of lipids. Ice nuclei are released in the growth medium of recombinant H. elongata cells probably because of inefficient anchoring of the ice-nucleation protein aggregates in the outer membrane. The ice+ recombinant H. elongata cells could be useful for future use as a source of active cell-free ice nucleation protein.

Effects of biofouling on the sinking behavior of microplastics

NASA Astrophysics Data System (ADS)

Kaiser, David; Kowalski, Nicole; Waniek, Joanna J.

2017-12-01

Although plastic is ubiquitous in marine systems, our current knowledge of transport mechanisms is limited. Much of the plastic entering the ocean sinks; this is intuitively obvious for polymers such as polystyrene (PS), which have a greater density than seawater, but lower density polymers like polyethylene (PE) also occur in sediments. Biofouling can cause large plastic objects to sink, but this phenomenon has not been described for microplastics <5 mm. We incubated PS and PE microplastic particles in estuarine and coastal waters to determine how biofouling changes their sinking behavior. Sinking velocities of PS increased by 16% in estuarine water (salinity 9.8) and 81% in marine water (salinity 36) after 6 weeks of incubation. Thereafter sinking velocities decreased due to lower water temperatures and reduced light availability. Biofouling did not cause PE to sink during the 14 weeks of incubation in estuarine water, but PE started to sink after six weeks in coastal water when sufficiently colonized by blue mussels Mytilus edulis, and its velocity continued to increase until the end of the incubation period. Sinking velocities of these PE pellets were similar irrespective of salinity (10 vs. 36). Biofilm composition differed between estuarine and coastal stations, presumably accounting for differences in sinking behavior. We demonstrate that biofouling enhances microplastic deposition to marine sediments, and our findings should improve microplastic transport models.

Studies of the San Francisco Bay, California, estuarine ecosystem regional monitoring program results, 1996

USGS Publications Warehouse

Baylosis, Jelriza I.; Edmunds, Jody L.; Cole, Brian E.; Cloern, James E.

1997-01-01

As part of a regional monitoring program, water samples were collected in the San Francisco Bay estuary during 21 cruises from January through December 1996. Conductivity, temperature, light attenuation, turbidity, oxygen, and in-vivo chlorophyll fluorescence were measured longitudinally and vertically in the main channel of the estuary from south of the Dumbarton Bridge in the southern part of the Bay to Rio Vista on the Sacramento River. Discrete water samples were analyzed for chlorophyll a, phaeopigments, suspended participate matter, and dissolved oxygen. Water density was calculated from salinity, temperature, and pressure (depth), and is included in the data summaries.

The effects of mercury on developing larvae of Rhithropanopeus harrisii (Gould) . I. Interactions of temperature, salinity and mercuryon larval development

NASA Astrophysics Data System (ADS)

McKenney, C. L.; Costlow, J. D.

1982-02-01

Larvae of the estuarine xanthid crab Rhithropanopeus harrisii were reared inthe laboratory from hatch through completion of metamorphosis to postlarva in 64 combinations of temperature (20-35°C), salinity (10-40‰) and mercury (0-20 parts 10 -9 Hg 2+). Multiple linear regression analysis and response surface methodology were used to determine and visually display the individual and interactive effects of the various constant temperature-salinity-mercury combinations on both survival and developmental rates of developing larvae throughout total larval development and for zoeae and megalopae separately, to distinguish any differential sensitivity between the two larval forms. Survival capacity of larvae under a broad range of salinities and temperatures characteristic of temperate estuarine conditions was progressively reduced upon continual exposure to mercury ranging from 5 to 20 parts 10 -9 Hg 2+. Exposure concentrations as low as 5 parts 10 -9 Hg 2+ reduced the salinity and temperature plasciticity of the normally euryhalinic and eurythermal larvae. Larval survival from hatch to postlarva was affected by both mercury-salinity and mercury-temperature interactions with mercury toxicity increasing under suboptimal temperatures and salinities. Viability of early zoeal stages proved more sensitive to mercury exposure than the final megalopa stage. Exposure to mercury concentrations from 5-20 parts 10 -9, Hg 2+ prolonged complete developmental duration by 3 to 4 days with zoeal developmental rates retarded more than megalopal rates. Developmental rates of the megalopa were more reduced by mercury at higher salinities, and both zoeal and megalopal developmental rates were more retarded by mercury at lower temperatures. The reduced plasticity of larvae to estuarine conditions, and retarded developmental rates by low mercury concentrations may reduce recruitment into adult benthic populations and alter the distributional patterns of pelagic R. harrisii larvae.

High salinity relay as a post-harvest processing method for reducing Vibrio vulnificus levels in oysters (Crassostrea virginica).

PubMed

Audemard, Corinne; Kator, Howard I; Reece, Kimberly S

2018-08-20

High salinity relay of Eastern oysters (Crassostrea virginica) was evaluated as a post-harvest processing (PHP) method for reducing Vibrio vulnificus. This approach relies on the exposure of oysters to natural high salinity waters and preserves a live product compared to previously approved PHPs. Although results of prior studies evaluating high salinity relay as a means to decrease V. vulnificus levels were promising, validation of this method as a PHP following approved guidelines is required. This study was designed to provide data for validation of this method following Food and Drug Administration (FDA) PHP validation guidelines. During each of 3 relay experiments, oysters cultured from 3 different Chesapeake Bay sites of contrasting salinities (10-21 psu) were relayed without acclimation to high salinity waters (31-33 psu) for up to 28 days. Densities of V. vulnificus and densities of total and pathogenic Vibrio parahaemolyticus (as tdh positive strains) were measured using an MPN-quantitative PCR approach. Overall, 9 lots of oysters were relayed with 6 exhibiting initial V. vulnificus >10,000/g. As recommended by the FDA PHP validation guidelines, these lots reached both the 3.52 log reduction and the <30 MPN/g densities requirements for V. vulnificus after 14 to 28 days of relay. Densities of total and pathogenic V. parahaemolyticus in relayed oysters were significantly lower than densities at the sites of origin suggesting an additional benefit associated with high salinity relay. While relay did not have a detrimental effect on oyster condition, oyster mortality levels ranged from 2 to 61% after 28 days of relay. Although the identification of the factors implicated in oyster mortality will require further examination, this study strongly supports the validation of high salinity relay as an effective PHP method to reduce levels of V. vulnificus in oysters to endpoint levels approved for human consumption. Copyright © 2018 Elsevier B.V. All rights reserved.

Salinity and Temperature Tolerance Experiments on Selected Florida Bay Mollusks

USGS Publications Warehouse

Murray, James B.; Wingard, G. Lynn

2006-01-01

The ultimate goal of the Comprehensive Everglades Restoration Plan (CERP) is to restore and preserve the unique ecosystems of South Florida, including the estuaries. Understanding the effect of salinity and temperature changes, beyond typical oscillations, on the biota of South Florida's estuaries is a necessary component of achieving the goal of restoring the estuaries. The U.S. Geological Survey has been actively involved in researching the history of the South Florida Ecosystem, to provide targets, performance measures, and baseline data for restoration managers. These experiments addressed two aspects of ecosystem history research: 1) determining the utility of using molluscan shells as recorders of change in water chemistry parameters, primarily salinity, and 2) enhancing our in situ observations on modern assemblages by exceeding typically observed aquatic conditions. This set of experiments expanded our understanding of the effects of salinity, temperature and other water chemistry parameters on the reproduction, growth and overall survivability of key species of mollusks used in interpreting sediment core data. Observations on mollusks, plants and microbes made as part of these experiments have further refined our knowledge and understanding of the effects of ecosystem feedback and the role salinity and temperature play in ecosystem stability. The results have demonstrated the viability of several molluscan species as indicators of atypical salinity, and possibly temperature, modulations. For example Cerithium muscarum and Bulla striata demonstrated an ability to withstand a broad salinity and temperature range, with reproduction occurring in atypically high salinities and temperatures. These experiments also provided calibration data for the shell biogeochemistry of Chione cancellata and the possible use of this species as a water chemistry recorder. Observations made in the mesocosms, on a scale not normally observable in the field, have led to new questions about the influence of salinity on the localized ecosystem. The next phase of these experiments; to calibrate growth rate and reproductive viability in atypical salinities is currently underway.

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

NASA Astrophysics Data System (ADS)

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 and monthly water mass formation rates for different SST and SSS ranges are presented. The formation peaks are remapped geographically, to analyze the extent of the formation area. Water mass formation derived from SMOS and OSTIA compares well with the results obtained from in-situ data, although slight differences in magnitude and peak location occur. Known water masses can then be identified. Ongoing/future work aims at extending this study along different avenues by: 1) expand systematically the spatial and temporal domain of the study to additional ocean basins and to the entire time period of available SSS observations from SMOS/Aquarius; 2) perform a thorough error propagation to assess how errors in satellite SSS and SST translate into errors in water masses formation rates and geographical areas extent; and 3) explore the different options to connect the surface information to the vertical buoyancy structure to assess potential density instability (e.g., Turner angle). References [1] Sabia, R., M. Klockmann, D. Fernández-Prieto, and C. Donlon (2014), A first estimation of SMOS-based ocean surface T-S diagrams, J. Geophys. Res. Oceans, 119, 7357-7371, doi:10.1002/2014JC010120. [2] Klockmann, M., R. Sabia, D. Fernández-Prieto, C. Donlon, J. Font; Towards an estimation of water masses formation areas from SMOS-based T-S diagrams; EGU general assembly 2014, April 27-May 2, 2014. [3] Klockmann, M., R. Sabia, D. Fernández-Prieto, C. Donlon, Linking satellite SSS and SST to water mass formation; Ocean salinity science and salinity remote sensing workshop, Exeter, UK, November 26-28, 2014. [4] Font, J., A. Camps, A. Borges, M. Martín-Neira, J. Boutin, N. Reul, Y. H. Kerr, A. Hahne, and S. Mecklenburg, "SMOS: The challenging sea surface salinity measurement from space," Proceedings of the IEEE, vol. 98, pp. 649-665, 2010. [5] Le Vine, D.M.; Lagerloef, G.S.E.; Torrusio, S.E.; "Aquarius and Remote Sensing of Sea Surface Salinity from Space," Proceedings of the IEEE , vol.98, no.5, pp.688-703, May 2010, doi: 10.1109/JPROC.2010.2040550.

Near-surface salinity and temperature structure observed with dual-sensor drifters in the subtropical South Pacific

NASA Astrophysics Data System (ADS)

Dong, Shenfu; Volkov, Denis; Goni, Gustavo; Lumpkin, Rick; Foltz, Gregory R.

2017-07-01

Three surface drifters equipped with temperature and salinity sensors at 0.2 and 5 m depths were deployed in April/May 2015 in the subtropical South Pacific with the objective of measuring near-surface salinity differences seen by satellite and in situ sensors and examining the causes of these differences. Measurements from these drifters indicate that water at a depth of 0.2 m is about 0.013 psu fresher than at 5 m and about 0.024°C warmer. Events with large temperature and salinity differences between the two depths are caused by anomalies in surface freshwater and heat fluxes, modulated by wind. While surface freshening and cooling occurs during rainfall events, surface salinification is generally observed under weak wind conditions (≤4 m/s). Further examination of the drifter measurements demonstrates that (i) the amount of surface freshening and strength of the vertical salinity gradient heavily depend on wind speed during rain events, (ii) salinity differences between 0.2 and 5 m are positively correlated with the corresponding temperature differences for cases with surface salinification, and (iii) temperature exhibits a diurnal cycle at both depths, whereas the diurnal cycle of salinity is observed only at 0.2 m when the wind speed is less than 6 m/s. The amplitudes of the diurnal cycles of temperature at both depths decrease with increasing wind speed. The mean diurnal cycle of surface salinity is dominated by events with winds less than 2 m/s.

Near-surface Salinity and Temperature structure Observed with Dual-Sensor Drifters in the Subtropical South Pacific

NASA Astrophysics Data System (ADS)

Dong, S.; Volkov, D.; Goni, G. J.; Lumpkin, R.; Foltz, G. R.

2017-12-01

Three surface drifters equipped with temperature and salinity sensors at 0.2 m and 5 m depths were deployed in April/May 2015 in the subtropical South Pacific with the objective of measuring near-surface salinity differences seen by satellite and in situ sensors and examining the causes of these differences. Measurements from these drifters indicate that water at a depth of 0.2 m is about 0.013 psu fresher than at 5 m and about 0.024°C warmer. Events with large temperature and salinity differences between the two depths are caused by anomalies in surface freshwater and heat fluxes, modulated by wind. While surface freshening and cooling occurs during rainfall events, surface salinification is generally observed under weak wind conditions (≤4 m/s). Further examination of the drifter measurements demonstrates that (i) the amount of surface freshening and strength of the vertical salinity gradient heavily depend on wind speed during rain events, (ii) salinity differences between 0.2 m and 5 m are positively correlated with the corresponding temperature differences for cases with surface salinification, and (iii) temperature exhibits a diurnal cycle at both depths, whereas the diurnal cycle of salinity is observed only at 0.2 m when the wind speed is less than 6 m/s. The amplitudes of the diurnal cycles of temperature at both depths decrease with increasing wind speed. The mean diurnal cycle of surface salinity is dominated by events with winds less than 2 m/s.

Survival and development of horseshoe crab (Limulus polyphemus) embryos and larvae in hypersaline conditions.

PubMed

Ehlinger, Gretchen S; Tankersley, Richard A

2004-04-01

The horseshoe crab Limulus polyphemus spawns in the mid- to upper intertidal zone where females deposit eggs in nests below the sediment surface. Although adult crabs generally inhabit subtidal regions of estuaries with salinities from 5 to 34 ppt, developing embryos and larvae within nests are often exposed to more extreme conditions of salinity and temperature during summer spawning periods. To test whether these conditions have a negative impact on early development and survival, we determined development time, survival, and molt cycle duration for L. polyphemus embryos and larvae raised at 20 combinations of salinity (range: 30-60 ppt) and temperature (range: 25-40 degrees C). Additionally, the effect of hyperosmotic and hypoosmotic shock on the osmolarity of the perivitelline fluid of embryos was determined at salinities between 5 and 90 ppt. The embryos completed their development and molted at salinities below 60 ppt, yet failed to develop at temperatures of 35 degrees C or higher. Larval survival was high at salinities of 10-70 ppt but declined significantly at more extreme salinities (i.e., 5, 80, and 90 ppt). Perivitelline fluid remained nearly isoosmotic over the range of salinities tested. Results indicate that temperature and salinity influence the rate of crab development, but only the extremes of these conditions have an effect on survival.

Seagrass Proliferation Precedes Mortality during Hypo-Salinity Events: A Stress-Induced Morphometric Response

PubMed Central

Collier, Catherine J.; Villacorta-Rath, Cecilia; van Dijk, Kor-jent; Takahashi, Miwa; Waycott, Michelle

2014-01-01

Halophytes, such as seagrasses, predominantly form habitats in coastal and estuarine areas. These habitats can be seasonally exposed to hypo-salinity events during watershed runoff exposing them to dramatic salinity shifts and osmotic shock. The manifestation of this osmotic shock on seagrass morphology and phenology was tested in three Indo-Pacific seagrass species, Halophila ovalis, Halodule uninervis and Zostera muelleri, to hypo-salinity ranging from 3 to 36 PSU at 3 PSU increments for 10 weeks. All three species had broad salinity tolerance but demonstrated a moderate hypo-salinity stress response – analogous to a stress induced morphometric response (SIMR). Shoot proliferation occurred at salinities <30 PSU, with the largest increases, up to 400% increase in shoot density, occurring at the sub-lethal salinities <15 PSU, with the specific salinity associated with peak shoot density being variable among species. Resources were not diverted away from leaf growth or shoot development to support the new shoot production. However, at sub-lethal salinities where shoots proliferated, flowering was severely reduced for H. ovalis, the only species to flower during this experiment, demonstrating a diversion of resources away from sexual reproduction to support the investment in new shoots. This SIMR response preceded mortality, which occurred at 3 PSU for H. ovalis and 6 PSU for H. uninervis, while complete mortality was not reached for Z. muelleri. This is the first study to identify a SIMR in seagrasses, being detectable due to the fine resolution of salinity treatments tested. The detection of SIMR demonstrates the need for caution in interpreting in-situ changes in shoot density as shoot proliferation could be interpreted as a healthy or positive plant response to environmental conditions, when in fact it could signal pre-mortality stress. PMID:24705377

Influence of salinity and temperature on acute toxicity of cadmium to Mysidopsis bahia molenock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voyer, R.A.; Modica, G.

1990-01-01

Acute toxicity tests were conducted to compare estimates of toxicity, as modified by salinity and temperature, based on response surface techniques with those derived using conventional test methods, and to compare effect of a single episodic exposure to cadmium as a function of salinity with that of continuous exposure. Regression analysis indicated that mortality following continuous 96-hr exposure is related to linear and quadratic effects of salinity and cadmium at 20 C, and to the linear and quadratic effects of cadmium only at 25C. LC50s decreased with increases in temperature and decreases in salinity. Based on the regression model developed,more » 96-hr LC50s ranged from 15.5 to 28.0 micro Cd/L at 10 and 30% salinities, respectively, at 25C; and from 47 to 85 microgram Cd/L at these salinities at 20C.« less

Temperature-salinity structure of the AMOC in high-resolution ocean simulations and in CMIP5 models

NASA Astrophysics Data System (ADS)

Wang, F.; Xu, X.; Chassignet, E.

2017-12-01

On average, the CMIP5 models represent the AMOC structure, water properties, Heat transport and Freshwater transport reasonably well. For temperature, CMIP5 models exhibit a colder northward upper limb and a warmer southward lower limb. the temperature contrast induces weaker heat transport than observation. For salinity, CMIP5 models exhibit saltier southward lower limb, thus contributes to weaker column freshwater transport. Models have large spread, among them, AMOC strength contributes to Heat transport but not freshwater transport. AMOC structure (the overturning depth) contributes to transport-weighted temperature not transport-weighted salinity in southward lower limb. The salinity contrast in upper and lower limb contributes to freshwater transport, but temperature contrast do not contribute to heat transport.

Distribution of the Euryhaline Squid Lolliguncula brevis in Chesapeake Bay: Effects of Selected Abiotic Factors

DTIC Science & Technology

2002-01-31

salinity , water temperature, dissolved oxy- gen and water clarity. Since temporal variation in the Chesapeake Bay ecosystem is high, the effects of year...temperature (p ɘ.001; ψ = 2.42) had significant impacts on squid catch probability, although the effects were con- founded by a water temperature × salinity ...commonly encountered in such waters during VIMS Trawl Surveys The synergistic and independent effects of salinity , water temperature and dissolved oxygen

The Effects of Temperature and Salinity on Mg Incorporation in Planktonic Foraminifera Globigerinoides ruber (white): Results from a Global Sediment Trap Mg/Ca Database

NASA Astrophysics Data System (ADS)

Gray, W. R.; Weldeab, S.; Lea, D. W.

2015-12-01

Mg/Ca in Globigerinoides ruber is arguably the most important proxy for sea surface temperature (SST) in tropical and sub tropical regions, and as such guides our understanding of past climatic change in these regions. However, the sensitivity of Mg/Ca to salinity is debated; while analysis of foraminifera grown in cultures generally indicates a sensitivity of 3 - 6% per salinity unit, core-top studies have suggested a much higher sensitivity of between 15 - 27% per salinity unit, bringing the utility of Mg/Ca as a SST proxy into dispute. Sediment traps circumvent the issues of dissolution and post-depositional calcite precipitation that hamper core-top calibration studies, whilst allowing the analysis of foraminifera that have calcified under natural conditions within a well constrained period of time. We collated previously published sediment trap/plankton tow G. ruber (white) Mg/Ca data, and generated new Mg/Ca data from a sediment trap located in the highly-saline tropical North Atlantic, close to West Africa. Calcification temperature and salinity were calculated for the time interval represented by each trap/tow sample using World Ocean Atlas 2013 data. The resulting dataset comprises >240 Mg/Ca measurements (in the size fraction 150 - 350 µm), that span a temperature range of 18 - 28 °C and 33.6 - 36.7 PSU. Multiple regression of the dataset reveals a temperature sensitivity of 7 ± 0.4% per °C (p < 2.2*10-16) and a salinity sensitivity of 4 ± 1% per salinity unit (p = 2*10-5). Application of this calibration has significant implications for both the magnitude and timing of glacial-interglacial temperature changes when variations in salinity are accounted for.

[Joint effects of water temperature and salinity on the expression of gill Hsp70 gene in Pinctada martensii (Dunker)].

PubMed

Wang, Ya-Nan; Wang, Hui; Zhu, Xiao-Wen; Luo, Ming-Ming; Liu, Zhi-Gang; Du, Xiao-Dong

2012-12-01

By using central composite experimental design and response surface method, the joint effects of water temperature (16-40 degrees C) and salinity (10-50) on the expression of gill Hsp70 gene in Pinctada martensii (Dunker) were studied under laboratory conditions. The results showed that the linear and quadratic effects of temperature on the expression of gill Hsp70 gene were significant, the linear effect of salinity was not significant, while the quadratic effect of salinity was significant. The interactive effect of temperature and salinity was not significant, and the effect of temperature was greater than that of salinity. The model equation of the gill Hsp70 gene expression was established, with the R2, Adj. R2, and Pred. R2 as high as 98.7%, 97.4%, and 89.2%, respectively, suggesting that the overarching predictive capability of the model was very satisfactory, and could be practicably applied for prediction. Through the optimization of the model, the expression of the gill Hsp70 gene reached its minimum (0.5276) when the temperature was 26.78 degrees C and the salinity was 29.33, with the desirability value being 98%. These experimental results could offer theoretical reference for the high expression of gill Hsp70 gene in P. martensii, the maintenance of cell internal environment stability, and the enhancement of P. martensii stress resistance.

Large Eddy Simulations of Compositional Density Currents Flowing Over a Mobile Bed

NASA Astrophysics Data System (ADS)

Kyrousi, Foteini; Zordan, Jessica; Leonardi, Alessandro; Juez, Carmelo; Zanello, Francesca; Armenio, Vincenzo; Franca, Mário J.

2017-04-01

Density currents are a ubiquitous phenomenon caused by natural events or anthropogenic activities, and play an important role in the global sediment cycle; they are agents of long distance sediment transport in lakes, seas and oceans. Density gradients induced by salinity, temperature differences, or by the presence of suspended material are all possible triggers of a current. Such flows can travel long distances while eroding or depositing bed materials. This can provoke rapid topological changes, which makes the estimation of their transport capacity of prime interest for environmental engineering. Despite their relevance, field data regarding their dynamics is limited due to density currents scattered and unpredictable occurrence in nature. For this reason, laboratory experiments and numerical simulations have been a preferred way to investigate sediment transport processes associated to density currents. The study of entrainment and deposition processes requires detailed data of velocities spatial and temporal distributions in the boundary layer and bed shear stress, which are troublesome to obtain in laboratory. Motivated by this, we present 3D wall-resolved Large Eddy Simulations (LES) of density currents generated by lock-exchange. The currents travel over a smooth flat bed, which includes a section composed by erodible fine sediment susceptible of eroding. Several sediment sizes and initial density gradients are considered. The grid is set to resolve the velocity field within the boundary layer of the current (a tiny fraction of the total height), which in turn allows to obtain predictions of the bed shear stress. The numerical outcomes are compared with experimental data obtained with an analogous laboratory setting. In laboratory experiments salinity was chosen for generating the initial density gradient in order to facilitate the identification of entrained particles, since salt does not hinder the possibility to track suspended particles. Under these circumstances, it is possible to focus alone on the effect of the dynamics of the current on the particles entrainment. To achieve this, LES-filtered Navier-Stokes equations are coupled with two scalar transport equations: one for salinity and one for sediment concentration. We discuss the use of different sediment pick-up and settling formulations, which are key factors in reproducing the correct erosion and sedimentation mechanisms. The simulations show the emergence of longitudinal bed forms, and highlight the role of turbulent structures in the entrainment pattern for different regions within the current.

The influence of double-diffusive processes on the melting of ice in the Arctic Ocean: laboratory analogue experiments and their interpretation

NASA Astrophysics Data System (ADS)

Turner, J. S.; Veronis, G.

2004-03-01

This study has been motivated by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water across the Arctic below the halocline over the last few decades. A series of laboratory experiments has been carried out in order to explore the physical principles underlying these phenomena, and the possibility that the extra heating at depth is responsible for the enhanced melting rate. A tank was filled with salt solution having various constant vertical density gradients. A block of ice one third of the length of the tank was floated on the surface at one end, and the rest of the surface and the walls of the tank were insulated. When no extra heat was supplied the melting rate (loss of weight of the ice in 1 h) systematically decreased as the stratification was changed from homogeneous fluid to increasingly large density gradients, while keeping the salinity of the solution in contact with the ice constant. An analogue of the intruding Atlantic water was produced by heating the lower portion of the vertical end wall at the end of the tank opposite to the ice end, keeping its temperature constant, and using the same range of salinity gradients as in the unheated experiments. Again the melting rate decreased as the density gradient was increased, but for low gradients it was larger than that in the unheated experiments. Above a certain intermediate gradient there was no significant difference in melting rate between the unheated and heated runs. The melting data were supplemented by photographs and vertical temperature and salinity profiles. The upward transfer of heat from the body of the fluid to melt the ice was clearly double-diffusive: overturning layers, separated by 'diffusive' interfaces, were visible on shadowgraphs, and the thickness of the layers decreased as the density gradient increased. The mean thickness of the layers through the depth of the tank also systematically decreased as the density gradient increased. With weak gradients an extra heat flux to the ice came from the intruding heated layer, but at large gradients this tongue of warm water at depth did not add to the flux near the surface. Though they were obtained in a simple, arbitrary and fixed geometry, we believe that the results of these experiments can be used as the basis for a better physical understanding of the melting rates of ice in the Arctic under various conditions.

Correlation between Environmental Factors and Prevalence of Vibrio parahaemolyticus in Oysters Harvested in the Southern Coastal Area of Sao Paulo State, Brazil▿

PubMed Central

Sobrinho, Paulo de Souza Costa; Destro, Maria T.; Franco, Bernadette D. G. M.; Landgraf, Mariza

2010-01-01

The presence of Vibrio parahaemolyticus in 123 oyster samples collected from an estuary on the southern coast of Sao Paulo state, Brazil, was investigated. Of the 123 samples, 99.2% were positive with densities ranging from <3 to 105 most probable number (MPN)/g. Densities correlated significantly with water temperature (r = 0.48; P < 0.001) but not with salinity (r = −0.09; P = 0.34). The effect of harvest site on counts was not significant (P > 0.05). These data provide information for the assessment of exposure of V. parahaemolyticus in oysters at harvest. PMID:20023076

Performance of Mixed Layer Models in Simulating SST in the Equatorial Pacific Ocean

DTIC Science & Technology

2008-02-23

also used Environmental Model ( GDEM ) climatology [NA VOCEANO, for global validation. 2003]. The density difference values were chosen, so that the [6...were initialized from the monthly different at two different locations. Values of SS range from mean temperature and salinity for August from the GDEM ...environmental model ( GDEM -V) Version 3.0, OAML-DBD-72, 34 pp, Chassignet, E. P., H. E. Hurlburt, 0. M. Smedstad, G. R. Halliwell, A. J. Stennis Space Center

Estuarine turbidity, flushing, salinity, and circulation

NASA Technical Reports Server (NTRS)

Pritchard, D. W.

1972-01-01

The effects of estuarine turbidity, flushing, salinity, and circulation on the ecology of the Chesapeake Bay are discussed. The sources of fresh water, the variations in salinity, and the circulation patterns created by temperature and salinity changes are analyzed. The application of remote sensors for long term observation of water temperatures is described. The sources of sediment and the biological effects resulting from increased sediments and siltation are identified.

Seasonal variation in chaetognath and parasite species assemblages along the northeastern coast of the Yucatan Peninsula.

PubMed

Lozano-Cobo, Horacio; Prado-Rosas, María Del Carmen Gómez Del; Sánchez-Velasco, Laura; Gómez-Gutiérrez, Jaime

2017-03-30

Chaetognaths are abundant carnivores with broad distributions that are intermediate hosts of trophically transmitted parasites. Monthly variations in chaetognath and parasite species distributions, abundance, prevalence, and intensity related to seasonal environmental changes were recorded in 2004 and 2005 in Laguna Nichupté, a coral reef, and the adjoining continental shelf of Quintana Roo, Mexico. Of 12 chaetognath species plus Sagitta spp., only 5 (Ferosagitta hispida, Flaccisagitta enflata, Sagitta spp., Serratosagitta serratodentata, and Pterosagitta draco) were parasitized. These species were parasitized with 33 types of flatworms and unidentified cysts (likely protozoan ciliates), having an overall mean prevalence of 6%. Digenean metacercaria larvae numerically dominated the parasite assemblages. Cluster analysis defined 2 chaetognath species assemblages. One included 7 species inside Laguna Nichupté, where F. hispida was numerically dominant (98.9%); the other contained 13 chaetognath species in the continental shelf-coral reef region, where F. enflata was abundant (53%). Canonical correspondence analysis showed that Laguna Nichupté had highly variable and hostile conditions (relatively low salinity and high temperature) for chaetognath species except for F. hispida. The higher density of F. hispida promoted greater parasite diversity (23 types), dominated by Brachyphallus sp. metacercariae. F. enflata prevailed in the continental shelf-coral reef area, which had stable high salinity and relatively low temperature. Monilicaecum and unidentified digenean 'type g' infected 5 chaetognath species on the continental shelf. Distinct primary hosts (mollusks and copepods) and contrasting environmental conditions (salinity, dissolved oxygen concentration, and temperature) between Laguna Nichupté and the continental shelf promoted distinct chaetognath species assemblages, resulting in distinct parasite diversity and prevalence patterns.

Modeling the seasonal circulation in Massachusetts Bay

USGS Publications Warehouse

Signell, Richard P.; Jenter, Harry L.; Blumberg, Alan F.; ,

1994-01-01

An 18 month simulation of circulation was conducted in Massachusetts Bay, a roughly 35 m deep, 100??50 km embayment on the northeastern shelf of the United States. Using a variant of the Blumberg-Mellor (1987) model, it was found that a continuous 18 month run was only possible if the velocity field was Shapiro filtered to remove two grid length energy that developed along the open boundary due to mismatch in locally generated and climatologically forced water properties. The seasonal development of temperature and salinity stratification was well-represented by the model once ??-coordinate errors were reduced by subtracting domain averaged vertical profiles of temperature, salinity and density before horizontal differencing was performed. Comparison of modeled and observed subtidal currents at fixed locations revealed that the model performance varies strongly with season and distance from the open boundaries. The model performs best during unstratified conditions, and in the interior of the bay. The model performs poorest during stratified conditions and in the regions where the bay is driven predominantly by remote fluctuations from the Gulf of Maine.

Modelling Greenland icebergs

NASA Astrophysics Data System (ADS)

Marson, Juliana M.; Myers, Paul G.; Hu, Xianmin

2017-04-01

The Atlantic Meridional Overturning Circulation (AMOC) is well known for carrying heat from low to high latitudes, moderating local temperatures. Numerical studies have examined the AMOC's variability under the influence of freshwater input to subduction and deep convections sites. However, an important source of freshwater has often been overlooked or misrepresented: icebergs. While liquid runoff decreases the ocean salinity near the coast, icebergs are a gradual and remote source of freshwater - a difference that affects sea ice cover, temperature, and salinity distribution in ocean models. Icebergs originated from the Greenland ice sheet, in particular, can affect the subduction process in Labrador Sea by decreasing surface water density. Our study aims to evaluate the distribution of icebergs originated from Greenland and their contribution to freshwater input in the North Atlantic. To do that, we use an interactive iceberg module coupled with the Nucleus for European Modelling of the Ocean (NEMO v3.4), which will calve icebergs from Greenland according to rates established by Bamber et al. (2012). Details on the distribution and trajectory of icebergs within the model may also be of use for understanding potential navigation threats, as shipping increases in northern waters.

Bolus oral or continuous intestinal amino acids reduce hypothermia during anesthesia in rats.

PubMed

Imoto, Akinobu; Yokoyama, Takeshi; Suwa, Kunio; Yamasaki, Fumiyasu; Yatabe, Tomoaki; Yokoyama, Reiko; Yamashita, Koichi; Selldén, Eva

2010-01-01

We hypothesized that, with oral or intestinal administration of amino acids (AA), we may reduce hypothermia during general anesthesia as effectively as with intravenous AA. We, therefore, examined the effect of bolus oral and continuous intestinal AA in preventing hypothermia in rats. Male Wistar rats were anesthetized with sevoflurane for induction and with propofol for maintenance. In the first experiment, 30 min before anesthesia, rats received one bolus 42 mL/kg of AA solution (100 g/L) or saline orally. Then for the next 3 h during anesthesia, they received 14 mL/kg/h of AA and/or saline intravenously. They were in 4 groups: I-A/A, both AA; I-A/S, oral AA and intravenous saline; I-S/A, oral saline and intravenous AA; I-S/S, both saline. In the second experiment, rats received 14 mL/kg/h duodenal AA and/or saline for 2 h. They were in 3 groups: II-A/S, duodenal AA and intravenous saline; II-S/A, duodenal saline and intravenous AA; II-S/S, both saline. Core body temperature was measured rectally. After the second experiment, serum electrolytes were examined. In both experiments, rectal temperature decreased in all groups during anesthesia. However, the decrease in rectal temperature was significantly less in groups receiving AA than in groups receiving only saline. In the second experiment, although there was no significant difference in the decrease in body temperature between II-A/S and II-S/A, Na(+) concentration was significantly lower in II-S/A. In conclusion, AA, administered orally or intestinally, tended to keep the body temperature stable during anesthesia without disturbing electrolyte balance. These results suggest that oral or enteral AA may be useful for prevention of hypothermia in patients.

Responses of trophic structure and zooplankton community to salinity and temperature in Tibetan lakes: Implication for the effect of climate warming.

PubMed

Lin, Qiuqi; Xu, Lei; Hou, Juzhi; Liu, Zhengwen; Jeppesen, Erik; Han, Bo-Ping

2017-11-01

Warming has pronounced effects on lake ecosystems, either directly by increased temperatures or indirectly by a change in salinity. We investigated the current status of zooplankton communities and trophic structure in 45 Tibetan lakes along a 2300 m altitude and a 76 g/l salinity gradient. Freshwater to hyposaline lakes mainly had three trophic levels: phytoplankton, small zooplankton and fish/Gammarus, while mesosaline to hypersaline lakes only had two: phytoplankton and large zooplankton. Zooplankton species richness declined significantly with salinity, but did not relate with temperature. Furthermore, the decline in species richness with salinity in lakes with two trophic levels was much less abrupt than in lakes with three trophic levels. The structural variation of the zooplankton community depended on the length of the food chain, and was significantly explained by salinity as the critical environmental variable. The zooplankton community shifted from dominance of copepods and small cladoceran species in the lakes with low salinity and three trophic levels to large saline filter-feeding phyllopod species in those lakes with high salinity and two trophic levels. The zooplankton to phytoplankton biomass ratio was positively related with temperature in two-trophic-level systems and vice versa in three-trophic-level systems. As the Tibetan Plateau is warming about three times faster than the global average, our results imply that warming could have a considerable impact on the structure and function of Tibetan lake ecosystems, either via indirect effects of salinization/desalinization on species richness, composition and trophic structure or through direct effects of water temperature on trophic interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

The campi flegrei (Italy) geothermal system: A fluid inclusion study of the mofete and San Vito fields

USGS Publications Warehouse

de, Vivo B.; Belkin, H.E.; Barbieri, M.; Chelini, W.; Lattanzi, P.; Lima, A.; Tolomeo, L.

1989-01-01

A fluid inclusion study of core from the Mofete 1, Mofete 2, Mofete 5, San Vito 1, and San Vito 3 geothermal wells (Campi Flegrei, Campania, Italy) indicates that the hydrothermal minerals were precipitated from aqueous fluids (??CO2) that were moderately saline (3-4 wt.% NaCl equiv.) to hypersaline (> 26 wt.% NaCl equiv.) and at least in part, boiling. Three types of primary fluid inclusions were found in authigenic K-feldspar, quartz, calcite, and epidote: (A) two-phase [liquid (L) + vapor (V)], liquid-rich inclusions with a range of salinity; (B) two-phase (L + V), vaporrich inclusions with low salinity; and (C) three-phase [L + V + crystals (NaCL)], liquid-rich inclusions with hypersalinity. Results of microthermometric and crushing studies are reported for twenty drill core samples taken from the lower portions of the five vertical wells. Data presented for selected core samples reveal a general decrease in porosity and increase in bulk density with increasing depth and temperature. Hydrothermal minerals commonly fill fractures and pore-spaces and define a zonation pattern, similar in all five wells studied, in response to increasing depth (pressure) and temperature. A greenschist facies assemblage, defined by albite + actinolite, gives way to an amphibolite facies, defined by plagioclase (andesine) + hornblende, in the San Vito 1 well at about 380??C. The fluid inclusion salinity values mimic the saline and hypersaline fluids found by drilling. Fluid inclusion V/L homogenization temperatures increase with depth and generally correspond to the extrapolated down-hole temperatures. However, fluid inclusion data for Mofete 5 and mineral assemblage data for San Vito 3, indicate fossil, higher-temperature regimes. A limited 87Sr/86Sr study of leachate (carbonate) and the leached cores shows that for most samples (except San Vito 3) the carbonate deposition has been from slightly 87Sr-enriched fluids and that Sr isotopic exchange has been incomplete. However, San Vito 3 cores show an approach to fluid/rock Sr equilibrium with a fluid similar to modern ocean water in 87Sr/86Sr ratio. The Campi Flegrei volcanic system has evolved undersaturated products, mostly trachyte, and defines a large (??? 12 km) caldera. The hydrothermal system developed in this location can be used as an analog for fossil systems in similar trachytic environments. The potential for ore mineralization is expressed by the recognition, from fluid inclusion and drilling data, of ore-forming environments such as boiling and brine stratification. ?? 1989.

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2011–13

USGS Publications Warehouse

Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Shellenbarger, Gregory; Weidich, Kurt

2014-01-01

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. To understand this environment, the USGS, along with its partners, has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay. Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically change on a daily cycle: consequently, salinity, water temperature, suspendedsediment concentration, and dissolvedoxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet is to inform the public and resource managers of the availability of these water-quality data.

Trapping of Momentum due to Low Salinity Water in the north Bay of Bengal

NASA Astrophysics Data System (ADS)

Chaudhuri, D.; Tandon, A.; Farrar, T.; Weller, R. A.; Venkatesan, R.; S, S.; MacKinnon, J. A.; D'Asaro, E. A.; Sengupta, D.

2016-02-01

We study the relation between near-surface ocean stratification and upper ocean currents (momentum) during the diurnal cycle and subseasonal "active-break cycle" of the summer monsoon in the north Bay of Bengal. We use time series of hourly observations from NIOT moorings BD08, BD09 and an INCOIS mooring near 18 N, 89 E in 2013, and data collected during two research cruises of ORV Sagar Nidhi in August-September 2014 and 2015. Our analyses are based on upper ocean profiles of temperature, salinity and density (from moorings and a shipborne underway conductivity-temperature-depth profiler), velocity (Acoustic Doppler Current Profiler), and surface forcing (meterology sensors on moored buoy and ship). Monsoon breaks are characterized by low rainfall, low wind speed (0-5 m/s) and high incident shortwave radiation, whereas active phases are marked by intense rainfall, high wind speed (8-16 m/s) and low incident sunlight. Our main findings are: (i) Net surface heat flux is positive (ocean gains heat) during break spells, and sea surface temperature (SST) rises by upto 1.5 C in 1-2 weeks. (ii) During breaks, day-night SST difference can reach 1.5C; mixed layer depth (MLD) shoals to 5m during day time, and deepens to 15-20 m by late night/early morning. (iii) During active spells, SST cools on subseasonal scales; MLD is deep (exceeding 20 m), and diurnal re-stratification is weak or absent. (iv) Once very low-salinity water (<30 psu) from rivers arrives at the moorings in late August, MLD remains shallow, and is insensitive to subseasonal changes in surface forcing. (v) Moored data and high-resolution observations from the summer 2014 and 2015 cruises reveal trapping of momentum from winds in a relatively thin surface layer when surface salinity is low and the shallow stratification is strong. Results of ingoing analyses will be presented at the meeting.

Kidney stone ablation times and peak saline temperatures during Holmium:YAG and Thulium fiber laser lithotripsy, in vitro, in a ureteral model

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2015-02-01

Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental Thulium fiber laser (TFL) was studied and compared to clinical gold standard Holmium:YAG laser. The Holmium laser (λ = 2120 nm) was operated with standard parameters of 600 mJ, 350 μs, 6 Hz, and 270-μm-core optical fiber. TFL (λ = 1908 nm) was operated with 35 mJ, 500 μs, 150-500 Hz, and 100-μm-core fiber. Urinary stones (60% calcium oxalate monohydrate / 40% calcium phosphate), of uniform mass and diameter (4-5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 ml/min and 13.7 ml/min for the TFL and Holmium laser, respectively. The temperature 3 mm from tube's center and 1 mm above mesh sieve was measured by a thermocouple and recorded during experiments. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. Holmium laser time measured 167 +/- 41 s (n = 12). TFL times measured 111 +/- 49 s, 39 +/- 11 s, and 23 +/- 4 s, for pulse rates of 150, 300, and 500 Hz (n = 12 each). Mean peak saline irrigation temperatures reached 24 +/- 1 °C for Holmium, and 33 +/- 3 °C, 33 +/- 7 °C, and 39 +/- 6 °C, for TFL at pulse rates of 150, 300, and 500 Hz. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and reduced stone retropulsion, and may provide a clinical alternative to the conventional Holmium laser for lithotripsy.

Effect of salinity on the upper lethal temperature tolerance of early-juvenile red drum.

PubMed

McDonald, Dusty; Bumguardner, Britt; Cason, Paul

2015-10-01

Previous work investigating the temperature tolerance of juvenile red drum ranging 18-50mm TL found evidence for positive size dependence (smaller fish less tolerant to higher temperatures) suggesting smaller size classes (<18mm TL) potentially may succumb to extreme summer water temperatures. Here, we explored the upper lethal temperature tolerance (ULT) in smaller-sized red drum which ranged from 10 to 20mm TL across multiple salinities to further understand the thermal limitations of this propagated game fish. In order to investigate the combined effect of temperature and salinity on ULT, temperature trials were conducted under three levels of salinity which commonly occur along the coast of Texas (25, 35, and 45ppt). The rate of temperature increase (+0.25°C/h) was designed to mimic a natural temperature increase of a summer day in Texas. We determined that the lethal temperature at 50% (LT50) did not differ between the three salinities examined statistically; median lethal temperature for individuals exposed to 25ppt ranged from 36.4 to 37.7°C, 35ppt ranged from 36.4 to 37.7°C, and 45ppt ranged from 36.1 to 37.4°C. Further, LT50 data obtained here for early-juvenile red drum did not differ from data of a similar experiment examining 25mm TL sized fish. Published by Elsevier Ltd.

High salinity relay as a postharvest processing strategy to reduce vibrio vulnificus levels in Chesapeake Bay oysters (Crassostrea virginica).

PubMed

Audemard, Corinne; Kator, Howard I; Rhodes, Martha W; Gallivan, Thomas; Erskine, A J; Leggett, A Thomas; Reece, Kimberly S

2011-11-01

In 2009 the U.S. Food and Drug Administration (FDA) announced its intention to implement postharvest processing (PHP) methods to eliminate Vibrio vulnificus from oysters intended for the raw, half-shell market that are harvested from the Gulf of Mexico during warmer months. FDA-approved PHP methods can be expensive and may be associated with unfavorable responses from some consumers. A relatively unexplored PHP method that uses relaying to high salinity waters could be an alternative strategy, considering that high salinities appear to negatively affect the survival of V. vulnificus. During relay, however, oysters may be exposed to rapid and large salinity increases that could cause increased mortality. In this study, the effectiveness of high salinity relay to reduce V. vulnificus to <30 most probable number (MPN) per g and the impact on oyster mortality were assessed in the lower Chesapeake Bay. Two relay experiments were performed during the summer and fall of 2010. Oysters collected from three grow-out sites, a low salinity site (14 to 15 practical salinity units [psu]) and two moderate salinity sites (22 to 25 psu), were relayed directly to a high salinity site (≥30 psu) on Virginia's Eastern Shore. Oysters were assayed for V. vulnificus and Vibrio parahaemolyticus (another Vibrio species of concern) densities at time 0 prior to relay and after 7 and 14 days of relay, using the FDA MPN enrichment method combined with detection by real-time PCR. After 14 days, both V. vulnificus and V. parahaemolyticus densities were ≤0.8 MPN/g, and decreases of 2 to 3 log in V. vulnificus densities were observed. Oyster mortalities were low (≤4%) even for oysters from the low salinity harvest site, which experienced a salinity increase of approximately 15 psu. Results, although preliminary and requiring formal validation and economic analysis, suggest that high salinity relay could be an effective PHP method.

Remote Sensing of Salinity: The Dielectric Constant of Sea Water

NASA Technical Reports Server (NTRS)

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%.

Molecular Gibbs Surface Excess and CO2-Hydrate Density Determine the Strong Temperature- and Pressure-Dependent Supercritical CO2-Brine Interfacial Tension.

PubMed

Ji, Jiayuan; Zhao, Lingling; Tao, Lu; Lin, Shangchao

2017-06-29

In CO 2 geological storage, the interfacial tension (IFT) between supercritical CO 2 and brine is critical for the storage capacitance design to prevent CO 2 leakage. IFT relies not only on the interfacial molecule properties but also on the environmental conditions at different storage sites. In this paper, supercritical CO 2 -NaCl solution systems are modeled at 343-373 K and 6-35 MPa under the salinity of 1.89 mol/L using molecular dynamics simulations. After computing and comparing the molecular density profile across the interface, the atomic radial distribution function, the molecular orientation distribution, the molecular Gibbs surface excess (derived from the molecular density profile), and the CO 2 -hydrate number density under the above environmental conditions, we confirm that only the molecular Gibbs surface excess of CO 2 molecules and the CO 2 -hydrate number density correlate strongly with the temperature- and pressure-dependent IFTs. We also compute the populations of two distinct CO 2 -hydrate structures (T-type and H-type) and attribute the observed dependence of IFTs to the dominance of the more stable, surfactant-like T-type CO 2 -hydrates at the interface. On the basis of these new molecular mechanisms behind IFT variations, this study could guide the rational design of suitable injecting environmental pressure and temperature conditions. We believe that the above two molecular-level metrics (Gibbs surface excess and hydrate number density) are of great fundamental importance for understanding the supercritical CO 2 -water interface and engineering applications in geological CO 2 storage.

Etched FBG coated with polyimide for simultaneous detection the salinity and temperature

NASA Astrophysics Data System (ADS)

Luo, Dong; Ma, Jianxun; Ibrahim, Zainah; Ismail, Zubaidah

2017-06-01

In marine environment, concrete structures can corrode because of the PH alkalinity of concrete paste; and the salinity PH is heavily related with the concentration of salt in aqueous solutions. In this study, an optical fiber salinity sensor is proposed on the basis of an etched FBG (EFBG) coated with a layer of polyimide. Chemical etching is employed to reduce the diameter of FBG and to excite Cladding Mode Resonance Wavelengths (CMRWs). CMRW and Fundamental Mode Resonance Wavelength (FMRW) can be used to measure the Refractive index (RI) and temperature of salinity. The proposed sensor is then characterized with a matrix equation. Experimental results show that FMRW and 5th CMRW have the detection sensitivities of 15.407 and 125.92 nm/RIU for RI and 0.0312 and 0.0435 nm/°C for temperature, respectively. The proposed sensor can measure salinity and temperature simultaneously.

Critical thresholds in sea lice epidemics: evidence, sensitivity and subcritical estimation

PubMed Central

Frazer, L. Neil; Morton, Alexandra; Krkošek, Martin

2012-01-01

Host density thresholds are a fundamental component of the population dynamics of pathogens, but empirical evidence and estimates are lacking. We studied host density thresholds in the dynamics of ectoparasitic sea lice (Lepeophtheirus salmonis) on salmon farms. Empirical examples include a 1994 epidemic in Atlantic Canada and a 2001 epidemic in Pacific Canada. A mathematical model suggests dynamics of lice are governed by a stable endemic equilibrium until the critical host density threshold drops owing to environmental change, or is exceeded by stocking, causing epidemics that require rapid harvest or treatment. Sensitivity analysis of the critical threshold suggests variation in dependence on biotic parameters and high sensitivity to temperature and salinity. We provide a method for estimating the critical threshold from parasite abundances at subcritical host densities and estimate the critical threshold and transmission coefficient for the two epidemics. Host density thresholds may be a fundamental component of disease dynamics in coastal seas where salmon farming occurs. PMID:22217721

Accurate Measurements of the Dielectric Constant of Seawater at L Band

NASA Technical Reports Server (NTRS)

Lang, Roger; Zhou, Yiwen; Utku, Cuneyt; Le Vine, David

2016-01-01

This paper describes measurements of the dielectric constant of seawater at a frequency of 1.413 GHz, the center of the protected band (i.e., passive use only) used in the measurement of sea surface salinity from space. The objective of the measurements is to accurately determine the complex dielectric constant of seawater as a function of salinity and temperature. A resonant cylindrical microwave cavity in transmission mode has been employed to make the measurements. The measurements are made using standard seawater at salinities of 30, 33, 35, and 38 practical salinity units over a range of temperatures from 0 degree C to 35 degree C in 5 degree C intervals. Repeated measurements have been made at each temperature and salinity. Mean values and standard deviations are then computed. The total error budget indicates that the real and imaginary parts of the dielectric constant have a combined standard uncertainty of about 0.3 over the range of salinities and temperatures considered. The measurements are compared with the dielectric constants obtained from the model functions of Klein and Swift and those of Meissner and Wentz. The biggest differences occur at low and high temperatures.

Time evolving bed shear stress due the passage of gravity currents estimated with ADVP velocity measurements

NASA Astrophysics Data System (ADS)

Zordan, Jessica; Schleiss, Anton J.; Franca, Mário J.

2016-04-01

Density or gravity currents are geophysical flows driven by density gradients between two contacting fluids. The physical trigger mechanism of these phenomena lays in the density differences which may be caused by differences in the temperature, dissolved substances or concentration of suspended sediments. Saline density currents are capable to entrain bed sediments inducing signatures in the bottom of sedimentary basins. Herein, saline density currents are reproduced in laboratory over a movable bed. The experimental channel is of the lock-exchange type, it is 7.5 m long and 0.3 m wide, divided into two sections of comparable volumes by a sliding gate. An upstream reach serves as a head tank for the dense mixture; the current propagates through a downstream reach where the main measurements are made. Downstream of the channel a tank exist to absorb the reflection of the current and thus artifacts due to the limited length of the channel. High performance thermoplastic polyurethane simulating fine sediments forms the movable bed. Measures of 3D instantaneous velocities will be made with the use of the non-intrusive technique of the ADV (Acoustic Doppler Current Profiler). With the velocity measurements, the evolution in time of the channel-bed shear stress due the passage of gravity currents is estimated. This is in turn related to the observed erosion and to such parameters determinant for the dynamics of the current as initial density difference, lock length and channel slope. This work was funded by the ITN-Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7-PEOPLE-2013-ITN under REA grant agreement n_607394-SEDITRANS.

Water-mass dynamics of an Arctic cold-water coral reef: First results from a new ocean observatory system

NASA Astrophysics Data System (ADS)

Flögel, Sascha; Karstensen, Johannes; Linke, Peter; Pfannkuche, Olaf; Ashastina, Kseniia; Dullo, Christian

2015-04-01

Cold-water coral reefs occur at various sites along the European continental margin, like in the Mediterranean Sea, on carbonate mounds West off Ireland, or at shallower depths between 100 and 350 m on the Norwegian shelf. Their occurrence is related to different physical parameters like temperature, salinity, seawater density, dissolved oxygen, and to other environmental parameters such as internal wave activity, nutrient supply, strong currents, which keep sediment input low, etc. Here, we present first results from a long-term observation in one of the nortnermost cold-water coral reefs at 70.5°N - the Stjernsund in northern Norway. The Stjernsund is a 30 km long and up to 3.5 km wide sound connecting the open North Atlantic with a fjord system. A deep-seated SW-NE oriented morainic sill with varying depths (203-236 m) splits the more than 400 m deep sound into two troughs. Living Lophelia pertusa dominated reef complexes occur on the NW slope between 235 and 305 m water depths and on the SE slope between 245 and 280 m. To investigate the dominating physical and biogeochemical boundary conditions a new modular seafloor observatory, MoLab, consisting of five sea-floor observatories and two moorings was deployed for 100 days during the summer of 2012. The various lander systems and moorimgs were equipped with sensors to measure current velocities and directions, temperature, salinity, pressure, pH, turbidity, fluorescence, oxygen concentration and saturation. Results showed that near-bottom salinities, temperature and current velocities are dominated by a semi-diurnal tidal forcing (pronounced M2 constituent), which cause vertical water mass movements of up to 100 m. These influence large parts of the living reef. Closer examination revealed overturning cells on the south-eastern slope of the sill during high tide, when Atlantic Water flows over the sill. The appearance of living cold-water corals is limited to a density envelope of sigma-theta=27.25-27.50 kg/m-3, which marks the boundary between Norwegian Coastal Water and Atlantic Water. Globally, Lophelia pertusa lives in waters covering a wide range of physical and biogeochemical parameters. This new data sets indicates parameter ranges, of e.g. current velocities (15-30 cm/s), temperature (6.0-6.8°C) and salinity (34.1-34.8), pH (8.22-7.39), turbidity (0.1-0.9 NTU), and oxygen concentration (300-339 μM) that are in agreement with other cold-water coral reefs in the NE Atlantic. The overall circulation depicts a complex dynamic system with pronounced differences not only vertically, but also important horizontal changes on top of the sill.

Remote sensing of salinity

NASA Technical Reports Server (NTRS)

Thomann, G. C.

1975-01-01

The complex dielectric constant of sea water is a function of salinity at 21 cm wavelength, and sea water salinity can be determined by a measurement of emissivity at 21 cm along with a measurement of thermodynamic temperature. Three aircraft and one helicopter experiments using two different 21 cm radiometers were conducted under different salinity and temperature conditions. Single or multiple ground truth measurements were used to calibrate the data in each experiment. It is inferred from these experiments that accuracies of 1 to 2%/OO are possible with a single surface calibration point necessary only every two hours if the following conditions are met--water temperatures above 20 C, salinities above 10%/OO, and level plane flight. More frequent calibration, constraint of the aircraft's orientation to the same as it was during calibration, and two point calibration (at a high and low salinity level) rather than single point calibration may give even better accuracies in some instances.

Delineating recurrent fish spawning habitats in the North Sea

NASA Astrophysics Data System (ADS)

Lelièvre, S.; Vaz, S.; Martin, C. S.; Loots, C.

2014-08-01

The functional value of spawning habitats makes them critically important for the completion of fish life cycles and spawning grounds are now considered to be “essential habitats”. Inter-annual fluctuations in spawning ground distributions of dab (Limanda Limanda), plaice (Pleuronectes platessa), cod (Gadus morhua) and whiting (Merlangius merlangus) were investigated in the southern North Sea and eastern English Channel, from 2006 to 2009. The preferential spawning habitats of these species were modelled using generalised linear models, with egg distribution being used as proxy of spawners' location. Egg spatial and temporal distributions were explored based on six environmental variables: sea surface temperature and salinity, chlorophyll a concentration, depth, bedstress and seabed sediment types. In most cases, egg density was found to be strongly related to these environmental variables. Egg densities were positively correlated with shallow to intermediate depths having low temperature and relatively high salinity. Habitat models were used to map annual, i.e. 2006 to 2009, winter spatial distributions of eggs, for each species separately. Then, annual maps were combined to explore the spatial variability of each species' spawning grounds, and define recurrent, occasional, rare and unfavourable spawning areas. The recurrent spawning grounds of all four species were located in the south-eastern part of the study area, mainly along the Dutch and German coasts. This study contributes knowledge necessary to the spatial management of fishery resources in the area, and may also be used to identify marine areas with particular habitat features that need to be preserved.

Mode Water Formation via Cabbeling and Submesoscale Lateral Mixing at a Strained Thermohaline Front

NASA Astrophysics Data System (ADS)

Thomas, L. N.; Shakespeare, C. J.

2014-12-01

Mode waters play an important role in interannual climate variability through the temporary storage of heat and carbon in the ocean. The mechanisms explaining their formation are not well understood but appear to be shaped by the dynamics of the ocean fronts that mark their poleward extent. We explore a mode water formation mechanism that has a clear connection to fronts and involves cabbeling. Cabbeling refers to the process by which two water masses of equal density but different temperature and salinity are combined to create a new, denser water mass, as a result of nonlinearities in the equation of state for seawater. The work is motivated in part by recent observations of an extremely sharp, density-compensated front at the north wall of the Gulf Stream, the boundary between the subtropical and subpolar gyres. Here, the inter-gyre salinity/temperature difference is compressed into a span of a few kilometers, making the flow susceptible to cabbeling. The sharpness of the front is caused by frontogenetic strain, which is presumably balanced by submesoscale lateral mixing processes. We study this balance with a simple analytical model of a thermohaline front forced by uniform strain and derive a scaling for the amount of water mass transformation resulting from the ensuing cabbeling. The theory suggests that this mechanism could be responsible for persistent, hence significant, mode water formation. As such, it represents a submesoscale process that impacts the ocean on basin scales that should be resolved or parameterized in realistic numerical simulations.

Effects of temperature and salinity on larval survival and development in the invasive shrimp Palaemon macrodactylus (Caridea: Palaemonidae) along the reproductive season

NASA Astrophysics Data System (ADS)

Guadalupe Vázquez, M.; Bas, Claudia C.; Kittlein, Marcelo; Spivak, Eduardo D.

2015-05-01

The invasive shrimp Palaemon macrodactylus is associated mainly with brackish waters. Previous studies raised the question if tolerance to low salinities differs between larvae and adults. To answer this question, the combined effects of two temperatures (20 and 25 °C) and four salinities (5, 12, 23 and 34 psu) on survival and development of larvae that hatched at the beginning, in the midpoint and near the end of a reproductive season (denoted early, middle season and late larvae respectively) were examined. The three types of larvae were able to survive and reach juvenile phase at salinities between 12 and 34 psu and at both temperatures. At 5 psu all larvae died, but 45% molted at least once. Temperature and salinity to a lesser extent, had effects on the duration of development and on the number of larval stages in all larval types. Development was longer at the lower temperature, especially in middle season and late larvae. Most early larvae reached the juvenile phase through 5 larval stages; the number of larval stages of middle season and late larvae was higher at 20 °C and in late larvae also low salinity produced extra stages. Low salinity (12 psu) and, in early and middle season larvae, low temperature produced lighter and smaller individuals. Response of larvae to environmental factors seems to be related in part to the previous conditions (maternal effects and/or embryo development conditions). The narrower salinity tolerance of larvae compared to adults and the ability of zoea I to survive at least some days at 5 psu may be related with an export larval strategy.

Upper-Ocean Variability in the Arctic’s Amundsen and Nansen Basins

DTIC Science & Technology

2017-05-01

collect vertical profiles of ocean temperature, salinity and horizontal velocity at few- hour interval as well as sample for specified time periods...deployed for the MIZ program - specifically, vertical temperature, salinity and velocity profiles were collected every 3 hours in the upper 250m of the...the system), this ITP-V returned 5+ months of upper ocean temperature, salinity , velocity and turbulence data from the Makarov Basin, a region of

Experimental studies on the larval development of the shrimps Crangon crangon and C. allmanni

NASA Astrophysics Data System (ADS)

Criales, M. M.; Anger, K.

1986-09-01

Larvae of the shrimps Crangon crangon L. and C. allmanni Kinahan were reared in the laboratory from hatching through metamorphosis. Effects of rearing methods (larval density, application of streptomycin, food) and of salinity on larval development were tested only in C. crangon, influence of temperature was studied in both species. Best results were obtained when larvae were reared individually, with a mixture of Artemia sp. and the rotifer Brachionus plicatilis as food. Streptomycin had partly negative effects and was thus not adopted for standard rearing techniques. All factors tested in this study influenced not only the rates of larval survival and moulting, but also morphogenesis. In both species, in particular in C. crangon, a high degree of variability in larval morphology and in developmental pathways was observed. Unsuitable conditions, e.g. crowding in mass culture, application of antibiotics, unsuitable food (rotifers, phytoplankton), extreme temperatures and salinities, tend to increase the number of larval instars and of morphological forms. The frequency of moulting is controlled mainly by temperature. Regression equations describing the relations between the durations of larval instars and temperature are given for both Crangon species. The number of moults is a linear function of larval age and a power function of temperature. There is high variation in growth (measured as carapace length), moulting frequency, morphogenesis, and survival among hatches originating from different females. The interrelations between these different measures of larval development in shrimps and prawns are discussed.

PETher - Physical Properties of Thermal Water under In-situ-Conditions

NASA Astrophysics Data System (ADS)

Herfurth, Sarah; Schröder, Elisabeth

2016-04-01

The objective of PETher, a research project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), is to experimentally determine thermo-physical properties (specific isobaric heat capacity, kinematic viscosity, density and thermal conductivity) of geothermal water in-situ-conditions (pressure, temperature, chemical composition including gas content of the brine) present in geothermal applications. Knowing these thermo-physical properties reduces the uncertainties with respect to estimating the thermal output and therefore the economic viability of the power plant. Up to now, only a limited number of measurements of selected physical properties have been made, usually under laboratory conditions and for individual geothermal plants. In-situ measured parameters, especially in the temperature range of 120°C and higher, at pressures of 20 bar and higher, as well as with a salinity of up to 250 g/l, are sparse to non-existing. Therefore, pure water properties are often used as reference data and for designing the power plant and its components. Currently available numerical models describing the thermo-physical properties are typically not valid for the conditions in geothermal applications and do not consider the substantial influence of the chemical composition of the thermal water. Also, actual geothermal waters have not been subject of detailed measurements systematically performed under operational conditions on a large-scale basis. Owing to the lack of reliable data, a validation of numerical models for investigating geothermal systems is not possible. In order to determine the dependency of the thermo-physical properties of geothermal water on temperature, pressure and salinity in-situ measurements are conducted. The measurements are taking place directly at several geothermal applications located in Germany's hydrogeothermal key regions. In order to do this, a mobile testing unit was developed and refined with instruments specifically designed in-house to meet any geothermal reservoir conditions present in Germany. The obtained results will be compared with standard analytical methods as well as used to calibrate laboratory measurements that simulate the encountered in-situ conditions. A series of measurements will be performed to create a data base. In addition, these data can be used as reference data for developing and validating numerical models. In-situ measurements - in contrast to laboratory measurements - record the data online and instantaneously during normal operation of the plant and without changing the properties of the investigated fluid (pressure, temperature, etc.). Due to this, the uncertainties in the thermo-physical properties caused by degassing and precipitation are studiously avoided. As a result, the thermo-physical properties density, specific isobaric heat capacity, kinematic viscosity and thermal conductivity have been measured as functions of the geothermal water temperature, pressure and salinity at five sites, up to now. The measurements show that the thermo-physical properties correlate strongly with the salinity and therefore differ considerably from pure water values when a significant salt content is present.

The salinity, temperature, and delta18O of the glacial deep ocean.

PubMed

Adkins, Jess F; McIntyre, Katherine; Schrag, Daniel P

2002-11-29

We use pore fluid measurements of the chloride concentration and the oxygen isotopic composition from Ocean Drilling Program cores to reconstruct salinity and temperature of the deep ocean during the Last Glacial Maximum (LGM). Our data show that the temperatures of the deep Pacific, Southern, and Atlantic oceans during the LGM were relatively homogeneous and within error of the freezing point of seawater at the ocean's surface. Our chloride data show that the glacial stratification was dominated by salinity variations, in contrast with the modern ocean, for which temperature plays a primary role. During the LGM the Southern Ocean contained the saltiest water in the deep ocean. This reversal of the modern salinity contrast between the North and South Atlantic implies that the freshwater budget at the poles must have been quite different. A strict conversion of mean salinity at the LGM to equivalent sea-level change yields a value in excess of 140 meters. However, the storage of fresh water in ice shelves and/or groundwater reserves implies that glacial salinity is a poor predictor of mean sea level.

Effects of Salinity and Temperature on Growth and Survival of Juvenile Iwagaki Oyster Crassostrea nippona

NASA Astrophysics Data System (ADS)

Wang, Tao; Li, Qi

2018-03-01

Iwagaki oyster Crassostrea nippona occurs naturally along the coasts of Japan and Korea. Because of its unique flavor, delicious taste, edibility during the summer and high commercial value, it has been identified as a potential aquaculture species. To determine the optimum aquaculture conditions and provide necessary information for mass production of the juvenile, the effects of six salinities (15, 20, 25, 30, 35 and 40) and five temperatures (16, 20, 24, 28 and 32₿ on growth and survival of juvenile C. nippona were examined in this study. In the salinity experiment, the largest values of mean shell height and growth rate were observed at salinity 25 (20.96 ± 0.36 mm and 172.0 μm d↿, respectively), which were significantly different (P < 0.05) with those of other treatments, except at salinity 30 (20.56 ± 1.05 mm and 160.3 μm d↿, respectively) (P > 0.05). The maximum survival rate 84.44% was always observed at salinity 20, and there was no significant difference (P > 0.05) in survival rate among salinities varying between 15 and 35. In the temperature-related experiments, the highest growth and survival rates of juvenile were observed at 24₿(180.8 μm d↿ and 84.4%) and 28₿(190.7 μm d↿ and 83.3%), respectively, on day 20, and showed significantly (P < 0.05) larger size and higher survival rate than any other groups. Both juvenile survival and growth were significantly depressed at extreme salinities (15, 40) and temperatures (16₿ 32₿. Based on the results of the present study, a salinity range from 25 to 30 and a temperature range from 24 to 28₿are considered optimal conditions for survival and growth of juvenile C. nippona.

Effect of elevated pCO2 on metabolic responses of porcelain crab (Petrolisthes cinctipes) Larvae exposed to subsequent salinity stress.

PubMed

Miller, Seth H; Zarate, Sonia; Smith, Edmund H; Gaylord, Brian; Hosfelt, Jessica D; Hill, Tessa M

2014-01-01

Future climate change is predicted to alter the physical characteristics of oceans and estuaries, including pH, temperature, oxygen, and salinity. Investigating how species react to the influence of such multiple stressors is crucial for assessing how future environmental change will alter marine ecosystems. The timing of multiple stressors can also be important, since in some cases stressors arise simultaneously, while in others they occur in rapid succession. In this study, we investigated the effects of elevated pCO2 on oxygen consumption by larvae of the intertidal porcelain crab Petrolisthes cinctipes when exposed to subsequent salinity stress. Such an exposure mimics how larvae under future acidified conditions will likely experience sudden runoff events such as those that occur seasonally along portions of the west coast of the U.S. and in other temperate systems, or how larvae encounter hypersaline waters when crossing density gradients via directed swimming. We raised larvae in the laboratory under ambient and predicted future pCO2 levels (385 and 1000 µatm) for 10 days, and then moved them to seawater at ambient pCO2 but with decreased, ambient, or elevated salinity, to monitor their respiration. While larvae raised under elevated pCO2 or exposed to stressful salinity conditions alone did not exhibit higher respiration rates than larvae held in ambient conditions, larvae exposed to elevated pCO2 followed by stressful salinity conditions consumed more oxygen. These results show that even when multiple stressors act sequentially rather than simultaneously, they can retain their capacity to detrimentally affect organisms.

Effect of Elevated pCO2 on Metabolic Responses of Porcelain Crab (Petrolisthes cinctipes) Larvae Exposed to Subsequent Salinity Stress

PubMed Central

Miller, Seth H.; Zarate, Sonia; Smith, Edmund H.; Gaylord, Brian; Hosfelt, Jessica D.; Hill, Tessa M.

2014-01-01

Future climate change is predicted to alter the physical characteristics of oceans and estuaries, including pH, temperature, oxygen, and salinity. Investigating how species react to the influence of such multiple stressors is crucial for assessing how future environmental change will alter marine ecosystems. The timing of multiple stressors can also be important, since in some cases stressors arise simultaneously, while in others they occur in rapid succession. In this study, we investigated the effects of elevated pCO2 on oxygen consumption by larvae of the intertidal porcelain crab Petrolisthes cinctipes when exposed to subsequent salinity stress. Such an exposure mimics how larvae under future acidified conditions will likely experience sudden runoff events such as those that occur seasonally along portions of the west coast of the U.S. and in other temperate systems, or how larvae encounter hypersaline waters when crossing density gradients via directed swimming. We raised larvae in the laboratory under ambient and predicted future pCO2 levels (385 and 1000 µatm) for 10 days, and then moved them to seawater at ambient pCO2 but with decreased, ambient, or elevated salinity, to monitor their respiration. While larvae raised under elevated pCO2 or exposed to stressful salinity conditions alone did not exhibit higher respiration rates than larvae held in ambient conditions, larvae exposed to elevated pCO2 followed by stressful salinity conditions consumed more oxygen. These results show that even when multiple stressors act sequentially rather than simultaneously, they can retain their capacity to detrimentally affect organisms. PMID:25295878

Climate change and soil salinity: The case of coastal Bangladesh.

PubMed

Dasgupta, Susmita; Hossain, Md Moqbul; Huq, Mainul; Wheeler, David

2015-12-01

This paper estimates location-specific soil salinity in coastal Bangladesh for 2050. The analysis was conducted in two stages: First, changes in soil salinity for the period 2001-2009 were assessed using information recorded at 41 soil monitoring stations by the Soil Research Development Institute. Using these data, a spatial econometric model was estimated linking soil salinity with the salinity of nearby rivers, land elevation, temperature, and rainfall. Second, future soil salinity for 69 coastal sub-districts was projected from climate-induced changes in river salinity and projections of rainfall and temperature based on time trends for 20 Bangladesh Meteorological Department weather stations in the coastal region. The findings indicate that climate change poses a major soil salinization risk in coastal Bangladesh. Across 41 monitoring stations, the annual median projected change in soil salinity is 39 % by 2050. Above the median, 25 % of all stations have projected changes of 51 % or higher.

Characteristics of the ichthyofauna of a temperate microtidal estuary with a reverse salinity gradient, including inter-decadal comparisons.

PubMed

Veale, L; Tweedley, J R; Clarke, K R; Hallett, C S; Potter, I C

2014-11-01

Data on the fish fauna of the Leschenault Estuary on the lower west coast of Australia were collected and used as a model to elucidate the characteristics of permanently open estuaries with a reverse salinity gradient, which undergo seasonal changes similar to many other estuaries with Mediterranean climate. Focus was placed on determining (1) the relationships of the number of species, density, life cycle category and species composition of fishes with region (within estuary), season and year and salinity, (2) whether species are partitioned along the lengths of such systems and (3) the extent and significance of any inter-decadal changes in species composition. The analyses and interpretation involved using multi-factorial permutational multivariate analysis of variance (PERMANOVA) and analysis of similarity (ANOSIM) designs, and three new or recently published visualization tools, i.e. modified non-metric multidimensional scaling (nMDS) plots, coherent species curves and segmented bubble plots. The base, lower, upper and apex regions of the Leschenault Estuary, along which the salinity increased in each season except in winter when most rainfall occurs, were sampled seasonally for the 2 years between winter 2008 and autumn 2010. Estuarine residents contributed twice as many individuals, but less than half the number of species as marine taxa. While the numbers of marine species and estuarine residents declined between the base or lower and apex regions, the individuals of marine species dominated the catches in the base region and estuarine residents in the other three regions. Ichthyofaunal composition in each region underwent conspicuous annual cyclical changes, due to time-staggered differences in recruitment among species, and changed sequentially along the estuary, both paralleling salinity trends. Different groups of species characterized the fauna in the different regions and seasons, thereby partitioning resources among species. The ichthyofauna of the apex region, in which salinities reached 54 and temperatures 36° C, recorded the highest maximum density and, in terms of abundance, was dominated (90%) by three atherinid species, emphasizing the ability of this family to tolerate extreme conditions. Comparisons between the data for 2008-2010 and 1994 demonstrate that the spotted hardyhead Craterocephalus mugiloides and the common hardyhead Atherinomorus vaigiensis had colonized and become abundant in the Leschenault Estuary in the intervening period. This represents a southwards extension of the distribution of these essentially tropical species during a period of increasing coastal water temperatures as a result of climate change. The abundance of weed-associated species, e.g. the western gobbleguts Ostorhinchus rueppellii and the soldier Gymnapistes marmoratus, increased, whereas that of the longfinned goby Favonigobius lateralis decreased, probably reflecting increases in eutrophication and siltation, respectively. © 2014 The Fisheries Society of the British Isles.

A multilevel trait-based approach to the ecological performance of Microcystis aeruginosa complex from headwaters to the ocean.

PubMed

Kruk, Carla; Segura, Angel M; Nogueira, Lucía; Alcántara, Ignacio; Calliari, Danilo; Martínez de la Escalera, Gabriela; Carballo, Carmela; Cabrera, Carolina; Sarthou, Florencia; Scavone, Paola; Piccini, Claudia

2017-12-01

The Microcystis aeruginosa complex (MAC) clusters cosmopolitan and conspicuous harmful bloom-forming cyanobacteria able to produce cyanotoxins. It is hypothesized that low temperatures and brackish salinities are the main barriers to MAC proliferation. Here, patterns at multiple levels of organization irrespective of taxonomic identity (i.e. a trait-based approach) were analyzed. MAC responses from the intracellular (e.g. respiratory activity) to the ecosystem level (e.g. blooms) were evaluated in wide environmental gradients. Experimental results on buoyancy and respiratory activity in response to increased salinity (0-35) and a literature review of maximum growth rates under different temperatures and salinities were combined with field sampling from headwaters (800km upstream) to the marine end of the Rio de la Plata estuary (Uruguay-South America). Salinity and temperature were the major variables affecting MAC responses. Experimentally, freshwater MAC cells remained active for 24h in brackish waters (salinity=15) while colonies increased their flotation velocity. At the population level, maximum growth rate decreased with salinity and presented a unimodal exponential response with temperature, showing an optimum at 27.5°C and a rapid decrease thereafter. At the community and ecosystem levels, MAC occurred from fresh to marine waters (salinity 30) with a sustained relative increase of large mucilaginous colonies biovolume with respect to individual cells. Similarly, total biomass and, specific and morphological richness decreased with salinity while blooms were only detected in freshwater both at high (33°C) and low (11°C) temperatures. In brackish waters, large mucilaginous colonies presented advantages under osmotic restrictive conditions. These traits values have also been associated with higher toxicity potential. This suggest salinity or low temperatures would not represent effective barriers for the survival and transport of potentially toxic MAC under likely near future scenarios of increasing human impacts (i.e. eutrophication, dam construction and climate change). Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of effects of temperature, salinity, and electrode design on the performance of an electrochemical coliform detector

NASA Technical Reports Server (NTRS)

Grana, D. C.

1979-01-01

The results of two research programs to determine the optimum detector design for measuring fecal coliforms in saline waters for operational systems are presented. One program was concerned with the effects of temperature and salinity on endpoint response time, and the other, the interaction between electrode configurations and the test organisms. Test results show that the endpoint response time is related to salinity and seawater temperature; however, these results can be minimized by the correct choice of growth media. Electrode configurations were developed from stainless steel, Parlodion-coated stainless steel, and platinum that circumvented problems associated with the commercial redox electrodes.

Hemolymph chemistry and histopathological changes in Pacific oysters (Crassostrea gigas) in response to low salinity stress.

PubMed

Knowles, Graeme; Handlinger, Judith; Jones, Brian; Moltschaniwskyj, Natalie

2014-09-01

This study described seasonal differences in the histopathological and hemolymph chemistry changes in different family lines of Pacific oysters, Crassostrea gigas, in response to the stress of an abrupt change to low salinity, and mechanical grading. The most significant changes in pallial cavity salinity, hemolymph chemistry and histopathological findings occurred in summer at low salinity. In summer (water temperature 18°C) at low salinity, 9 (25.7% of full salinity), the mean pallial cavity salinity in oysters at day 3 was 19.8±1.6 (SE) and day 10 was 22.8±1.6 (SE) lower than oysters at salinity 35. Associated with this fall in pallial cavity salinity, mean hemolymph sodium for oysters at salinity 9 on day 3 and 10 were 297.2mmol/L±20(SE) and 350.4mmol/L±21.3(SE) lower than oysters at salinity 35. Similarly mean hemolymph potassium in oysters held at salinity 9 at day 3 and 10 were 5.6mmol/L±0.6(SE) and 7.9mmol/L±0.6 (SE) lower than oysters at salinity 35. These oysters at low salinity had expanded intercellular spaces and significant intracytoplasmic vacuolation distending the cytoplasm of epithelial cells in the alimentary tract and kidney and hemocyte infiltrate (diapedesis) within the alimentary tract wall. In contrast, in winter (water temperature 8°C) oyster mean pallial cavity salinity only fell at day 10 and this was by 6.0±0.6 (SE) compared to that of oysters at salinity 35. There were limited histopathological changes (expanded intercellular spaces and moderate intracytoplasmic vacuolation of renal epithelial cells) in these oysters at day 10 in low salinity. Mechanical grading and family line did not influence the oyster response to sudden low salinity. These findings provide additional information for interpretation of non-lethal, histopathological changes associated with temperature and salinity variation. Copyright © 2014 Elsevier Inc. All rights reserved.

Diatom Cell Size, Coloniality and Motility: Trade-Offs between Temperature, Salinity and Nutrient Supply with Climate Change

PubMed Central

Svensson, Filip; Norberg, Jon; Snoeijs, Pauline

2014-01-01

Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how “body size” (cells and colonies) and motility change along temperature (2–26°C) and salinity (0.5–7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels. PMID:25279720

Coastal circulation and sediment dynamics along West Maui, Hawaii; PART IV: measurements of waves, currents, temperature, salinity and turbidity in Honolua Bay, Northwest Maui: 2003-2004

USGS Publications Warehouse

Storlazzi, Curt D.; Presto, M. Kathy

2005-01-01

High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Honolua Bay, northwest Maui, Hawaii, during 2003 and 2004 to better understand coastal dynamics in coral reef habitats. Measurements were acquired through two different collection methods. Two hydrographic survey cruises were conducted to acquire spatially-extensive, but temporally-limited, three-dimensional measurements of currents, temperature, salinity and turbidity in the winter and summer of 2003. From mid 2003 through early 2004, a bottom-mounted instrument package was deployed in a water depth of 10 m to collect long-term, single-point high-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity. The purpose of these measurements was to collect hydrographic data to learn how waves, currents and water column properties such as water temperature, salinity and turbidity vary spatially and temporally in a near-shore coral reef system adjacent to a major stream drainage. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. This report, the final part in a series, describes data acquisition, processing and analysis. Previous reports provided data and results on: Long-term measurements of currents, temperature, salinity and turbidity off Kahana (PART I), the spatial structure of currents, temperature, salinity and suspended sediment along West Maui (PART II), and flow and coral larvae and sediment dynamics during the 2003 summer spawning season (PART III).

Diatom cell size, coloniality and motility: trade-offs between temperature, salinity and nutrient supply with climate change.

PubMed

Svensson, Filip; Norberg, Jon; Snoeijs, Pauline

2014-01-01

Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how "body size" (cells and colonies) and motility change along temperature (2-26°C) and salinity (0.5-7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels.

Interactive effects of water temperature and salinity on growth and mortality of eastern oysters, Crassostrea virginica: A meta-analysis using 40 years of monitoring data

USGS Publications Warehouse

Lowe, Michael R.; Sehlinger, Troy; Soniat, Thomas M.; LaPeyre, Megan K.

2017-01-01

Despite nearly a century of exploitation and scientific study, predicting growth and mortality rates of the eastern oyster (Crassostrea virginica) as a means to inform local harvest and management activities remains difficult. Ensuring that models reflect local population responses to varying salinity and temperature combinations requires locally appropriate models. Using long-term (1988 to 2015) monitoring data from Louisiana's public oyster reefs, we develop regionally specific models of temperature- and salinity-driven mortality (sack oysters only) and growth for spat (<25 mm), seed (25–75 mm), and sack (>75 mm) oyster size classes. The results demonstrate that the optimal combination of temperature and salinity where Louisiana oysters experience reduced mortality and fast growth rates is skewed toward lower salinities and higher water temperatures than previous models have suggested. Outside of that optimal range, oysters are commonly exposed to combinations of temperature and salinity that are correlated with high mortality and reduced growth. How these combinations affect growth, and to a lesser degree mortality, appears to be size class dependent. Given current climate predictions for the region and ongoing large-scale restoration activities in coastal Louisiana, the growth and mortality models are a critical step toward ensuring sustainable oyster reefs for long-term harvest and continued delivery of the ecological services in a changing environment.

Spatial and temporal variability of thermohaline properties in the Bay of Koper (northern Adriatic Sea)

NASA Astrophysics Data System (ADS)

Soczka Mandac, Rok; Žagar, Dušan; Faganeli, Jadran

2013-04-01

In this study influence of fresh water discharge on the spatial and temporal variability of thermohaline (TH) conditions is explored for the Bay of Koper (Bay). The Bay is subject to different driving agents: wind stress (bora, sirocco), tidal and seiches effect, buoyancy fluxes, general circulation of the Adriatic Sea and discharge of the Rizana and Badaševica rivers. These rivers have torrential characteristics that are hard to forecast in relation to meteorological events (precipitation). Therefore, during episodic events the spatial and temporal variability of TH properties in the Bay is difficult to determine [1]. Measurements of temperature, salinity and turbidity were conducted monthly on 35 sampling points in the period: June 2011 - December 2012. The data were processed and spatial interpolated with an objective analysis method. Furthermore, empirical orthogonal function analysis (EOF) [2] was applied to investigate spatial and temporal TH variations. Strong horizontal and vertical stratification was observed in the beginning of June 2011 due to high fresh water discharge of the Rizana (31 m3/s) and Badaševica (2 m3/s) rivers. The horizontal gradient (ΔT = 6°C) was noticed near the mouth of the Rizana river. Similar pattern was identified for salinity field on the boundary of the front where the gradient was ΔS = 20 PSU. Vertical temperature gradient was ΔT = 4°C while salinity gradient was ΔS = 18 PSU in the subsurface layer at depth of 3 m. Spatial analysis of the first principal component (86% of the total variance) shows uniform temperature distribution in the surface layer (1m) during the studied period. Furthermore, temporal variability of temperature shows seasonal variation with a minimum in February and maximum in August. This confirms that episodic events have a negligible effect on spatial and temporal variation of temperature in the subsurface layer. Further analysis will include application of EOF on the salinity, density and total suspended matter. Additionally, we will investigate the cross correlations between the above mentioned parameters with singular value decomposition method. Reference: 1. Faganeli, J., Planinc, R., Pezdic, J., Smodis, B., Stegnar, P., and Ogorelec, B. 1991. Marine geology of Gulf of Trieste (northern Adriatic): Geochemical aspects. Marine Geology, 99: 93-108. 2. Glover, M., Jenkins, J., and Doney, S. C. 2011. Modeling methods for marine science. Cambridge University Press, 571 p.

Change in coccolith size and morphology due to response to temperature and salinity in coccolithophore Emiliania huxleyi (Haptophyta) isolated from the Bering and Chukchi seas

NASA Astrophysics Data System (ADS)

Saruwatari, Kazuko; Satoh, Manami; Harada, Naomi; Suzuki, Iwane; Shiraiwa, Yoshihiro

2016-05-01

Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic oceans in 2010 were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains, namely MR57N isolated from the northern Bering Sea and MR70N at the Chukchi Sea. This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (estimated as the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters. The central area elements of coccoliths varied from thin lath type to well-calcified lath type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities with change in their morphology. Because all coccolith biometric parameters followed the scaling law, the decrease in coccolith size was caused simply by the reduced calcification. Taken together, our results suggest that calcification productivity may be used to predict future oceanic environmental conditions in the polar regions.

Comparison of energy efficiency and power density in pressure retarded osmosis and reverse electrodialysis.

PubMed

Yip, Ngai Yin; Elimelech, Menachem

2014-09-16

Pressure retarded osmosis (PRO) and reverse electrodialysis (RED) are emerging membrane-based technologies that can convert chemical energy in salinity gradients to useful work. The two processes have intrinsically different working principles: controlled mixing in PRO is achieved by water permeation across salt-rejecting membranes, whereas RED is driven by ion flux across charged membranes. This study compares the energy efficiency and power density performance of PRO and RED with simulated technologically available membranes for natural, anthropogenic, and engineered salinity gradients (seawater-river water, desalination brine-wastewater, and synthetic hypersaline solutions, respectively). The analysis shows that PRO can achieve both greater efficiencies (54-56%) and higher power densities (2.4-38 W/m(2)) than RED (18-38% and 0.77-1.2 W/m(2)). The superior efficiency is attributed to the ability of PRO membranes to more effectively utilize the salinity difference to drive water permeation and better suppress the detrimental leakage of salts. On the other hand, the low conductivity of currently available ion exchange membranes impedes RED ion flux and, thus, constrains the power density. Both technologies exhibit a trade-off between efficiency and power density: employing more permeable but less selective membranes can enhance the power density, but undesired entropy production due to uncontrolled mixing increases and some efficiency is sacrificed. When the concentration difference is increased (i.e., natural → anthropogenic → engineered salinity gradients), PRO osmotic pressure difference rises proportionally but not so for RED Nernst potential, which has logarithmic dependence on the solution concentration. Because of this inherently different characteristic, RED is unable to take advantage of larger salinity gradients, whereas PRO power density is considerably enhanced. Additionally, high solution concentrations suppress the Donnan exclusion effect of the charged RED membranes, severely reducing the permselectivity and diminishing the energy conversion efficiency. This study indicates that PRO is more suitable to extract energy from a range of salinity gradients, while significant advancements in ion exchange membranes are likely necessary for RED to be competitive with PRO.

Comparison of Energy Efficiency and Power Density in Pressure Retarded Osmosis and Reverse Electrodialysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yip, NY; Elimelech, M

Pressure retarded osmosis (PRO) and reverse electrodialysis (RED) are emerging membrane-based technologies that can convert chemical energy in salinity gradients to useful work. The two processes have intrinsically different working principles: controlled mixing in PRO is achieved by water permeation across salt-rejecting membranes, whereas RED is driven by ion flux across charged membranes. This study compares the energy efficiency and power density performance of PRO and RED with simulated technologically available membranes for natural, anthropogenic, and engineered salinity gradients (seawater-river water, desalination brine-wastewater, and synthetic hypersaline solutions, respectively). The analysis shows that PRO can achieve both greater efficiencies (54-56%) andmore » higher power densities (2.4-38 W/m(2)) than RED (18-38% and 0.77-1.2 W/m(2)). The superior efficiency is attributed to the ability of PRO membranes to more effectively utilize the salinity difference to drive water permeation and better suppress the detrimental leakage of salts. On the other hand, the low conductivity of currently available ion exchange membranes impedes RED ion flux and, thus, constrains the power density. Both technologies exhibit a trade-off between efficiency and power density: employing more permeable but less selective membranes can enhance the power density, but undesired entropy production due to uncontrolled mixing increases and some efficiency is sacrificed. When the concentration difference is increased (i.e., natural -> anthropogenic -> engineered salinity gradients), PRO osmotic pressure difference rises proportionally but not so for RED Nernst potential, which has logarithmic dependence on the solution concentration. Because of this inherently different characteristic, RED is unable to take advantage of larger salinity gradients, whereas PRO power density is considerably enhanced. Additionally, high solution concentrations suppress the Donnan exclusion effect of the charged RED membranes, severely reducing the permselectivity and diminishing the energy conversion efficiency. This study indicates that PRO is more suitable to extract energy from a range of salinity gradients, while significant advancements in ion exchange membranes are likely necessary for RED to be competitive with PRO.« less

Global climate change and its potential impact on disease transmission by salinity-tolerant mosquito vectors in coastal zones.

PubMed

Ramasamy, Ranjan; Surendran, Sinnathamby Noble

2012-01-01

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5-30 ppt and >30 ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross-McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal transmission of mosquito-borne diseases consequent to climate change and a rise in sea levels. It is proposed that the Jaffna peninsula in Sri Lanka may be a useful case study for the impact of rising sea levels on mosquito vectors in tropical coasts.

Global Climate Change and Its Potential Impact on Disease Transmission by Salinity-Tolerant Mosquito Vectors in Coastal Zones

PubMed Central

Ramasamy, Ranjan; Surendran, Sinnathamby Noble

2012-01-01

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5–30 ppt and >30 ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross–McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal transmission of mosquito-borne diseases consequent to climate change and a rise in sea levels. It is proposed that the Jaffna peninsula in Sri Lanka may be a useful case study for the impact of rising sea levels on mosquito vectors in tropical coasts. PMID:22723781

Salinity bias on the foraminifera Mg/Ca thermometry: Correction procedure and implications for past ocean hydrographic reconstructions

NASA Astrophysics Data System (ADS)

Mathien-Blard, Elise; Bassinot, Franck

2009-12-01

Mg/Ca in foraminiferal calcite has recently been extensively used to estimate past oceanic temperatures. Here we show, however, that the Mg/Ca temperature relationship of the planktonic species Globigerinoides ruber is significantly affected by seawater salinity, with a +1 psu change in salinity resulting in a +1.6°C bias in Mg/Ca temperature calculations. If not accounted for, such a bias could lead, for instance, to systematic overestimations of Mg/Ca temperatures during glacial periods, when global ocean salinity had significantly increased compared to today. We present here a correction procedure to derive unbiased sea surface temperatures (SST) and δ18Osw from G. ruber TMg/Ca and δ18Of measurements. This correction procedure was applied to a sedimentary record to reconstruct hydrographic changes since the Last Glacial Maximum (LGM) in the Western Pacific Warm Pool. While uncorrected TMg/Ca data indicate a 3°C warming of the Western Pacific Warm Pool since the LGM, the salinity-corrected SST result in a stronger warming of 4°C.

Results from a lab study of melting sea ice

NASA Astrophysics Data System (ADS)

Wiese, M.; Griewank, P.; Notz, D.

2012-04-01

Sea-ice melting is a complex process which is not fully understood yet. In order to study sea-ice melt in detail we perform lab experiments in an approximately 2x0.7x1.2 m large tank in a cold room. We grow sea ice with different salinities at least 10 cm thick. Then we let the ice melt at different air temperatures and oceanic heat fluxes. During the melt period, we measure the evolution of ice thickness, internal temperature, salinity and surface temperature. We will present results from roughly five months of experiments. Topics will include the influence of bulk salinity on melt rates and the surface temperature. The effects of flushing on the salinity evolution and detailed thermal profiles will also be included. To investigate these processes we focus on the energy budget and the salinity evolution. These topics are linked since the thermodynamic properties of sea ice (heat capacity, heat conductivity and latent heat of fusion) are very sensitive to salinity variations. For example the heat capacity of sea ice increases greatly as the temperature approaches the melting point. This increase results in non-linear temperature profiles and enhances heat conduction into the ice. The salinity evolution during the growth phase has been investigated and measured in multiple studies over the last decades. In contrast there are no detailed lab measurements of melting ice available to quantify the effects of flushing melt water and ponding. This is partially due to the fact that the heterogeneity of melting sea ice makes it much more difficult to measure representative values.

Comparative sensitivity of Crassostrea angulata and Crassostrea gigas embryo-larval development to As under varying salinity and temperature.

PubMed

Moreira, Anthony; Figueira, Etelvina; Libralato, Giovanni; Soares, Amadeu M V M; Guida, Marco; Freitas, Rosa

2018-06-07

Oysters are a diverse group of marine bivalves that inhabit coastal systems of the world's oceans, providing a variety of ecosystem services, and represent a major socioeconomic resource. However, oyster reefs have become inevitably impacted from habitat destruction, overfishing, pollution and disease outbreaks that have pushed these structures to the break of extinction. In addition, the increased frequency of climate change related events promise to further challenge oyster species survival worldwide. Oysters' early embryonic development is likely the most vulnerable stage to climate change related stressors (e.g. salinity and temperature shifts) as well as to pollutants (e.g. arsenic), and therefore can represent the most important bottleneck that define populations' survival in a changing environment. In light of this, the present study aimed to assess two important oyster species, Crassostrea angulata and Crassostrea gigas embryo-larval development, under combinations of salinity (20, 26 and 33), temperature (20, 24 and 28 °C) and arsenic (As) exposure (0, 30, 60, 120, 240, 480, 960 and 1920 μg. As L -1 ), to infer on different oyster species capacity to cope with these environmental stressors under the eminent threat of climate change and increase of pollution worldwide. Results showed differences in each species range of salinity and temperature for successful embryonic development. For C angulata, embryo-larval development was successful at a narrower range of both salinity and temperature, compared to C. gigas. Overall, As induced higher toxicity to C. angulata embryos, with calculated EC50 values at least an order of magnitude lower than those calculated for C. gigas. The toxicity of As (measured as median effective concentration, EC50) showed to be influenced by both salinity and temperature in both species. Nonetheless, salinity had a greater influence on embryos' sensitivity to As. This pattern was mostly noticed for C. gigas, with lower salinity inducing higher sensitivity to As. Results were discussed considering the existing literature and suggest that C. angulata populations are likely to become more vulnerable under near future predictions for temperature rise, salinity shifts and pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). Blue Crab

DTIC Science & Technology

1989-03-01

size only by Music 1979). molting (Hay 1905). Zoeal development depends on salinity and temperature, Growth and maturation proceed but development time...substrates. the effects depends on the toxicant, concentration, time exposed, salinity , tidal cycle, age and molt phase of Other Environmental Factors...Temperature .......................................................... 11 Salinity ............................................................. I11

Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

PubMed

Martins, Y S; Melo, R M C; Campos-Junior, P H A; Santos, J C E; Luz, R K; Rizzo, E; Bazzoli, N

2014-06-01

The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment. Copyright © 2014 Elsevier Inc. All rights reserved.

Impact of Satellite Remote Sensing Data on Simulations of ...

EPA Pesticide Factsheets

We estimated surface salinity flux and solar penetration from satellite data, and performed model simulations to examine the impact of including the satellite estimates on temperature, salinity, and dissolved oxygen distributions on the Louisiana continental shelf (LCS) near the annual hypoxic zone. Rainfall data from the Tropical Rainfall Measurement Mission (TRMM) were used for the salinity flux, and the diffuse attenuation coefficient (Kd) from Moderate Resolution Imaging Spectroradiometer (MODIS) were used for solar penetration. Improvements in the model results in comparison with in situ observations occurred when the two types of satellite data were included. Without inclusion of the satellite-derived surface salinity flux, realistic monthly variability in the model salinity fields was observed, but important inter-annual variability wasmissed. Without inclusion of the satellite-derived light attenuation, model bottom water temperatures were too high nearshore due to excessive penetration of solar irradiance. In general, these salinity and temperature errors led to model stratification that was too weak, and the model failed to capture observed spatial and temporal variability in water-column vertical stratification. Inclusion of the satellite data improved temperature and salinity predictions and the vertical stratification was strengthened, which improved prediction of bottom-water dissolved oxygen. The model-predicted area of bottom-water hypoxia on the

Notes on a Mesodinium rubrum red tide in San Francisco Bay (California, USA)

USGS Publications Warehouse

Cloern, James E.; Cole, Brian E.; Hager, Stephen W.

1994-01-01

Discrete red patches of water were observed in South San Francisco Bay (USA) on 30 April 1993, and examination of live samples showed that this red tide was caused by surface accumulations of the pigmented ciliate Mesodinium rubrum . Vertical profiles showed strong salinity and temperature stratification in the upper 5 m, peak chlorophyll fluorescence in the upper meter, and differences in the small-scale density structure and fluorescence distribution among red patches. Events preceding this Mesodinium red tide included: (i) heavy precipitation and run-off, allowing for strong salinity stratification; (ii) a spring diatom bloom where the chlorophyll a concentration reached 50 mg m −3 ; (ii) depletions of dissolved inorganic N and Si in the photic zone; and (iv) several days of rapid warming and stabilization of the upper surface layer. These conditions may be general prerequisites for M.rubrum blooms in temperate estuaries.

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico). COMMON RANGIA.

DTIC Science & Technology

1985-04-01

osmoconformer at salinities greater ENVIRONMENTAL REQUIREMENTS than 10 ppt, and an osmoregulator at lower salinities (Bedford and Anderson 1972a,b; Otto...1973, 1974) tested the combined effects of temperature (8 to 32°C) and salinity (0 to 20 ppt) on .. k6.. Temperature embryos and larvae of common...Bedford, W. B. , and J. W. Anderson. Allen, K. 1961. The effect of salin - 1972a. The physiological response ity on the amino acid concentra- of the

Are the spring and fall blooms on the Scotian Shelf related to short-term physical events?

NASA Astrophysics Data System (ADS)

Greenan, B. J. W.; Petrie, B. D.; Harrison, W. G.; Oakey, N. S.

2004-03-01

Physical, chemical and biological data from the Scotian Shelf indicate that short-term physical events affect the dynamics of spring and fall blooms. This is based on results from a three-week mooring deployment measuring currents, temperature, salinity and fluorescence in October 2000, combined with biweekly sampling of temperature, salinity, nutrients and chlorophyll throughout the year at this mooring site. A wind-driven upwelling event in mid-October shows temperature, salinity and density iso-surfaces rising by approximately 20 m. During this event, a bloom with peak chlorophyll concentrations of about 2.5 mg m -3 began as nutrients are brought into the upper part of the water column. Gradient Richardson Numbers ( Ri), a proxy for vertical mixing, are estimated for the mooring period in 2 m vertical bins using SeaHorse CTD data and nearby ADCP current measurements. These data indicate that vertical mixing may have played a complementary role to the upwelling in bringing nutrients into the euphotic zone. A trend of decreasing Ri in the ocean mixed layer with increasing surface wind stress is suggested. It appears that this short-term physical event is a primary factor in initiating the fall bloom on the inner Scotian Shelf in 2000. In April of that year, the termination of the spring bloom coincided with a downwelling event suggesting that it played a role in determining the duration of the bloom. SeaWiFS ocean color satellite provided a spatial context for chlorophyll observations, however, the lack of temporal resolution due to poor atmospheric conditions means that these data provide limited information on short-term chlorophyll variability.

The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

NASA Astrophysics Data System (ADS)

Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

2016-11-01

The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

Inclusions in diamonds constrain thermo-chemical conditions during Mesozoic metasomatism of the Kaapvaal cratonic mantle

NASA Astrophysics Data System (ADS)

Weiss, Yaakov; Navon, Oded; Goldstein, Steven L.; Harris, Jeff W.

2018-06-01

Fluid/melt inclusions in diamonds, which were encapsulated during a metasomatic event and over a short period of time, are isolated from their surrounding mantle, offering the opportunity to constrain changes in the sub-continental lithospheric mantle (SCLM) that occurred during individual thermo-chemical events, as well as the composition of the fluids involved and their sources. We have analyzed a suite of 8 microinclusion-bearing diamonds from the Group I De Beers Pool kimberlites, South Africa, using FTIR, EPMA and LA-ICP-MS. Seven of the diamonds trapped incompatible-element-enriched saline high density fluids (HDFs), carry peridotitic mineral microinclusions, and substitutional nitrogen almost exclusively in A-centers. This low-aggregation state of nitrogen indicates a short mantle residence times and/or low mantle ambient temperature for these diamonds. A short residence time is favored because, elevated thermal conditions prevailed in the South African lithosphere during and following the Karoo flood basalt volcanism at ∼180 Ma, thus the saline metasomatism must have occurred close to the time of kimberlite eruptions at ∼85 Ma. Another diamond encapsulated incompatible-element-enriched silicic HDFs and has 25% of its nitrogen content residing in B-centers, implying formation during an earlier and different metasomatic event that likely relates to the Karoo magmatism at ca. 180 Ma. Thermometry of mineral microinclusions in the diamonds carrying saline HDFs, based on Mg-Fe exchange between garnet-orthopyroxene (Opx)/clinopyroxene (Cpx)/olivine and the Opx-Cpx thermometer, yield temperatures between 875-1080 °C at 5 GPa. These temperatures overlap with conditions recorded by touching inclusion pairs in diamonds from the De Beers Pool kimberlites, which represent the mantle ambient conditions just before eruption, and are altogether lower by 150-250 °C compared to P-T gradients recorded by peridotite xenoliths from the same locality. Oxygen fugacity (fO2) differs as well. The fO2 calculated for the saline HDF compositions (Δlog ⁡ fO 2 (FMQ) = - 2.47 to -1.34) are higher by about a log unit compared with that recorded by xenoliths at 4-7 GPa. We conclude that enriched saline HDFs mediated the metasomatism that preceded Group I kimberlite eruptions in the southwestern Kaapvaal craton, and that their 'cold and oxidized' nature reflects their derivation from a deep subducting slab. This event had little impact on the temperature and redox state of the Kaapvaal lithosphere as a reservoir, however, it likely affected its properties along limited metasomatized veins and their wall rock. To reconcile the temperature and oxygen fugacity discrepancy between inclusions in diamonds and xenoliths, we argue that xenoliths did not equilibrate during the last saline metasomatic event or kimberlite eruption. Thus the P-T- fO2 gradients they record express pre-existing lithospheric conditions that were likely established during the last major thermal event in the Kaapvaal craton (i.e. the Karoo magmatism at ca. 180 Ma).

Ocean acidification narrows the acute thermal and salinity tolerance of the Sydney rock oyster Saccostrea glomerata.

PubMed

Parker, Laura M; Scanes, Elliot; O'Connor, Wayne A; Coleman, Ross A; Byrne, Maria; Pörtner, Hans-O; Ross, Pauline M

2017-09-15

Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO 2 -induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO 2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15-33°C) and salinity (34.2-20) treatments. Oysters acclimated to elevated CO 2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO 2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effects of temperature and salinity on phosphate levels in two euryhaline crustacean species

NASA Astrophysics Data System (ADS)

Spaargaren, D. H.; Richard, P.; Ceccaldi, H. J.

Total phoshate, inorganic phosphate and organic (phospholipid) phosphate concentrations were determined in the blood of Carcinus maenas and in whole-animal homogenates of Penaeus japonicus acclimatized to various salinities and a high or a low temperature. In the blood of Carcinus, total and inorganic P concentrations range between 1.0 and 4.5 mmol · l -1; the amount of phospholipids is negligeable. The higher values were found at more extreme salinities. Low temperature is associated with low phosphate concentrations, particularly at intermediate salinities. Total P concentrations in Penaeus homogenates range between 10 and 60 mmol · 1 -1; phospholipid concentrations range between zero and 50 mmol · 1 -1. The higher values are again found at the extreme salinities. Inorganic P concentrations are almost constant — ca 10 mmol · 1 -1. No apparent effect of temperature on phosphate concentrations was observed. The results show clearly that osmotic stress influences severely the phosphate metabolism of the two species studied. Both species are able to accumulate phosphate at all experimental temperature/salinity combinations used, even when deprived of food. At extreme salinities, large quantities of phosphate are accumulated and converted to organic P compounds, most likely as phospholipids associated with the cell membranes. These effects of osmotic conditions in phosphate metabolism may offer an explanation for the effect of Ca ++ on membrane permeability as the regulation of both ions may be strongly interrelated, often under hormonal control.

Henry's law constant for phosphine in seawater: determination and assessment of influencing factors

NASA Astrophysics Data System (ADS)

Fu, Mei; Yu, Zhiming; Lu, Guangyuan; Song, Xiuxian

2013-07-01

The Henry's Law constant ( k) for phosphine in seawater was determined by multiple phase equilibration combined with headspace gas chromatography. The effects of pH, temperature, and salinity on k were studied. The k value for phosphine in natural seawater was 6.415 at room temperature (approximately 23°C). This value increases with increases in temperature and salinity, but no obvious change was observed at different pH levels. At the same temperature, there was no significant difference between the k for phosphine in natural seawater and that in artificial seawater. This implies that temperature and salinity are major determining factors for k in marine environment. Double linear regression with Henry's Law constants for phosphine as a function of temperature and salinity confirmed our observations. These results provide a basis for the measurement of trace phosphine concentrations in seawater, and will be helpful for future research on the status of phosphine in the oceanic biogeochemical cycle of phosphorus.

Integrating Reverse-Electrodialysis Stacks with Flow Batteries for Improved Energy Recovery from Salinity Gradients and Energy Storage.

PubMed

Zhu, Xiuping; Kim, Taeyoung; Rahimi, Mohammad; Gorski, Christopher A; Logan, Bruce E

2017-02-22

Salinity gradient energy can be directly converted into electrical power by using reverse electrodialysis (RED) and other technologies, but reported power densities have been too low for practical applications. Herein, the RED stack performance was improved by using 2,6-dihydroxyanthraquinone and ferrocyanide as redox couples. These electrolytes were then used in a flow battery to produce an integrated RED stack and flow battery (RED-FB) system capable of capturing, storing, and discharging salinity gradient energy. Energy captured from the RED stack was discharged in the flow battery at a maximum power density of 3.0 kW m -2 -anode, which was similar to the flow batteries charged by electrical power and could be used for practical applications. Salinity gradient energy captured from the RED stack was recovered from the electrolytes as electricity with 30 % efficiency, and the maximum energy density of the system was 2.4 kWh m -3 -anolyte. The combined RED-FB system overcomes many limitations of previous approaches to capture, store, and use salinity gradient energy from natural or engineered sources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of temperature, salinity, and irradiance on the growth of harmful algal bloom species Phaeocystis globosa Scherffel (Prymnesiophyceae) isolated from the South China Sea

NASA Astrophysics Data System (ADS)

Xu, Ning; Huang, Bozhu; Hu, Zhangxi; Tang, Yingzhong; Duan, Shunshan; Zhang, Chengwu

2017-05-01

Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth of P. globosa ( I s) was 60 μmol/(m2•s), which was lower than those of other harmful algal species (70-114 μmol/(m2•s)). A moderate growth rate of 0.22/d was observed at 2 μmol/(m2•s) (the minimum irradiance in the experiment), and photo-inhibition did not occur at 230 μmol/(m2•s) (the maximum irradiance in the experiment). Exposed to 42 different combinations of temperatures (10-31°C) and salinities (10-40) under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24°C and 35, and 27°C and 40. The optimum growth rates (>0.80/d) were observed at temperatures ranging from 24 to 27°C and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20°C to 31°C and salinities from 20 to 40, it could not grow at temperatures lower than 15°C or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain of P. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.

The interaction between sea ice and salinity-dominated ocean circulation: implications for halocline stability and rapid changes of sea-ice cover

NASA Astrophysics Data System (ADS)

Jensen, M. F.; Nilsson, J.; Nisancioglu, K. H.

2016-02-01

In this study, we develop a simple conceptual model to examine how interactions between sea ice and oceanic heat and freshwater transports affect the stability of an upper-ocean halocline in a semi-enclosed basin. The model represents a sea-ice covered and salinity stratified ocean, and consists of a sea-ice component and a two-layer ocean; a cold, fresh surface layer above a warmer, more saline layer. The sea-ice thickness depends on the atmospheric energy fluxes as well as the ocean heat flux. We introduce a thickness-dependent sea-ice export. Whether sea ice stabilizes or destabilizes against a freshwater perturbation is shown to depend on the representation of the vertical mixing. In a system where the vertical diffusivity is constant, the sea ice acts as a positive feedback on a freshwater perturbation. If the vertical diffusivity is derived from a constant mixing energy constraint, the sea ice acts as a negative feedback. However, both representations lead to a circulation that breaks down when the freshwater input at the surface is small. As a consequence, we get rapid changes in sea ice. In addition to low freshwater forcing, increasing deep-ocean temperatures promote instability and the disappearance of sea ice. Generally, the unstable state is reached before the vertical density difference disappears, and small changes in temperature and freshwater inputs can provoke abrupt changes in sea ice.

Density-stratified flow events in Great Salt Lake, Utah, USA: implications for mercury and salinity cycling

USGS Publications Warehouse

Naftz, David L.; Carling, Gregory T.; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Pazmiño, Eddy

2014-01-01

Density stratification in saline and hypersaline water bodies from throughout the world can have large impacts on the internal cycling and loading of salinity, nutrients, and trace elements. High temporal resolution hydroacoustic and physical/chemical data were collected at two sites in Great Salt Lake (GSL), a saline lake in the western USA, to understand how density stratification may influence salinity and mercury (Hg) distributions. The first study site was in a causeway breach where saline water from GSL exchanges with less saline water from a flow restricted bay. Near-surface-specific conductance values measured in water at the breach displayed a good relationship with both flow and wind direction. No diurnal variations in the concentration of dissolved (total and MeHg loadings was observed during periods of elevated salinity. The second study site was located on the bottom of GSL where movement of a high-salinity water layer, referred to as the deep brine layer (DBL), is restricted to a naturally occurring 1.5-km-wide “spillway” structure. During selected time periods in April/May, 2012, wind-induced flow reversals in a railroad causeway breach, separating Gunnison and Gilbert Bays, were coupled with high-velocity flow pulses (up to 55 cm/s) in the DBL at the spillway site. These flow pulses were likely driven by a pressure response of highly saline water from Gunnison Bay flowing into the north basin of Gilbert Bay. Short-term flow reversal events measured at the railroad causeway breach have the ability to move measurable amounts of salt and Hg from Gunnison Bay into the DBL. Future disturbance to the steady state conditions currently imposed by the railroad causeway infrastructure could result in changes to the existing chemical balance between Gunnison and Gilbert Bays. Monitoring instruments were installed at six additional sites in the DBL during October 2012 to assess impacts from any future modifications to the railroad causeway.

Near-surface Salinity and Temperature Structure Observed with Dual-Sensor Drifters in the Subtropical South Pacific

NASA Astrophysics Data System (ADS)

Dong, Shenfu; Goni, Gustavo; Volkov, Denis; Lumpkin, Rick; Foltz, Gregory

2017-04-01

Three surface drifters equipped with temperature and salinity sensors at 0.2 m and 5 m depths were deployed in April/May 2015 in the subtropical South Pacific Ocean with the objective of measuring near-surface salinity differences seen by satellite and in situ sensors and examining the causes of the differences. Measurements from these drifters indicate that, on average, water at a depth of 0.2 m is about 0.013 psu fresher than at 5 m and about 0.024°C warmer. Events with large temperature and salinity differences between the two depths often occur when surface winds are weak. In addition to the expected surface freshening and cooling during rainfall events, surface salinification occurs under weak wind conditions when there is strong surface warming that enhances evaporation and upper ocean stratification. Further examination of the drifter measurements demonstrate that (i) the amount of surface freshening and vertical salinity gradient heavily depend on wind speed during rain events, (ii) salinity differences between 0.2 m and 5 m are positively correlated with the corresponding temperature differences, and (iii) temperature exhibits a diurnal cycle at both depths, whereas the diurnal cycle of salinity is observed only at 0.2 m when the wind speed is less than 4 m/s. Its phase is consistent with diurnal changes in surface temperature-induced evaporation. Below a wind speed of 6 m/s, the amplitudes of the diurnal cycles of temperature at both depths decrease with increasing wind speed. Wind speed also affects the phasing of the diurnal cycle of T5m with the time of maximum T5m increasing gradually with decreasing wind speed. Wind speed does not affect the phasing of the diurnal cycle of T0.2m. At 0.2 m and 5 m, the diurnal cycle of temperature also depends on surface solar radiation, with the amplitude and time of diurnal maximum increasing as solar radiation increases.

Warming and Inhibition of Salinization at the Ocean's Surface by Cyanobacteria

NASA Astrophysics Data System (ADS)

Wurl, O.; Bird, K.; Cunliffe, M.; Landing, W. M.; Miller, U.; Mustaffa, N. I. H.; Ribas-Ribas, M.; Witte, C.; Zappa, C. J.

2018-05-01

This paper describes high-resolution in situ observations of temperature and, for the first time, of salinity in the uppermost skin layer of the ocean, including the influence of large surface blooms of cyanobacteria on those skin properties. In the presence of the blooms, large anomalies of skin temperature and salinity of 0.95°C and -0.49 practical salinity unit were found, but a substantially cooler (-0.22°C) and saltier skin layer (0.19 practical salinity unit) was found in the absence of surface blooms. The results suggest that biologically controlled warming and inhibition of salinization of the ocean's surface occur. Less saline skin layers form during precipitation, but our observations also show that surface blooms of Trichodesmium sp. inhibit evaporation decreasing the salinity at the ocean's surface. This study has important implications in the assessment of precipitation over the ocean using remotely sensed salinity, but also for a better understanding of heat exchange and the hydrologic cycle on a regional scale.

Dynamics of harmful dinoflagellates driven by temperature and salinity in a northeastern Mediterranean lagoon.

PubMed

Dhib, Amel; Frossard, Victor; Turki, Souad; Aleya, Lotfi

2013-04-01

To attempt to determine the effects of temperature and salinity on the dynamics of the dinoflagellate community, a monthly sampling was carried out from October 2008 to March 2009 at eight sampling stations in Ghar El Melh Lagoon (GML; Mediterranean Sea, Northern Tunisia). Dinoflagellates were dominant among plankton, accounting for 73.9 % of the lagoon's overall plankton community, and were comprised of 25 different species among which 17 were reported in the literature as harmful. While no significant difference was found in the distribution of dinoflagellates among the stations, a strong monthly difference was observed. This temporal variability was due to an increase in the abundance of Prorocentrum micans from December to February, leading to a strong decrease in the Shannon diversity index from station to station. At the onset of P. micans development, dinoflagellate abundances reached 1.26.10(5) cells l(-1). A redundance analysis indicates that both temperature and salinity have a significant effect on the dynamics of the dinoflagellate community. Using a generalized additive model, both temperature and salinity appear to have significant nonlinear relationships with P. micans abundances. Model predictions indicate that outbreaks of P. micans may occur at a temperature below 22.5 °C and with salinity above 32.5. We discuss our results against a backdrop of climate change which, by affecting temperature and salinity, is likely to have an antagonistic impact on P. micans development and subsequently on the dinoflagellate dynamics in GML.

Quantification of Induced Hypothermia from Aseptic Scrub Applications during Rodent Surgery Preparation

PubMed Central

Skorupski, Anna M; Zhang, Jingyi; Ferguson, Danielle; Lawrence, Frank

2017-01-01

Laboratory mice (Mus musculus) are prone to develop hypothermia during anesthesia for surgery, thus potentially impeding anesthetic recovery, wound healing, and future health. The core body temperatures of isoflurane-anesthetized mice are influenced by the choice of supplemental heat sources; however, the contribution of various surgical scrubs on the body temperatures of mice under gas anesthesia has not been assessed. We sought to quantify the effect of using alcohol (70% isopropyl alcohol [IPA]) compared with saline to rinse away surgical scrub on the progression of hypothermia in anesthetized mice (n = 47). IPA, room-temperature saline, or warmed saline (37 °C) was combined with povidone–iodine and then assessed for effects on core (rectal) and surface (infrared) temperatures. Agents were applied to a 2×2-cm shaved abdominal area of mice maintained on a water-recirculating blanket (at 38 °C) under isoflurane anesthesia (1.5% to 2.0% at 0.6 L/min) for 30 min. Although all scrub regimens significantly decreased body temperature at the time of application, treatments that included povidone–iodine led to the coldest core temperatures, which persisted while mice were anesthetized. Compared with room-temperature saline and when combined with povidone–iodine, warming of saline did not ameliorate heat loss. IPA alone demonstrated the most dramatic cooling of both surface and core readings at application but generated an unanticipated warming (rebound) phase during which body temperatures equilibrated with those of controls within minutes of application. Although alcohol is inappropriate as a stand-alone agent for surgical skin preparation, IPA is a viable alternative to saline-based rinses in this context, and its use should be encouraged within institutional guidance for rodent surgical procedures without concern for prolonged hypothermia in mice. PMID:28903829

Distribution and significance of long-chain alkenones as salinity and temperature indicators in Spanish saline lake sediments

NASA Astrophysics Data System (ADS)

Pearson, Emma J.; Juggins, Steve; Farrimond, Paul

2008-08-01

We investigated relationships between sedimentary solvent-extractable long-chain alkenone (LCA) concentration and composition and environmental factors in a suite of endorheic lakes from inland Spain. LCAs were found in 14 of the 54 lakes examined, with concentrations comparable with those from previously published lacustrine settings. The composition of LCAs in our sites, however, contrast from the majority of those previously reported from lake environments; in our study the tri-unsaturated component is the most abundant component at most sites where LCAs are detected, and C 38:3 is the most abundant LCA in the majority of sites. LCA occurrence appears to be restricted to brackish-hypersaline sites and C 37 LCAs are absent above a salinity of ˜40 g L -1 suggesting a salinity control on LCA-producing organisms in these sites. Low concentrations of C 37 LCA components means U37k and U37k temperature indices are generally not applicable. Instead we find good relationships between C 38 components and (in particular mean autumn) temperature and the strongest LCA-temperature relationships are found when using a combination of all C 37 and C 38 compounds. We propose a new alkenone temperature index for lakes with elevated salinity and where the C 38 components dominate the LCA distributions. This is expressed as U3738k=0.0464×MAutAT-0.867 ( r2 = 0.80, n = 13). In this paper, we provide the first account of sedimentary LCA distributions from lakes in inland Spain, extending the range of environments within which these compounds have been found and highlighting their significance as indicators of both salinity and temperature in saline, endorheic lake environments. This has important implications for extending the potential role of LCAs as palaeoclimatic indicators in lacustrine environments.

Soil salinity assessment through satellite thermography for different irrigated and rainfed crops

NASA Astrophysics Data System (ADS)

Ivushkin, Konstantin; Bartholomeus, Harm; Bregt, Arnold K.; Pulatov, Alim; Bui, Elisabeth N.; Wilford, John

2018-06-01

The use of canopy thermography is an innovative approach for salinity stress detection in plants. But its applicability for landscape scale studies using satellite sensors is still not well investigated. The aim of this research is to test the satellite thermography soil salinity assessment approach on a study area with different crops, grown both in irrigated and rainfed conditions, to evaluate whether the approach has general applicability. Four study areas in four different states of Australia were selected to give broad representation of different crops cultivated under irrigated and rainfed conditions. The soil salinity map was prepared by the staff of Geoscience Australia and CSIRO Land and Water and it is based on thorough soil sampling together with environmental modelling. Remote sensing data was captured by the Landsat 5 TM satellite. In the analysis we used vegetation indices and brightness temperature as an indicator for canopy temperature. Applying analysis of variance and time series we have investigated the applicability of satellite remote sensing of canopy temperature as an approach of soil salinity assessment for different crops grown under irrigated and rainfed conditions. We concluded that in all cases average canopy temperatures were significantly correlated with soil salinity of the area. This relation is valid for all investigated crops, grown both irrigated and rainfed. Nevertheless, crop type does influence the strength of the relations. In our case cotton shows only minor temperature difference compared to other vegetation classes. The strongest relations between canopy temperature and soil salinity were observed at the moment of a maximum green biomass of the crops which is thus considered to be the best time for application of the approach.

An axisymmetric non-hydrostatic model for double-diffusive water systems

NASA Astrophysics Data System (ADS)

Hilgersom, Koen; Zijlema, Marcel; van de Giesen, Nick

2018-02-01

The three-dimensional (3-D) modelling of water systems involving double-diffusive processes is challenging due to the large computation times required to solve the flow and transport of constituents. In 3-D systems that approach axisymmetry around a central location, computation times can be reduced by applying a 2-D axisymmetric model set-up. This article applies the Reynolds-averaged Navier-Stokes equations described in cylindrical coordinates and integrates them to guarantee mass and momentum conservation. The discretized equations are presented in a way that a Cartesian finite-volume model can be easily extended to the developed framework, which is demonstrated by the implementation into a non-hydrostatic free-surface flow model. This model employs temperature- and salinity-dependent densities, molecular diffusivities, and kinematic viscosity. One quantitative case study, based on an analytical solution derived for the radial expansion of a dense water layer, and two qualitative case studies demonstrate a good behaviour of the model for seepage inflows with contrasting salinities and temperatures. Four case studies with respect to double-diffusive processes in a stratified water body demonstrate that turbulent flows are not yet correctly modelled near the interfaces and that an advanced turbulence model is required.

Relationship between organic pollution and the occurrence of toxic Phytoplankton species in the Lebanese coastal waters

NASA Astrophysics Data System (ADS)

El Rahman Hassoun, Abed

2017-04-01

Aiming to evaluate the effects of organic pollution, environmental parameters and phytoplankton community were monitored during a two-year period (from April 2010 till March 2012) in the central coast of Lebanon in the Levantine Sub-basin. Data were collected for hydrological (temperature and salinity), chemical (nitrites, nitrates and phosphates), and biological (chlorophyll-a and phytoplankton populations) parameters. Our results show that temperature follows its normal seasonal and annual cycles, usually noted in the Lebanese coastal waters. Salinity presents spatial and temporal variations with low values (19.07 - 39.6) in the areas affected by continental inputs. Significant fluctuations (P < 0.05) of nutrients, Chl-a concentrations and density of total phytoplanktonic cells were observed between the sites and through the years. Moreover, a perturbation of the natural phytoplanktonic succession and an occurrence of toxic or potentially harmful algae were noticed in the polluted sites, reflecting the influence of wastewater effluents on the coastal seawater equilibrium and thus on the Lebanese marine biodiversity. This study sheds the light on the current environmental condition of few coastal areas which could facilitate the management of their pollution sources. Keywords: Organic pollution, phytoplankton community, toxic algae, coastal water quality, Lebanon, Mediterranean Sea.

What are the main environmental factors driving the development of the neurotoxic dinoflagellate Vulcanodinium rugosum in a Mediterranean ecosystem (Ingril lagoon, France)?

PubMed

Abadie, Eric; Chiantella, Claude; Crottier, Anaïs; Rhodes, Lesley; Masseret, Estelle; Berteaux, Tom; Laabir, Mohamed

2018-05-01

Vulcanodinium rugosum, a dinoflagellate developing in Ingril Lagoon (Mediterranean, France) is responsible for shellfish intoxications due to the neurotoxin pinnatoxin G. A one year survey (March 2012-April 2013) was conducted in this oligotrophic shallow lagoon and key environmental parameters were recorded (temperature, salinity and nutrients). The spatio-temporal distribution of V. rugosum in water column and on macrophytes was also determined. Planktonic cells of V. rugosum were observed at all sampling stations, but in relatively low concentrations (maximum of 1000 cell/L). The highest abundances were observed from June to September 2012. There was a positive correlation between cell densities and both temperature and salinity. Non-motile cells were detected on macrophytes, with a maximum concentration of 6300 cells/g wet weight. Nitrite and ammonium were negatively related to V. rugosum abundance whereas total nitrogen, total phosphorus and phosphates showed a positive correlation. Altogether, in situ results suggest that V. rugosum is rather thermophilic and that organic nutrients should be considered when studying the nutrition requirements for this noxious expanding dinoflagellate. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of Climate Change on Temperature and Salinity in the Yaquina Estuary, Oregon (USA)

EPA Science Inventory

As part of a larger study to examine the effect of climate change (CC) on estuarine resources, we simulated the effect of rising sea level, alterations in river discharge, and increasing atmospheric temperatures on water properties (temperature and salinity) in the Yaquina Estuar...

Seasonal induced changes in spinach rhizosphere microbial community structure with varying salinity and drought.

PubMed

Mark Ibekwe, A; Ors, Selda; Ferreira, Jorge F S; Liu, Xuan; Suarez, Donald L

2017-02-01

Salinity is a common problem under irrigated agriculture, especially in low rainfall and high evaporative demand areas of southwestern United States and other semi-arid regions around the world. However, studies on salinity effects on soil microbial communities are relatively few while the effects of irrigation-induced salinity on soil chemical and physical properties and plant growth are well documented. In this study, we examined the effects of salinity, temperature, and temporal variability on soil and rhizosphere microbial communities in sand tanks irrigated with prepared solutions designed to simulate saline wastewater. Three sets of experiments with spinach (Spinacia oleracea L., cv. Racoon) were conducted under saline water during different time periods (early winter, late spring, and early summer). Bacterial 16S V4 rDNA region was amplified utilizing fusion primers designed against the surrounding conserved regions using MiSeq® Illumina sequencing platform. Across the two sample types, bacteria were relatively dominant among three phyla-the Proteobacteria, Cyanobacteria, and Bacteroidetes-accounted for 77.1% of taxa detected in the rhizosphere, while Proteobacteria, Bacteroidetes, and Actinobacteria accounted for 55.1% of taxa detected in soil. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity, abundance, community structure, and specific bacterial groups in soil and rhizosphere samples. Permutational analysis of variance (PERMANOVA) analysis showed that soil temperature (P=0.001), rhizosphere temperature (P=0.001), rhizosphere salinity (P=0.032), and evapotranspiration (P=0.002) significantly affected beta diversity of soil and rhizosphere microbial communities. Furthermore, salinity had marginal effects (P=0.078) on soil beta diversity. However, temporal variability differentially affected rhizosphere microbial communities irrigated with saline wastewater. Therefore, microbial communities in soils impacted by saline irrigation water respond differently to irrigation water quality and season of application due to temporal effects associated with temperature. Published by Elsevier B.V.

Production of consistent pain by intermittent infusion of sterile 5% hypertonic saline, followed by decrease of pain with cryotherapy.

PubMed

Long, Blaine C; Knight, Kenneth L; Hopkins, Ty; Parcell, Allen C; Feland, J Brent

2012-08-01

It is suggested that postinjury pain is difficult to examine; thus, investigators have developed experimental pain models. To minimize pain, cryotherapy (cryo) is applied, but reports on its effectiveness are limited. To investigate a pain model for the anterior knee and examine cryo in reducing the pain. Controlled laboratory study. Therapeutic modality laboratory. 30 physically active healthy male subjects who were free from any lower extremity orthopedic, neurological, cardiovascular, or endocrine pathologies. Perceived pain was measured every minute. Surface temperature was also assessed in the center of the patella and the popliteal fossa. There was a significant interaction between group and time (F68,864 = 3.0, P = .0001). At the first minute, there was no difference in pain between the 3 groups (saline/cryo = 4.80 ± 4.87 mm, saline/sham = 2.80 ± 3.55 mm, no saline/cryo = 4.00 ± 3.33 mm). During the first 5 min, pain increased from 4.80 ± 4.87 to 45.90 ± 21.17 mm in the saline/cryo group and from 2.80 ± 3.55 to 31.10 ± 20.25 mm in the saline/sham group. Pain did not change within the no-saline/cryo group, 4.00 ± 3.33 to 1.70 ± 1.70 mm. Pain for the saline/sham group remained constant for 17 min. Cryo decreased pain for 16 min in the saline/cryo group. There was no difference in preapplication surface temperature between or within each group. No change in temperature occurred within the saline/sham. Cooling and rewarming were similar in both cryo groups. Ambient temperature fluctuated less than 1°C during data collection. Intermittent infusion of sterile 5% hypertonic saline may be a useful experimental pain model in establishing a constant level of pain in a controlled laboratory setting. Cryotherapy decreased the induced anterior knee pain for 16 min.

On the calculation of air-sea fluxes of CO2 in the presence of temperature and salinity gradients

NASA Astrophysics Data System (ADS)

Woolf, D. K.; Land, P. E.; Shutler, J. D.; Goddijn-Murphy, L. M.; Donlon, C. J.

2016-02-01

The presence of vertical temperature and salinity gradients in the upper ocean and the occurrence of variations in temperature and salinity on time scales from hours to many years complicate the calculation of the flux of carbon dioxide (CO2) across the sea surface. Temperature and salinity affect the interfacial concentration of aqueous CO2 primarily through their effect on solubility with lesser effects related to saturated vapor pressure and the relationship between fugacity and partial pressure. The effects of temperature and salinity profiles in the water column and changes in the aqueous concentration act primarily through the partitioning of the carbonate system. Climatological calculations of flux require attention to variability in the upper ocean and to the limited validity of assuming "constant chemistry" in transforming measurements to climatological values. Contrary to some recent analysis, it is shown that the effect on CO2 fluxes of a cool skin on the sea surface is large and ubiquitous. An opposing effect on calculated fluxes is related to the occurrence of warm layers near the surface; this effect can be locally large but will usually coincide with periods of low exchange. A salty skin and salinity anomalies in the upper ocean also affect CO2 flux calculations, though these haline effects are generally weaker than the thermal effects.

Holocene oscillations in temperature and salinity of the surface subpolar North Atlantic.

PubMed

Thornalley, David J R; Elderfield, Harry; McCave, I Nick

2009-02-05

The Atlantic meridional overturning circulation (AMOC) transports warm salty surface waters to high latitudes, where they cool, sink and return southwards at depth. Through its attendant meridional heat transport, the AMOC helps maintain a warm northwestern European climate, and acts as a control on the global climate. Past climate fluctuations during the Holocene epoch ( approximately 11,700 years ago to the present) have been linked with changes in North Atlantic Ocean circulation. The behaviour of the surface flowing salty water that helped drive overturning during past climatic changes is, however, not well known. Here we investigate the temperature and salinity changes of a substantial surface inflow to a region of deep-water formation throughout the Holocene. We find that the inflow has undergone millennial-scale variations in temperature and salinity ( approximately 3.5 degrees C and approximately 1.5 practical salinity units, respectively) most probably controlled by subpolar gyre dynamics. The temperature and salinity variations correlate with previously reported periods of rapid climate change. The inflow becomes more saline during enhanced freshwater flux to the subpolar North Atlantic. Model studies predict a weakening of AMOC in response to enhanced Arctic freshwater fluxes, although the inflow can compensate on decadal timescales by becoming more saline. Our data suggest that such a negative feedback mechanism may have operated during past intervals of climate change.

Geology, mineralization, and fluid inclusion study of the Kuru-Tegerek Au-Cu-Mo skarn deposit in the Middle Tien Shan, Kyrgyzstan

NASA Astrophysics Data System (ADS)

Soloviev, Serguei G.; Kryazhev, Sergey; Dvurechenskaya, Svetlana

2018-02-01

The Kuru-Tegerek Cu-Au-Mo deposit is situated in a system of Late Carboniferous subduction-related magmatic arcs of the Middle Tien Shan, which together constitute a metallogenic belt of Cu-Au-Mo (±W) porphyry, with local skarns, deposits. The deposit is related to magnetite-series gabbro-diorite to tonalite intrusion. It contains prograde magnesian and calcic skarns with abundant magnetite, associated with gabbro-diorite, and retrograde skarn with Cu mineralization, formed after intrusion of tonalite. Subsequent propylitic alteration introduced abundant chalcopyrite and pyrrhotite, and native Au culminating in zones overprinting magnetite and garnet skarn. Later quartz-muscovite-carbonate veins, formed after intrusion of late mafic quartz monzogabbro dikes, contain chalcopyrite, pyrite, arsenopyrite and other sulfides and sulfosalts, tellurides, and native Au. The earliest retrograde skarn garnet contains gaseous low-salinity (1.7-3.4 wt.% NaCl eq.) fluid inclusions homogenizing at 460-500 °C into vapor, indicating that the early fluid released from crystallizing magma was a low-density vapor. It was followed by more saline (4.0-5.0 wt.% NaCl eq.), high-temperature (400-440 °C) aqueous fluid, as fluid release from the magma progressed. Boiling of this fluid at temperatures of 420 to 370 °C and a pressure of 350-300 bar produced a low-salinity (0.6-1.2 wt.% NaCl eq.), essentially gaseous, and high-salinity (from 39 to 31 wt.% NaCl eq.) brine, with possible metal (including Cu) partitioning into both gaseous and aqueous-saline phases. Boiling was coeval with sulfide deposition in the retrograde skarn. The latest episode of the retrograde skarn stage included direct separation of saline ( 40-42 wt.% NaCl eq.) fluid from crystallizing magma. The separation of saline ( 40 to 14 wt.% NaCl eq.) fluids from a crystallizing magmatic melt continued during the propylitic stage, when fluid cooling from 370 to 320 °C, together with decreasing fO2, caused Cu and especially Au precipitation. A new influx of possibly magma-derived, low-salinity (4.5-6.7 wt.% NaCl eq.) aqueous, and then NaCl-CO2-H2O fluids, corresponds to the phyllic (quartz-muscovite-carbonate-sulfide) stage. These fluids may have a deeper source, associated with the late mafic quartz monzogabbro dikes. Fluid cooling (from 340 to 255 °C) and boiling of the NaCl-CO2-H2O fluid, together with increased fS2, increased the Au endowment.

Effects of temperature and salinity on light scattering by water

NASA Astrophysics Data System (ADS)

Zhang, Xiaodong; Hu, Lianbo

2010-04-01

A theoretical model on light scattering by water was developed from the thermodynamic principles and was used to evaluate the effects of temperature and salinity. The results agreed with the measurements by Morel within 1%. The scattering increases with salinity in a non-linear manner and the empirical linear model underestimate the scattering by seawater for S < 40 psu. Seawater also exhibits an 'anomalous' scattering behavior with a minimum occurring at 24.64 °C for pure water and this minimum increases with the salinity, reaching 27.49 °C at 40 psu.

Brain temperature changes during selective cooling with endovascular intracarotid cold saline infusion: simulation using human data fitted with an integrated mathematical model.

PubMed

Neimark, Matthew Aaron Harold; Konstas, Angelos Aristeidis; Lee, Leslie; Laine, Andrew Francis; Pile-Spellman, John; Choi, Jae

2013-03-01

The feasibility of rapid cerebral hypothermia induction in humans with intracarotid cold saline infusion (ICSI) was investigated using a hybrid approach of jugular venous bulb temperature (JVBT) sampling and mathematical modeling of transient and steady state brain temperature distribution. This study utilized both forward mathematical modeling, in which brain temperatures were predicted based on input saline temperatures, and inverse modeling, where brain temperatures were inferred based on JVBT. Changes in ipsilateral anterior circulation territory temperature (IACT) were estimated in eight patients as a result of 10 min of a cold saline infusion of 33 ml/min. During ICSI, the measured JVBT dropped by 0.76±0.18°C while the modeled JVBT decreased by 0.86±0.18°C. The modeled IACT decreased by 2.1±0.23°C. In the inverse model, IACT decreased by 1.9±0.23°C. The results of this study suggest that mild cerebral hypothermia can be induced rapidly and safely with ICSI in the neuroangiographical setting. The JVBT corrected mathematical model can be used as a non-invasive estimate of transient and steady state cerebral temperature changes.

Infections may select for filial cannibalism by impacting egg survival in interactions with water salinity and egg density.

PubMed

Lehtonen, Topi K; Kvarnemo, Charlotta

2015-07-01

In aquatic environments, externally developing eggs are in constant contact with the surrounding water, highlighting the significance of water parameters and pathogens for egg survival. In this study we tested the impact of water salinity, egg density and infection potential of the environment on egg viability in the sand goby (Pomatoschistus minutus), a small fish that exhibits paternal egg care and has a marine origin, but which in the Baltic Sea lives in brackish water. To manipulate the infection potential of the environment, we added either a Saprolegnia infection vector into UV-filtered water or a fungicide into natural Baltic Sea water. Saprolegnia are widely spread water moulds that are a key cause of egg mortality in aquatic organisms in fresh- and brackish water. We found that increased water salinity indeed decreased the egg infection rate and had a positive effect on egg viability, while high egg density tended to have the opposite effect. However, the different factors influenced egg viability interactively, with a higher egg density having negative effects at low, but not in high, salinity. Thus, the challenges facing marine organisms adapting to lower salinity levels can be amplified by Saprolegnia infections that reduce egg survival in interaction with other environmental factors. Our results support the hypothesis that suppressing egg infections is an important aspect of parental care that can select for filial cannibalism, a common but poorly understood behaviour, especially in fish with parental care.

Hydrographic survey in the dying Aral Sea

NASA Astrophysics Data System (ADS)

Zavialov, P. O.; Kostianoy, A. G.; Emelianov, S. V.; Ni, A. A.; Ishniyazov, D.; Khan, V. M.; Kudyshkin, T. V.

2003-07-01

We report the results of a hydrographic survey conducted in November, 2002, in the Uzbekistan part of the western basin of the dying Aral Sea. There were very few hydrographic measurements in this region since at least early 1990s. The salinity in the western deep basin of the Aral Sea varied from about 82 psu at the surface to over 94 psu at the bottom. The absolute lake surface level was about 30.5 m. Hence, the observed salinity values were much higher, and the level much lower, than expected according to earlier predictions. The density in the western basin exhibited an extremely strong stratification of ~11 kg/m3 per ~20 m in the bottom layer. The picnocline was accompanied by a temperature inversion whose magnitude was ~4°C. The observed density stratification effectively isolating the lower part of the water column from surface exchanges may be responsible for the increase of summer SSTs and evaporation rates reported in previous studies. We discovered the hydrogen sulphide contamination in the bottom layer whose upper limit was at the depth of approximately 22 m. Estimates suggest that the western basin salinization occurs not only because of the local evaporation, but also because of the assimilation of the saltier eastern basin water in the course of the interbasin exchange through the connecting channel. The satellite imagery analysis, in particular the Maximum Cross-Correlation method, suggests that the circulation pattern in the Aral Sea in its present limits is cyclonic under the eastern winds that are predominant in the region throughout the year.

The Effect of Alongcoast Advection on Pacific Northwest Shelf and Slope Water Properties in Relation to Upwelling Variability

NASA Astrophysics Data System (ADS)

Stone, Hally B.; Banas, Neil S.; MacCready, Parker

2018-01-01

The Northern California Current System experiences highly variable seasonal upwelling in addition to larger basin-scale variability, both of which can significantly affect its water chemistry. Salinity and temperature fields from a 7 year ROMS hindcast model of this region (43°N-50°N), along with extensive particle tracking, were used to study interannual variability in water properties over both the upper slope and the midshelf bottom. Variation in slope water properties was an order of magnitude smaller than on the shelf. Furthermore, the primary relationship between temperature and salinity anomalies in midshelf bottom water consisted of variation in density (cold/salty versus warm/fresh), nearly orthogonal to the anomalies along density levels (cold/fresh versus warm/salty) observed on the upper slope. These midshelf anomalies were well-explained (R2 = 0.6) by the combination of interannual variability in local and remote alongshore wind stress, and depth of the California Undercurrent (CUC) core. Lagrangian analysis of upper slope and midshelf bottom water shows that both are affected simultaneously by large-scale alongcoast advection of water through the northern and southern boundaries. The amplitude of anomalies in bottom oxygen and dissolved inorganic carbon (DIC) on the shelf associated with upwelling variability are larger than those associated with typical variation in alongcoast advection, and are comparable to observed anomalies in this region. However, a large northern intrusion event in 2004 illustrates that particular, large-scale alongcoast advection anomalies can be just as effective as upwelling variability in changing shelf water properties on the interannual scale.

The Effect of Alongcoast Advection on Pacific Northwest Shelf and Slope Water Properties in Relation to Upwelling Variability

PubMed Central

Banas, Neil S.; MacCready, Parker

2018-01-01

Abstract The Northern California Current System experiences highly variable seasonal upwelling in addition to larger basin‐scale variability, both of which can significantly affect its water chemistry. Salinity and temperature fields from a 7 year ROMS hindcast model of this region (43°N–50°N), along with extensive particle tracking, were used to study interannual variability in water properties over both the upper slope and the midshelf bottom. Variation in slope water properties was an order of magnitude smaller than on the shelf. Furthermore, the primary relationship between temperature and salinity anomalies in midshelf bottom water consisted of variation in density (cold/salty versus warm/fresh), nearly orthogonal to the anomalies along density levels (cold/fresh versus warm/salty) observed on the upper slope. These midshelf anomalies were well‐explained (R 2 = 0.6) by the combination of interannual variability in local and remote alongshore wind stress, and depth of the California Undercurrent (CUC) core. Lagrangian analysis of upper slope and midshelf bottom water shows that both are affected simultaneously by large‐scale alongcoast advection of water through the northern and southern boundaries. The amplitude of anomalies in bottom oxygen and dissolved inorganic carbon (DIC) on the shelf associated with upwelling variability are larger than those associated with typical variation in alongcoast advection, and are comparable to observed anomalies in this region. However, a large northern intrusion event in 2004 illustrates that particular, large‐scale alongcoast advection anomalies can be just as effective as upwelling variability in changing shelf water properties on the interannual scale. PMID:29938149

Effect of povidone-iodine addition on the corrosion behavior of cp-Ti in normal saline.

PubMed

Bhola, Rahul; Bhola, Shaily M; Mishra, Brajendra; Olson, David L

2010-05-01

The effect of various concentrations of povidone-iodine (PI) on the corrosion behavior of a commercially pure titanium alloy (Ti-1) has been investigated in normal saline solution to simulate the povidone-iodine addition in an oral environment. The open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization measurements have been used to characterize the electrochemical phenomena occurring on the alloy surface. The open circuit potential values for Ti-1 in various concentrations of PI shift considerably towards noble direction as compared to pure normal saline. In the potentiodynamic polarization curve for Ti-1 in various solutions, the cathodic current density has increased for all concentrations of PI and the anodic current density has decreased. Only the 0.1% PI concentration is able to inhibit corrosion of Ti-1 in normal saline and the other higher concentrations studied, accelerate corrosion. The EIS data for Ti-1 in normal saline and in various concentrations of PI follows a one time constant circuit, suggesting the formation of a single passive film on Ti-1 which is not altered by the addition of PI to normal saline.

Structure and composition of oligohaline marsh plant communities exposed to salinity pulses

USGS Publications Warehouse

Howard, R.J.; Mendelssohn, I.A.

2000-01-01

The response of two oligohaline marsh macrophyte communities to pulses of increased salinity was studied over a single growing season in a greenhouse experiment. The plant communities were allowed a recovery period in freshwater following the pulse events. The experimental treatments included: (1) salinity influx rate (rate of salinity increase from 0 to 12 gl-1); (2) duration of exposure to elevated salinity; and (3) water depth. The communities both included Sagittaria lancifolia L.; the codominant species were Eleocharis palustris (L.) Roemer and J.A. Schultes in community 1 and Schoenoplectus americanus (Pers.) Volk. ex Schinz and R. Keller in community 2. Effects of the treatments on sediment chemical characteristics (salinity, pH, redox potential, and sulfide and ammonium concentrations) and plant community attributes (aboveground and belowground biomass, stem density, leaf tissue nutrients, and species richness) were examined. The treatment effects often interacted to influence sediment and plant communities characteristics following recovery in fresh water. Salinity influx rate per se, however, had little effect on the abiotic or biotic response variables; significant influx effects were found when the 0 gl-1 (zero influx) treatment was compared to the 12 gl-1 treatments, regardless of the rate salinity was raised. A salinity level of 12 gl-1 had negative effects on plant community structure and composition; these effects were usually associated with 3 months of salinity exposure. Water depth often interacted with exposure duration, but increased water depth did independently decrease the values of some community response measures. Community 1 was affected more than community 2 in the most extreme salinity treatment (3 months exposure/15-cm water depth). Although species richness in both communities was reduced, structural changes were more dramatic in community 1. Biomass and stem density were reduced in community 1 overall and in both dominant species. Structural changes in community 2 consisted of reduced biomass and stem density in the community overall and in S. lancifolia; S. americanus was not affected by salinity. In this most extreme treatment, community 2 tended to change to a monospecific S. americanus stand while community 1 was reduced to a few surviving stems of secondary species. Our results suggest that vegetation recovery or establishment of new species following a temporary increase in soil water salinity will vary with exposure duration and water depth. (C) 2000 Elsevier Science B.V.

The salinity effect in a mixed layer ocean model

NASA Technical Reports Server (NTRS)

Miller, J. R.

1976-01-01

A model of the thermally mixed layer in the upper ocean as developed by Kraus and Turner and extended by Denman is further extended to investigate the effects of salinity. In the tropical and subtropical Atlantic Ocean rapid increases in salinity occur at the bottom of a uniformly mixed surface layer. The most significant effects produced by the inclusion of salinity are the reduction of the deepening rate and the corresponding change in the heating characteristics of the mixed layer. If the net surface heating is positive, but small, salinity effects must be included to determine whether the mixed layer temperature will increase or decrease. Precipitation over tropical oceans leads to the development of a shallow stable layer accompanied by a decrease in the temperature and salinity at the sea surface.

Irrigation scheduling, freeze warning and soil salinity detecting. [in Cameron County Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Correlations of multispectral scanner (MSS) digital data differences between vegetated and bare soil areas with salinity levels from the eight saline areas using MSS bands seven and ten in the infrared region were significant. Correlations were derived for Cameron County, Texas. Detection of saline soils may be possible, using either film density readings or multispectral scanner data, when the lower reflectance of vegetation on highly saline soil and the higher reflectance of vegetation on lower saline soil are considered by using film on MSS contrasts between vegetation and bare soil.

Pattern variation of fish fingerling abundance in the Na Thap Tidal river of Southern Thailand: 2005-2015

NASA Astrophysics Data System (ADS)

Donroman, T.; Chesoh, S.; Lim, A.

2018-04-01

This study aimed to investigate the variation patterns of fish fingerling abundance based on month, year and sampling site. Monthly collecting data set of the Na Thap tidal river of southern Thailand, were obtained from June 2005 to October 2015. The square root transformation was employed for maintaining the fingerling data normality. Factor analysis was applied for clustering number of fingerling species and multiple linear regression was used to examine the association between fingerling density and year, month and site. Results from factor analysis classified fingerling into 3 factors based on saline preference; saline water, freshwater and ubiquitous species. The results showed a statistically high significant relation between fingerling density, month, year and site. Abundance of saline water and ubiquitous fingerling density showed similar pattern. Downstream site presented highest fingerling density whereas almost of freshwater fingerling occurred in upstream. This finding confirmed that factor analysis and the general linear regression method can be used as an effective tool for predicting and monitoring wild fingerling density in order to sustain fish stock management.

Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

NASA Astrophysics Data System (ADS)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2011-01-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical oceanography. The other two salinity variables provide alternative measures of the mass fraction of dissolved material in seawater. "Solution Salinity", denoted SAsoln, is the most obvious extension of Reference Salinity to allow for composition anomalies; it provides a direct estimate of the mass fraction of dissolved material in solution. "Added-Mass Salinity", denoted SAadd, is motivated by a method used to report laboratory experiments; it represents the component of dissolved material added to Standard Seawater in terms of the mass of material before it enters solution. We also discuss a constructed conservative variable referred to as "Preformed Salinity", denoted S∗, which will be useful in process-oriented numerical modelling studies. Finally, a conceptual framework for the incorporation of composition anomalies in numerical models is presented that builds from studies in which composition anomalies are simply ignored up to studies in which the influences of composition anomalies are accounted for using the results of biogeochemical models. 1TEOS-10: international Thermodynamic Equation of Seawater 2010, http://www.teos-10.org/.

Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

NASA Astrophysics Data System (ADS)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2010-08-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical oceanography. The other two salinity variables provide alternative measures of the mass fraction of dissolved material in seawater. "Solution Salinity", denoted SAsoln, is the most obvious extension of Reference Salinity to allow for composition anomalies; it provides a direct estimate of the mass fraction of dissolved material in solution. "Added-Mass Salinity", denoted SAadd, is motivated by a method used to report laboratory experiments; it represents the component of dissolved material added to Standard Seawater in terms of the mass of material before it enters solution. We also discuss a constructed conservative variable referred to as "Preformed Salinity", denoted S*, which will be useful in process-oriented numerical modelling studies. Finally, a conceptual framework for the incorporation of composition anomalies in numerical models is presented that builds from studies in which composition anomalies are simply ignored up to studies in which the influences of composition anomalies are accounted for using the results of biogeochemical models. 1TEOS-10: international thermodynamic equation of seawater 2010, http://www.teos-10.org.

Simulation of submarine groundwater discharge salinity and temperature variations: Implications for remote detection

USGS Publications Warehouse

Dausman, A.M.; Langevin, C.D.; Sukop, M.C.

2007-01-01

A hydrological analysis using a numerical simulation was done to identify the transient response of the salinity and temperature of submarine groundwater discharge (SGD) and utilize the results to guide data collection. Results indicate that the amount of SGD fluctuates depending on the ocean stage and geology, with the greatest amount of SGD delivered at low tide when the aquifer is in direct hydraulic contact with the ocean. The salinity of SGD remains lower than the ocean throughout the year; however, the salinity difference between the aquifer and ocean is inversely proportional to the ocean stage. The temperature difference between the ocean and SGD fluctuates seasonally, with the greatest temperature differences occurring in summer and winter. The outcome of this research reveals that numerical modelling could potentially be used to guide data collection including aerial surveys using electromagnetic (EM) resistivity and thermal imagery.

Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

PubMed

Berry, Bonnie J; Jenkins, David G; Schuerger, Andrew C

2010-04-01

Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30 degrees C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl(2), MgSO(4), NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20 degrees C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO(4) maintained at 20 or 30 degrees C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and -50 degrees C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m(-2) for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive effects of desiccation, UV irradiation, high salinity, and low pressure (in decreasing order of importance). Results suggest that E. coli may be able to survive, but not grow, in surficial soils on Mars.

Use of intertidal areas by shrimps (Decapoda) in a Brazilian Amazon estuary.

PubMed

Sampaio, Hebert A; Martinelli-Lemos, Jussara M

2014-03-01

The present work investigated the occupation and the correlation of the shrimp abundance in relation to environmental variables in different habitats (mangroves, salt marshes and rocky outcrops) in an Amazon estuary. The collections were made in August and November 2009, at low syzygy tide on Areuá Beach, situated in the Extractive Reserve of Mãe Grande de Curuçá, Pará, Brazil totaling 20 pools. In each environment, we recorded the physical-chemical factors (pH, salinity, and temperature) and measured the area (m2) and volume (m3) of every pool through bathymetry. The average pH, salinity, temperature, area and volume of tide pools were 8.75 (± 0.8 standard deviation), 35.45 (± 3), 29.49 °C (± 2.32), 27.41 m2 (± 41.18), and 5.19 m3 (± 8.01), respectively. We caught a total of 4,871 shrimps, distributed in three families and four species: Farfantepenaeus subtilis (98.36%) (marine) followed by Alpheus pontederiae (0.76%) (estuarine), Macrobrachium surinamicum (0.45%) and Macrobrachium amazonicum (0.43%) predominantly freshwater. The species F. subtilis and A. pontederiae occurred in the three habitats, whereas M. surinamicum occurred in salt marsh and rocky outcrop and M. amazonicum only in marisma. Temperature and pH were the most important environmental descriptors that significantly affected the density and biomass of shrimps.

High-dose diazepam facilitates core cooling during cold saline infusion in healthy volunteers.

PubMed

Hostler, David; Northington, William E; Callaway, Clifton W

2009-08-01

Studies have suggested that inducing mild hypothermia improves neurologic outcomes after traumatic brain injury, major stroke, cardiac arrest, or exertional heat illness. While infusion of cold normal saline is a simple and inexpensive method for reducing core temperature, human cold-defense mechanisms potentially make this route stressful or ineffective. We hypothesized that intravenous administration of diazepam during a rapid infusion of 30 mL.kg-1 of cold (4 degrees C) 0.9% saline to healthy subjects would be more comfortable and reduce core body temperature more than the administration of cold saline alone. Fifteen subjects received rapidly infused cold (4 degrees C) 0.9% saline. Subjects were randomly assigned to receive, intravenously, 20 mg diazepam (HIGH), 10 mg diazepam (LOW), or placebo (CON). Main outcomes were core temperature, skin temperature, and oxygen consumption. Data for the main outcomes were analyzed with generalized estimating equations to identify differences in group, time, or a group x time interaction. Core temperature decreased in all groups (CON, 1.0 +/- 0.2 degrees C; LOW, 1.4 +/- 0.2 degrees C; HIGH, 1.5 +/- 0.2 degrees C), while skin temperature was unchanged. Mean (95% CI) oxygen consumption was 315.3 (253.8, 376.9) mL.kg-1.min-1 in the CON group, 317.9 (275.5, 360.3) in the LOW group, and 226.1 (216.4, 235.9) in the HIGH group. Significant time and group x time interaction was observed for core temperature and oxygen consumption (p < 0.001). Administration of high-dose diazepam resulted in decreased oxygen consumption during cold saline infusion, suggesting that 20 mg of intravenous diazepam may reduce the shivering threshold without compromising respiratory or cardiovascular function.

Chesapeake Bay Low Freshwater Inflow Study. Biota Assessment. Phase I. Volume II.

DTIC Science & Technology

1980-08-01

which can regulate in water of reduced salinity , but not fresh water, e holeuryhaline osmoregulators , which can regulate from fresh to full oceanic...salini- ties , and * oligohaline osmoregulators , which can regulate only in fresh water and very low salinities , and maintain blood hyperosmotic to the...areas, or oysters their upstream beds. Temperature: The synergistic effects of temperature and salinity have been described by Kinne (1963, 1964) and

Development and Testing of a Coupled Ocean-atmosphere Mesoscale Ensemble Prediction System

DTIC Science & Technology

2011-06-28

wind, temperature, and moisture variables, while the oceanographic ET is derived from ocean current, temperature, and salinity variables. Estimates of...wind, temperature, and moisture variables while the oceanographic ET is derived from ocean current temperature, and salinity variables. Estimates of...uncertainty in the model. Rigorously accurate ensemble methods for describing the distribution of future states given past information include particle

Observations of currents and density structure across a buoyant plume front

USGS Publications Warehouse

Gelfenbaum, G.; Stumpf, R.P.

1993-01-01

Observations of the Mobile Bay, Alabama, plume during a flood event in April 1991 reveal significant differences in the current field on either side of a front associated with the buoyant plume. During a strong southeasterly wind, turbid, low salinity water from Mobile Bay was pushed through an opening in the west side of the ebb-tidal delta and moved parallel to the coast. A stable front developed between the low salinity water of the buoyant plume (11‰) and the high salinity coastal water (>23‰) that was being forced landward by the prevailing winds. Despite the shallow water depth of 6 m, measurements of currents, temperature, and salinity show large shears and density gradients in both the vertical and the horizontal directions. At a station outside of the buoyant plume, currents at 0.5 m and 1.5 m below the surface were in the same direction as the wind. Inside the plume, however, currents at 0.5 m below the surface were parallel to the coast, 45°, off the direction of the wind and the magnitude was 45% larger than the magnitude of the surface currents outside the plume. Beneath the level of the plume, the currents were identical to the wind-driven currents in the ambient water south of the front. Our observations suggest that the wind-driven surface currents of the ambient water converged with the buoyant plume at the front and were subducted beneath the plume. The motion of the ambient coastal surface water was in the direction of the local wind stress, however, the motion of the plume had no northerly component of motion. The plume also did not show any flow toward the front, suggesting a balance between the northerly component of wind stress and the southerly component of buoyant spreading. In addition, the motion of the plume did not appear to affect the motion of the underlying ambient water, suggesting a lack of mixing between the two waters.

Water mass modification at the Agulhas retroflection: chlorofluoromethane studies

NASA Astrophysics Data System (ADS)

Fine, Rana A.; Warner, Mark J.; Weiss, Ray F.

1988-03-01

Chlorofluoromethane (CFM) and hydrographic data from the 1983 Agulhas Retroflection cruise are used to show the importance of the region in ventilating thermocline and Intermediate Waters of the southwest Indian ocean gyre. Generally South Atlantic waters are more recently ventilated by at least two years than those of the South Indian Ocean, probably because the latter are farther downstream from the source regions near the South Atlantic subantarctic sector. A two-component mixing model shows that the outflow from the Agulhas Retroflection (14-4°C) was composed of South Indian water and at least 23% South Atlantic water. However, at the density of Indian sector Subantarctic Mode Water the inflow into the Agulhas Retroflection was well preserved in the outflow, and the South Atlantic and Indian waters appear to be ventilated by different water masses. In addition, strong interleaving was found throughout the survey area (between 14 and 4°C), characterized by correlations of negative salinity anomalies with high CFM concentrations. At the density of Antarctic Intermediate Water (AAIW) there was interleaving of both low salinity water and higher salinity Red Sea Water. Using estimates of past atmospheric ratios of two CFMs, we calculate that AAIW within the retroflection was 50-75% diluted by mixing with CFM-free water since leaving the source region. Results from the two-component mixing model, which show substantial contributions of South Atlantic water in the outflow, suggest that the return flow for the 10 Sv leakage of Indian Ocean water via the Agulhas Current into the South Atlantic [ GORDON (1985) Science, 227, 1030-1033; GORDONet al. (1987) Deep-Sea Research, 34, 565-600] is occurring at thermocline and intermediate depths. A combination of active mixing in this region and similarity in the ventilation processes may be the reason that the South Atlantic and Indian thermoclines are coincident in temperature and salinity space (between 15 and 7°C) as noted by Gordon.

Salinity controls on Na incorporation in Red Sea planktonic foraminifera

NASA Astrophysics Data System (ADS)

Mezger, E. M.; de Nooijer, L. J.; Boer, W.; Brummer, G. J. A.; Reichart, G. J.

2016-12-01

Whereas several well-established proxies are available for reconstructing past temperatures, salinity remains challenging to assess. Reconstructions based on the combination of (in)organic temperature proxies and foraminiferal stable oxygen isotopes result in relatively large uncertainties, which may be reduced by application of a direct salinity proxy. Cultured benthic and planktonic foraminifera showed that Na incorporation in foraminiferal shell calcite provides a potential independent proxy for salinity. Here we present the first field calibration of such a potential proxy. Living planktonic foraminiferal specimens from the Red Sea surface waters were collected and analyzed for their Na/Ca content using laser ablation quadrupole inductively coupled plasma mass spectrometry. Using the Red Sea as a natural laboratory, the calibration covers a broad range of salinities over a steep gradient within the same water mass. For both Globigerinoides ruber and Globigerinoides sacculifer calcite Na/Ca increases with salinity, albeit with a relatively large intraspecimen and interspecimen variability. The field-based calibration is similar for both species from a salinity of 36.8 up to 39.6, while values for G. sacculifer deviate from this trend in the northernmost transect. It is hypothesized that the foraminifera in the northernmost part of the Red Sea are (partly) expatriated and hence should be excluded from the Na/Ca-salinity calibration. Incorporation of Na in foraminiferal calcite therefore provides a potential proxy for salinity, although species-specific calibrations are still required and more research on the effect of temperature is needed.

The Effects of In-Hospital Intravenous Cold Saline in Postcardiac Arrest Patients Treated with Targeted Temperature Management.

PubMed

Suppogu, Nissi; Panza, Gregory A; Kilic, Sena; Gowdar, Shreyas; Kallur, Kamala R; Jayaraman, Ramya; Lundbye, Justin; Fernandez, Antonio B

2018-03-01

Recent data suggest that rapid infusion of intravenous (IV) cold saline for Targeted Temperature Management (TTM) after cardiac arrest is associated with higher rates of rearrest, pulmonary edema, and hypoxia, with no difference in neurologic outcomes or survival when administered by Emergency Medical Services. We sought to determine the effects of IV cold saline administration in the hospital setting in postcardiac arrest patients to achieve TTM and its effect on clinical parameters and neurologic outcomes. A cohort of 132 patients who completed TTM after cardiac arrest in a single institution was retrospectively studied. Patients who did not receive cold saline were matched by age, gender, Glasgow coma scale, downtime, and presenting rhythm to patients who received cold saline. Demographics, cardiac rearrest, diuretic use, time to target temperature, and Cerebral Performance Category (CPC) scores were recorded among other variables. Patients who received cold saline achieved target temperature sooner (280 vs. 345 minutes, p = 0.05), had lower lactate levels on day 1 (4.2 ± 3.5 mM vs. 6.0 ± 4.9 mM, p = 0.019) and day 2 (1.3 ± 2.2 mM vs. 2.2 ± 3.2 mM, p = 0.046), increased incidence of pulmonary edema (51.5% vs. 31.8%, p = 0.006), and increased diuretic utilization (63.6% vs. 42.4%, p = 0.014). There was no significant difference in cardiac rearrest, arterial oxygenation, and CPC scores (ps > 0.05). Infusion of IV cold saline is associated with shorter time to target temperature, increased incidence of pulmonary edema, and diuretic use, with no difference in cardiac rearrest, survival, and neurologic outcomes.

Observations of Inner Shelf Flows Influenced by a Small-Scale River Plume in the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Roth, M.; MacMahan, J.; Reniers, A.; Ozgokmen, T. M.

2016-02-01

Recent work has demonstrated that wind and waves are important forcing mechanisms for the inner shelf vertical current structure. Here, the inner shelf flows are evaluated away from an adjacent inlet where a small-scale buoyant plume emerges. The plume's nearshore extent, speed, vertical thickness, and density are controlled by the passage of low-pressure extratropical cyclones that are common in the northern Gulf of Mexico. The colder, brackish plume water provides vertical stratification and a cross-shore density gradient with the warmer, saline oceanic water. An Acoustic Doppler Current Profiler (ADCP) was deployed in 10m water depth as part of an intensive 2-week experiment (SCOPE), which also obtained wind and cross-shelf temperature, salinity, and velocity. The 10m ADCP remained collecting an additional year of velocity observations. The plume was not always present, but episodically influenced the experiment site. When the plume reached the site, the alongshore surface and subsurface typically flowed in opposite directions, likely caused by plume-induced pressure gradients. Plumes that extended into the subsurface appear to have caused depth-averaged onshore flow above that expected from wind and wave-driven forcing. Observations from SCOPE and the 1-year ADCP are used to describe seasonal full-depth flow patterns influenced by wind, waves, and plume presence.

ECO2N V2.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Lehua; Spycher, Nicolas; Doughty, Christine

2015-02-01

ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300oC whereas V1.0 can only be used for temperatures below about 110oC. V2.0 includes a comprehensive description of the thermodynamic and thermophysical properties of H2O - NaCl - CO2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10 °C 109oC). In the transition range (99-109oC), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO2-rich) phase, as well as two-phase (brine-CO2) mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. Note that the model cannot be applied to subcritical conditions that involves both liquid and gaseous CO2 unless thermol process is ignored (i.e.,isothermal run). For those cases, a user may use the fluid property module ECO2M (Pruess, 2011) instead« less

ECO2N V. 2.0: A New TOUGH2 Fluid Property Module for Mixtures of Water, NaCl, and CO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, L.; Spycher, N.; Doughty, C.

2014-12-01

ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO 2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300°C whereas V1.0 can only be used for temperatures below about 110°C. V2.0 includes a comprehensive description of the thermodynamics and thermophysical properties of H 2O - NaCl -CO 2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions ofmore » interest (10 °C < T < 300 °C; P < 600 bar; salinity up to halite saturation). This includes density, viscosity, and specific enthalpy of fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H 2O, NaCl and CO 2 among the different phases. In particular, V2.0 accounts for the effects of water on the thermophysical properties of the CO 2-rich phase, which was ignored in V1.0, using a model consistent with the solubility models developed by Spycher and Pruess (2005, 2010). In terms of solubility models, V2.0 uses the same model for partitioning of mass components among the different phases (Spycher and Pruess, 2005) as V1.0 for the low temperature range (<99°C) but uses a new model (Spycher and Pruess, 2010) for the high temperature range (>109°C). In the transition range (99-109°C), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO 2-rich) phase, as well as two-phase mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. This report gives technical specifications of ECO2N V2.0 and includes instructions for preparing input data« less

Hematocrit and plasma osmolality values of young-of-year shortnose sturgeon following acute exposures to combinations of salinity and temperature

USGS Publications Warehouse

Ziegeweid, J.R.; Black, M.C.

2010-01-01

Little is known about the physiological capabilities of young-of-year (YOY) shortnose sturgeon. In this study, plasma osmolality and hematocrit values were measured for YOY shortnose sturgeon following 48-h exposures to 12 different combinations of salinity and temperature. Hematocrit levels varied significantly with temperature and age, and plasma osmolalities varied significantly with salinity and age. Plasma osmolality and hematocrit values were similar to previously published values for other sturgeons of similar age and size in similar treatment conditions. ?? 2010 Springer Science+Business Media B.V.

Salinization of the soil solution decreases the further accumulation of salt in the root zone of the halophyte Atriplex nummularia Lindl. growing above shallow saline groundwater.

PubMed

Alharby, Hesham F; Colmer, Timothy D; Barrett-Lennard, Edward G

2018-01-01

Water use by plants in landscapes with shallow saline groundwater may lead to the accumulation of salt in the root zone. We examined the accumulation of Na + and Cl - around the roots of the halophyte Atriplex nummularia Lindl. and the impacts of this increasing salinity for stomatal conductance, water use and growth. Plants were grown in columns filled with a sand-clay mixture and connected at the bottom to reservoirs containing 20, 200 or 400 mM NaCl. At 21 d, Na + and Cl - concentrations in the soil solution were affected by the salinity of the groundwater, height above the water table and the root fresh mass density at various soil depths (P < 0.001). However, by day 35, the groundwater salinity and height above the water table remained significant factors, but the root fresh mass density was no longer significant. Regression of data from the 200 and 400 mM NaCl treatments showed that the rate of Na + accumulation in the soil increased until the Na + concentration reached ~250 mM within the root zone; subsequent decreases in accumulation were associated with decreases in stomatal conductance. Salinization of the soil solution therefore had a feedback effect on further salinization within the root zone. © 2017 John Wiley & Sons Ltd.

Nearshore Fish Distributions in an Alaskan Estuary in Relation to Stratification, Temperature and Salinity

NASA Astrophysics Data System (ADS)

Abookire, A. A.; Piatt, J. F.; Robards, M. D.

2000-07-01

Fish were sampled with beach seines and small-meshed beam trawls in nearshore (<1 km) and shallow (<25 m) habitats on the southern coast of Kachemak Bay, Cook Inlet, Alaska, from June to August, 1996-1998. Fish distributions among habitats were analysed for species composition, catch-per-unit-effort (CPUE) and frequency of occurrence. Two oceanographically distinct areas of Kachemak Bay were sampled and compared: the Outer Bay and the Inner Bay. Outer Kachemak Bay is exposed and receives oceanic, upwelled water from the Gulf of Alaska, whereas the Inner Bay is more estuarine. Thermohaline properties of bottom water in the Outer and Inner Bay were essentially the same, whereas the Inner Bay water-column was stratified with warmer, less saline waters near the surface. Distribution and abundance of pelagic schooling fish corresponded with area differences in stratification, temperature and salinity. The Inner Bay supported more species and higher densities of schooling and demersal fish than the Outer Bay. Schooling fish communities sampled by beach seine differed between the Outer and Inner Bays. Juvenile and adult Pacific sand lance ( Ammodytes hexapterus), Pacific herring ( Clupea harengus pallasi), osmerids (Osmeridae) and sculpins (Cottidae) were all more abundant in the Inner Bay. Gadids (Gadidae) were the only schooling fish taxa more abundant in the Outer Bay. Thermohaline characteristics of bottom water were similar throughout Kachemak Bay. Correspondingly, bottom fish communities were similar in all areas. Relative abundances (CPUE) were not significantly different between areas for any of the five demersal fish groups: flatfishes (Pleuronectidae), ronquils (Bathymasteridae), sculpins (Cottidae), gadids (Gadidae) and pricklebacks (Stichaeidae).

Nearshore fish distributions in an Alaskan estuary in relation to stratification, temperature, and salinity

USGS Publications Warehouse

Abookire, Alisa A.; Piatt, John F.; Robards, Martin D.

2000-01-01

Fish were sampled with beach seines and small-meshed beam trawls in nearshore ( < 1 km) and shallow ( < 25 m) habitats on the southern coast of Kachemak Bay, Cook Inlet, Alaska, from June to August, 1996-1998. Fish distributions among habitats were analysed for species composition, catch-per-unit-effort (CPUE) and frequency of occurrence. Two oceanographically distinct areas of Kachemak Bay were sampled and compared: the Outer Bay and the Inner Bay. Outer Kachemak Bay is exposed and receives oceanic, upwelled water from the Gulf of Alaska, whereas the Inner Bay is more estuarine. Thermohaline properties of bottom water in the Outer and Inner Bay were essentially the same, whereas the Inner Bay water-column was stratified with warmer, less saline waters near the surface. Distribution and abundance of pelagic schooling fish corresponded with area differences in stratification, temperature and salinity. The Inner Bay supported more species and higher densities of schooling and demersal fish than the Outer Bay. Schooling fish communities sampled by beach seine differed between the Outer and Inner Bays. Juvenile and adult Pacific sand lance (Ammodytes hexapterus), Pacific herring (Clupea harengus pallasi), osmerids (Osmeridae) and sculpins (Cottidae) were all more abundant in the Inner Bay. Gadids (Gadidae) were the only schooling fish taxa more abundant in the Outer Bay. Thermohaline characteristics of bottom water were similar throughout Kachemak Bay. Correspondingly, bottom fish communities were similar in all areas. Relative abundances (CPUE) were not significantly different between areas for any of the five demersal fish groups: flatfishes (Pleuronectidae), ronquils (Bathymasteridae), sculpins (Cottidae), gadids (Gadidae) and pricklebacks (Stichaeidae).

Mild hypothermia alters midazolam pharmacokinetics in normal healthy volunteers.

PubMed

Hostler, David; Zhou, Jiangquan; Tortorici, Michael A; Bies, Robert R; Rittenberger, Jon C; Empey, Philip E; Kochanek, Patrick M; Callaway, Clifton W; Poloyac, Samuel M

2010-05-01

The clinical use of therapeutic hypothermia has been rapidly expanding due to evidence of neuroprotection. However, the effect of hypothermia on specific pathways of drug elimination in humans is relatively unknown. To gain insight into the potential effects of hypothermia on drug metabolism and disposition, we evaluated the pharmacokinetics of midazolam as a probe for CYP3A4/5 activity during mild hypothermia in human volunteers. A second objective of this work was to determine whether benzodiazepines and magnesium administered intravenously would facilitate the induction of hypothermia. Subjects were enrolled in a randomized crossover study, which included two mild hypothermia groups (4 degrees C saline infusions and 4 degrees C saline + magnesium) and two normothermia groups (37 degrees C saline infusions and 37 degrees C saline + magnesium). The lowest temperatures achieved in the 4 degrees C saline + magnesium and 4 degrees C saline infusions were 35.4 +/- 0.4 and 35.8 +/- 0.3 degrees C, respectively. A significant decrease in the formation clearance of the major metabolite 1'-hydroxymidazolam was observed during the 4 degrees C saline + magnesium compared with that in the 37 degrees C saline group (p < 0.05). Population pharmacokinetic modeling identified a significant relationship between temperature and clearance and intercompartmental clearance for midazolam. This model predicted that midazolam clearance decreases 11.1% for each degree Celsius reduction in core temperature from 36.5 degrees C. Midazolam with magnesium facilitated the induction of hypothermia, but shivering was minimally suppressed. These data provided proof of concept that even mild and short-duration changes in body temperature significantly affect midazolam metabolism. Future studies in patients who receive lower levels and a longer duration of hypothermia are warranted.

Numerical study of hydrodynamic and salinity transport processes in the Pink Beach wetlands of the Liao River estuary, China

NASA Astrophysics Data System (ADS)

Qiao, Huiting; Zhang, Mingliang; Jiang, Hengzhi; Xu, Tianping; Zhang, Hongxing

2018-06-01

Interaction studies of vegetation within flow environments are essential for the determination of bank protection, morphological characteristics and ecological conditions for wetlands. This paper uses the MIKE 21 hydrodynamic and salinity model to simulate the hydrodynamic characteristics and salinity transport processes in the Pink Beach wetlands of the Liao River estuary. The effect of wetland plants on tidal flow in wetland areas is represented by a varying Manning coefficient in the bottom friction term. Acquisition of the vegetation distribution is based on Landsat TM satellites by remote sensing techniques. Detailed comparisons between field observation and simulated results of water depth, salinity and tidal currents are presented in the vegetated domain of the Pink Beach wetlands. Satisfactory results were obtained from simulations of both flow characteristics and salinity concentration, with or without vegetation. A numerical experiment was conducted based on variations in vegetation density, and compared with the tidal currents in non-vegetated areas; the computed current speed decreased remarkably with an increase in vegetation density. The impact of vegetation on water depth and salinity was simulated, and the findings revealed that wetland vegetation has an insignificant effect on the water depth and salinity in this wetland domain. Several stations (from upstream to downstream) in the Pink Beach wetlands were selected to estimate the longitudinal variation of salinity under different river runoff conditions; the results showed that salinity concentration decreases with an increase in river runoff. This study can consequently help increase the understanding of favourable salinity conditions for particular vegetation growth in the Pink Beach wetlands of the Liao River estuary. The results also provide crucial guidance for related interaction studies of vegetation, flow and salinity in other wetland systems.

The larvae of congeneric gastropods showed differential responses to the combined effects of ocean acidification, temperature and salinity.

PubMed

Zhang, Haoyu; Cheung, S G; Shin, Paul K S

2014-02-15

The tolerance and physiological responses of the larvae of two congeneric gastropods, the intertidal Nassarius festivus and subtidal Nassarius conoidalis, to the combined effects of ocean acidification (pCO2 at 380, 950, 1250 ppm), temperature (15, 30°C) and salinity (10, 30 psu) were compared. Results of three-way ANOVA on cumulative mortality after 72-h exposure showed significant interactive effects in which mortality increased with pCO2 and temperature, but reduced at higher salinity for both species, with higher mortality being obtained for N. conoidalis. Similarly, respiration rate of the larvae increased with temperature and pCO2 level for both species, with a larger percentage increase for N. conoidalis. Larval swimming speed increased with temperature and salinity for both species whereas higher pCO2 reduced swimming speed in N. conoidalis but not N. festivus. The present findings indicated that subtidal congeneric species are more sensitive than their intertidal counterparts to the combined effects of these stressors. Copyright © 2014 Elsevier Ltd. All rights reserved.

(abstract) Variations in Polarimetric Backscatter of Saline Ice Grown Under Diurnal Thermal Cycling Condition

NASA Technical Reports Server (NTRS)

Nghiem, S. V.; Kwok, R.; Yueh, S. H.; Kong, J. A.; Hsu, C. C.; Ding, K. H.

1995-01-01

An experiment was carried out in January 1994 at the Geophysical Research Facility in the Cold Regions Research and Engineering Laboratory. To investigate effects on polarimetric scattering signatures of sea ice growth under diurnal temperature variations, an ice sheet was grown for 2.5 days for the thickness of 10 cm and a polarimetric radar operating at C-band was used to obtain backscattering data in conjunction with ice-characterization measurements. The ice sheet was grown in the late morning of January 19, 1994. The initial growth rate was slow due to high insolation and temperature. As the air temperature dropped during the night, the growth rate increased significantly. The air temperature changed drastically from about -10(deg)C to -35(deg)C between day and night. The temperature cycle was repeated during the next day and the growth rate varied in the same manner. The surface of the ice was partially covered by frost flowers and the areal coverage increased as the ice became thicker. Throughout the ice growth duration of 2.5 days, polarimetric backscatter data were collected at roughly every centimeter of ice growth. For each set of radar measurements of saline ice, a set of calibration measurements was carried out with trihedrial corner reflectors and a metallic sphere. Measured polarimetric backscattering coefficients of the ice sheet reveal a strong correlation between radar data and temperature variations. As the temperature increased (decreased), the backscatter increased (decreased) correspondingly. From the ice-characterization data, temperatures of the air, at the ice-air interface, and in the ice layer had the same variation trend. Another interesting experimental observation is that the salinity measured as a function of ice depth from a sample of 10-cm thich ice indicated that the salinity variations had a similar cycle as the temperature; i.e., the salinity profile recorded the history of the temperature variations. Characterization data of the ice sheet are used in a theoretical model for scattering from saline ice with frost cover to explain the observed polarimetric signatures.

The influence of temperature and salinity on mortality of recently recruited blue crabs, Callinectes sapidus, naturally infected with Hematodinium perezi (Dinoflagellata).

PubMed

Huchin-Mian, Juan Pablo; Small, Hamish J; Shields, Jeffrey D

2018-02-01

The parasitic dinoflagellate Hematodinium perezi is highly prevalent in juvenile blue crabs, Callinectes sapidus, along the eastern seaboard of the USA. Although the parasite is known to kill adult crabs, the mortality rate of naturally infected juvenile crabs remains unknown. We analyzed the influence of temperature and salinity on the mortality of recently recruited blue crabs that were naturally infected with H. perezi. Over 492 juvenile crabs (infected, n = 282; uninfected controls, n = 210) were held individually in six-well plates and held at six temperatures (4, 10, 15, 20, 25, and 30 °C) or three salinities (5, 15, and 30 psu) for a maximum of 90 days. Mortality of infected crabs was 10 times higher at elevated temperatures (25 and 30 °C) and salinity (30 psu) compared to uninfected control treatments. By contrast, infected crabs exposed to mild temperatures (10, 15, and 20 °C) showed a high survival (>80%), no different than uninfected control treatments. Infected crabs at the lowest temperature (4 °C) exhibited a high mortality, but the intensity of infection was lower than in the other temperature treatments. In addition, this study revealed the optimal temperature (25 °C) and salinity (30 psu) for H. perezi to progress in its life cycle leading to sporulation in juvenile crabs; 31.6% (19/60) of crabs held under these conditions released dinospores of H. perezi after 10 days. Crabs held at other temperatures did not release dinospores over the time course of the experiment. Infected crabs were capable of molting and in most cases molted at the same frequency as uninfected crabs serving as controls. The mortality observed in this study indicates that early benthic juveniles will experience significant mortality due to H. perezi with increasing ocean temperatures and that this mortality may be a significant factor in the recruitment of blue crabs to high salinity regions. Copyright © 2018. Published by Elsevier Inc.

An Annotated Bibliography of Seagrasses with Emphasis on Planting and Propagation Techniques.

DTIC Science & Technology

1980-09-01

34The Effect of Salinity on Widgeongrass, Ruppia maritima," Journal of Witdlife Management, Vol. 34, No. 3, July 1970, pp. 658-661. The effects of...the period from April to mid-June. The effects of salinity , temperature, and photo- period were studied in the laboratory and monitored in the bay. Of...the species on which most information has been collected. The adverse effects of dredging and filling, sewage, changing temperature, and salinity on

Hydrodynamic measurements in Suisun Bay, California, 1992-93

USGS Publications Warehouse

Gartner, Jeffrey W.; Burau, Jon R.

1999-01-01

Sea level, velocity, temperature, and salinity (conductivity and temperature) data collected in Suisun Bay, California, from December 11, 1992, through May 31, 1993, by the U.S. Geological Survey are documented in this report. Sea-level data were collected at four locations and temperature and salinity data were collected at seven locations. Velocity data were collected at three locations using acoustic Doppler current profilers and at four other locations using point velocity meters. Sea-level and velocity data are presented in three forms (1) harmonic analysis results, (2) time-series plots (sea level, current speed, and current direction versus time), and (3) time-series plots of the low-pass filtered data. Temperature and salinity data are presented as plots of raw and low-pass filtered time series. The velocity and salinity data collected during this study document a period when the residual current patterns and salt field were significantly altered by large Delta outflow (three peaks in excess of 2,000 cubic meters per second). Residual current profiles were consistently seaward with magnitudes that fluctuated primarily in concert with Delta outflow and secondarily with the spring-neap tide cycle. The freshwater inputs advected salinity seaward of Suisun Bay for most of this study. Except for a 10-day period at the beginning of the study, dynamically significant salinities (>2) were seaward of Suisun Bay, which resulted in little or no gravitational circulation transport.

Effects of salinity, pH and temperature on the re-establishment of bioluminescence and copper or SDS toxicity in the marine dinoflagellate Pyrocystis lunula using bioluminescence as an endpoint

USGS Publications Warehouse

Craig, J.M.; Klerks, P.L.; Heimann, K.; Waits, J.L.

2003-01-01

Pyrocystis lunula is a unicellular, marine, photoautotrophic, bioluminescent dinoflagellate. This organism is used in the Lumitox ?? bioassay with inhibition of bioluminescence re-establishment as the endpoint. Experiments determined if acute changes in pH, salinity, or temperature had an effect on the organisms' ability to re-establish bioluminescence, or on the bioassay's potential to detect sodium dodecyl sulfate (SDS) and copper toxicity. The re-establishment of bioluminescence itself was not very sensitive to changes in pH within the pH 6-10 range, though reducing pH from 8 to levels below 6 decreased this capacity. Increasing the pH had little effect on Cu or SDS toxicity, but decreasing the pH below 7 virtually eliminated the toxicity of either compound in the bioassay. Lowering the salinity from 33 to 27??? or less resulted in a substantial decrease in re-establishment of bioluminescence, while increasing the salinity to 43 or 48 ??? resulted in a small decline. Salinity had little influence on the bioassay's quantification of Cu toxicity, while the data showed a weak negative relationship between SDS toxicity and salinity. Re-establishment of bioluminescence showed a direct dependence on temperature, but only at 10??C did temperature have an obvious effect on the toxicity of Cu in this bioassay. ?? 2003 Elsevier Science Ltd. All rights reserved.

Change in coccolith morphology by responding to temperature and salinity in coccolithophore Emiliania huxleyi (Haptophyta) isolated from the Bering and Chukchi Seas

NASA Astrophysics Data System (ADS)

Saruwatari, K.; Satoh, M.; Harada, N.; Suzuki, I.; Shiraiwa, Y.

2015-11-01

Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic Oceans during the R/V MIRAI cruise in 2010 (MR10-05) were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains of MR57N isolated from the northern Bering Sea (56°58' N, 167°11' W) and MR70N at the Chukchi Sea (69°99' N, 168° W). This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of strain MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters, such as length of the distal shield (LDS), length of the inner central area (LICA), and the thickness of distal shield elements. The central area elements of coccoliths varied from grilled type to closed type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities due to their marked morphometric adaptation ability. Because all coccolith biometric parameters followed the scaling law, the decrease in coccolith size was caused simply by the reduced calcification. Taken together, our results suggest that calcification productivity may be used to predict future oceanic environmental conditions in the Polar Regions.

Quinoa Seed Quality Response to Sodium Chloride and Sodium Sulfate Salinity

PubMed Central

Wu, Geyang; Peterson, Adam J.; Morris, Craig F.; Murphy, Kevin M.

2016-01-01

Quinoa (Chenopodium quinoa Willd.) is an Andean crop with an edible seed that both contains high protein content and provides high quality protein with a balanced amino acid profile in embryonic tissues. Quinoa is a halophyte adapted to harsh environments with highly saline soil. In this study, four quinoa varieties were grown under six salinity treatments and two levels of fertilization, and then evaluated for quinoa seed quality characteristics, including protein content, seed hardness, and seed density. Concentrations of 8, 16, and 32 dS m-1 of NaCl and Na2SO4, were applied to the soil medium across low (1 g N, 0.29 g P, 0.29 g K per pot) and high (3 g N, 0.85 g P, 0.86 g K per pot) fertilizer treatments. Seed protein content differed across soil salinity treatments, varieties, and fertilization levels. Protein content of quinoa grown under salinized soil ranged from 13.0 to 16.7%, comparable to that from non-saline conditions. NaCl and Na2SO4 exhibited different impacts on protein content. Whereas the different concentrations of NaCl did not show differential effects on protein content, the seed from 32 dS m-1 Na2SO4 contained the highest protein content. Seed hardness differed among varieties, and was moderately influenced by salinity level (P = 0.09). Seed density was affected significantly by variety and Na2SO4 concentration, but was unaffected by NaCl concentration. The samples from 8 dS m-1 Na2SO4 soil had lower density (0.66 g/cm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4, 0.74 and 0.72g/cm3, respectively. This paper identifies changes in critical seed quality traits of quinoa as influenced by soil salinity and fertility, and offers insights into variety response and choice across different abiotic stresses in the field environment. PMID:27375648

Environmental and Cultural Impact. Proposed Tennessee Colony Reservoir, Trinity River, Texas. Volume II. Appendices A, B and C.

DTIC Science & Technology

1972-01-01

in a considerable increase in the water salinity . Density stratification of the water is possible, the denser saline water forming the lower water...layer in the lake basin which causes anaerobic, toxic conditions. Salinity causes also an increase in flocculation and sedi- mentation of clay minerals...increased salin - ity of the lake water. Excessive water seepage in the fault zone intersecting the northern most part of the reservoir will probably

Salinity and Temperature Constraints on Microbial Methanogenesis in the Lei-Gong-Huo Mud Volcano of Eastern Taiwan

NASA Astrophysics Data System (ADS)

Sun, W.; Lin, L.; Wang, P.

2012-12-01

Terrestrial mud volcano is thought to be one of the most important natural sources of methane emission. Previous studies have shown that methane cycling in terrestrial mud volcanoes involves a complex reaction network driven by the interactions between subsurface and surface abiotic and microbial processes. In situ methanogenesis appears to produce methane at quantities exceeding those of deeply-sourced thermogenic methane and the capacities of anaerobic methanotrophy at shallow depth levels, thereby contributing significantly to the methane emission. Various degrees of evaporation at surface also lead to the enhancement of chloride concentrations in pore water, favoring the proliferation of halo-tolerant and/or halophilic methanogens. The goal of this study is to investigate the extent of methanogenesis in terrestrial mud volcanoes by incubating mud slurries with various precursors (H2/CO2, acetate, methanol, and methylamine) at different salinities (up to 2000 mM) and temperatures (up to 50 oC). Methane concentrations were monitored through time and molecular analyses were applied to investigate the changes of methanogenic communities. Methanogenesis was stimulated by any investigated precursor at room temperature. However, the methanogenic response to salinity varied. Of the investigated precursors, H2/CO2 and methyl-compounds (methanol and methylamine) stimulated methanogenesis at all investigated salinities. The rates and yields of hydrogen- and methyl-utilizing methanogenesis declined significantly at salinities greater than 1500 mM. Acetate-utilizing methanogenesis proceeded at salinities less than 700 mM. At 40 oC, methanogenesis was stimulated by all investigated precursors at the in situ salinity (~400 mM). At 50 oC, only H2-utilizing methanogenesis was stimulated. Analyses of terminal restriction fragment length polymorphism (TRFLP) for 16S rRNA genes revealed various patterns upon different precursors and salinities. The TRFLP results combined with clone library analyses indicated that major RFs recovered from incubations with methyl-compounds at room temperature and 40 oC were represented by sequences affiliated with Methanococcoides spp., Methanosarcina spp., and Methanolobus spp. In particular, only Methanosarcina- and Methanococcoides-related members were detected at salinities greater than 1000 mM or at 40 oC. RFs recovered from incubations with H2/CO2 at room temperature and 40 oC were represented by sequences related to different Methanococcus spp. Overall, methanogens utilizing H2/CO2 and methyl-compounds appear to be capable of actively producing methane at salinities greater than acetate-utilizing methanogens could tolerate. These methanogens might adapt better to the fluctuation of salinity or extremely high salinity induced by the surface evaporation in terrestrial mud volcanoes. When considering the overall methane emission from terrestrial mud volcanoes, these halo-tolerant methanogens become a significant factor. Key words: mud volcano, Methane, Methanogenesis, Salinity

On the relative roles of hydrology, salinity, temperature, and root productivity in controlling soil respiration from coastal swamps (freshwater)

USGS Publications Warehouse

Krauss, Ken W.; Whitbeck, Julie L.; Howard, Rebecca J.

2012-01-01

Background and aims Soil CO2 emissions can dominate gaseous carbon losses from forested wetlands (swamps), especially those positioned in coastal environments. Understanding the varied roles of hydroperiod, salinity, temperature, and root productivity on soil respiration is important in discerning how carbon balances may shift as freshwater swamps retreat inland with sea-level rise and salinity incursion, and convert to mixed communities with marsh plants. Methods We exposed soil mesocosms to combinations of permanent flooding, tide, and salinity, and tracked soil respiration over 2 1/2 growing seasons. We also related these measurements to rates from field sites along the lower Savannah River, Georgia, USA. Soil temperature and root productivity were assessed simultaneously for both experiments. Results Soil respiration from mesocosms (22.7-1678.2 mg CO2 m-2 h-1) differed significantly among treatments during four of the seven sampling intervals, where permanently flooded treatments contributed to low rates of soil respiration and tidally flooded treatments sometimes contributed to higher rates. Permanent flooding reduced the overall capacity for soil respiration as soils warmed. Salinity did reduce soil respiration at times in tidal treatments, indicating that salinity may affect the amount of CO2 respired with tide more strongly than under permanent flooding. However, soil respiration related greatest to root biomass (mesocosm) and standing root length (field); any stress reducing root productivity (incl. salinity and permanent flooding) therefore reduces soil respiration. Conclusions Overall, we hypothesized a stronger, direct role for salinity on soil respiration, and found that salinity effects were being masked by varied capacities for increases in respiration with soil warming as dictated by hydrology, and the indirect influence that salinity can have on plant productivity.

Ocean Surface Emissivity at L-band (1.4 GHz): The Dependence on Salinity and Roughness

NASA Technical Reports Server (NTRS)

LeVine, D. M.; Lang, R.; Wentz, F.; Messiner, T.

2012-01-01

A characterization of the emissivity of sea water at L-band is important for the remote sensing of sea surface salinity. Measurements of salinity are currently being made in the radio astronomy band at 1.413 GHz by ESA's Soil Moisture and Ocean Salinity (SMOS) mission and NASA's Aquarius instrument aboard the Aquarius/SAC-D observatory. The goal of both missions is accuracy on the order of 0.1 psu. This requires accurate knowledge of the dielectric constant of sea water as a function of salinity and temperature and also the effect of waves (roughness). The former determines the emissivity of an ideal (i.e. flat) surface and the later is the major source of error from predictions based on a flat surface. These two aspects of the problem of characterizing the emissivity are being addressed in the context of the Aquarius mission. First, laboratory measurements are being made of the dielectric constant of sea water. This is being done at the George Washington University using a resonant cavity. In this technique, sea water of known salinity and temperature is fed into the cavity along its axis through a narrow tube. The sea water changes the resonant frequency and Q of the cavity which, if the sample is small enough, can be related to the dielectric constant of the sample. An extensive set of measurements have been conducted at 1.413 GHz to develop a model for the real and imaginary part of the dielectric constant as a function of salinity and temperature. The results are compared to the predictions of models based on parameterization of the Debye resonance of the water molecule. The models and measurements are close; however, the differences are significant for remote sensing of salinity. This is especially true at low temperatures where the sensitivity to salinity is lowest.

High salinity events in the northern Arabian Sea and Sea of Oman

NASA Astrophysics Data System (ADS)

Wang, Zhankun; DiMarco, Steven F.; Jochens, Ann E.; Ingle, Stephanie

2013-04-01

Moored observations in the northern Arabian Sea (NAS) show substantial velocity, temperature and dissolved oxygen fluctuations, accompanied by episodic high salinity intrusions with maximum values≥37.3 on time scales of 2-10 days after the passage of Cyclone Gonu in 2007. These events are characterized by a rapid increase in temperature, salinity and dissolved oxygen followed by an abrupt decline. The mechanisms behind these high salinity events are investigated using a comprehensive dataset of temperature and salinity profiles from ARGO floats and sea surface height anomaly maps. The spatial and temporal distribution of the Persian/Arabian Gulf outflow to the Sea of Oman is also studied using ARGO profiles. Persian Gulf water (PGW) is mainly measured close to the Strait of Hormuz or along the Oman coast on the continental slope in the Sea of Oman. Both mooring and ARGO data show that high salinity PGW can be advected off the slope and into the interior. More high salinity water is measured in the interior of the Sea of Oman within three months after the Gonu passage in summer 2007, which is caused by the combination effect of the oceanic responses to Cyclone Gonu and a clockwise eddy circulation located at northern Ras al Hadd. At other times, the high salinity water appears more in isolated patches and rare in the interior. This study provides a first look at the high salinity events appearing after Gonu and the properties and dynamics of the PGW in the northern Arabian Sea and Sea of Oman.

Important aspects of Eastern Mediterranean large-scale variability revealed from data of three fixed observatories

NASA Astrophysics Data System (ADS)

Bensi, Manuel; Velaoras, Dimitris; Cardin, Vanessa; Perivoliotis, Leonidas; Pethiakis, George

2015-04-01

Long-term variations of temperature and salinity observed in the Adriatic and Aegean Seas seem to be regulated by larger-scale circulation modes of the Eastern Mediterranean (EMed) Sea, such as the recently discovered feedback mechanisms, namely the BiOS (Bimodal Oscillating System) and the internal thermohaline pump theories. These theories are the results of interpretation of many years' observations, highlighting possible interactions between two key regions of the EMed. Although repeated oceanographic cruises carried out in the past or planned for the future are a very useful tool for understanding the interaction between the two basins (e.g. alternating dense water formation, salt ingressions), recent long time-series of high frequency (up to 1h) sampling have added valuable information to the interpretation of internal mechanisms for both areas (i.e. mesoscale eddies, evolution of fast internal processes, etc.). During the last 10 years, three deep observatories were deployed and maintained in the Adriatic, Ionian, and Aegean Seas: they are respectively, the E2-M3A, the Pylos, and the E1-M3A. All are part of the largest European network of Fixed Point Open Ocean Observatories (FixO3, http://www.fixo3.eu/). Herein, from the analysis of temperature and salinity, and potential density time series collected at the three sites from the surface down to the intermediate and deep layers, we will discuss the almost perfect anti-correlated behavior between the Adriatic and the Aegean Seas. Our data, collected almost continuously since 2006, reveal that these observatories well represent the thermohaline variability of their own areas. Interestingly, temperature and salinity in the intermediate layer suddenly increased in the South Adriatic from the end of 2011, exactly when they started decreasing in the Aegean Sea. Moreover, Pylos data used together with additional ones (e.g. Absolute dynamic topography, temperature and salinity data from other platforms) collected along the typical pathway of the Levantine/Cretan intermediate waters towards the Adriatic Sea, reveal variability of the subsurface/intermediate layers (100-400m depth), which could possibly be attributed to seasonal variability or influences from dynamical features such as the Pelops Gyre. References Bensi, M., V. Cardin, A. Rubino, G. Notarstefano, and P. M. Poulain (2013), Effects of winter convection on the deep layer of the Southern Adriatic Sea in 2012, J. Geophys. Res. Oceans, 118, doi:10.1002/2013JC009432. Velaoras, D., G. Krokos, K. Nittis, and A. Theocharis (2014), Dense intermediate water outflow from the Cretan Sea: A salinity driven, recurrent phenomenon, connected to thermohaline circulation changes, J. Geophys. Res. Oceans, 119, doi:10.1002/2014JC009937.

Spatio-temporal variations in bloom of the red-tide dinoflagellate Karenia mikimotoi in Imari Bay, Japan, in 2014: Factors controlling horizontal and vertical distribution.

PubMed

Aoki, Kazuhiro; Kameda, Takahiko; Yamatogi, Toshifumi; Ishida, Naoya; Hirae, Sou; Kawaguchi, Mayumi; Syutou, Toshio

2017-11-15

A massive bloom of the dinoflagellate Karenia mikimotoi appeared in 2014 in Imari Bay, Japan. Bloom dynamics and hydrographical conditions were examined by field survey. The bloom initially developed in the eastern area of Imari Bay, subsequently after rainfall during the neap tides, cell density exceeded over 10,000cellsml. Vertical distribution of K. mikimotoi was primarily controlled by the light intensity and secondarily by the water quality during the daytime. Almost all cell-density maxima occurred in depths with weak daytime light intensities of <300μmolm -2 s -1 . In some cases of weak light intensity, cell-density maxima occurred in depths with favorable hydrodynamic conditions for the growth. Spatially classified areas were identified by cluster analysis using the growth rate calculated from seawater temperature and salinity. This study quantitatively evaluated the environmental factors of the eastern area, where the bloom initially occurred, during the development of the bloom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Global carbon sequestration in tidal, saline wetland soils

USGS Publications Warehouse

Chmura, G.L.; Anisfeld, S.C.; Cahoon, D.R.; Lynch, J.C.

2003-01-01

Wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. Most global carbon budgets, however, have focused on dry land ecosystems that extend over large areas and have not accounted for the many small, scattered carbon-storing ecosystems such as tidal saline wetlands. We compiled data for 154 sites in mangroves and salt marshes from the western and eastern Atlantic and Pacific coasts, as well as the Indian Ocean, Mediterranean Ocean, and Gulf of Mexico. The set of sites spans a latitudinal range from 22.4??S in the Indian Ocean to 55.5??N in the northeastern Atlantic. The average soil carbon density of mangrove swamps (0.055 ?? 0.004 g cm-3) is significantly higher than the salt marsh average (0.039 ?? 0.003 g cm-3). Soil carbon density in mangrove swamps and Spartina patens marshes declines with increasing average annual temperature, probably due to increased decay rates at higher temperatures. In contrast, carbon sequestration rates were not significantly different between mangrove swamps and salt marshes. Variability in sediment accumulation rates within marshes is a major control of carbon sequestration rates masking any relationship with climatic parameters. Globally, these combined wetlands store at least 44.6 Tg C yr-1 and probably more, as detailed areal inventories are not available for salt marshes in China and South America. Much attention has been given to the role of freshwater wetlands, particularly northern peatlands, as carbon sinks. In contrast to peatlands, salt marshes and mangroves release negligible amounts of greenhouse gases and store more carbon per unit area. Copyright 2003 by the American Geophysical Union.

Biophysical Processes at the Boundary between the Arctic and Subarctic in the Barents Sea

NASA Astrophysics Data System (ADS)

Drinkwater, K.

2016-02-01

The boundary between the Arctic and Subarctic is often in the form of a strong front. Results from field studies on the Polar Front in the Barents Sea separating Arctic and Atlantic waters are presented. The focus is on the physical dynamics of the front and their influence on the structure and function of the associated marine biology from biogeochemistry and nutrient dynamics through plankton ecology up to fish. Data were collected using CTDs, autonomous gliders, microstructure profilers, a Fast Repetition Rate Flourometer (FRRF) and conventional nets for capturing plankton and fish. The Polar Front exhibits strong horizontal gradients in temperature and salinity but weak density gradients owing to density compensation of the water mass characteristics. Intense interleaving of the water masses occurs at the front along isopycnals resulting in large variability in the vertical profiles of the temperature-salinity characteristics. Although there are elevated turbulence levels in the vicinity of the front owing to both current shear and double diffusion, turbulence levels are still relatively weak and not strong enough to create strong vertical mixing. As a result nutrient levels in the near surface layers remain low through the summer following the spring bloom and there is no evidence of greatly enhanced primary production or high phytoplankton biomass in the front. Small zooplankton appear to be more prominent at the front and large zooplankton away from the front. Capelin show a similar distribution with small individuals in the front and larger capelin away from the front, mainly in the Arctic waters. Hypotheses on the relationship between the frontal dynamics and fish distributions are presented. Changes in the frontal position and intensity under climate change will also be discussed.

Predicting CO2-H2O Interfacial Tension Using COSMO-RS.

PubMed

Silvestri, A; Stipp, S L S; Andersson, M P

2017-02-14

Knowledge about the interaction between fluids and solids and the interfacial tension (IFT) that results is important for predicting behavior and properties in industrial systems and in nature, such as in rock formations before, during, and after CO 2 injection for long-term storage. Many authors have studied the effect of the environmental variables on the IFT in the CO 2 -H 2 O system. However, experimental measurements above CO 2 supercritical conditions are scarce and sometimes contradictory. Molecular modeling is a valuable tool for complementing experimental IFT determination, and it can help us interpret results and gain insight under conditions where experiments are difficult or impossible. Here, we report predictions for CO 2 -water interfacial tension performed using density functional theory (DFT) combined with the COSMO-RS implicit solvent model. We predicted the IFT dependence as a function of pressure (0-50 MPa), temperature (273-383 K), and salinity (0-5 M NaCl). The results agree well with literature data, within the estimated uncertainty for experiments and for molecular dynamics (MD) simulations, suggesting that the model can be used as a fast alternative to time-consuming computational approaches for predicting the CO 2 -water IFT over a range of pressures, temperatures, and salinities.

The effect of multiple stressors on salt marsh end-of-season biomass

USGS Publications Warehouse

Visser, J.M.; Sasser, C.E.; Cade, B.S.

2006-01-01

It is becoming more apparent that commonly used statistical methods (e.g., analysis of variance and regression) are not the best methods for estimating limiting relationships or stressor effects. A major challenge of estimating the effects associated with a measured subset of limiting factors is to account for the effects of unmeasured factors in an ecologically realistic matter. We used quantile regression to elucidate multiple stressor effects on end-of-season biomass data from two salt marsh sites in coastal Louisiana collected for 18 yr. Stressor effects evaluated based on available data were flooding, salinity, air temperature, cloud cover, precipitation deficit, grazing by muskrat, and surface water nitrogen and phosphorus. Precipitation deficit combined with surface water nitrogen provided the best two-parameter model to explain variation in the peak biomass with different slopes and intercepts for the two study sites. Precipitation deficit, cloud cover, and temperature were significantly correlated with each other. Surface water nitrogen was significantly correlated with surface water phosphorus and muskrat density. The site with the larger duration of flooding showed reduced peak biomass, when cloud cover and surface water nitrogen were optimal. Variation in the relatively low salinity occurring in our study area did not explain any of the variation in Spartina alterniflora biomass. ?? 2006 Estuarine Research Federation.

The effect of multiple stressors on salt marsh end-of-season biomass

USGS Publications Warehouse

Visser, J.M.; Sasser, C.E.; Cade, B.S.

2006-01-01

It is becoming more apparent that commonly used statistical methods (e.g. analysis of variance and regression) are not the best methods for estimating limiting relationships or stressor effects. A major challenge of estimating the effects associated with a measured subset of limiting factors is to account for the effects of unmeasured factors in an ecologically realistic matter. We used quantile regression to elucidate multiple stressor effects on end-of-season biomass data from two salt marsh sites in coastal Louisiana collected for 18 yr. Stressor effects evaluated based on available data were flooding, salinity air temperature, cloud cover, precipitation deficit, grazing by muskrat, and surface water nitrogen and phosphorus. Precipitation deficit combined with surface water nitrogen provided the best two-parameter model to explain variation in the peak biomass with different slopes and intercepts for the two study sites. Precipitation deficit, cloud cover, and temperature were significantly correlated with each other. Surface water nitrogen was significantly correlated with surface water phosphorus and muskrat density. The site with the larger duration of flooding showed reduced peak biomass, when cloud cover and surface water nitrogen were optimal. Variation in the relatively low salinity occurring in our study area did not explain any of the variation in Spartina alterniflora biomass.

Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice.

PubMed

Ewert, Marcela; Deming, Jody W

2014-08-01

Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between -7 and -25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Salinity surveys using an airborne microwave radiometer

NASA Technical Reports Server (NTRS)

Paris, J. F.; Droppleman, J. D.; Evans, D. E.

1972-01-01

The Barnes PRT-5 infrared radiometer and L-band channel of the multifrequency microwave radiometer are used to survey the distribution of surface water temperature and salinity. These remote sensors were flown repetitively in November 1971 over the outflow of the Mississippi River into the Gulf of Mexico. Data reduction parameters were determined through the use of flight data obtained over a known water area. With these parameters, the measured infrared and microwave radiances were analyzed in terms of the surface temperature and salinity.

Evaluating Battery-like Reactions to Harvest Energy from Salinity Differences using Ammonium Bicarbonate Salt Solutions.

PubMed

Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

2016-05-10

Mixing entropy batteries (MEBs) are a new approach to generate electricity from salinity differences between two aqueous solutions. To date, MEBs have only been prepared from solutions containing chloride salts, owing to their relevance in natural salinity gradients created from seawater and freshwater. We hypothesized that MEBs could capture energy using ammonium bicarbonate (AmB), a thermolytic salt that can be used to convert waste heat into salinity gradients. We examined six battery electrode materials. Several of the electrodes were unstable in AmB solutions or failed to produce expected voltages. Of the electrode materials tested, a cell containing a manganese oxide electrode and a metallic lead electrode produced the highest power density (6.3 mW m(-2) ). However, this power density is still low relative to previously reported NaCl-based MEBs and heat recovery systems. This proof-of-concept study demonstrated that MEBs could indeed be used to generate electricity from AmB salinity gradients. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

PubMed Central

Lugnani, Franco; Macchioro, Matteo

2017-01-01

Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion Electrolysis can occur in a frozen domain at high subfreezing temperature, probably above the eutectic. It appears that the most effective period for delivering electrolytic currents in cryoelectrolysis is during the high subzero temperatures stage while freezing and immediately after cooling has stopped, throughout the thawing stage. PMID:28123904

Cryoelectrolysis-electrolytic processes in a frozen physiological saline medium.

PubMed

Lugnani, Franco; Macchioro, Matteo; Rubinsky, Boris

2017-01-01

Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Electrolysis can occur in a frozen domain at high subfreezing temperature, probably above the eutectic. It appears that the most effective period for delivering electrolytic currents in cryoelectrolysis is during the high subzero temperatures stage while freezing and immediately after cooling has stopped, throughout the thawing stage.

High tolerance to temperature and salinity change should enable scleractinian coral Platygyra acuta from marginal environments to persist under future climate change.

PubMed

Chui, Apple Pui Yi; Ang, Put

2017-01-01

With projected changes in the marine environment under global climate change, the effects of single stressors on corals have been relatively well studied. However, more focus should be placed on the interactive effects of multiple stressors if their impacts upon corals are to be assessed more realistically. Elevation of sea surface temperature is projected under global climate change, and future increases in precipitation extremes related to the monsoon are also expected. Thus, the lowering of salinity could become a more common phenomenon and its impact on corals could be significant as extreme precipitation usually occurs during the coral spawning season. Here, we investigated the interactive effects of temperature [24, 27 (ambient), 30, 32°C] and salinity [33 psu (ambient), 30, 26, 22, 18, 14 psu] on larval settlement, post-settlement survival and early growth of the dominant coral Platygyra acuta from Hong Kong, a marginal environment for coral growth. The results indicate that elevated temperatures (+3°C and +5°C above ambient) did not have any significant effects on larval settlement success and post-settlement survival for up to 56 days of prolonged exposure. Such thermal tolerance was markedly higher than that reported in the literature for other coral species. Moreover, there was a positive effect of these elevated temperatures in reducing the negative effects of lowered salinity (26 psu) on settlement success. The enhanced settlement success brought about by elevated temperatures, together with the high post-settlement survival recorded up to 44 and 8 days of exposure under +3°C and +5°C ambient respectively, resulted in the overall positive effects of elevated temperatures on recruitment success. These results suggest that projected elevation in temperature over the next century should not pose any major problem for the recruitment success of P. acuta. The combined effects of higher temperatures and lowered salinity (26 psu) could even be beneficial. Therefore, corals that are currently present in marginal environments like Hong Kong, as exemplified by the dominant P. acuta, are likely to persist in a warmer and intermittently less saline, future ocean.

High tolerance to temperature and salinity change should enable scleractinian coral Platygyra acuta from marginal environments to persist under future climate change

PubMed Central

Chui, Apple Pui Yi; Ang, Put

2017-01-01

With projected changes in the marine environment under global climate change, the effects of single stressors on corals have been relatively well studied. However, more focus should be placed on the interactive effects of multiple stressors if their impacts upon corals are to be assessed more realistically. Elevation of sea surface temperature is projected under global climate change, and future increases in precipitation extremes related to the monsoon are also expected. Thus, the lowering of salinity could become a more common phenomenon and its impact on corals could be significant as extreme precipitation usually occurs during the coral spawning season. Here, we investigated the interactive effects of temperature [24, 27 (ambient), 30, 32°C] and salinity [33 psu (ambient), 30, 26, 22, 18, 14 psu] on larval settlement, post-settlement survival and early growth of the dominant coral Platygyra acuta from Hong Kong, a marginal environment for coral growth. The results indicate that elevated temperatures (+3°C and +5°C above ambient) did not have any significant effects on larval settlement success and post-settlement survival for up to 56 days of prolonged exposure. Such thermal tolerance was markedly higher than that reported in the literature for other coral species. Moreover, there was a positive effect of these elevated temperatures in reducing the negative effects of lowered salinity (26 psu) on settlement success. The enhanced settlement success brought about by elevated temperatures, together with the high post-settlement survival recorded up to 44 and 8 days of exposure under +3°C and +5°C ambient respectively, resulted in the overall positive effects of elevated temperatures on recruitment success. These results suggest that projected elevation in temperature over the next century should not pose any major problem for the recruitment success of P. acuta. The combined effects of higher temperatures and lowered salinity (26 psu) could even be beneficial. Therefore, corals that are currently present in marginal environments like Hong Kong, as exemplified by the dominant P. acuta, are likely to persist in a warmer and intermittently less saline, future ocean. PMID:28622371

High-Density Linkage Map Construction and Mapping of Salt-Tolerant QTLs at Seedling Stage in Upland Cotton Using Genotyping by Sequencing (GBS).

PubMed

Diouf, Latyr; Pan, Zhaoe; He, Shou-Pu; Gong, Wen-Fang; Jia, Yin Hua; Magwanga, Richard Odongo; Romy, Kimbembe Romesh Eric; Or Rashid, Harun; Kirungu, Joy Nyangasi; Du, Xiongming

2017-12-05

Over 6% of agricultural land is affected by salinity. It is becoming obligatory to use saline soils, so growing salt-tolerant plants is a priority. To gain an understanding of the genetic basis of upland cotton tolerance to salinity at seedling stage, an intra-specific cross was developed from CCRI35, tolerant to salinity, as female with Nan Dan (NH), sensitive to salinity, as the male. A genetic map of 5178 SNP markers was developed from 277 F 2:3 populations. The map spanned 4768.098 cM, with an average distance of 0.92 cM. A total of 66 QTLs for 10 traits related to salinity were detected in three environments (0, 110, and 150 mM salt treatment). Only 14 QTLs were consistent, accounting for 2.72% to 9.87% of phenotypic variation. Parental contributions were found to be in the ratio of 3:1, 10 QTLs from the sensitive and four QTLs from the resistant parent. Five QTLs were located in A t and nine QTLs in the D t sub-genome. Moreover, eight clusters were identified, in which 12 putative key genes were found to be related to salinity. The GBS-SNPs-based genetic map developed is the first high-density genetic map that has the potential to provide deeper insights into upland cotton salinity tolerance. The 12 key genes found in this study could be used for QTL fine mapping and cloning for further studies.

GROWTH RATES AND ELEMENTAL COMPOSITION OF ALEXANDRIUM MONILATUM, A REDTIDE DINOFLAGELLATE

EPA Science Inventory

The combined effects of temperature and salinity on growth of Alexandrium monilatum were studied in laboratory cultures. This toxic, red-tide dinoflagellate grew faster with higher temperatures, up to a maximum of approximately 1 division d-1 at 31 C. Salinities above 15 psu had ...

Laser measure of sea salinity, temperature and turbidity in depth

NASA Technical Reports Server (NTRS)

Hirschberg, J. G.; Wouters, A. W.; Byrne, J. D.

1974-01-01

A method is described in which a pulsed laser is used to probe the sea. Backscattered light is analyzed in time, intensity and wavelength. Tyndall, Raman and Brillouin scattering are used to obtain the backscatter turbidity, sound velocity, salinity, and the temperature as a function of depth.

PHYSIOLOGICAL STUDIES ON 'CANCER IRRORATUS' LARVAE. II. EFFECTS OF TEMPERATURE AND SALINITY ON PHYSIOLOGICAL PERFORMANCE

EPA Science Inventory

Larvae of the rock crab Cancer irroratus were cultured under specific environmental regimes to examine the influence of temperature and salinity on respiration and excretion rates during development. In addition, the type of biochemical substrate used for energy production was de...

Temporal variation of intertidal seagrass in southern China (2008-2014)

NASA Astrophysics Data System (ADS)

Qiu, Guanglong; Short, Frederick T.; Fan, Hangqing; Liu, Guohua

2017-09-01

Understanding the temporal dynamics of seagrasses and the major influences on seagrass growth is critical for seagrass habitat conservation and administration. However, little work has been done regarding these issues in southern China. To examine inter-annual and seasonal variations of the intertidal Halophila ovalis community in southern China, we conducted quarterly sampling using the SeagrassNet methodology and assessed environmental conditions as well as direct anthropogenic impacts on the seagrass meadow from July 2008 to October 2014. Our study demonstrated strong inter-annual and seasonal dynamics of the intertidal seagrass meadow in the study area. Generally, the community performed best (highest seagrass cover, leaf area, shoot density, total biomass) in summer and worst in spring among the 4 seasons. The temporal variations in the seagrass community attributes (e.g. above-ground biomass) were significantly affected by precipitation, atmospheric visibility, and salinity, while leaf width was significantly negatively correlated with temperature, atmospheric visibility and salinity. Temperature was a major factor influencing the seagrass community (both macroalgae and seagrass), with temperature data showing an inverse relationship between seagrass and macroalgae. The above-ground: below-ground biomass ratio and leaf width of H. ovalis were the most sensitive plant parameters monitored when assessing environmental interactions. Human physical disturbances did not have a significant effect on seagrass dynamics in the study area. We concluded that long-term monitoring (like SeagrassNet) is valuable in understanding the relationship between environmental variables and seagrasses.

Estimation of the Barrier Layer Thickness in the Indian Ocean Using Aquarius Salinity

DTIC Science & Technology

2014-07-08

number of temperature and salinity measurements in ocean basins . In 2005, buoy coverage in the Indian Ocean began meeting Argo program sampling...distribution of salinity in the Indian Ocean is unique when compared to the other basins with higher salinity in the western contrasted Journal of...eastern regions of the basin (Figure 2). In the Arabian Sea, evaporation (E) greatly exceeds precipitation (P) resulting in high salinity (>36 PSU

Use of Advanced Meteorological Model Output for Coastal Ocean Modeling in Puget Sound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Khangaonkar, Tarang; Wang, Taiping

2011-06-01

It is a great challenge to specify meteorological forcing in estuarine and coastal circulation modeling using observed data because of the lack of complete datasets. As a result of this limitation, water temperature is often not simulated in estuarine and coastal modeling, with the assumption that density-induced currents are generally dominated by salinity gradients. However, in many situations, temperature gradients could be sufficiently large to influence the baroclinic motion. In this paper, we present an approach to simulate water temperature using outputs from advanced meteorological models. This modeling approach was applied to simulate annual variations of water temperatures of Pugetmore » Sound, a fjordal estuary in the Pacific Northwest of USA. Meteorological parameters from North American Region Re-analysis (NARR) model outputs were evaluated with comparisons to observed data at real-time meteorological stations. Model results demonstrated that NARR outputs can be used to drive coastal ocean models for realistic simulations of long-term water-temperature distributions in Puget Sound. Model results indicated that the net flux from NARR can be further improved with the additional information from real-time observations.« less

The GEOS-iODAS: Description and Evaluation

NASA Technical Reports Server (NTRS)

Vernieres, Guillaume; Rienecker, Michele M.; Kovach, Robin; Keppenne, Christian L.

2012-01-01

This report documents the GMAO's Goddard Earth Observing System sea ice and ocean data assimilation systems (GEOS iODAS) and their evolution from the first reanalysis test, through the implementation that was used to initialize the GMAO decadal forecasts, and to the current system that is used to initialize the GMAO seasonal forecasts. The iODAS assimilates a wide range of observations into the ocean and sea ice components: in-situ temperature and salinity profiles, sea level anomalies from satellite altimetry, analyzed SST, and sea-ice concentration. The climatological sea surface salinity is used to constrain the surface salinity prior to the Argo years. Climatological temperature and salinity gridded data sets from the 2009 version of the World Ocean Atlas (WOA09) are used to help constrain the analysis in data sparse areas. The latest analysis, GEOS ODAS5.2, is diagnosed through detailed studies of the statistics of the innovations and analysis departures, comparisons with independent data, and integrated values such as volume transport. Finally, the climatologies of temperature and salinity fields from the Argo era, 2002-2011, are presented and compared with the WOA09.

Distribution and Abundance of Dungeness Crab and Crangon Shrimp and Dredging-Related Mortality of Invertebrates and Fish in Grays Harbor, Washington,

DTIC Science & Technology

1982-01-01

Cont’d). salinity . Crabs were most abundant in spring and least abundant in summer. Diel migrations were evident and dependent upon tidal level, light...driving cycles include: 1. Density- dependent mechanisms based on compensatory influences such as competition for food between young and older crabs...and salinity . Annual mean crab density was greater in the channel than on the flats. Crabs generally changed their diet with age from one consisting

Interactive effects of ocean acidification, elevated temperature, and reduced salinity on early-life stages of the pacific oyster.

PubMed

Ko, Ginger W K; Dineshram, R; Campanati, Camilla; Chan, Vera B S; Havenhand, Jon; Thiyagarajan, Vengatesen

2014-09-02

Ocean acidification (OA) effects on larvae are partially attributed for the rapidly declining oyster production in the Pacific Northwest region of the United States. This OA effect is a serious concern in SE Asia, which produces >80% of the world's oysters. Because climate-related stressors rarely act alone, we need to consider OA effects on oysters in combination with warming and reduced salinity. Here, the interactive effects of these three climate-related stressors on the larval growth of the Pacific oyster, Crassostrea gigas, were examined. Larvae were cultured in combinations of temperature (24 and 30 °C), pH (8.1 and 7.4), and salinity (15 psu and 25 psu) for 58 days to the early juvenile stage. Decreased pH (pH 7.4), elevated temperature (30 °C), and reduced salinity (15 psu) significantly delayed pre- and post-settlement growth. Elevated temperature lowered the larval lipid index, a proxy for physiological quality, and negated the negative effects of decreased pH on attachment and metamorphosis only in a salinity of 25 psu. The negative effects of multiple stressors on larval metamorphosis were not due to reduced size or depleted lipid reserves at the time of metamorphosis. Our results supported the hypothesis that the C. gigas larvae are vulnerable to the interactions of OA with reduced salinity and warming in Yellow Sea coastal waters now and in the future.

Influence of predicted climage change elements on Z. ...

EPA Pesticide Factsheets

Global climate change (GCC) is expected to have pronounced impacts on estuarine and marine habitats including sea level rise, increased storm intensity, increased air and water temperatures, changes in upwelling dynamics and ocean acidification. All of these elements are likely to impact the growth and potential distribution of the non-indigenous seagrass Zostera japonica both within the State of Washington and within the region. Understanding how Z. japonica will respond to GCC requires a thorough understanding of plant physiology and predictions of GCC effects. Furthermore, Washington State is proposing to list Z. japonica as a “noxious weed” which will allow the state to use herbicide controls for management. We present data from manipulative experiments designed to better understand how Z. japonica photosynthetic physiology responds to temperature, salinity and light. We found that Z. japonica is well adapted to moderate temperatures and salinity with maximum photosynthesis of salinity of 20. The Coos Bay population had greater Pmax and saturation irradiance (Ik) than the Padilla bay population (p < 0.001) and tolerates daily exposure to both freshwater and marine water, suggesting that this population tolerates fairly extreme environmental fluctuations. Extreme temperatures (35 °C) were generally lethal to Z. japonica populations from Padilla, Coos and Yaquina Bays. High salinity (35) had lower mortality than either salinity of 5 or 20 (p = 0.0

Formulation Development of High Strength Gel System and Evaluation on Profile Control Performance for High Salinity and Low Permeability Fractured Reservoir

PubMed Central

Zhang, Chengli; Qu, Guodong

2017-01-01

For the large pores and cracks of reservoirs with low temperatures, high salinity, and low permeability, a new type of high strength gel ABP system is developed in this paper. The defects of conventional gels such as weak gel strength, no gelling, and easy dehydration are overcome under the conditions of low temperature and high salinity. The temperature and salt resistance, plugging characteristics, and EOR of the gel system are studied. Under the condition of 32°C and 29500 mg/L salinity, the ABP system formulation is for 0.3% crosslinking agent A + 0.09% coagulant B + 3500 mg/L polymer solution P. The results show that when the temperature was increased, the delayed crosslinking time of the system was shortened and the gel strength was increased. The good plugging characteristics of the ABP system were reached, and the plugging rate was greater than 99% in cores with different permeability. A good profile control performance was achieved, and the recovery rate was improved by 19.27% on the basis of water flooding. In the practical application of the gel system, the salinity of formation water and the permeability of fractures are necessary to determine the appropriate formulation. PMID:28592971

Alkenone temperature and salinity: An evaluation of long chain C37 alkenone in Lake Qinghai, China

NASA Astrophysics Data System (ADS)

Liu, W.; Liu, Z.; Fu, M.; An, Z.

2007-12-01

In recently years, the alkenone unsaturation index (Uk'37=C37:.2/(C37:2+ C37:3)) has been used to reconstructed paleo-temperature for lacustrine sediments. However, few studies have addressed whether the relative abundance of the C37:4 alkenone to the total C37 production (C37:4 percent) can reflect surface salinity changes in lake systems. Here we present the distribution of C37 long chain alkenone of modern lake sediments in Qinghai Lake, Qing-Tibet Plateau, to evaluate significance of abundance change of long chain C37 alkenone as an indicator of lake paleo-enviromental evolution. A group of surface sediments from different locations in the lake have been analyzed in this study. The results of long chain C37 alkenone from 28 surface sediments analyses shown relative abundance of C37:4 alkenone to total C37 production (C37:4 percent) change from 14.5 to 48.6 percent and the abundance of C37:4 alkenone is increasing with decreasing salinity of lake water. For the salinity lake in land, we suggested the relative abundance of C37:4 alkenone in lake sediments may be a indicator of paleo-silinity; We have also found that Uk'37 values are weakly correlated with salinity and C37:4 percent changes, implying that potential minor contributions of temperature and salinity effects to C37:4 percent and Uk'37 respectively cannot be excluded in this study. However, since these contributions are weak, we suggest that the C37:4 percent proxy can be used to reconstruct paleo-salinity changes at a regional scale, especially in lake systems, while Uk'37 remains as a powerful tool for reconstructions of paleo-temperature changes in the lake systems.

Effects of low and high salinity regimes on seasonal gametogenesis of the ribbed mussel Geukensia granosissima in coastal Louisiana, USA

USGS Publications Warehouse

Honig, Aaron; LaPeyre, Megan K.; Supan, John

2014-01-01

Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and host vegetation productivity. As such, ecosystem level changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences, making it important to better understand the population ecology of native bivalves. In order to determine potential impacts of shifting salinity and temperature regimes along the northern Gulf of Mexico, the seasonal timing of gametogenesis in the Gulf estuarine ribbed mussel, Geukensia granossisima, was examined across a salinity gradient in southeastern Louisiana, from July 2011 through October 2012. Ten mussels were randomly sampled monthly from low (~ 5) and high (~25) salinity marsh sites in southeastern Louisiana, and histologically processed to determine the seasonal progression of gametogenesis. Peak ripeness occurred at both sites between April and September, was positively correlated with temperature, and coincided with seasonal shifts in salinity. Mussels located in lower salinity waters demonstrated a shorter period of gametogenesis, and lower rates of ripeness indicating that changes in salinity regimes may impact long-term population dynamics.

Pilot-scale studies on biological treatment of hypersaline wastewater at low temperature.

PubMed

Peng, Y Z; Zhu, G B; Wang, S Y; Yu, D S; Cui, Y W; Meng, X S

2005-01-01

In order to investigate the feasibility of biological treatment of hypersaline wastewater produced from toilet flushing with seawater at low temperature, pilot-scale studies were established with plug-flow activated sludge process at low temperature (5-9 degrees C) based on bench-scale experiments. The critical salinity concentration of 30 g/L, which resulted from the cooperation results of the non-halophilic bacteria and the halophilic bacteria, was drawn in bench-scale experiments. Pilot-scale studies showed that high COD removal efficiency, higher than 80%, was obtained at low temperature when 30 percent seawater was introduced. The salinity improved the settleability of activated sludge, and average sludge value dropped down from 38% to 22.5% after adding seawater. Seawater salinity had a strong negative effect on notronomonas and nitrobacter growth, but much more on the nitrobacter. The nitrification action was mainly accomplished by nitrosomonas. Bench-scale experiments using two SBRs were carried out for further investigation under different conditions of salinities, ammonia loadings and temperatures. Biological nitrogen removal via nitrite pathway from wastewater containing 30 percent seawater was achieved, but the ammonia removal efficiency was strongly related not only to the influent ammonia loading at different salinities but also to temperature. When the ratio of seawater to wastewater was 30 percent, and the ammonia loading was below the critical value of 0.15 kgNH4+-N/(kgMLSS.d), the ammonia removal efficiency via nitrite pathway was above 90%. The critical level of ammonia loading was 0.15, 0.08 and 0.03 kgNH4+-N/(kgMLSS.d) respectively at the different temperature 30 degrees C, 25 degrees C and 20 degrees C when the influent ammonia concentration was 60-80 mg/L and pH was 7.5-8.0.

The Bairendaba silver polymetallic deposit in Inner Mongolia, China: characteristics of ore-forming fluid and genetic type of ore deposit

NASA Astrophysics Data System (ADS)

Wang, Ying; Xie, Yuling; Wu, Haoran

2018-02-01

Bairendaba silver-polymetallic deposit is located in the middle south of the Xing Meng orogenic belt, and in the silver-polymetallic metallogenic belt on the west slope of the southern of Great Xing’an Range. Based on studying of the fluid inclusion, we discuss the characteristics of ore-forming fluid and the metallic genesis of the Bairendaba silver-polymetallic deposit. By means of the analysis of the fluid inclusions, homogenization temperature, salinity and composition were studied in quartz and fluorite. The result is as the follows: with homogenization temperatures of fluid inclusions in quartz veins being 196∼312 °C, the average 244.52 °C, and fluid salinity 2.90∼9.08 wt%NaCl; with homogenization temperatures of fluid inclusions in fluorite being 127∼306 °C, the average 196.92 °C, and fluid salinity 2.90∼9.34 wt% NaCl. The ore-forming fluid is mainly composed of water and the gas. The results of laser Raman analysis show that the gas phase is mainly CH4. It shows that the ore-forming fluid is characterized by medium-low temperature and low-salinity system. The temperature of ore-forming fluid is from high to low, and the salinity from high to low, and the meteoric water or metamorphic water is added during deposit. According to the geological characteristics of the mining area, it is considered that the genetic type of the ore deposit should be the fault-controlled and the medium-low temperature hydrothermal deposit related to magmatic hydrothermal activities.

Temperature effect on high salinity depuration of Vibrio vulnificus and V. parahaemolyticus from the Eastern oyster (Crassostrea virginica).

PubMed

Larsen, A M; Rikard, F S; Walton, W C; Arias, C R

2015-01-02

Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are opportunistic human pathogens naturally associated with the Eastern oyster Crassostrea virginica. The abundances of both pathogens in oysters are positively correlated with temperature, thus ingestion of raw oysters during the warm summer months is a risk factor for contracting illness from these bacteria. Current post-harvest processing (PHP) methods for elimination of these pathogens are expensive and kill the oyster, changing their organoleptic properties and making them less appealing to some consumers. High salinity has proven effective in reducing Vv numbers in the wild and our research aims at developing an indoor recirculating system to reduce pathogenic Vibrios while maintaining the taste and texture of live oysters. The goal of this study was to determine the influence of temperature on the efficacy of high salinity depuration. Vv was enumerated as most probable number (MPN) per gram of oyster tissue using the FDA-approved modified cellobiose polymyxin colistin (mCPC) protocol and with an alternative Vibrio specific media CHROMagar™ Vibrio (CaV). CaV was also used to quantify Vp. Oysters were held at 35 psu for 10 days at three temperatures: low (20°C), mid (22.5°C) and high (25°C). There was no difference in MPN/g of Vv between media; however more Vv isolates were obtained from mCPC than CaV. There was no significant effect of temperature on reduction of Vv or Vp throughout depuration but there was a tendency for low temperatures to be less effective than the higher ones. High salinity resulted in a significant decrease in Vv by day 3 and again by day 10, and a decrease in Vp by day 3. Oyster condition indices were maintained throughout depuration and mortality was low (4% across three trials). Overall these results support the use of mCPC for Vv enumeration and demonstrate the promise of high salinity depuration for PHP of the Eastern oyster. The trend for lower temperatures to be less effective is surprising and indicates a potential interaction between salinity and temperature that should be further investigated. Copyright © 2014. Published by Elsevier B.V.

The feasibility of inducing mild therapeutic hypothermia after cardiac resuscitation using iced saline infusion via an intraosseous needle.

PubMed

Mader, Timothy J; Walterscheid, Joshua K; Kellogg, Adam R; Lodding, Cynthia C

2010-01-01

This study was done, using a swine model of prolonged ventricular fibrillation out-of-hospital cardiac arrest, to determine the feasibility of inducing therapeutic hypothermia after successful resuscitation by giving an intraosseous infusion of iced saline. This study was IACUC approved. Liter bags of normal saline, after being refrigerated for at least 24h, were placed in an ice filled cooler. Female Yorkshire swine weighing between 27 and 35 kg were sedated and instrumented under general anesthesia. A temperature probe was inserted 10 cm into the esophagus. Ventricular fibrillation was electrically induced and allowed to continue untreated for 10 min. Animals were randomized to one of two resuscitation schemes for the primary study (N=53). One group had central intravenous access for drug delivery and the other had an intraosseous needle inserted into the proximal tibia for drug administration. Animals in which spontaneous circulation was restored were immediately cooled, for this secondary study, by means of a rapid, pump-assisted infusion of 1L of iced saline either through the intraosseous needle (n=8), the central access (n=6), or a peripheral intravenous catheter (n=7) in a systematic, non-randomized fashion. Room, animal, and saline temperatures were recorded at initiation and upon completion of infusion. The data were analyzed descriptively using Stata SE v8.1 for Macintosh. The baseline characteristics of all three groups were mathematically the same. The average ambient room temperature during the experimental sessions was 25.5 degrees C (SD=1.3 degrees C). There were no statistically significant differences between the three groups with regard to saline temperature, rate of infusion, or decrease in core body temperature. The decrease in core temperature for the intraosseous group was 2.8 degrees C (95% CI=1.8, 3.8) over the infusion period. Mild therapeutic hypothermia can be effectively induced in swine after successful resuscitation of prolonged ventricular fibrillation by infusion of iced saline through an IO needle. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Myofibril Changes in the Copepod Pseudodiaptomus marinus Exposed to Haline and Thermal Stresses.

PubMed

Ibrahim, Ali; Souissi, Anissa; Leray, Aymeric; Héliot, Laurent; Vandenbunder, Bernard; Souissi, Sami

2016-01-01

Copepods are small crustaceans capable to survive in various aquatic environments. Their responses to changes in different external factors such as salinity and temperature can be observed at different integration levels from copepod genes to copepod communities. Until now, no thorough observation of the temperature or salinity effect stresses on copepods has been done by optical microscopy. In this study, we used autofluorescence to visualize these effects on the morphology of the calanoid copepod Pseudodiaptomus marinus maintained during several generations in the laboratory at favorable and stable conditions of salinity (30 psu) and temperature (18°C). Four different stress experiments were conducted: at a sharp decrease in temperature (18 to 4°C), a moderate decrease in salinity (from 30 to 15 psu), a major decrease in salinity (from 30 to 0 psu), and finally a combined stress with a decrease in both temperature and salinity (from 18°C and 30 psu to 4°C and 0 psu). After these stresses, images acquired by confocal laser scanning microscopy (CLSM) revealed changes in copepod cuticle and muscle structure. Low salinity and/or temperature stresses affected both the detection of fluorescence emitted by muscle sarcomeres and the distance between them. In the remaining paper we will use the term sarcomeres to describe the elements located within sarcomeres and emitted autofluorescence signals. Quantitative study showed an increase in the average distance between two consecutive sarcomeres from 2.06 +/- 0.11 μm to 2.44 +/- 0.42 μm and 2.88 +/- 0.45μm after the exposure to major haline stress (18°C, 0 psu) and the combined stress (4°C, 0 psu), respectively. These stresses also caused cuticle cracks which often occurred at the same location, suggesting the cuticle as a sensitive area for osmoregulation. Our results suggest the use of cuticular and muscle autofluorescence as new biomarkers of stress detectable in formalin-preserved P. marinus individuals. Our label-free method can be easily applied to a large number of other copepod species or invertebrates with striated musculature.

The low salinity effect at high temperatures

DOE PAGES

Xie, Quan; Brady, Patrick V.; Pooryousefy, Ehsan; ...

2017-04-05

The mechanism(s) of low salinity water flooding (LSWF) must be better understood at high temperatures and pressures if the method is to be applied in high T/P kaolinite-bearing sandstone reservoirs. We measured contact angles between a sandstone and an oil (acid number, AN = 3.98 mg KOH/g, base number, BN = 1.3 mg KOH/g) from a reservoir in the Tarim Field in western China in the presence of various water chemistries. We examined the effect of aqueous ionic solutions (formation brine, 100X diluted formation brine, and softened water), temperature (60, 100 and 140 °C) and pressure (20, 30, 40, andmore » 50 MPa) on the contact angle. We also measured the zeta potential of the oil/water and water/rock interfaces to calculate oil/brine/rock disjoining pressures. A surface complexation model was developed to interpret contact angle measurements and compared with DLVO theory predictions. Contact angles were greatest in formation water, followed by the softened water, and low salinity water at the same pressure and temperature. Contact angles increased slightly with temperature, whereas pressure had little effect. DLVO and surface complexation modelling predicted similar wettability trends and allow reasonably accurate interpretation of core-flood results. Water chemistry has a much larger impact on LSWF than reservoir temperature and pressure. As a result, low salinity water flooding should work in high temperature and high pressure kaolinite-bearing sandstone reservoirs.« less

The low salinity effect at high temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Quan; Brady, Patrick V.; Pooryousefy, Ehsan

The mechanism(s) of low salinity water flooding (LSWF) must be better understood at high temperatures and pressures if the method is to be applied in high T/P kaolinite-bearing sandstone reservoirs. We measured contact angles between a sandstone and an oil (acid number, AN = 3.98 mg KOH/g, base number, BN = 1.3 mg KOH/g) from a reservoir in the Tarim Field in western China in the presence of various water chemistries. We examined the effect of aqueous ionic solutions (formation brine, 100X diluted formation brine, and softened water), temperature (60, 100 and 140 °C) and pressure (20, 30, 40, andmore » 50 MPa) on the contact angle. We also measured the zeta potential of the oil/water and water/rock interfaces to calculate oil/brine/rock disjoining pressures. A surface complexation model was developed to interpret contact angle measurements and compared with DLVO theory predictions. Contact angles were greatest in formation water, followed by the softened water, and low salinity water at the same pressure and temperature. Contact angles increased slightly with temperature, whereas pressure had little effect. DLVO and surface complexation modelling predicted similar wettability trends and allow reasonably accurate interpretation of core-flood results. Water chemistry has a much larger impact on LSWF than reservoir temperature and pressure. As a result, low salinity water flooding should work in high temperature and high pressure kaolinite-bearing sandstone reservoirs.« less

Sea surface temperature and salinity from French research vessels, 2001–2013

PubMed Central

Gaillard, Fabienne; Diverres, Denis; Jacquin, Stéphane; Gouriou, Yves; Grelet, Jacques; Le Menn, Marc; Tassel, Joelle; Reverdin, Gilles

2015-01-01

French Research vessels have been collecting thermo-salinometer (TSG) data since 1999 to contribute to the Global Ocean Surface Underway Data (GOSUD) programme. The instruments are regularly calibrated and continuously monitored. Water samples are taken on a daily basis by the crew and later analysed in the laboratory. We present here the delayed mode processing of the 2001–2013 dataset and an overview of the resulting quality. Salinity measurement error was a few hundredths of a unit or less on the practical salinity scale (PSS), due to careful calibration and instrument maintenance, complemented with a rigorous adjustment on water samples. In a global comparison, these data show excellent agreement with an ARGO-based salinity gridded product. The Sea Surface Salinity and Temperature from French REsearch SHips (SSST-FRESH) dataset is very valuable for the ‘calibration and validation’ of the new satellite observations delivered by the Soil Moisture and Ocean Salinity (SMOS) and Aquarius missions. PMID:26504523

Quantification of surface charge density and its effect on boundary slip.

PubMed

Jing, Dalei; Bhushan, Bharat

2013-06-11

Reduction of fluid drag is important in the micro-/nanofluidic systems. Surface charge and boundary slip can affect the fluid drag, and surface charge is also believed to affect boundary slip. The quantification of surface charge and boundary slip at a solid-liquid interface has been widely studied, but there is a lack of understanding of the effect of surface charge on boundary slip. In this paper, the surface charge density of borosilicate glass and octadecyltrichlorosilane (OTS) surfaces immersed in saline solutions with two ionic concentrations and deionized (DI) water with different pH values and electric field values is quantified by fitting experimental atomic force microscopy (AFM) electrostatic force data using a theoretical model relating the surface charge density and electrostatic force. Results show that pH and electric field can affect the surface charge density of glass and OTS surfaces immersed in saline solutions and DI water. The mechanisms of the effect of pH and electric field on the surface charge density are discussed. The slip length of the OTS surface immersed in saline solutions with two ionic concentrations and DI water with different pH values and electric field values is measured, and their effects on the slip length are analyzed from the point of surface charge. Results show that a larger absolute value of surface charge density leads to a smaller slip length for the OTS surface.

Application of ERTS-1 data to the harvest model of the US menhaden fishery. [Gulf of Mexico

NASA Technical Reports Server (NTRS)

Maughan, P. M. (Principal Investigator); Marmelstein, A. D.

1974-01-01

The author has identified the following significant results. The project was conducted in Mississippi Sound in the north-central Gulf of Mexico. It utilized conventional surface data, obtained from fishing and other vessels, as well as aircraft and spacecraft remote data. A relationship was established between surface measured water transparency, temperature and salinity, and commercial fish-stock availability. Numerical models of the relationships were derived. A multiple regression was performed relating ERTS-1 MSS Band 5 image density to measured transparency and water depth. It is concluded that remotely acquired data can play a role in harvest decisions of commercial fisheries.

Long Island Sound Water Temperatures During the Last Two Thousand Years

NASA Astrophysics Data System (ADS)

Warren, C. E.; Varekamp, J. C.; Thomas, E.

2010-12-01

The Long Island Sound (LIS), sometimes called the “urban sea”, is a large estuary in the heavily populated coastal zone between New York City and the Connecticut - Rhode Island border. LIS has seen dramatic environmental shifts since colonial times, including major changes in aquatic food extraction, land use, contaminant and nutrient inputs, and climate change. Annual seasonal hypoxic/anoxic events, especially common in westernmost LIS, have been identified as potentially severe stressors for LIS biota including valuable fisheries species such as lobsters and shellfish. These conditions develop when the Sound becomes stratified in midsummer and oxygen consumption from the oxidation of organic matter exceeds oxygen resupply from the atmosphere or photosynthesis. Severity, lateral extent and frequency of hypoxia/anoxia is influenced by the amount of organic matter available for oxidation, both marine organic matter (produced by algal blooms in response to influx of N-rich effluents from waste water treatment plants) and terrestrial organic matter. These events are also influenced by the severity of stratification, determined by differences in density from temperature and salinity gradients of surface and bottom waters. Studies of cores in western and central LIS, dated using Hg-pollution profiles, 210Pb - 137Cs, and 14C, indicate that eutrophication and hypoxia have occurred in LIS only over the last ~150 years, with the possible exception of the Narrows (closest to NY) where it may have occurred before colonial times. Salinity decreased as well over the last 150 years, possibly due to changes in land use or deflection of fresh water from the Hudson River. Temperature variability in LIS over the last few thousand years has not been clearly documented, as several paleotemperature proxies are difficult to use in estuarine settings. Oxygen isotope values of carbonate microfossils are influenced by salinity fluctuations, and Mg/Ca values in these shells may be influenced by the carbonate saturation state of the water. The tetraether index (TEX86) temperature proxy is based on the number of cyclopentane rings in the glycerol dialkyl glycerol tetraethers (GDGTs) from the membrane lipids of marine Crenarchaeota, which changes in response to temperature. Crenarcheota are one of the three major groups of non-thermophilic Archaea, a widely distributed, abundant and ecologically diverse group. This proxy can be used in organic-rich sediments deposited in many different settings. We analyzed samples for TEX86 in LIS cores in order to generate a 2,000 year temperature record. We compare the TEX86 paleotemperature record data (dominantly reflecting surface water temperatures) with a Mg/Ca record based on benthic foraminifera (reflecting bottom water temperatures), and an oxygen isotope record based on benthic foraminifera and corrected for salinity changes by using the Mg/Ca record. The Mg/Ca record appears to show evidence for the Little Ice Age and Medieval Warm Period. Preliminary TEX86 data indicate that temperatures of LIS waters, as averaged over the part of the year that the proxy organisms are biologically active, generally fluctuated between 12-14°C.

Effect of Temperature, Light and Salinity on Seed Germination and Radicle Growth of the Geographically Widespread Halophyte Shrub Halocnemum strobilaceum

PubMed Central

Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M.; Baskin, Carol C.

2008-01-01

Background and Aims The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from ‘salt steppes’ in the Mediterranean region of Spain. Methods Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 °C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Key Results Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0·1 to 0·75 m NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by ≥2·0 m NaCl. Elongation of radicles from salt solutions <3·0 m resumed after seedlings were transferred to deionized water. Conclusions The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean ‘salt steppe’ of Spain and the inland cold salt desert of north-west China. PMID:17428834

Effect of temperature, light and salinity on seed germination and radicle growth of the geographically widespread halophyte shrub Halocnemum strobilaceum.

PubMed

Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M; Baskin, Carol C

2008-01-01

The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from 'salt steppes' in the Mediterranean region of Spain. Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 degrees C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0.1 to 0.75 M NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by > or = 2.0 M NaCl. Elongation of radicles from salt solutions < 3.0 M resumed after seedlings were transferred to deionized water. The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean 'salt steppe' of Spain and the inland cold salt desert of north-west China.

Submesoscale features and their interaction with fronts and internal tides in a high-resolution coupled atmosphere-ocean-wave model of the Bay of Bengal

NASA Astrophysics Data System (ADS)

Jensen, Tommy G.; Shulman, Igor; Wijesekera, Hemantha W.; Anderson, Stephanie; Ladner, Sherwin

2018-03-01

Large freshwater fluxes into the Bay of Bengal by rainfall and river discharges result in strong salinity fronts in the bay. In this study, a high-resolution coupled atmosphere-ocean-wave model with comprehensive physics is used to model the weather, ocean circulation, and wave field in the Bay of Bengal. Our objective is to explore the submesoscale activity that occurs in a realistic coupled model that resolves mesoscales and allows part of the submesoscale field. Horizontal resolution in the atmosphere varies from 2 to 6 km and is 13 km for surface waves, while the ocean model is submesoscale permitting with resolutions as high as 1.5 km and a vertical resolution of 0.5 m in the upper 10 m. In this paper, three different cases of oceanic submesoscale features are discussed. In the first case, heavy rainfall and intense downdrafts produced by atmospheric convection are found to force submesoscale currents, temperature, and salinity anomalies in the oceanic mixed layer and impact the mesoscale flow. In a second case, strong solitary-like waves are generated by semidiurnal tides in the Andaman Sea and interact with mesoscale flows and fronts and affect submesoscale features generated along fronts. A third source of submesoscale variability is found further north in the Bay of Bengal where river outflows help maintain strong salinity gradients throughout the year. For that case, a comparison with satellite observations of sea surface height anomalies, sea surface temperature, and chlorophyll shows that the model captures the observed mesoscale eddy features of the flow field, but in addition, submesoscale upwelling and downwelling patterns associated with ageostrophic secondary circulations along density fronts are also captured by the model.

An improved understanding of the Alaska coastal current: The application of a bivalve growth-temperature model to reconstruct freshwater-influenced paleoenvironments

USGS Publications Warehouse

Hallmann, N.; Schone, B.R.; Irvine, G.V.; Burchell, M.; Cokelet, E.D.; Hilton, M.R.

2011-01-01

Shells of intertidal bivalve mollusks contain sub-seasonally to interannually resolved records of temperature and salinity variations in coastal settings. Such data are essential to understand changing land-sea interactions through time, specifically atmospheric (precipitation rate, glacial meltwater, river discharge) and oceanographic circulation patterns; however, independent temperature and salinity proxies are currently not available. We established a model for reconstructing daily water temperatures with an average standard error of ???1.3 ??C based on variations in the width of lunar daily growth increments of Saxidomus gigantea from southwestern Alaska, United States. Temperature explains 70% of the variability in shell growth. When used in conjunction with stable oxygen isotope data, this approach can also be used to identify changes in past seawater salinity. This study provides a better understanding of the hydrological changes related to the Alaska Coastal Current (ACC). In combination with ??18Oshell values, increment-derived temperatures were used to estimate salinity changes with an average error of 1.4 ?? 1.1 PSU. Our model was calibrated and tested with modern shells and then applied to archaeological specimens. As derived from the model, the time interval of 988-1447 cal yr BP was characterized by ???1-2 ??C colder and much drier (2-5 PSU) summers. During that time, the ACC was likely flowing much more slowly than at present. In contrast, between 599-1014 cal yr BP, the Aleutian low may have been stronger, which resulted in a 3 ??C temperature decrease during summers and 1-2 PSU fresher conditions than today; the ACC was probably flowing more quickly at that time. The shell growth-temperature model can be used to estimate seasonal to interannual salinity and temperature changes in freshwater-influenced environments through time. ?? 2011 SEPM (Society for Sedimentary Geology).

A newly developed container for safe, easy, and cost-effective overnight transportation of tissues and organs by electrically keeping tissue or organ temperature at 3 to 6°C.

PubMed

Ohkawara, H; Kitagawa, T; Fukushima, N; Ito, T; Sawa, Y; Yoshimine, T

2012-05-01

As there is only one skin procurement organization in Japan the Japan Skin Bank Network (JSBN), all skin grafts procured in Japan are sent by a commercialized delivery system. Preliminarily, bottles containing saline were transported in a cardboard box using a so-called "cooled home delivery service" using a truck with a refrigerated cargo container. During transportation the temperature in the cardboard box increased to 18°C in summer and decreased to -5°C in winter. For these reasons, we investigated whether a newly developed container "Medi Cube" would be useful to transport skin grafts. Four bottles with a capacity of 300 mL containing 150 mL of saline in a Medi Cube container were transported from Osaka to the JSBN in Tokyo between 4 PM and 10 AM using a commercialized cooled home delivery service. Two bottles were transported in a Medi Cube container without phase change materials (PCM) in winter and summer, respectively. Another two bottles were transported in the Medi Cube with PCMs in winter. The temperatures inside saline, inside a transportation container, and outside the container, and air temperature were monitored continuously with a recordable thermometer. The temperatures inside saline and inside a Medi Cube container were maintained between 3 and 6°C, even when the temperature outside the container increased during parking. The temperature inside a Medi Cube container without PCM decreased to -3°C when the inside of the cargo container was overcooled in winter. However, the temperatures inside saline and inside a Medi Cube container with PCM were between 3 and 6°C, even when the temperature outside the container decreased to below 0°C in winter. A Medi Cube container with PCM provided a safe, easy, and cost-effective method for overnight transportation of skin grafts. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantifying salinity and season effects on eastern oyster clearance and oxygen consumption rates

USGS Publications Warehouse

Casas, S.M.; Lavaud, Romain; LaPeyre, Megan K.; Comeau, L. A.; Filgueira, R.; LaPeyre, Jerome F.

2018-01-01

There are few data on Crassostrea virginica physiological rates across the range of salinities and temperatures to which they are regularly exposed, and this limits the applicability of growth and production models using these data. The objectives of this study were to quantify, in winter (17 °C) and summer (27 °C), the clearance and oxygen consumption rates of C. virginica from Louisiana across a range of salinities typical of the region (3, 6, 9, 15 and 25). Salinity and season (temperature and reproduction) affected C. virginica physiology differently; salinity impacted clearance rates with reduced feeding rates at low salinities, while season had a strong effect on respiration rates. Highest clearance rates were found at salinities of 9–25, with reductions ranging from 50 to 80 and 90 to 95% at salinities of 6 and 3, respectively. Oxygen consumption rates in summer were four times higher than in winter. Oxygen consumption rates were within a narrow range and similar among salinities in winter, but varied greatly among individuals and salinities in summer. This likely reflected varying stages of gonad development. Valve movements measured at the five salinities indicated oysters were open 50–60% of the time in the 6–25 salinity range and ~ 30% at a salinity of 3. Reduced opening periods, concomitant with narrower valve gap amplitudes, are in accord with the limited feeding at the lowest salinity (3). These data indicate the need for increased focus on experimental determination of optimal ranges and thresholds to better quantify oyster population responses to environmental changes.

Polyculture Engineering technology of larasati red tilapia (Oreochromis niloticus) and white shrimp (Litopenaeus vannamei) based for protease enzyme

NASA Astrophysics Data System (ADS)

Samidjan, I.; Rachmawati, D.

2018-04-01

The objective is polyculture technology of red tilapia larasati fish and white shrimp with different combinations density. The material is saline red tilapia larasati 3.29 ± 0.018 g and white shrimp with initial weight 1.39 ± 0.025 g. Seeds are density of red tilapia larasati larvae 5 and 10 larvae / m2 fish. And white shrimp 5 larvae / m2 and 10 larvae / m2. An artificial feed used enzyme dose of 2.25 g / kg. The experimental using complete randomized design 4 treatments and 3 replications that is given seeds 5 larvae / m2 larvae red tilapia larasati and given 5 larvae / m2 white shrimp (A), 5 larvae / m2 red tilapia) and 10 m2 / m2 of white shrimp (B), 10 m2 larvae and 5 m2 white shrimp (C), 10 m2 larvae and 10 m2 white shrimp (D)). The data were growth of absolute weight, survival rate, FCR, and water quality data (temperature, salinity, pH, O2, NO2, NH3). Data were analyzed of variance (F test). The results showed significantly effect (P <0.01) on the growth. The highest absolute growth in D treatment were red tilapia larasati (185.75 ± 0.50g) and white shrimp (25.25 ± 0.95 g).

Arctic Intermediate Water in the Nordic Seas, 1991-2009

NASA Astrophysics Data System (ADS)

Jeansson, Emil; Olsen, Are; Jutterström, Sara

2017-10-01

The evolution of the different types of Arctic Intermediate Water (AIW) in the Nordic Seas is evaluated and compared utilising hydro-chemical data from 1991 to 2009. It has been suggested that these waters are important components of the Norwegian Sea Arctic Intermediate Water (NSAIW), and of the dense overflows to the North Atlantic. Thus, it is important to understand how their properties and distribution vary with time. The AIWs from the Greenland and Iceland Seas, show different degrees of variability during the studied period; however, only the Greenland Sea Arctic Intermediate Water (GSAIW) shows an increasing temperature and salinity throughout the 2000s, which considerably changed the properties of this water mass. Optimum multiparameter (OMP) analysis was conducted to assess the sources of the NSAIW. The analysis shows that the Iceland Sea Arctic Intermediate Water (ISAIW) and the GSAIW both contribute to NSAIW, at different densities corresponding to their respective density range. This illustrates that they flow largely isopycnally from their source regions to the Norwegian Sea. The main source of the NSAIW, however, is the upper Polar Deep Water, which explains the lower concentrations of oxygen and chlorofluorocarbons, and higher salinity and nutrient concentrations of the NSAIW layer compared with the ISAIW and GSAIW. This shows how vital it is to include chemical tracers in any water mass analysis to correctly assess the sources of the water mass being studied.

Numerical Study of Groundwater Flow and Salinity Distribution Cycling Controlled by Seawater/Freshwater Interaction in Karst Aquifer Using SEAWAT

NASA Astrophysics Data System (ADS)

Xu, Z.; Hu, B.

2017-12-01

The interest to predict seawater intrusion and salinity distribution in Woodville Karst Plain (WKP) has increased due to the huge challenge on quality of drinkable water and serious environmental problems. Seawater intrudes into the conduit system from submarine karst caves at Spring Creek Spring due to density difference and sea level rising, nowadays the low salinity has been detected at Wakulla Spring which is 18 km from coastal line. The groundwater discharge at two major springs and salinity distribution in this area is controlled by the seawater/freshwater interaction under different rainfall conditions: during low rainfall periods, seawater flow into the submarine spring through karst windows, then the salinity rising at the submarine spring leads to seawater further intrudes into conduit system; during high rainfall periods, seawater is pushed out by fresh water discharge at submarine spring. The previous numerical studies of WKP mainly focused on the density independent transport modeling and seawater/freshwater discharge at major karst springs, in this study, a SEAWAT model has been developed to fully investigate the salinity distribution in the WKP under repeating phases of low rainfall and high rainfall periods, the conduit system was simulated as porous media with high conductivity and porosity. The precipitation, salinity and discharge at springs were used to calibrate the model. The results showed that the salinity distribution in porous media and conduit system is controlled by the rainfall change, in general, the salinity distribution inland under low rainfall conditions is much higher and wider than the high rainfall conditions. The results propose a prediction on the environmental problem caused by seawater intrusion in karst coastal aquifer, in addition, provide a visual and scientific basis for future groundwater remediation.

Ectomycorrhizal Community Structure of Salix and Betula spp. at a Saline Site in Central Poland in Relation to the Seasons and Soil Parameters.

PubMed

Hrynkiewicz, Katarzyna; Szymańska, Sonia; Piernik, Agnieszka; Thiem, Dominika

Saline stress is one of the most important abiotic factors limiting the growth and development of plants and associated microorganisms. While the impact of salinity on associations of arbuscular fungi is relatively well understood, knowledge of the ectomycorrhizal (EM) fungi of trees growing on saline land is limited. The main objective of this study was to determine the density and diversity of EM fungi associated with three tree species, Salix alba , Salix caprea and Betula pendula , growing in saline soil during two seasons, autumn and spring. The site was located in central Poland, and the increased salinity of the soil was of anthropogenic origin from soda production. The degree of EM colonisation of fine root tips varied between 9 and 34 % and depended on the tree species of interest ( S. caprea < S. alba < B. pendula ) and season (spring < autumn). Moreover, the ectomycorrhizal colonisation of B. pendula was positively correlated with pH and CaCO 3 , while for S. caprea and S. alba, colonisation was associated with most of the other soil parameters investigated; e.g. salinity, C org and N. Analysis of EM fungi revealed four to five different morphotypes per each season: Tomentella sp. Sa-A, Hebeloma collariatum Sc-A, Geopora sp. Sc-A, Helotiales sp. Bp-A in the autumn and Tomentella sp. Sa-S, Tomentella sp. Sc-S and three morphotypes from the families Thelephoraceae and Pyronemataceae in the spring. In conclusion, the density of EM is related to the level of salinity (EC e ), season and tree species. Tomentella spp., Hebeloma sp., Geopora sp. and Helotiales sp. are groups of species highly adapted to saline conditions.

A model for calculating effects of liquid waste disposal in deep saline aquifer

USGS Publications Warehouse

Intercomp Resource Development and Engineering, Inc.

1976-01-01

Injection of liquid industrial wastes into confined underground saline aquifers can offer a good disposal alternative from both environmental and economic considerations. One of the needs in choosing from among several disposal alternatives is a means of evaluating the influence such an injection will have on the aquifer system. This report describes a mathematical model to accomplish this purpose.The objective of the contract was to develop a three-dimensional transient mathematical model which would accurately simulate behavior of waste injection into deep saline aquifers. Fluid properties, density and viscosity are functions of pressure, temperature and composition to provide a comprehensive assessment tool. The model is a finite-difference numerical solution of the partial differential equations describingsingle phase flow in the aquifer,energy transport by convection and conduction, andcompositional changes in the aquifer fluid.The model is not restricted to examining waste disposal operations. It can be used effectively to evaluate fresh water storage in saline aquifers, hot water storage in underground aquifers, salt water intrusion into groundwater flow systems and other similar applications.The primary advantages of the present model can be summarized as:The model is user-oriented for easy application to full-scale evaluation needs.The model is fully three-dimensional and transient.The model is comprehensive accounting for density and viscosity variations in the aquifer due to temperature or compositional changes.The model includes the effects of hydrodynamic dispersion in both the temperature and compositional mixing between resident and injected fluids.The model energy balance includes the effects of pressure. This can be important in deep aquifer systems where the viscous pressure gradient is significant.The model uses second-order correct space and time approximations to the convective terms. This minimizes the numerical dispersion problem.The model is extremely flexible in providing a wide choice of boundary conditions. These include natural flow in the aquifer, aquifer influence functions around the perimeter of the grid in recognition that the gridded region does not have no-flow boundaries, heat losses into the overlying or underlying impermeable strata, and the wellbore heat and pressure drop calculations coupled to the aquifer flow equations.The limitations of the present techniques are:The use of the second-order correct finite-difference approximations introduces block size and time step restrictions. These restrictions, though considerably less stringent than explicit methods cause, depend upon the magnitude of the dispersivity.The comprehensive nature of the model makes the computer time and storage requirements significant.The model, because of its complexity, is not as efficient in reducing down to solve simpler problems as a specially written model would be.Included in the report are detailed descriptions of the approach used in the model, validation tests of the model, and a typical application of the model. A comparison volume documents the input data requirements, program structure, and an example problem for the model. '

A method of calculating quartz solubilities in aqueous sodium chloride solutions

USGS Publications Warehouse

Fournier, R.O.

1983-01-01

The aqueous silica species that form when quartz dissolves in water or saline solutions are hydrated. Therefore, the amount of quartz that will dissolve at a given temperature is influenced by the prevailing activity of water. Using a standard state in which there are 1,000 g of water (55.51 moles) per 1,000 cm3 of solution allows activity of water in a NaCl solution at high temperature to be closely approximated by the effective density of water, pe, in that solution, i.e. the product of the density of the NaCl solution times the weight fraction of water in the solution, corrected for the amount of water strongly bound to aqueous silica and Na+ as water of hydration. Generally, the hydration of water correction is negligible. The solubility of quartz in pure water is well known over a large temperature-pressure range. An empirical formula expresses that solubility in terms of temperature and density of water and thus takes care of activity coefficient and pressure-effect terms. Solubilities of quartz in NaCl solutions can be calculated by using that equation and substituting pe, for the density of pure water. Calculated and experimentally determined quartz solubilities in NaCl solutions show excellent agreement when the experiments were carried out in non-reactive platinum, gold, or gold plus titanium containers. Reactive metal containers generally yield dissolved silica concentrations higher than calculated, probably because of the formation of metal chlorides plus NaOH and H2. In the absence of NaOH there appears to be no detectable silica complexing in NaCl solutions, and the variation in quartz solubility with NaCl concentration at constant temperature can be accounted for entirely by variations in the activity of water. The average hydration number per molecule of dissolved SiO2 in liquid water and NaCl solutions decreases from about 2.4 at 200??C to about 2.1 at 350??C. This suggests that H4SiO4 may be the dominant aqueous silica species at 350??C, but other polymeric forms become important at lower temperatures. ?? 1983.

Using Heat as a Tracer to Estimate Saline Groundwater Fluxes from the Deep Aquifer System to the Shallow Aquifers and the Rio Grande in the Mesilla Basin, New Mexico, USA

NASA Astrophysics Data System (ADS)

Pepin, J. D.; Robertson, A.; Ferguson, C.; Burns, E. R.

2017-12-01

Heat is used as a tracer to estimate vertical groundwater flow and associated saline fluxes from deep (greater than 1 km) parts of the Mesilla Basin regional aquifer to the Rio Grande. Profiles of temperature with depth below ground surface are used to locate groundwater upflow zones and to estimate associated salinity fluxes. The results of this study will inform understanding of the impact of deep saline groundwater on regional water supplies. The Mesilla Basin in southern New Mexico, Texas, and Chihuahua, Mexico was designated by the U.S. as a priority transboundary aquifer in part because of the presence of the Rio Grande within the basin. Declining water levels, deteriorating water quality in both the aquifer and the river, and increasing use of water resources on both sides of the international border raise concerns about the sustainability of regional water supplies. The Rio Grande chloride concentration increases by about 130% (120 ppm to 280 ppm) as the river traverses the Mesilla Basin. Previous research attributed this reduction in water quality to the upwelling of deep sedimentary brines and geothermal waters within the basin. However, the spatial distribution of these upflow zones and their groundwater flow rates are poorly understood. Temperature profiles from 374 existing boreholes within the Mesilla Basin indicate that temperature-profile shape is affected by heat advection in the basin. Three distinct geothermal upflow zones were identified along regional fault zones in the study area based on the temperature profiles. Groundwater in these zones is considered thermal, having temperatures greater than 50°C at depths of less than 200 m. Identification of upflow-zone profiles combines analysis of temperature profiles, lithologic records, well-completion data, and profile derivatives. The Bredehoeft and Papadopulos (1965) one-dimensional heat-transport analytical solution will be applied to upflow-zone profiles to estimate the corresponding vertical groundwater flow rates. Temperature, heat flow, and salinity maps will be constructed to approximate the areal extents of identified upflow zones. These areal estimates will then be combined with the 1D vertical groundwater flow calculations and salinity data to quantify volumetric salinity fluxes to the shallow aquifer system and Rio Grande.

Relationships between wintering waterbirds and invertebrates, sediments and hydrology of coastal marsh ponds

USGS Publications Warehouse

Bolduc, F.; Afton, A.D.

2004-01-01

We studied relationships among sediment variables (carbon content, C:N, hardness, oxygen penetration, silt-clay fraction), hydrologic variables (dissolved oxygen, salinity, temperature, transparency, water depth), sizes and biomass of common invertebrate classes, and densities of 15 common waterbird species in ponds of impounded freshwater, oligohaline, mesohaline, and unimpounded mesohaline marshes during winters 1997-98 to 1999-2000 on Rockefeller State Wildlife Refuge, Louisiana, USA. Canonical correspondence analysis and forward selection was used to analyze the above variables. Water depth and oxygen penetration were the variables that best segregated habitat characteristics that resulted in maximum densities of common waterbird species. Most common waterbird species were associated with specific marsh types, except Green-winged Teal (Anas crecca) and Northern Shoveler (Anas clypeata). We concluded that hydrologic manipulation of marsh ponds is the best way to manage habitats for these birds, if the hydrology can be controlled adequately.

A dinoflagellate Cochlodinium geminatum bloom in the Zhujiang (Pearl) River estuary in autumn 2009

NASA Astrophysics Data System (ADS)

Ke, Zhixin; Huang, Liangmin; Tan, Yehui; Song, Xingyu

2012-05-01

A severe Cochlodinium geminatum red tide (>300 km2) was observed in the Zhujiang (Pearl) River estuary, South China Sea in autumn 2009. We evaluated the environmental conditions and phytoplankton community structure during the outbreak. The red tide water mass had significantly higher dissolved inorganic phosphate (DIP), ammonia, and temperature, but significantly lower nitrite, nitrate, dissolved inorganic nitrogen (DIN), and DIN/DIP relative to the non-red-tide zones. The phytoplankton assemblage was dominated by dinoflagellates and diatoms during the red tide. C. geminatum was the most abundant species, with a peak density of 4.13×107 cell/L, accounting for >65% of the total phytoplankton density. The DIN/DIP ratio was the most important predictor of species, accounting for 12.45% of the total variation in the phytoplankton community. Heavy phosphorus loading, low precipitation, and severe saline intrusion were likely responsible for the bloom of C. geminatum.

Relation between gas hydrate and physical properties at the Mallik 2L-38 research well in the Mackenzie delta

USGS Publications Warehouse

Winters, W.J.; Dallimore, S.R.; Collett, T.S.; Jenner, K.A.; Katsube, J.T.; Cranston, R.E.; Wright, J.F.; Nixon, F.M.; Uchida, T.

2000-01-01

As part of an interdisciplinary field program, a 1150-m deep well was drilled in the Canadian Arctic to determine, among other goals, the location, characteristics, and properties of gas hydrate. Numerous physical properties of the host sediment were measured in the laboratory and are presented in relation to the lithology and quantity of in situ gas hydrate. Profiles of measured and derived properties presented from that investigation include: sediment wet bulk density, water content, porosity, grain density, salinity, gas hydrate content (percent occupancy of non-sediment grain void space), grain size, porosity, and post-recovery core temperature. The greatest concentration of gas hydrate is located within sand and gravel deposits between 897 and 922 m. Silty sediment between 926 and 952 m contained substantially less, or no, gas hydrate perhaps because of smaller pore size.

Climatology and seasonality of upper ocean salinity: a three-dimensional view from argo floats

NASA Astrophysics Data System (ADS)

Chen, Ge; Peng, Lin; Ma, Chunyong

2018-03-01

Primarily due to the constraints of observation technologies (both field and satellite measurements), our understanding of ocean salinity is much less mature compared to ocean temperature. As a result, the characterizations of the two most important properties of the ocean are unfortunately out of step: the former is one generation behind the latter in terms of data availability and applicability. This situation has been substantially changed with the advent of the Argo floats which measure the two variables simultaneously on a global scale since early this century. The first decade of Argo-acquired salinity data are analyzed here in the context of climatology and seasonality, yielding the following main findings for the global upper oceans. First, the six well-defined "salty pools" observed around ±20° in each hemisphere of the Pacific, Atlantic and Indian Oceans are found to tilt westward vertically from the sea surface to about 600 m depth, forming six saline cores within the subsurface oceans. Second, while potential temperature climatology decreases monotonically to the bottom in most places of the ocean, the vertical distribution of salinity can be classified into two categories: A double-halocline type forming immediately above and below the local salinity maximum around 100-150 m depths in the tropical and subtropical oceans, and a single halocline type existing at about 100 m depth in the extratropical oceans. Third, in contrast to the midlatitude dominance for temperature, seasonal variability of salinity in the oceanic mixed layer has a clear tropical dominance. Meanwhile, it is found that a two-mode structure with annual and semiannual periodicities can effectively penetrate through the upper ocean into a depth of 2000 m. Fourth, signature of Rossby waves is identified in the annual phase map of ocean salinity within 200-600 m depths in the tropical oceans, revealing a strongly co-varying nature of ocean temperature and salinity at specific depths. These results serve as significant contributions to improving our knowledge on the haline aspect of the ocean climate.

Physiological and behavioral responses of the mud snails Hydrobia glyca and Hydrobia ulvae to extreme water temperatures and salinities: implications for their spatial distribution within a system of temperate lagoons.

PubMed

Pascual, Emilio; Drake, Pilar

2008-01-01

Physiological responses (oxygen consumption) and behavioral responses (feeding and activity) of the mud snails Hydrobia ulvae and Hydrobia glyca at different salinities (20 per thousand-80 per thousand) and temperatures (20 degrees and 30 degrees C) were studied. After 24 h under experimental conditions, both Hydrobia species already showed maximal activities (>90%) for a wide salinity range (30 per thousand-70 per thousand), with significant differences in activity between species only outside the usual salinity range of the studied lagoon. In contrast, egestion rates of H. glyca were significantly higher at the lowest salinities tested (30 per thousand and 40 per thousand) irrespective of water temperature, whereas egestion rates of H. ulvae were always significantly higher (57% on average) at 20 degrees C than at 30 degrees C and at the usual salinities found in the field (40 per thousand and 50 per thousand). Both species showed an oxyregulatory response to dissolved oxygen concentrations ranging from saturation to 1.5 mg O(2) L(-1), although specific oxygen consumption rates were significantly higher at 30 degrees C than at 20 degrees C (Q(10)=1.47+/-0.08 for H. ulvae and Q(10)=12.1+/-0.06 for H. glyca) and at the lowest salinities (30 per thousand-50 per thousand for H. ulvae and 30 per thousand-40 per thousand for H. glyca). On average, specific rates were higher for the smaller-sized H. glyca (1.64+/-0.03 microg O(2) mg(-1) ash-free dry weight [AFDW]) than for H. ulvae (1.35+/-0.03 microg O(2) mg(-1) AFDW). Despite the overlapping of their tolerances to high temperatures and salinities, the observed interspecies differences could play a certain role in the distribution of H. ulvae and H. glyca in the studied habitat. In particular, the decreasing feeding activity but increasing respiration of H. ulvae at 30 degrees C for salinities that usually occur in the studied lagoon could represent disadvantages to H. glyca during the warm period.

Estimation of solar energy resources for low salinity water desalination in several regions of Russia

NASA Astrophysics Data System (ADS)

Tarasenko, A. B.; Kiseleva, S. V.; Shakun, V. P.; Gabderakhmanova, T. S.

2018-01-01

This paper focuses on estimation of demanded photovoltaic (PV) array areas and capital expenses to feed a reverse osmosis desalination unit (1 m3/day fresh water production rate). The investigation have been made for different climatic conditions of Russia using regional data on ground water salinity from different sources and empirical dependence of specific energy consumption on salinity and temperature. The most optimal results were obtained for Krasnodar, Volgograd, Crimea Republic and some other southern regions. Combination of salinity, temperature and solar radiation level there makes reverse osmosis coupled with photovoltaics very attractive to solve infrastructure problems in rural areas. Estimation results are represented as maps showing PV array areas and capital expenses for selected regions.

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15

USGS Publications Warehouse

Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Livsey, Daniel N.

2018-03-08

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay (bay) as part of a multi-agency effort to address management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the bay teems both with resident and with migratory wildlife, plants, and fish. Freshwater mixes with salt water in the bay, which is subject both to riverine influences (floods, droughts, managed reservoir releases and freshwater diversions) and to marine influences (tides, waves, effects of salt water). To understand this environment, the USGS, along with its partners (see “Acknowledgements”), has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay (fig. 1). Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which controls gravity-driven circulation patterns and stratification in the water column. Turbidity, a measure of light scattered from suspended particles in the water, is used to estimate suspended-sediment concentration (SSC). Suspended sediment affects the bay in multiple ways: attenuation of sunlight in the water column, affecting phytoplankton growth; deposition on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; deposition in ports and shipping channels, which can necessitate dredging; and often, adsorption of contaminants, affecting their distribution and concentrations in the environment. Dissolved oxygen concentration, essential to a healthy ecosystem and a fundamental indicator of water quality, is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically vary on a daily cycle. Consequently, salinity, water temperature, SSC, and dissolved-oxygen concentration vary spatially and temporally throughout the bay. Therefore, continuous measurements are needed to observe these changes. The purpose of this fact sheet is to provide information about these variables, as well as internet links to access these continuous water-quality data collected by the USGS.

What Drives Saline Circulation Cells in Coastal Aquifers? An Energy Balance for Density-Driven Groundwater Systems

NASA Astrophysics Data System (ADS)

Harvey, C. F.; Michael, H. A.

2017-12-01

We formulate the energy balance for coastal groundwater systems and apply it to: (1) Explain the energy driving offshore saline circulation cells, and; (2) Assess the accuracy of numerical simulations of coastal groundwater systems. The flow of fresh groundwater to the ocean is driven by the loss of potential energy as groundwater drops from the elevation of the inland watertable, where recharge occurs, to discharge at sea level. This freshwater flow creates an underlying circulation cell of seawater, drawn into coastal aquifers offshore and discharging near shore, that adds to total submarine groundwater discharge. The saline water in the circulation cell enters and exits the aquifer through the sea floor at the same hydraulic potential. Existing theory explains that the saline circulation cell is driven by mixing of fresh and saline without any additional source of potential or mechanical power. This explanation raises a basic thermodynamic question: what is the source of energy that drives the saline circulation cell? Here, we resolve this question by building upon Hubbert's conception of hydraulic potential to formulate an energy balance for density-dependent flow and salt transport through an aquifer. We show that, because local energy dissipation within the aquifer is proportional to the square of the groundwater velocity, more groundwater flow may be driven through an aquifer for a given energy input if local variations in velocity are smoothed. Our numerical simulations of coastal groundwater systems show that dispersion of salt across the fresh-saline interface spreads flow over larger volumes of the aquifer, smoothing the velocity field, and increasing total flow and submarine groundwater discharge without consuming more power. The energy balance also provides a criterion, in addition to conventional mass balances, for judging the accuracy of numerical solutions of non-linear density-dependent flow problems. Our results show that some numerical simulations of saline circulation converge to excellent balances of both mass and energy, but that other simulations may poorly balance energy even after converging to a good mass balance. Thus, the energy balance can be used to identify incorrect simulations that pass convential mass balance criteria for accuracy.

A simplified regional-scale electromagnetic induction - Salinity calibration model using ANOCOVA modeling techniques

USDA-ARS?s Scientific Manuscript database

Directed soil sampling based on geospatial measurements of apparent soil electrical conductivity (ECa) is a potential means of characterizing the spatial variability of any soil property that influences ECa including soil salinity, water content, texture, bulk density, organic matter, and cation exc...

Influence of temperature, oxygen and salinity on the metabolism of the European sea bass

NASA Astrophysics Data System (ADS)

Claireaux, G.; Lagardère, J.-P.

1999-09-01

Standard (SMR) and routine (RMR) metabolic rates of groups (4 to 5 individuals) of European sea bass ( Dicentrarchus labrax) were measured at combinations of the following factors: temperature (10, 15, 20 and 25°C), oxygenation level (air saturation to 1.5 mg dm -3) and salinity (30, 20, 10 and 5‰). The influence of these environmental conditions on fish metabolic demand was then analysed through ANOVA. At 10, 15, 20 and 25°C, standard metabolic rates were 36, 65, 89, and 91 mg O 2 kg -1 h -1, respectively, while routine oxygen consumptions covered most of the metabolic range accessible. Osmoregulatory costs are linked to metabolic activity through ventilation. This relationship was highlighted by the observed interaction between environmental salinity and temperature. We were, however, unable to detect interactions between salinity and routine metabolic rate, or between salinity and oxygenation level. In order to delineate more precisely the restrictions imposed by water oxygenation on fish metabolic performance we determined the limiting oxygen concentration curves at each experimental temperature. We followed up by modelling the bass active metabolic rate (AMR) and metabolic scope (MS) as functions of both ambient temperature and oxygenation. These mathematical models allowed the characterisation of the controlling and limiting effects of water temperature and oxygen content on the metabolic capacity of the species. Thus, AMR at 10, 15 and 20°C were estimated at 65, 160 and 360 mg O 2 kg -1 h -1, respectively. However, at higher temperature (25°C) AMR dropped slightly (to 340 mg O 2 kg -1 h -1). Bass MS increased by a factor of 9 between 10 and 20°C, but diminished at higher temperatures. The present study contributes to our current understanding of the influences of environmental factors on the metabolism of sea bass and provides a bioenergetic basis for a study of how environmental constraints govern the spatial and temporal distribution pattern of this species.

Salinity fronts in the tropical Pacific Ocean.

PubMed

Kao, Hsun-Ying; Lagerloef, Gary S E

2015-02-01

This study delineates the salinity fronts (SF) across the tropical Pacific, and describes their variability and regional dynamical significance using Aquarius satellite observations. From the monthly maps of the SF, we find that the SF in the tropical Pacific are (1) usually observed around the boundaries of the fresh pool under the intertropical convergence zone (ITCZ), (2) stronger in boreal autumn than in other seasons, and (3) usually stronger in the eastern Pacific than in the western Pacific. The relationship between the SF and the precipitation and the surface velocity are also discussed. We further present detailed analysis of the SF in three key tropical Pacific regions. Extending zonally around the ITCZ, where the temperature is nearly homogeneous, we find the strong SF of 1.2 psu from 7° to 11°N to be the main contributor of the horizontal density difference of 0.8 kg/m 3 . In the eastern Pacific, we observe a southward extension of the SF in the boreal spring that could be driven by both precipitation and horizontal advection. In the western Pacific, the importance of these newly resolved SF associated with the western Pacific warm/fresh pool and El Niño southern oscillations are also discussed in the context of prior literature. The main conclusions of this study are that (a) Aquarius satellite salinity measurements reveal the heretofore unknown proliferation, structure, and variability of surface salinity fronts, and that (b) the fine-scale structures of the SF in the tropical Pacific yield important new information on the regional air-sea interaction and the upper ocean dynamics.

Environmental Determinants of the Occurrence and Distribution of Vibrio parahaemolyticus in the Rias of Galicia, Spain▿

PubMed Central

Martinez-Urtaza, Jaime; Lozano-Leon, Antonio; Varela-Pet, Jose; Trinanes, Joaquin; Pazos, Yolanda; Garcia-Martin, Oscar

2008-01-01

Infections associated with Vibrio parahaemolyticus on the coast of Galicia (in northwestern Spain) were reported to be linked to large outbreaks of illness during 1999 and 2000. Little information is available about the ecological factors that influence the emergence of V. parahaemolyticus infections in this temperate region. We carried out a 3-year study to investigate the occurrence and distribution of V. parahaemolyticus at 26 sites located in the four main rias of Galicia in association with environmental and oceanographic variables. V. parahaemolyticus was detected in all the areas investigated and throughout the complete period of study with an overall incidence of 12.5%. Salinity was the primary factor governing the temporal and spatial distribution of V. parahaemolyticus, whereas seawater temperature had a secondary effect and only modulated the abundance in periods and areas of reduced salinities. Higher occurrence of V. parahaemolyticus was observed during periods of lower salinity in autumn, with a total of 61 positive samples (18%) and a mean density of 1,234 most probable number/100 g. V. parahaemolyticus was primarily detected in areas of reduced salinity close to freshwater discharge points, where it was found in up to 45% of the samples. Characterization of the isolates obtained from the study resulted in the first identification of two pathogenic tdh-positive strains of V. parahaemolyticus recovered from the marine environment in Galicia. These isolates showed serotypes identical to and DNA profiles indistinguishable from those of the clinical clone of V. parahaemolyticus dominant in infections in Spain in the last 10 years. PMID:17981951

Difference in responses of two coastal species to fluctuating salinities and temperatures: Potential modification of specific distribution areas in the context of global change

NASA Astrophysics Data System (ADS)

Trancart, Thomas; Feunteun, Eric; Lefrançois, Christel; Acou, Anthony; Boinet, Christophe; Carpentier, Alexandre

2016-05-01

In the past several years, all numerical models have forecasted an increase in extreme climatic events linked to global change. Estuarine waters at the interface of marine and freshwater bodies are among the most volatile ecosystems, particularly for aquatic species, and will be strongly influenced by the temperature with extreme flooding events. This study aimed to quantify the acclimation capacity of coastal fish species to estuarine plume modifications. The thicklip mullet (Chelon labrosus) and European seabass (Dicentrarchus labrax) were selected as representative species of estuarine ecological guilds. These fish were subjected to an experiment mimicking a brief freshwater intrusion (35-5). These experiments were conducted at two different temperatures that these two species would encounter during their incursion from the sea through estuarine waters to freshwater habitats. The experimental results confirmed the high capacity for acclimation of both species to changes in salinity and temperature. Interspecific differences were observed. For example, the salinity has a greater effect on the metabolism of the seabass than on that of the mullets. Meanwhile, the temperature has a greater effect on the mullets. These differences in metabolic responses to fluctuating salinities and temperatures may modify the use of estuarine waters by these species and should be considered when predicting future specific distribution areas in the context of global change.

Accurate Measurements of the Dielectric Constant of Seawater at L Band

NASA Technical Reports Server (NTRS)

Lang, Roger H.; Utku, Cuneyt; Tarkocin, Yalcin; LeVine, David M.

2010-01-01

This report describes measurements of the dielectric constant of seawater at a frequency of 1.413 GHz that is at the center of the L-Sand radiometric protected frequency spectrum. Aquarius will be sensing the sea surface salinity from space in this band. The objective of the project is to refine the model function for the dielectric constant as a function of salinity and temperature so that remote sensing measurements can be made with the accuracy needed to meet the measurement goals (0.2 psu) of the Aquarius mission. The measurements were made, using a microwave cavity operated in the transmission configuration. The cavity's temperature was accurately regulated to 0.02 C by immersing it in a temperature controlled bath of distilled water and ethanol glycol. Seawater had been purchased from Ocean Scientific International Limited (OS1L) at salinities of 30, 35 and 38 psu. Measurements of these seawater samples were then made over a range of temperatures, from l0 C to 35 C in 5 C intervals. Repeated measurements were made at each temperature and salinity, Mean values and standard deviations were then computed. Total error budgets indicated that the real and imaginary parts of the dielectric constant had a relative accuracy of about l%.

Long Term Surface Salinity Measurements

NASA Technical Reports Server (NTRS)

Schmitt, Raymond W.; Brown, Neil L.

2005-01-01

Our long-term goal is to establish a reliable system for monitoring surface salinity around the global ocean. Salinity is a strong indicator of the freshwater cycle and has a great influence on upper ocean stratification. Global salinity measurements have potential to improve climate forecasts if an observation system can be developed. This project is developing a new internal field conductivity cell that can be protected from biological fouling for two years. Combined with a temperature sensor, this foul-proof cell can be deployed widely on surface drifters. A reliable in-situ network of surface salinity sensors will be an important adjunct to the salinity sensing satellite AQUARIUS to be deployed by NASA in 2009. A new internal-field conductivity cell has been developed by N Brown, along with new electronics. This sensor system has been combined with a temperature sensor to make a conductivity - temperature (UT) sensor suitable for deployment on drifters. The basic sensor concepts have been proven on a high resolution CTD. A simpler (lower cost) circuit has been built for this application. A protection mechanism for the conductivity cell that includes antifouling protection has also been designed and built. Mr. A.Walsh of our commercial partner E-Paint has designed and delivered time-release formulations of antifoulants for our application. Mr. G. Williams of partner Clearwater Instrumentation advised on power and communication issues and supplied surface drifters for testing.

Thermographic visualization of the superficial vein and extravasation using the temperature gradient produced by the injected materials

NASA Astrophysics Data System (ADS)

Nakamura, Katsumasa; Sasaki, Tomonari; Ohga, Saiji; Yoshitake, Tadamasa; Terashima, Kotaro; Asai, Kaori; Matsumoto, Keiji; Shinoto, Makoto; Shioyama, Yoshiyuki; Nishie, Akihoro; Honda, Hiroshi

2014-11-01

There are few effective methods to detect or prevent the extravasation of injected materials such as chemotherapeutic agents and radiographic contrast materials. To investigate whether a thermographic camera could visualize the superficial vein and extravasation using the temperature gradient produced by the injected materials, an infrared thermographic camera with a high resolution of 0.04 °C was used. At the room temperature of 26 °C, thermal images and the time course of the temperature changes of a paraffin phantom embedded with rubber tubes (diameter 3.2 mm, wall thickness 0.8 mm) were evaluated after the tubes were filled with water at 15 °C or 25 °C. The rubber tubes were embedded at depths of 0 mm, 1.5 mm, and 3.0 mm from the surface of the phantom. Temperature changes were visualized in the areas of the phantom where the tubes were embedded. In general, changes were more clearly detected when greater temperature differences between the phantom and the water and shallower tube locations were employed. The temperature changes of the surface of a volunteer's arm were also examined after a bolus injection of physiological saline into the dorsal hand vein or the subcutaneous space. The injection of 5 ml room-temperature (26 °C) saline into the dorsal hand vein enabled the visualization of the vein. When 3 ml of room-temperature saline was injected through the vein into the subcutaneous space, extravasation was detected without any visualization of the vein. The subtraction image before and after the injection clearly showed the temperature changes induced by the saline. Thermography may thus be useful as a monitoring system to detect extravasation of the injected materials.

Archaea in aquaria: Investigating the role of environmental influences on TEX86 in long-term culture experiments

NASA Astrophysics Data System (ADS)

Warren, C.; Pagani, M.

2016-12-01

The TEX86 paleotemperature proxy has experienced a recent rise in application, due in part to its capacity to estimate temperatures above 30°C, and to the ubiquity of the archaeal membrane lipids that comprise it. Studies comparing environmental influences and archaeal lipids - specifically core glycerol dibiphytanyl glycerol tetraethers (GDGTs) - offer insights into non-temperature influences on TEX86. Here we present environmental measurements and lipid distributions from >200 long-running aquarium systems using source water from North American coastal sites ranging in latitude from 60.12ºN to 24.56ºN. The influence of 32 environmental variables (depth, pH, etc.) was evaluated in the entire dataset, as well as in a subset that limited the influence of community structure. Based on multiple correlation analyses we demonstrate that temperature is the central factor influencing the distribution of core GDGTs in aquarium tanks, with the possible exception of GDGT-1, for which dissolved oxygen concentration is equivocally significant when GDGT-4 is included in the calculation of relative abundances. Temperature was found to have the most significant relationship with TEX86, with neither oxygen concentration nor water density making comparable contributions. Salinity, pH, and community structure have emerged as important, but less significant secondary influences of TEX86. Low salinity (<15 PSU) was consistently associated with TEX86 values that substantially overestimate tank temperature. The presence and abundance of MG-II Euryarchaeota, when considered, do not appear to significantly change the TEX86-temperature relationship. In addition, Illumina MiSeq 16S rDNA sequencing was used to assess whether archaeal communities differed along a spectrum of TEX86 values and environmental conditions. This technique allowed for the assessment of a taxonomically constrained subset of samples (n=54) where the archaeal tank populations were >98% sequences recognized as associated with the genus Nitrosopumilus (cultured ammonia oxidizers). In this dataset the relative abundance of GDGT-0 provided a better estimate of temperature than TEX86, and unusually high nitrite concentrations strongly correlated with underestimates of TEX86-based temperature relative to measured water temperature.

Process for producing modified microorganisms for oil treatment at high temperatures, pressures and salinity

DOEpatents

Premuzic, Eugene T.; Lin, Mow

1996-02-20

This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil. The processes are comprised of steps which successively limit the carbon sources and increase the temperature, pressure and salinity of the media. This is done until microbial strains are obtained that are capable of growing in essentially crude oil as a carbon source and at a temperature range from about 70.degree. C. to 90.degree. C., at a pressure range from about 2,000 to 2,500 psi and at a salinity range from about 1.3 to 35%.

Process for producing modified microorganisms for oil treatment at high temperatures, pressures and salinity

DOEpatents

Premuzic, E.T.; Lin, M.

1996-02-20

This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil. The processes are comprised of steps which successively limit the carbon sources and increase the temperature, pressure and salinity of the media. This is done until microbial strains are obtained that are capable of growing in essentially crude oil as a carbon source and at a temperature range from about 70 C to 90 C, at a pressure range from about 2,000 to 2,500 psi and at a salinity range from about 1.3 to 35%. 68 figs.

Characterization of saline groundwater across the coastal aquifer of Israel as resource for desalination

NASA Astrophysics Data System (ADS)

Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yospeh; Oren, Yoram; Kasher, Roni

2015-04-01

In arid countries with access to marine water seawater desalination is becoming an important water source in order to deal with the water scarcity and population growth. Seawater reverse osmosis (RO) facilities use open seawater intake, which requires pretreatment processes to remove particles in order to avoid fouling of the RO membrane. In small and medium size desalination facilities, an alternative water source can be saline groundwater in coastal aquifers. Using saline groundwater from boreholes near the shore as feed water may have the advantage of natural filtration and low organic content. It will also reduce operation costs of pretreatment. Another advantage of using groundwater is its availability in highly populated areas, where planning of large RO desalination plants is difficult and expensive due to real-estate prices. Pumping saline groundwater underneath the freshwater-seawater interface (FSI) might shift the interface towards the sea, thus rehabilitating the fresh water reservoirs in the aquifer. In this research, we tested the potential use of saline groundwater in the coastal aquifer of Israel as feed water for desalination using field work and desalination experiments. Specifically, we sampled the groundwater from a pumping well 100 m from the shore of Tel-Aviv and sea water from the desalination plant in Ashqelon, Israel. We used an RO cross flow system in a pilot plant in order to compare between the two water types in terms of permeate flux, permeate flux decline, salt rejection of the membrane and the fouling on the membrane. The feed, brine and fresh desalinated water from the outlet of the desalination system were chemically analyzed and compared. Field measurements of dissolved oxygen, temperature, pH and salinity were also conducted in situ. Additionally, SDI (silt density index), which is an important index for desalination, and total organic carbon that has a key role in organic fouling and development of biofouling, were measured and compared. The results have shown that using saline groundwater underneath the FSI as a resource for RO desalination process is beneficial in terms of fluxes: the flux reduction in the seawater desalination was 16% of the initial flux, while the flux reduction with the saline groundwater was only 9%. The SDI and total organic carbon were lower in saline groundwater than in seawater, which support the flux results. Therefore, using saline groundwater as feed water for desalination may be advantageous because of lower operational costs and reduced applied pressure needed and energy usage.

Impact of topography on groundwater salinization due to ocean surge inundation

NASA Astrophysics Data System (ADS)

Yu, Xuan; Yang, Jie; Graf, Thomas; Koneshloo, Mohammad; O'Neal, Michael A.; Michael, Holly A.

2016-08-01

Sea-level rise and increases in the frequency and intensity of ocean surges caused by climate change are likely to exacerbate adverse effects on low-lying coastal areas. The landward flow of water during ocean surges introduces salt to surficial coastal aquifers and threatens groundwater resources. Coastal topographic features (e.g., ponds, dunes, barrier islands, and channels) likely have a strong impact on overwash and salinization processes, but are generally highly simplified in modeling studies. To understand topographic impacts on groundwater salinization, we modeled a theoretical overwash event and variable-density groundwater flow and salt transport in 3-D using the fully coupled surface and subsurface numerical simulator, HydroGeoSphere. The model simulates the coastal aquifer as an integrated system considering overland flow, coupled surface and subsurface exchange, variably saturated flow, and variable-density groundwater flow. To represent various coastal landscape types, we simulated both synthetic fields and real-world coastal topography from Delaware, USA. The groundwater salinization assessment suggested that the topographic connectivity promoting overland flow controls the volume of aquifer that is salinized. In contrast, the amount of water that can be stored in surface depressions determines the amount of seawater that infiltrates the subsurface and the time for seawater to flush from the aquifer. Our study suggests that topography has a significant impact on groundwater salinization due to ocean surge overwash, with important implications for coastal land management and groundwater vulnerability assessment.

Saline-Induced Coronary Hyperemia: Mechanisms and Effects on Left Ventricular Function.

PubMed

De Bruyne, Bernard; Adjedj, Julien; Xaplanteris, Panagiotis; Ferrara, Angela; Mo, Yujing; Penicka, Martin; Floré, Vincent; Pellicano, Mariano; Toth, Gabor; Barbato, Emanuele; Duncker, Dirk J; Pijls, Nico H J

2017-04-01

During thermodilution-based assessment of volumetric coronary blood flow, we observed that intracoronary infusion of saline increased coronary flow. This study aims to quantify the extent and unravel the mechanisms of saline-induced hyperemia. Thirty-three patients were studied; in 24 patients, intracoronary Doppler flow velocity measurements were performed at rest, after intracoronary adenosine, and during increasing infusion rates of saline at room temperature through a dedicated catheter with 4 lateral side holes. In 9 patients, global longitudinal strain and flow propagation velocity were assessed by transthoracic echocardiography during a prolonged intracoronary saline infusion. Taking adenosine-induced maximal hyperemia as reference, intracoronary infusion of saline at rates of 5, 10, 15, and 20 mL/min induced 6%, 46%, 111%, and 112% of maximal hyperemia, respectively. There was a close agreement of maximal saline- and adenosine-induced coronary flow reserve (intraclass correlation coefficient, 0.922; P <0.001). The same infusion rates given through 1 end hole (n=6) or in the contralateral artery (n=6) did not induce a significant increase in flow velocity. Intracoronary saline given on top of an intravenous infusion of adenosine did not further increase flow. Intracoronary saline infusion did not affect blood pressure, systolic, or diastolic left ventricular function. Heart rate decreased by 15% during saline infusion ( P =0.021). Intracoronary infusion of saline at room temperature through a dedicated catheter for coronary thermodilution induces steady-state maximal hyperemia at a flow rate ≥15 mL/min. These findings open new possibilities to measure maximal absolute coronary blood flow and minimal microcirculatory resistance. © 2017 American Heart Association, Inc.

Fluid-inclusion evidence for previous higher temperatures in the miravalles geothermal field, Costa Rica

USGS Publications Warehouse

Bargar, K.E.; Fournier, R.O.

1988-01-01

Heating and freezing data were obtained for liquid-rich secondary fluid inclusions in magmatic quartz, hydrothermal calcite and hydrothermal quartz crystals from 19 sampled depths in eight production drill holes (PGM-1, 2, 3, 5, 10, 11, 12 and 15) of the Miravalles geothermal field in northwestern Costa Rica. Homogenization temperatures for 386 fluid inclusions range from near the present measured temperatures to as much as 70??C higher than the maximum measured well temperature of about 240??C. Melting-point temperature measurements for 76 fluid inclusions suggest a calculated salinity range of about 0.2-1.9 wt% NaCl equivalent. Calculated salinities as high as 3.1-4.0 wt% NaCl equivalent for 20 fluid inclusions from the lower part of drill hole PGM-15 (the deepest drill hole) indicate that higher salinity water probably was present in the deeper part of the Miravalles geothermal field at the time these fluid inclusions were formed. ?? 1988.

Depth, Salinity and Temperature Variability in the Maryland Coastal Lagoons

NASA Astrophysics Data System (ADS)

Chigbu, P.; Malagon, H.; Doctor, S.

2016-02-01

Alterations in temperature, precipitation, and sea level associated with global climate change will likely affect the hydrology and bathymetry of Maryland Coastal Bays (MCBs). This will in turn have effects on the abundance, distribution and diversity of the inhabiting biota, as well as the biogeochemistry and food web dynamics of the system. Depth, salinity and temperature data collected monthly (April to October) each year (1990 to 2012) from 20 sites in the MCBs were analyzed. Mean depth at most sites increased significantly with year (p<0.02). The rate of change in depth ranged from -0.02m/yr to 0.043m/yr (mean = 0.021m/yr), which is about seven times higher than the global rate of sea level rise. At the predicted mean rate of change in depth, the MCBs would have risen by 0.78m by the year 2050. Salinity varied between years of below average (e.g. 1990, 2003 and 2009), and above average (e.g. 1991, 1999, 2002 and 2007) levels. Inter-annual variability in salinity at most sites was significantly accounted for by variations in freshwater discharge, although the strength of the relationship decreased with proximity of the sites to the inlets. Measurements taken in April of each year since 1990 showed that temperature has increased significantly in the northern bays (Assawoman and Isle of Wight) and Chincoteague Bay, but not in Sinepuxent and Newport Bays. The observed changes in depth, salinity and temperature have important implications with regard to the functioning of the MCBs, and serve as a basis for evaluating future responses of the lagoons to climatic changes.

Matematical modeling of galophytic plants productivity taking into account the temperature factor and soil salinity level

NASA Astrophysics Data System (ADS)

Natalia, Slyusar; Pisman, Tamara; Pechurkin, Nikolai S.

Among the most challenging tasks faced by contemporary ecology is modeling of biological production process in different plant communities. The difficulty of the task is determined by the complexity of the study material. Models showing the influence of climate and climate change on plant growth, which would also involve soil site parameters, could be of both practical and theoretical interest. In this work a mathematical model has been constructed to describe the growth dynamics of different plant communities of halophytic meadows as dependent upon the temperature factor and soil salinity level, which could be further used to predict yields of these plant communities. The study was performed on plants of halophytic meadows in the coastal area of Lake of the Republic of Khakasia in 2004 - 2006. Every plant community grew on the soil of a different level of salinity - the amount of the solid residue of the saline soil aqueous extract. The mathematical model was analyzed using field data of 2004 and 2006, the years of contrasting air temperatures. Results of model investigations show that there is a correlation between plant growth and the temperature of the air for plant communities growing on soils containing the lowest (0.1Thus, results of our study, in which we used a mathematical model describing the development of plant communities of halophytic meadows and field measurements, suggest that both climate conditions (temperature) and ecological factors of the plants' habitat (soil salinity level) should be taken into account when constructing models for predicting crop yields.

Environmental Influences on the Fish Assemblage of the Humber Estuary, U.K.

NASA Astrophysics Data System (ADS)

Marshall, S.; Elliott, M.

1998-02-01

Salinity, temperature, turbidity and dissolved oxygen were measured in conjunction with a series of fish samples taken by a 2 m beam trawl from 14 sites throughout the Humber estuary, U.K., over the period April 1992 to November 1994. Sediment type was not measured as the literature indicates that the area is homogeneous. The influences of environmental factors and the characteristics of the fish assemblage were analysed using a range of multivariate techniques, including two-way indicator species analysis, canonical correspondence analysis, principal components analysis and Spearman rank correlation. The analyses indicate that salinity is the dominant factor influencing the distribution of the species, with temperature also having a major influence. Of the species examined, whiting (Merlangius merlangus), sole (Solea solea), flounder (Pleuronectes flesus), sprat (Sprattus sprattus) and herring (Clupea harengus) showed a correlation in distribution to temperature, sole, plaice (Pleuronectes platessa), pogge (Agonus cataphractus) and stickleback (Gasterosteus aculeatus) to salinity, and whiting, flounder, pogge and stickleback to dissolved oxygen. Only cod (Gadus morhua) showed a correlation with tidal state, while whiting, pogge and stickleback were correlated to depth. Unlike in some other estuaries, turbidity did not influence the composition of the fish assemblage. Temperature and salinity fluctuations appear to influence different aspects of the community, with temperature proving to be the best predictor of total abundance, while salinity influenced the species richness and total biomass. The analyses demonstrate the most important variables with regard to environmental-biotic interactions, although they also indicate that the variables measured do not account for all of the observed variation in fish biomass and abundance.

Sea Surface Salinity and Wind Retrieval Algorithm Using Combined Passive-Active L-Band Microwave Data

NASA Technical Reports Server (NTRS)

Yueh, Simon H.; Chaubell, Mario J.

2011-01-01

Aquarius is a combined passive/active L-band microwave instrument developed to map the salinity field at the surface of the ocean from space. The data will support studies of the coupling between ocean circulation, the global water cycle, and climate. The primary science objective of this mission is to monitor the seasonal and interannual variation of the large scale features of the surface salinity field in the open ocean with a spatial resolution of 150 kilometers and a retrieval accuracy of 0.2 practical salinity units globally on a monthly basis. The measurement principle is based on the response of the L-band (1.413 gigahertz) sea surface brightness temperatures (T (sub B)) to sea surface salinity. To achieve the required 0.2 practical salinity units accuracy, the impact of sea surface roughness (e.g. wind-generated ripples and waves) along with several factors on the observed brightness temperature has to be corrected to better than a few tenths of a degree Kelvin. To the end, Aquarius includes a scatterometer to help correct for this surface roughness effect.

Biosphere-atmosphere Exchange of CO2 in a Subtropical Mangrove Wetland in Hong Kong

NASA Astrophysics Data System (ADS)

Liu, J.; Neogi, S.; Lai, D. Y. F.

2017-12-01

Mangrove ecosystems play an important role in the global carbon cycle due to their high primary productivity, carbon-rich sediment, and sensitivity to climate change. Yet, there is currently a paucity of studies that quantify the biosphere-atmosphere exchange of GHGs in mangrove wetlands continuously at the ecosystem level. In this study, the temporal variability of net ecosystem CO2 exchange (NEE) between the Kandelia obovata mangrove and the atmosphere was determined in the Mai Po Marshes Nature Reserve of subtropical Hong Kong using an eddy covariance system between February 2016 and January 2017. The daytime half-hourly NEE ranged between -5.0 and +3.3 µmol m-2 s-1, while the maximum nighttime NEE could reach +5.0 µmol m-2 s-1 during the wet, warm season. Temperature, photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), and surface water salinity were some key physical and hydrological controls of NEE. Tidal activity could also exert profound influence on CO2 fluxes in this mangrove ecosystem by exporting dissolved carbon to adjacent estuary and inhibiting soil respiration during the inundation period. Overall, this coastal mangrove was a net sink of atmospheric CO2. Our results suggest that the ability of subtropical mangrove ecosystems in sequestering CO2 could be highly dependent on future changes in temperature, precipitation, and salinity.

Acoustic Seaglider: PhilSea10 Data Analysis

DTIC Science & Technology

2016-06-13

and (simple) Kalman filtering techniques will be explored to utilize the unique time-space sound speed sampling of the Seagliders to generate snapshots... temperature and salinity were deployed (Figure 1). General objectives of the experiment are to understand the acoustic propagation in the...an acoustic recording system (ARS) to record the moored source transmissions, as well as temperature , salinity and pressure sensors (from which

Factors influencing the sporulation and cyst formation of Aphanomyces invadans, etiological agent of ulcerative mycosis in Atlantic menhaden, Brevoortia tyrannus

USGS Publications Warehouse

Kiryu, Y.; Blazer, V.S.; Vogelbein, W.K.; Kator, H.; Shields, J.D.

2005-01-01

Oomycete infections caused by Aphanomyces invadans occur in freshwater and estuarine fishes around the world. Along the east coast of the USA, skin ulcers caused by A. invadans are prevalent in Atlantic menhaden, Brevoortia tyrannus. From laboratory observations low salinities appear crucial to transmission of the pathogen. To better understand aspects of transmission, we characterized sporulation and cyst formation of secondary zoospores of two isolates of A. invadans at different salinities and temperatures. Sporulation occurred only at low salinities. At room temperature (ca. 20-22 C), using "pond water" augmented with artificial sea salts, the endemic strain WIC and the Thailand strain PA7 of A. invadans produced free-swimming secondary zoospores at salinities of 0, 1 and 2 psu (practical salinity unit = ???), but not at 4 psu or higher. Secondary zoospores of another species, ATCC-62427 (Aphanomyces sp.), were observed at 1, 2, 4 and 8 psu but not at 0 and 12 psu. Secondary zoospores of all three isolates, especially WIC, were abundant and motile 1-2 d post-sporulation. Sporulation was temperature dependent and occurred over a relatively narrow range. No sporulation occurred at 4, 30 or 35 C for either WIC or PA7. For both strains zoospore production within 1-3 d after the initiation of sporulation was more prolific at 25 C than at 20 and 15 C. At 15 C production of zoospores was sustained over 11 d for WIC and 5 d for PA7. At room temperature single WIC secondary zoospores remained motile 12-18 h. Salinities exceeding 4 psu or vigorous shaking caused immediate cyst formation of WIC secondary zoospores. Exposure to menhaden tissue, but not tissues of other fishes to secondary zoospores (WIC), caused rapid (2 h) cyst formation. Cysts were capable of excysting when transferred to 1 psu water within 2-3 h of cyst formation. Cysts that had remained encysted in 6.5 psu for 24 h did not excyst when transferred to 1 psu water. Salinity and temperature requirements for sporulation indicate that juvenile menhaden must acquire infections during rain or in low salinity oligohaline waters. ?? 2005 by The Mycological Society of America.

Fluid Characteristics in the Giant Quartz Reef System of the Bundelkhand Craton, India: Constraints from Fluid Inclusion Study

NASA Astrophysics Data System (ADS)

Rout, D.; Panigrahi, M. K.; Pati, J. K.

2017-12-01

Giant quartz reefs are anomalous features indicating extensive mobilization of silica in the crust. Such reefs in the Abitibi belt, Canada and elsewhere are believed to be the result of activity of fluid of diverse sources on terrain boundaries. The Bundelkhand granitoid complex constituting a major part of the Bundelkhnad Craton in north-Central India is traversed by numerous such quartz reefs all across for a length of about 500 km. There are about 20 major reefs having dimensions of 35 to 40 km in length, 50 to 60 m in width standing out as prominent ridges in the region. Almost all are aligned parallel to each other in a sub-vertical to vertical manner following the NE-SW to NNE-SSW trend. Fluid inclusion petrography in quartz from these reefs reveal four types of inclusions viz. aqueous biphase (type-I), pure carbonic (type-II), aqueous carbonic (type-III) and polyphase (type-IV) inclusions. The type-I aqueous biphase inclusions are the dominant type in all the samples studied so far. Salinities calculated from temperature of melting of last ice (Tm) values are low to moderate, ranging from 0.18 to 18.19 wt% NaCl equivalents. Temperature of liquid-vapor homogenization (Th) values of these inclusions show a wide range from 101 ºC to 386 ºC (cluster around 150-250 ºC) essentially into liquid phase ruling out boiling during its course of evolution. Besides, aqueous Biphase inclusions, some data on pure CO2 inclusions furnish a near constant value of TmCO2 at -56.6 ºC in the Bundelkhand Craton indicating absence of CH4. Bivariate plot between Th and salinity suggest three possible water types which are controlling the overall activity of fluid in quartz reefs of Bundelkhand Craton viz. low-T low saline, high-T low saline and moderate-T and moderate saline. A low saline and CO2-bearing and higher temperature nature resembles a metamorphic fluid that may be a source for these giant quartz reefs. The low temperature low-salinity component could be a meteoric fluid that possibly mixed with a moderate salinity fluid. Such a moderate salinity fluid could represent a magmatic fluid that evolved to such low temperatures through prolonged fluid rock interaction. Although these quartz reefs do not bear any economic grade mineralization, the fluid characteristics compare well with mineralized reefs in the Dharwar and Bastar cratons.

Impact of physical and chemical characteristics of breeding sites on mosquito larval abundance at Ismailia Governorate, Egypt.

PubMed

Bahgat, Iman Mohamed

2013-08-01

The distribution and monthly abundance of mosquito larvae in released water, drainage canals and sewage water tanks in Ismailia governorate were investigated. The results obtained indicated the presence of five culicine (Culex. pipiens, Cx. pusillus, Cx. perexiguus, Cx. theleri and Ochlerotatus. caspius) and two anopheline (Anopheles. multicolor and An. pharoensis) mosquito species. Significantly higher larval density was recorded in sewage water (n= 5534; 46.08%) as compared with released water (n = 2903; 24.17%) and drainage water (n= 3573; 29.75%). Culex pipiens was the most dominant mosquito species in the three habitats. The effects of environmental parameters including pH, biological and chemical oxygen demands, day time water temperature, plant growth, salinity, total organic matter and concentrations of heavy metals on larval population density were investigated. The positive correlations observed between heavy metals concentrations in the three habitats suggested relative uniformity of the sources of metal pollutants. Culex pipiens larvae demonstrated high tolerance to elevated levels of heavy metals in sewage water and compensatory effects of high nutrient levels generally associated with sewage or domestic waste. High densities of culicine larvae were accompanied by low density of anopheline larvae. This was attributed to water chemistry & competitive interactions.

Coherent mesoscale eddies in the North Atlantic subtropical gyre: 3-D structure and transport with application to the salinity maximum

NASA Astrophysics Data System (ADS)

Amores, Angel; Melnichenko, Oleg; Maximenko, Nikolai

2017-01-01

The mean vertical structure and transport properties of mesoscale eddies are investigated in the North Atlantic subtropical gyre by combining historical records of Argo temperature/salinity profiles and satellite sea level anomaly data in the framework of the eddy tracking technique. The study area is characterized by a low eddy kinetic energy and sea surface salinity maximum. Although eddies have a relatively weak signal at surface (amplitudes around 3-7 cm), the eddy composites reveal a clear deep signal that penetrates down to at least 1200 m depth. The analysis also reveals that the vertical structure of the eddy composites is strongly affected by the background stratification. The horizontal patterns of temperature/salinity anomalies can be reconstructed by a linear combination of a monopole, related to the elevation/depression of the isopycnals in the eddy core, and a dipole, associated with the horizontal advection of the background gradient by the eddy rotation. A common feature of all the eddy composites reconstructed is the phase coherence between the eddy temperature/salinity and velocity anomalies in the upper ˜300 m layer, resulting in the transient eddy transports of heat and salt. As an application, a box model of the near-surface layer is used to estimate the role of mesoscale eddies in maintaining a quasi-steady state distribution of salinity in the North Atlantic subtropical salinity maximum. The results show that mesoscale eddies are able to provide between 4 and 21% of the salt flux out of the area required to compensate for the local excess of evaporation over precipitation.

Optimizing Surface Winds using QuikSCAT Measurements in the Mediterranean Sea During 2000-2006

DTIC Science & Technology

2009-02-28

Temperature and salinity from the 1/4° Generalized Digital Envi- ronmental Model ( GDEM ) monthly climatology developed at the Naval Oceanographic...monthly GDEM climatology was also used for relaxation of the sea-surface salinity (SSS) to keep the surface salinity balance on track. The net heat...salinity from the GDEM clima- tology are used to initialize themodel. There is a relaxation tomonthly mean SSS fromGDEM. The referencemixed-layer

Combined effects of Corexit EC 9500A with secondary abiotic and biotic factors in the rotifer Brachionus plicatilis.

PubMed

Williams, Michael B; Powell, Mickie L; Watts, Stephen A

2016-10-01

We examined lethality and behavioral effects of Corexit EC 9500A (C-9500A) exposure on the model marine zooplankton Brachionus plicatilis singularly and in combination with abiotic and biotic factors. C-9500A exposure at standard husbandry conditions (17.5ppt, 24°C, 200 rotifer*mL(-1) density) identified the 24h median lethal concentration, by Probit analysis, to be 107ppm for cultured B. plicatilis. Rotifers surviving exposure to higher concentrations (100 and 150ppm) exhibited a decreased swimming velocity and a reduced net to gross movement ratio. Significant interaction between C-9500A exposure and temperature or salinity was observed. Upper thermal range was reduced and maximal salinity stress was seen as ca. 25ppt. Increased or decreased nutritional availability over the exposure period did not significantly alter mortality of B. plicatilis populations at the concentrations tested. Results from this study may be useful for predicting possible outcomes on marine zooplankton following dispersant application under diverse natural conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Modeling the morphogenesis of brine channels in sea ice.

PubMed

Kutschan, B; Morawetz, K; Gemming, S

2010-03-01

Brine channels are formed in sea ice under certain constraints and represent a habitat of different microorganisms. The complex system depends on a number of various quantities as salinity, density, pH value, or temperature. Each quantity governs the process of brine channel formation. There exists a strong link between bulk salinity and the presence of brine drainage channels in growing ice with respect to both the horizontal and vertical planes. We develop a suitable phenomenological model for the formation of brine channels both referring to the Ginzburg-Landau theory of phase transitions as well as to the chemical basis of morphogenesis according to Turing. It is possible to conclude from the critical wave number on the size of the structure and the critical parameters. The theoretically deduced transition rates have the same magnitude as the experimental values. The model creates channels of similar size as observed experimentally. An extension of the model toward channels with different sizes is possible. The microstructure of ice determines the albedo feedback and plays therefore an important role for large-scale global circulation models.

Contrasting responses of the extended Gulf Stream to severe winter forcing

NASA Astrophysics Data System (ADS)

Jacobs, Z.; Grist, J. P.; Marsh, R.; Josey, S. A.; Sinha, B.

2015-12-01

Changes in the path and strength of the extended Gulf Stream, downstream of Cape Hatteras, and the North Atlantic Current (GSNAC), are associated with strong wintertime air-sea interactions that can further influence the atmospheric storm track. The GSNAC response to anomalous air-sea heat fluxes in particular is dependent on the location of excess heat loss, in turn related to meteorological circumstances. Outbreaks of cold continental air may lead to excess cooling over the Sargasso Sea, as in 1976-77. Under these circumstances, the Gulf Stream may intensify through a steepening of cross-stream density gradients. An alternative scenario prevailed during the cold outbreak of 2013-14 where excess cooling occurred over the central subpolar gyre and may have influenced the extreme storminess experienced in western Europe. An objectively-analysed temperature and salinity product (EN4) is used to investigate the variability of the GSNAC. Temperature and salinity profiles are used to obtain geostrophic transport at selected GSNAC transects, confirming strong horizontal temperature gradients and a positive geostrophic velocity anomaly at 70oW in spring 1977, the strongest spring transport seen in the 1970s at this location. In addition to observations, an eddy-resolving model hindcast spanning 1970-2013, is used to further characterise GSNAC transport variability, allowing a fuller assessment of the relationship between the winter surface heat flux, end-of-winter mixed layer depth, subtropical mode water volume and GSNAC transports. Preliminary results reveal a significant negative correlation between the winter surface heat flux over the Sargasso Sea and the GSNAC transport in the following spring.

An Evaluation of Antarctica as a Calibration Target for Passive Microwave Satellite Missions with Climate Data Record Applications

NASA Technical Reports Server (NTRS)

Kim, Edward

2011-01-01

Passive microwave remote sensing at L-band (1.4 GHz) is sensitive to soil moisture and sea surface salinity, both important climate variables. Science studies involving these variables can now take advantage of new satellite L-band observations. The first mission with regular global passive microwave observations at L-band is the European Space Agency's Soil Moisture and Ocean Salinity (SMOS), launched November, 2009. A second mission, NASA's Aquarius, was launched June, 201 I. A third mission, NASA's Soil Moisture Active Passive (SMAP) is scheduled to launch in 2014. Together, these three missions may provide a decade-long data record-provided that they are intercalibrated. The intercalibration is best performed at the radiance (brightness temperature) level, and Antarctica is proving to be a key calibration target. However, Antarctica has thus far not been fully characterized as a potential target. This paper will present evaluations of Antarctica as a microwave calibration target for the above satellite missions. Preliminary analyses have identified likely target areas, such as the vicinity of Dome-C and larger areas within East Antarctica. Physical sources of temporal and spatial variability of polar firn are key to assessing calibration uncertainty. These sources include spatial variability of accumulation rate, compaction, surface characteristics (dunes, micro-topography), wind patterns, and vertical profiles of density and temperature. Using primarily SMOS data, variability is being empirically characterized and attempts are being made to attribute observed variability to physical sources. One expected outcome of these studies is the potential discovery of techniques for remotely sensing--over all of Antarctica-parameters such as surface temperature.

An Evaluation of Antarctica as a Calibration Target for Passive Microwave Satellite Missions

NASA Technical Reports Server (NTRS)

Kim, Edward

2012-01-01

Passive microwave remote sensing at L-band (1.4 GHz) is sensitive to soil moisture and sea surface salinity, both important climate variables. Science studies involving these variables can now take advantage of new satellite L-band observations. The first mission with regular global passive microwave observations at L-band is the European Space Agency's Soil Moisture and Ocean Salinity (SMOS), launched November, 2009. A second mission, NASA's Aquarius, was launched June, 201l. A third mission, NASA's Soil Moisture Active Passive (SMAP) is scheduled to launch in 2014. Together, these three missions may provide a decade-long data record -- provided that they are intercalibrated. The intercalibration is best performed at the radiance (brightness temperature) level, and Antarctica is proving to be a key calibration target. However, Antarctica has thus far not been fully characterized as a potential target. This paper will present evaluations of Antarctica as a microwave calibration target for the above satellite missions. Preliminary analyses have identified likely target areas, such as the vicinity of Dome-C and larger areas within East Antarctica. Physical sources of temporal and spatial variability of polar firn are key to assessing calibration uncertainty. These sources include spatial variability of accumulation rate, compaction, surface characteristics (dunes, micro-topography), wind patterns, and vertical profiles of density and temperature. Using primarily SMOS data, variability is being empirically characterized and attempts are being made to attribute observed variability to physical sources. One expected outcome of these studies is the potential discovery of techniques for remotely sensing--over all of Antarctica--parameters such as surface temperature.

Nature of hydrothermal fluids at the shale-hosted Red Dog Zn-Pb-Ag deposits, Brooks Range, Alaska

USGS Publications Warehouse

Leach, David L.; Marsh, Erin E.; Emsbo, Poul; Rombach, Cameron; Kelley, Karen D.; Anthony, Michael W.

2004-01-01

The densities of the methane inclusions, together with the temperature of homogenization of coexisting aqueous fluid inclusions, show that these fluid inclusions were trapped between pressures of 800 and 3,400 bars and temperatures between 187° and 214°C. The pressures obtained provide unequivocal evidence that the quartz formed after ore deposition in the Carboniferous because such high fluid pressures could only have been produced from thrust loading during the Mesozoic Brookian orogeny. The observed large variation in pressure is best explained by transient fluid pressures from hydrostatic to lithostatic conditions during thrust loading. The 3,400 bars pressure corresponds with about 12 km of lithostatic burial, whereas the lower pressures (800 bars) correspond with about 8 km of hydrostatic pressure. Because of their low salinity (0-5 wt % NaCl equiv) the electrolyte compositions of the quartz fluid inclusions do not constrain their origin.

Multivariate Error Covariance Estimates by Monte-Carlo Simulation for Assimilation Studies in the Pacific Ocean

NASA Technical Reports Server (NTRS)

Borovikov, Anna; Rienecker, Michele M.; Keppenne, Christian; Johnson, Gregory C.

2004-01-01

One of the most difficult aspects of ocean state estimation is the prescription of the model forecast error covariances. The paucity of ocean observations limits our ability to estimate the covariance structures from model-observation differences. In most practical applications, simple covariances are usually prescribed. Rarely are cross-covariances between different model variables used. Here a comparison is made between a univariate Optimal Interpolation (UOI) scheme and a multivariate OI algorithm (MvOI) in the assimilation of ocean temperature. In the UOI case only temperature is updated using a Gaussian covariance function and in the MvOI salinity, zonal and meridional velocities as well as temperature, are updated using an empirically estimated multivariate covariance matrix. Earlier studies have shown that a univariate OI has a detrimental effect on the salinity and velocity fields of the model. Apparently, in a sequential framework it is important to analyze temperature and salinity together. For the MvOI an estimation of the model error statistics is made by Monte-Carlo techniques from an ensemble of model integrations. An important advantage of using an ensemble of ocean states is that it provides a natural way to estimate cross-covariances between the fields of different physical variables constituting the model state vector, at the same time incorporating the model's dynamical and thermodynamical constraints as well as the effects of physical boundaries. Only temperature observations from the Tropical Atmosphere-Ocean array have been assimilated in this study. In order to investigate the efficacy of the multivariate scheme two data assimilation experiments are validated with a large independent set of recently published subsurface observations of salinity, zonal velocity and temperature. For reference, a third control run with no data assimilation is used to check how the data assimilation affects systematic model errors. While the performance of the UOI and MvOI is similar with respect to the temperature field, the salinity and velocity fields are greatly improved when multivariate correction is used, as evident from the analyses of the rms differences of these fields and independent observations. The MvOI assimilation is found to improve upon the control run in generating the water masses with properties close to the observed, while the UOI failed to maintain the temperature and salinity structure.

Variations of summer phytoplankton community related to environmental factors in a macro-tidal estuarine embayment, Hangzhou Bay, China

NASA Astrophysics Data System (ADS)

Zhang, Yuexia; Yu, Jun; Jiang, Zhibing; Wang, Qin; Wang, Hui

2015-12-01

To explore the distribution and composition of phytoplankton community and their responses to environmental changes, summer net-collected phytoplankton and physicochemical parameters in the Hangzhou Bay during 2004-2010 were investigated. A total of four phyla and 84 species were identified, including 67 diatom and 12 dinoflagellate species. The dominant species constantly consisted of the diatoms, although the dominance of dinoflagellate and cyanobacteria increased recently. Due to great spatio-temporal variations in environmental factors (salinity, suspended solids, and nutrient concentration), significant heterogeneities in community compositions among different years and subregions (inner and middle sections, and bay mouth) were found based on the analyses of multidimensional scaling and similarity. Canonical correspondence analysis showed that salinity and Si/N were the main variables associated with algal assemblage. Compared with the historical data since the 1980s, eutrophication (N, P, and N/P increased with decreasing Si/N) was exacerbated drastically. Moreover, climatic forcing and human activities resulted in a series of physical alterations, including sediment retention, temperature increase, and salinity decrease as well as reduction in water exchanges. All these changes induced obvious increases in cell density and Chl- a while decreases in species diversity and diatom-dinoflagellate ratio as well as the shifting of dominant species. Therefore, the long-term phytoplankton variations were closely related to anthropogenic and climatic perturbations in the Hangzhou Bay.

Niche Limits of Symbiotic Gut Microbiota Constrain the Salinity Tolerance of Brine Shrimp.

PubMed

Nougué, Odrade; Gallet, Romain; Chevin, Luis-Miguel; Lenormand, Thomas

2015-09-01

Symbiosis generally causes an expansion of the niche of each partner along the axis for which a service is mutually provided. However, for other axes, the niche can be restricted to the intersection of each partner's niche and can thus be constrained rather than expanded by mutualism. We explore this phenomenon using Artemia as a model system. This crustacean is able to survive at very high salinities but not at low salinities, although its hemolymph's salinity is close to freshwater. We hypothesized that this low-salinity paradox results from poor performance of its associated microbiota at low salinity. We showed that, in sterile conditions, Artemia had low survival at all salinities when algae were the only source of carbon. In contrast, survival was high at all salinities when fed with yeast. We also demonstrated that bacteria isolated from Artemia's gut reached higher densities at high salinities than at low salinities, including when grown on algae. Taken together, our results show that Artemia can survive at low salinities, but their gut microbiota, which are required for algae digestion, have reduced fitness. Widespread facultative symbiosis may thus be an important determinant of niche limits along axes not specific to the mutualistic interaction.

Incorporating Density Properties of MgSO4 Brines Into Icy World Ocean Simulations

NASA Astrophysics Data System (ADS)

Goodman, J. C.; Vance, S.

2011-12-01

The structure and flow of the subsurface oceans in icy worlds depends on the sources of buoyancy within these oceans. Buoyancy is determined by the equation of state, in which density is a nonlinear function of temperature, salinity, and pressure. Equations of state for terrestrial seawater (with Na and Cl as the principal dissolved species) are well-developed, but icy world oceans may contain a different balance of species, including Na, Mg, SO4, and NH4 (Kargel et al, 2000). Recent work by Vance and Brown (2011, pers. comm.) has mapped out the density and thermodynamic properties of MgSO4 brines under icy world conditions. We have developed code to incorporate this equation of state data for MgSO4 brines into two different ocean simulation models. First, we investigate a single-column convection model, which is able to find the equilibrium structure and heat transport of an icy world ocean. We explore the heat transport through the ocean subject to a variety of assumptions about ocean salinity and seafloor heat and salt flux. We resolve the paradox posed by Vance and Brown (2004): warm salty MgSO4 brine emitted by a seafloor hydrothermal system may be positively buoyant at the seafloor, but become negatively buoyant (sinking) at lower pressure. How does heat escape the ocean, if it cannot be transported by convection? Second, we add MgSO4 dynamics to a full 3-D time-dependent general circulation model (the MIT GCM), which is able to simulate both the global-scale circulation of the world's ocean and investigate the highly turbulent dynamics of buoyant hydrothermal systems. We ask, "Are buoyancy-driven flows in a MgSO4 brine ocean significantly different than similarly-driven flows in terrestrial seawater?"

Diversity, distribution, and morphological deformities among living Foraminifera in hypersaline Salwa Bay, Saudi Arabia

NASA Astrophysics Data System (ADS)

Olalekan Amao, Abduljamiu; Kaminski, Michael

2016-04-01

The Arabian Gulf is considered a naturally stressed environment due to extremes of salinity and summer temperatures. Anthropogenic influences such as rapid urbanisation projects, maritime transport, and large numbers of desalination plants and oil-related activities compounds the problem. Foraminifera are known to be resilient under such stressful conditions. The purpose of our study is to document the foraminiferal diversity and abundance in the hypersaline Salwa Bay area, near the Saudi Arabian-Qatar Border. We expect the foraminiferal fauna in Salwa Bay to be adapted to extremes in salinity, and we wish to document any species that might be endemic or uniquely adapted to the area. Shannon-Wiener index, relative abundance, species richness, and the percentage of morphological deformities were determined for samples collected from the bay. Salwa Bay is the most saline extension of the Arabian Gulf with high salinity, water temperature and evaporation rate, which is attributed to slow flushing rates, coral reef barriers and higher residency time of the water. Environmental parameters measured at the time of collection were depth (10-110 cm), salinity (52.6-53.0) total dissolved solids (48.8-49.4 g/l), and temperature (27-27.6°C). The foraminiferal assemblages in Salwa Bay are dominated by porcelaneous foraminifera, which include Peneroplis pertusus, Peneroplis planatus, Coscinospira hemprichii and Coscinospira acicularis. The most common species across the sampled transect is Peneroplis pertusus. Hyaline species were also found, but agglutinated foraminifera are absent. Diversity in Salwa Bay is lower compared with localities that have "normal" salinity, and many of the foraminifera display conspicuous morphological deformities. Approximately 55% of the assemblage exhibits mild to severe deformities such as fusion of two adults or double tests, protuberance on the spiral side, abnormal arrangement of the chambers, abnormal shape of the proloculus and modification of the coiling plane in several chambers. We speculate that the combination of high summer temperatures and salinities may be the main cause of the deformities and comparatively low diversity.

Effect of salinity and temperature on treatment of concentrated wastewater from RO by FO-MD

NASA Astrophysics Data System (ADS)

Zhou, Yingru; Huang, Manhong; Deng, Qian

2018-02-01

In this study the appropriate temperature of the membrane distillation (MD) hot side (the permeation flux of MD was controlled by adjusting the hot side temperature) was selected according to the water flux of FO process so that the water transfer rate on both sides of FO and MD was consistent and the FO-MD process could be stable operation. When the salt concentration of feed solution was 30, 55, 80 and 100 g/L, the desalination rates changed little, which were 99.1%, 98.4%, 98.9% and 98.7%, respectively. The removal rate of COD was 93.8%, 94.2%, 91.6% and 92.7% which also changed little like the desalination rates. The removal rate of chromaticity increased with the increase of salinity, which attained 96.6%, 97.0%, 97.2% and 97.9%, respectively. This study proved that salinity of the feed solution affected little on the removal rate of contaminants but great on the water flux, with the increase of salinity from 30 to 100 g/L, the water flux was 6.05, 4.81, 4.33 and 3.87 LMH with the appropriate temperature (67.5±0.5, 64.5±0.5, 62.5±0.5 and 60.5±0.5 °C) of MD hot side. In a word, FO-MD was first used to treat the high salinity RO water with over 30 g/L total dissolved solids (TDS), FO-MD was a promising new process for high salinity wastewater treatment, and the hybrid system can solve the problem of lower draw solution concentration, and the high-quality production water will be obtained directly by this hybrid system with low membrane fouling tendency.

Numerical simulation of the effect of groundwater salinity on artificial freezing wall in coastal area

NASA Astrophysics Data System (ADS)

Hu, Rui; Liu, Quan

2017-04-01

During the engineering projects with artificial ground freezing (AFG) techniques in coastal area, the freezing effect is affected by groundwater salinity. Based on the theories of artificially frozen soil and heat transfer in porous material, and with the assumption that only the variations of total dissolved solids (TDS) impact on freezing point and thermal conductivity, a numerical model of an AFG project in a saline aquifer was established and validated by comparing the simulated temperature field with the calculated temperature based on the analytic solution of rupak (reference) for single-pipe freezing temperature field T. The formation and development of freezing wall were simulated with various TDS. The results showed that the variety of TDS caused the larger temperature difference near the frozen front. With increasing TDS in the saline aquifer (1 35g/L), the average thickness of freezing wall decreased linearly and the total formation time of the freezing wall increased linearly. Compared with of the scenario of fresh-water (<1g/L), the average thickness of frozen wall decreased by 6% and the total formation time of the freezing wall increased by 8% with each increasing TDS of 7g/L. Key words: total dissolved solids, freezing point, thermal conductivity, freezing wall, numerical simulation Reference D.J.Pringel, H.Eicken, H.J.Trodahl, etc. Thermal conductivity of landfast Antarctic and Arctic sea ice[J]. Journal of Geophysical Research, 2007, 112: 1-13. Lukas U.Arenson, Dave C.Sego. The effect of salinity on the freezing of coarse- grained sand[J]. Canadian Geotechnical Journal, 2006, 43: 325-337. Hui Bing, Wei Ma. Laboratory investigation of the freezing point of saline soil[J]. Cold Regions Science and Technology, 2011, 67: 79-88.

A Thermally-Regenerative Ammonia-Based Flow Battery for Electrical Energy Recovery from Waste Heat.

PubMed

Zhu, Xiuping; Rahimi, Mohammad; Gorski, Christopher A; Logan, Bruce

2016-04-21

Large amounts of low-grade waste heat (temperatures <130 °C) are released during many industrial, geothermal, and solar-based processes. Using thermally-regenerative ammonia solutions, low-grade thermal energy can be converted to electricity in battery systems. To improve reactor efficiency, a compact, ammonia-based flow battery (AFB) was developed and tested at different solution concentrations, flow rates, cell pairs, and circuit connections. The AFB achieved a maximum power density of 45 W m(-2) (15 kW m(-3) ) and an energy density of 1260 Wh manolyte (-3) , with a thermal energy efficiency of 0.7 % (5 % relative to the Carnot efficiency). The power and energy densities of the AFB were greater than those previously reported for thermoelectrochemical and salinity-gradient technologies, and the voltage or current could be increased using stacked cells. These results demonstrated that an ammonia-based flow battery is a promising technology to convert low-grade thermal energy to electricity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of an eddy resolving global model at the Bermuda Atlantic Time-series Study site

NASA Astrophysics Data System (ADS)

Hiron, L.; Goncalves Neto, A.; Bates, N. R.; Johnson, R. J.

2016-02-01

The Bermuda Atlantic Time-series Study (BATS) commenced monthly sampling in 1988 and thus provides an invaluable 27 years of ocean temperature and salinity profiles for inferring climate relevant processes. However, the passage of mesoscale eddies through this site complicates the local heat and salinity budgets due to inadequate spatial and temporal sampling of these eddy systems. Thus, application of high resolution operational numerical models potentially offers a framework for estimating the horizontal transport due to mesoscale processes. The goal of this research was to analyze the accuracy of the MERCATOR operational 1/12° global ocean model at the BATS site by comparing temperature, salinity and heat budgets for years 2008 - 2015. Overall agreement in the upper 540m for temperature and salinity is found to be very encouraging with significant (P< 0.01) correlations at all depths for both fields. The highest value of correlation coefficient for the temperature field is 0.98 at the surface which decreases to 0.66 at 150m and then reaches a minimum of 0.50 at 320 to 540m. Similarly, the highest correlation coefficient for salinity is found at the surface, with a value of 0.83 and then decreases to a minimum of 0.25 in the subtropical mode water though then increases to 0.5 at 540m. Mixing in the MERCATOR model is also very well captured with a mixed layer depth (MLD) correlation coefficient of 0.92 for the seven year period. Finally, the total heat budget (0-540m) from MERCATOR varies coherently with the BATS observations as shown by a high correlation coefficient of 0.84 (P < 0.01). According to these analyses, daily output from the MERCATOR model represents accurately the temperature, salinity, heat budget and MLD at the BATS site. We propose this model can be used in future research at the BATS site by providing information about mesoscale structure and importantly, advective fluxes at this site.

Benchmarking variable-density flow in saturated and unsaturated porous media

NASA Astrophysics Data System (ADS)

Guevara Morel, Carlos Roberto; Cremer, Clemens; Graf, Thomas

2015-04-01

In natural environments, fluid density and viscosity can be affected by spatial and temporal variations of solute concentration and/or temperature. These variations can occur, for example, due to salt water intrusion in coastal aquifers, leachate infiltration from waste disposal sites and upconing of saline water from deep aquifers. As a consequence, potentially unstable situations may exist in which a dense fluid overlies a less dense fluid. This situation can produce instabilities that manifest as dense plume fingers that move vertically downwards counterbalanced by vertical upwards flow of the less dense fluid. Resulting free convection increases solute transport rates over large distances and times relative to constant-density flow. Therefore, the understanding of free convection is relevant for the protection of freshwater aquifer systems. The results from a laboratory experiment of saturated and unsaturated variable-density flow and solute transport (Simmons et al., Transp. Porous Medium, 2002) are used as the physical basis to define a mathematical benchmark. The HydroGeoSphere code coupled with PEST are used to estimate the optimal parameter set capable of reproducing the physical model. A grid convergency analysis (in space and time) is also undertaken in order to obtain the adequate spatial and temporal discretizations. The new mathematical benchmark is useful for model comparison and testing of variable-density variably saturated flow in porous media.

Characterization of CCTα and evaluating its expression in the mud crab Scylla paramamosain when challenged by low temperatures alone and in combination with high and low salinity.

PubMed

Yu, Kun; Gong, Jie; Huang, Chencui; Huang, Huiyang; Ye, Haihui; Wang, Guizhong; Zeng, Chaoshu

2015-09-01

Chaperonin containing the T-complex polypeptide-1 (CCT), which is known to be involved in intracellular assembly and folding of proteins, is a class of chaperonin omnipresent in all forms of life. Previous studies showed that CCT played a vital role in cold hardiness of various animals. In order to understand the response of the polypeptide complex to low temperature challenge and other environmental stresses, a subunit of CCT (CCTα) was cloned from the mud crab Scylla paramamosain by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE). The full-length cDNA SpCCTα was of 1972 bp and contained a 1668 bp open reading frame (ORF) encoding a polypeptide of 555 amino acids with four conserved motifs. The messenger ribonucleic acid (mRNA) levels of SpCCTα in ten tissues of adult S. paramamosain was subsequently examined and the highest expression was found in muscle, followed by gill, hepatopancreas, thoracic ganglion, hemocyte, heart, cerebral ganglion, stomach, eyestalk ganglion, and epidermis. The expressions of SpCCTα in the muscle of sub-adult crabs (pre-acclimated to 28 °C) subjected to the challenges of both lower temperatures (25, 20, 15, and 10 °C) alone and low temperatures (15 and 10 °C) in combination with salinity of 35 and 10 were further investigated by fluorescent quantitative real-time PCR (qPCR). It was revealed that when exposed to lower temperatures alone, the mRNA transcripts of the SpCCTα gene in the muscle were generally induced for significant higher expression at 10 °C treatment than the 25, 20, and 15 °C treatments; meanwhile, exposure to 15 °C also frequently led to significantly higher expression than those at 20 and 25 °C. This finding indicated that the up-regulation of SpCCTα was closely related to the cold hardiness of S. paramamosain. The results of an additional experiment challenging the sub-adult crabs with various combinations of low temperatures with different salinity conditions generally demonstrated that at both 10 and 15 °C, the expression of SpCCTα under the high salinity of 35 was significantly lower than that at low salinity of 10, implying that the damages caused by low temperatures with high salinity were less than that under low salinity.

Mg/Ca-temperature calibration and flux variability of Globigerinoides ruber based on a bi-weekly resolved sediment trap

NASA Astrophysics Data System (ADS)

Monteagudo, M. M.; Weldeab, S.; Lea, D. W.; Karl, D. M.; Rosenthal, Y.

2016-12-01

Planktonic foraminiferal Mg/Ca is one of the most widely-applied proxies for sea surface temperature reconstructions. Current calibrations yield a temperature sensitivity of 9.0 ± 1.0% Mg/Ca per °C (1-2). According to culture studies (3-4), salinity may also influence Mg/Ca ratios by 3.3 ± 1.7% per salinity unit (4), though this effect has not been verified by a field-based study. Paired Mg/Ca-δ18O and faunal fluxes of Globigerinoides ruber (sensu lato) were measured from sediment trap samples at the Hawaii Ocean Time Series. Within the habitat depth range of G. ruber (0-50 m), seasonal temperature and salinity vary by 4 °C and 0.7 practical salinity units, respectively. Multivariate regression reveals that salinity influence is not significant at this site, allowing us to isolate and quantify the temperature influence on Mg/Ca using spatially and temporally highly-resolved temperature measurements. Our study shows an exponential Mg/Ca-temperature relationship of: Mg/Ca [mmol/mol] = (0.97 ± 0.39) exp ((0.063 ± 0.016)*T[°C]) (RMSE=0.32). The results of our faunal and geochemical analyses highlight two key findings. First, foraminiferal assemblage data reveals that the mean annual flux of G. ruber (13 shells/m2/day) is strongly skewed by flux during the summer (up to 63 shells/m2/day) with potential implications for reconstructing annual SST. Second, our results indicate a temperature sensitivity of 6.3 ± 1.6% Mg/Ca per °C, suggesting that the temperature influence on Mg/Ca may be lower than the canonical 9 ± 1 % Mg/Ca per °C value and is sensitive to the choice of habitat depth. 1. Anand et al., Paleoceanography, 18, 1050 (2003); 2. Dekens et al., G3, 3, 1022 (2002); 3. Hönisch et al., GCA, 121, 196-213 (2013); 4. Kisakürek et al., EPSL, 273, 260-269 (2008).

Spatial and temporal variability in estuary habitat use by American alligators

USGS Publications Warehouse

Fujisaki, Ikuko; Hart, Kristen M.; Cherkiss, Michael S.; Mazzotti, Frank J.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Brandt, Laura A.

2016-01-01

Estuarine habitat occupied by Alligator mississippiensis, a primarily freshwater species, is spatially and temporally heterogeneous largely due to a salinity gradient that fluctuates. Using long-term night light survey data, we examined seasonal patterns in alligators’ habitat use by size classes in midstream and downstream estuary zones of Shark River, Everglades National Park, in southern Florida. We observed predominantly large-sized alligators (total length ≥ 1.75 m); observations of alligators in the small size classes (0.5 m ≤ total length < 1.25 m) were rare especially in the higher-salinity downstream zone. The density of alligators in the downstream zone was lower than that of the midstream zone during the dry season when salinity increases due to reduced precipitation. Conversely, the density of the large size alligators was higher in the downstream zone than in the midstream zone during the wet season, likely because of reduced salinity. We also found a significant declining trend over time in the number of alligators in the dry season, which coincides with the reported decline in alligator relative density in southern Florida freshwater wetlands. Our results indicated high adaptability of alligators to the fluctuating habitat conditions. Use of estuaries by alligators is likely driven in part by physiology and possibly by reproductive cycle, and our results supported their opportunistic use of estuary habitat and ontogenetic niche shifts.

Main directions in the simulation of physical characteristics of the World Ocean and seas

NASA Astrophysics Data System (ADS)

Sarkisyan, A. S.

2016-07-01

A brief analysis of the oceanographic papers printed in this issue is presented. For convenience of the reader, the paper by K. Bryan, a prominent scientist and expert in modeling the physical characteristics of the ocean, is discussed in detail. The remaining studies are described briefly in several sections: direct prognostic modeling, diagnosis-adaptation, four-dimensional analysis, and operational oceanography. At the end of the study, we separately discuss the problem of the reproduction of coastal intensification of temperature, salinity, density, and currents. We believe that the quality of the simulation results can be best assessed in terms of the intensity of coastal currents. In conclusion, this opinion is justified in detail.

Microwave remote sensing of sea ice in the AIDJEX Main Experiment. [Arctic Ice Dynamics Joint Experiment

NASA Technical Reports Server (NTRS)

Campbell, W. J.; Wayenberg, J.; Ramseyer, J. B.; Ramseier, R. O.; Vant, M. R.; Weaver, R.; Redmond, A.; Arsenault, L.; Gloersen, P.; Zwally, H. J.

1978-01-01

A microwave remote sensing program of sea ice in the Beaufort Sea was conducted during the Arctic Ice Dynamics Joint Experiment (AIDJEX). Several types of both passive and active sensors were used to perform surface and aircraft measurements during all seasons of the year. In situ observations were made of physical properties (salinity, temperature, density, surface roughness), dielectric properties, and passive microwave measurements were made of first-year, multiyear, and first-year/multiyear mixtures. Airborne passive microwave measurements were performed with the electronically scanning microwave radiometer while airborne active microwave measurements were performed by synthetic aperture radar, X- and L-band radar, and a scatterometer.

Responses to salinity in invasive cordgrass hybrids and their parental species (Spartina) in a scenario of sea level rise and climate change

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Salinity is one of the main abiotic factors in salt marshes. Studies rooted to analyzed salinity tolerance of halophytes may help to relate their physiological tolerances with distribution limits in the field. Climate change-induced sea level rise and higher temperatures...

Optical Models for Remote Sensing of Colored Dissolved Organic Matter Absorption and Salinity in New England, Middle Atlantic and Gulf Coast Estuaries USA

EPA Science Inventory

In estuarine and nearshore ecosystems, salinity levels, along with temperature, control water column stratification, the types and locations of plants and animals, and the flocculation of particles. Salinity is also a key factor when monitoring water quality variables (e.g., diss...

Field and numerical studies of flow structure in Lake Shira (Khakassia) in summer

NASA Astrophysics Data System (ADS)

Yakubaylik, Tatyana; Kompaniets, Lidia

2014-05-01

Investigations of Lake Shira are conducted within a multidisciplinary approach that includes the study of biodiversity, biochemistry, geology of lake sediments, as well as its hydrophysics. Our report focuses on field measurements in the lake during the 2009 - 2013 and numerical modeling of flow structure. The flow velocity, temperature and salinity distribution and fluctuations of the thermocline (density) were measured in summer. An analysis of spatial and temporal variability of the major hydrophysical characteristics leads us to conclusion that certain meteorological conditions may cause internal waves in this lake. Digital terrain model is constructed from measurements of Lake bathymetry allowing us to carry out numerical simulation. Three-dimensional primitive equation numerical model GETM is applied to simulate hydrophysical processes in Lake Shira. The model is hydrostatic and Boussinesq. An algorithm of high order approximation is opted for calculating the equations of heat and salt transfer. Temperature and salinity distributions resulting from field observations are taken as initial data for numerical simulations. Model calculations as well as calculations with appropriate real wind pattern being observed on Lake Shira have been carried out. In the model calculations we follow (1). Significant differences are observed between model calculations with constant wind and calculations with real wind pattern. Unsteady wind pattern leads to the appearance of horizontal vortexes and a significant increase of vertical fluctuations in temperature (density, impurities). It causes lifting of the sediments to the upper layers at the areas where the thermocline contacts the bottom. It is important for understanding the overall picture of the processes occurring in the lake in summer. Comparison of the results of numerical experiments with the field data shows the possibility of such a phenomena in Lake Shira. The work was supported by the Russian Foundation for Fundamental Studies under Grant 13-05-00853 and interdisciplinary integration project of SB RAS 56. REFERENCES 1. Beletsky D. Numerical Simulation of Internal Kelvin Waves and Coastal Upwelling Fronts. D. Beletsky, W. P. O'Connor J. of Physical Oceanography. - v.27. - July 1997. - P. 1197-1215.

Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study.

PubMed

Drake, Bert G

2014-11-01

An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Preliminary Experimental Examination Of Controls On Methane Expulsion During Melting Of Natural Gas Hydrate Systems

NASA Astrophysics Data System (ADS)

Kneafsey, T. J.; Flemings, P. B.; Bryant, S. L.; You, K.; Polito, P. J.

2013-12-01

Global climate change will cause warming of the oceans and land. This will affect the occurrence, behavior, and location of subseafloor and subterranean methane hydrate deposits. We suggest that in many natural systems local salinity, elevated by hydrate formation or freshened by hydrate dissociation, may control gas transport through the hydrate stability zone. We are performing experiments and modeling the experiments to explore this behavior for different warming scenarios. Initially, we are exploring hydrate association/dissociation in saline systems with constant water mass. We compare experiments run with saline (3.5 wt. %) water vs. distilled water in a sand mixture at an initial water saturation of ~0.5. We increase the pore fluid (methane) pressure to 1050 psig. We then stepwise cool the sample into the hydrate stability field (~3 degrees C), allowing methane gas to enter as hydrate forms. We measure resistivity and the mass of methane consumed. We are currently running these experiments and we predict our results from equilibrium thermodynamics. In the fresh water case, the modeled final hydrate saturation is 63% and all water is consumed. In the saline case, the modeled final hydrate saturation is 47%, the salinity is 12.4 wt. %, and final water saturation is 13%. The fresh water system is water-limited: all the water is converted to hydrate. In the saline system, pore water salinity is elevated and salt is excluded from the hydrate structure during hydrate formation until the salinity drives the system to three phase equilibrium (liquid, gas, hydrate) and no further hydrate forms. In our laboratory we can impose temperature gradients within the column, and we will use this to investigate equilibrium conditions in large samples subjected to temperature gradients and changing temperature. In these tests, we will quantify the hydrate saturation and salinity over our meter-long sample using spatially distributed temperature sensors, spatially distributed resistivity probes, compressional wave velocities, and X-ray computed tomography scanning. Modeling of hydrate formation and dissociation for these conditions indicates that the transport of bulk fluid phases (gas and water) plays a crucial role in the overall behavior, and we will explore open-system boundary conditions in the experiments to test this prediction.

Do Assimilated Drifter Velocities Improve Lagrangian Predictability in an Operational Ocean Model?

DTIC Science & Technology

2015-05-01

extended Kalman filter . Molcard et al. (2005) used a statistical method to cor- relate model and drifter velocities. Taillandier et al. (2006) describe the... temperature and salinity observations. Trajectory angular differ- ences are also reduced. 1. Introduction The importance of Lagrangian forecasts was seen... Temperature , salinity, and sea surface height (SSH, measured along-track by satellite altimeters) observa- tions are typically assimilated in

Population structure of an invasive parthenogenetic gastropod in coastal lakes and estuaries of northern KwaZulu-Natal, South Africa.

PubMed

Miranda, Nelson A F; Perissinotto, Renzo; Appleton, Christopher C

2011-01-01

Estuaries and coastal lakes receive little attention despite being heavily invaded by non-indigenous invasive species (NIS). In these situations, studies of population dynamics in invaded habitats can provide valuable insights into how NIS interact with new environments. Tarebia granifera is a prosobranch gastropod from south-east Asia which has invaded other sub-tropical parts of the world. This study addresses whether a small number of key environmental factors influences gastropod communities, and specifically how the population density and size structure of T. granifera were influenced by environmental change in estuaries and coastal lakes in southern Africa. T. granifera's density, number of brooded juveniles and size structure were measured at the St. Lucia Estuary, Mgobozeleni Estuary, Lake Sibaya and Lake Nhlange. Size structure was classified according to shell height (SH). All dissected individuals were found to be female and free from trematode infection. Salinity, water depth, temperature, and pH were the main factors correlated with population density of gastropod communities. T. granifera often reached densities well over 1000 ind. m(-2), displacing indigenous gastropods and becoming a dominant component of the benthic community. T. granifera successfully invaded estuaries despite frequent exposure to high salinity and desiccation, which could together eliminate >97% of the population. The persistence of T. granifera was ensured due to its high fecundity and the environmental tolerance of large adults (20-30 mm SH) which carried an average of 158±12.8 SD brooded juveniles. Repeat introductions were not essential for the success of this parthenogenetic NIS. There is a need for a broader study on the reproductive biology of T. granifera (including the previously overlooked "brood pouch ecology"), which affects population dynamics and may be relevant to other parthenogenetic NIS, such as Melanoides tuberculata and Potamopyrgus antipodarum.

Modeling Diffusion as a Result of Observing Salinity, Water Temperature and Mixing of the Norwalk River into Long Island Sound

NASA Astrophysics Data System (ADS)

Giuliano, A. L.; Gillotte, C. N.; Wooldridge, T. R.

2016-02-01

This project investigates the space and time variability of salinity and temperature in the lower Norwalk River using a one-dimensional numerical model. The project uses surface measurements taken at two locations, one at the Norwalk Maritime Museum (NMM) and the other at the mouth of the river as it drains into the Norwalk Islands region adjacent to Long Island Sound (LIS). The model covers a relatively small distance of 1-2km. The size of the upriver neck and the first buoy is approximately five times smaller than the mouth between the second buoy site and Peach Island. The instrumentation will be responsible for generally characterizing the thermal physics occurring at the river-ocean environment. A one-dimensional advection-diffusion model will be used to simulate results. The data points will measure the salinity, water temperature, and pressure during a series of deployments in the river during a three-season period between 2013 and 2014. Further processes will ultimately show the overall advection occurring in the river. The upriver site is maintained by the Norwalk River Museum. A YSI XXX attached to a tether buoy is used to measure salinity and temperature at the surface.Preliminary results suggest typical temperature range at the upriver site is greater than at the mouth of the Norwalk River, and the daily peak temperature lag depends upon several factors, such as tidal state. The phenomenon of a salt wedge will also be considered.

Fifty Years of Water Cycle Change expressed in Ocean Salinity

NASA Astrophysics Data System (ADS)

Durack, P. J.; Wijffels, S.

2010-12-01

Using over 1.6 million profiles of salinity, potential temperature and density from historical archives and Argo, we derive the global field of linear change for ocean state properties over the period 1950-2008, taking care to minimise aliasing associated with seasonal and El Nino Southern Oscillation modes. We find large, robust and spatially coherent multi-decadal linear trends in ocean surface salinities. Increases are found in evaporation-dominated regions and freshening in precipitation-dominated regions. The spatial patterns of surface change strongly resemble the climatological mean surface salinity field, consistent with an amplification of the global water cycle. A robust amplification of the mean salinity pattern of 8% (to 200m depth) is found globally and 5-9% is found in each of the 3 key ocean basins. 20th century runs from the CMIP3 model suite support the relationship between amplified patterns of freshwater flux driving an amplified pattern of ocean surface salinity only in models that warm substantially. Models with volcanic aerosols show a diminished warming response and a corresponding weak response in ocean surface salinity change, which implies dampened changes to the global water cycle. The warming response represented in realistic (when compared to observations) 20th century simulations appear quite similar in their broad zonal patterns to those of the projected 21st century simulations, these projected runs being strongly forced by greenhouse gases. This pattern amplification is mostly absent from 20th century simulations which include volcanic forcing. While we confirm that global mean precipitation only weakly change with surface warming (2-3% K-1), the pattern amplification rate in both the freshwater flux and ocean salinity fields indicate larger responses. Our new observed salinity estimates suggest a change of between 8-16% K-1, close to, or greater than, the theoretical response described by the Clausius-Clapeyron relation. The underestimation of change patterns by the CMIP3 model suite is well documented in recent literature describing changes to the atmospheric and terrestrial arms of the global water cycle. These new observational ocean results add emphasis to the conclusion that the rate of observed changes in the 20th century are larger than CMIP3 models, and simplified physical theories predict. A) The 50-year linear surface salinity trend (pss/50-years). Contours every 0.25 pss are plotted in white. B) Ocean-atmosphere freshwater flux (m3 yr-1) averaged over 1980-1993 (Josey et al., 1998). Contours every 1 m3 yr-1 are in white. On both panels, the 1975 surface mean salinity is contoured black (contour interval 0.5 pss for thin lines, 1 for thick lines).

Evidence for Upward Flow of Saline Water from Depth into the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

NASA Astrophysics Data System (ADS)

Larsen, D.; Paul, J.

2017-12-01

Groundwater salinization is occurring in the Mississippi River Valley Alluvial (MRVA) aquifer in southeastern Arkansas (SE AR). Water samples from the MRVA aquifer in Chicot and Desha counties have yielded elevated Cl-concentrations with some as high as 1,639 mg/L. Considering that the MRVA aquifer is the principle source of irrigation water for the agricultural economy of SE AR, salinization needs to be addressed to ensure the sustainability of crop, groundwater, and soil resources in the area. The origin of elevated salinity in MRVA aquifer was investigated using spatial and factor analysis of historical water quality data, and sampling and tracer analysis of groundwater from irrigation, municipal, and flowing industrial wells in SE AR. Spatial analysis of Cl- data in relation to soil type, geomorphic features and sand-blow density indicate that the Cl- anomalies are more closely related to the sand-blow density than soil data, suggesting an underlying tectonic control for the distribution of salinity. Factor analysis of historical geochemical data from the MRVA and underlying Sparta aquifer shows dilute and saline groups, with saline groups weighted positively with Cl- or Na+ and Cl-. Tracer data suggest a component of evaporatively evolved crustal water of pre-modern age has mixed with younger, fresher meteoric sources in SE AR to create the saline conditions in the MRVA aquifer. Stable hydrogen and oxygen values of waters sampled from the Tertiary Sparta and MRVA aquifers deviate from the global and local meteoric water lines along an evaporative trend (slope=4.4) and mixing line with Eocene Wilcox Group groundwaters. Ca2+ and Cl- contents vary with Br- along mixing trends between dilute MRVA water and Jurassic Smackover Formation pore fluids in southern AR. Increasing Cl- content with C-14 age in MRVA aquifer groundwater suggests that the older waters are more saline. Helium isotope ratios decrease with He gas content for more saline water, consistent with crustal He production. Our model for the system invokes upward migration of Smackover pore fluids and other deep groundwater along faults in SE AR, whereby the saline fluids intrude and mix with dilute water in the MRVA aquifer to create saline conditions. Other processes, such as infiltration of saline irrigation runoff, may also be contributing to the problem.

Temperature and salinity regulation of growth and gas exchange of Salicornia fruticosa (L.) L.

PubMed

Abdulrahman, Farag Saleh; Williams, George J

1981-03-01

Salicornia fruticosa was collected from a salt marsh on the Mediterranean sea coast in Libya. Growth and gas exchange of this C 3 species were monitered in plants pretreated at various NaCl concentrations (0, 171, 342, 513 and 855 mM). Maximum growth was at 171 mM NaCl under cool growth conditions (20/10° C) and at 342 mM NaCl under warm growth conditions (30/15° C) with minimum growth at 0 mM NaCl (control). Net photosynthesis (Pn) was greatest in plants grown in 171 mM NaCl with plants grown at 513 and 855 mM having lowest rates. Maximum Pn was at 20-25° C shoot temperatures with statistically significant reductions at 30° C in control plants while salt treated plants showed such reductions at 35° C. Salt treatments increased dark respiration over the control at 171 and 342 mM but reduced it at higher concentrations. Photorespiration was reduced by salt treatment and increased by increasing shoot temperature. Greatest transpiration was in 171 mM NaCl treated plants and increasing shoot temperature increased transpiration in all treatments. Stomatal resistance to CO 2 influx was influenced only moderately by temperature while increasing salinity resulted in increased stomatal resistance. In general both temperature and salinity increased the mesophyll resistance to CO 2 influx. The species seems adapted to the warm saline habitat along the Mediterranean sea coast, at least partially, by its ability to maintain relatively high Pn at moderate NaCl concentrations over a broad range of shoot temperatures.

Stennis Space Center Salinity Drifter Project. A Collaborative Project with Hancock High School, Kiln, MS

NASA Technical Reports Server (NTRS)

Kalcic, Maria; Turowski, Mark; Hall, Callie

2010-01-01

Presentation topics include: importance of salinity of coastal waters, habitat switching algorithm, habitat switching module, salinity estimates from Landsat for Sabine Calcasieu Basin, percent of time inundated in 2006, salinity data, prototyping the system, system as packaged for field tests, salinity probe and casing, opening for water flow, cellular antenna used to transmit data, preparing to launch, system is launched in the Pearl River at Stennis Space Center, data are transmitted to Twitter by cell phone modem every 15 minutes, Google spreadsheet I used to import the data from the Twitter feed and to compute salinity (from conductivity) and display charts of salinity and temperature, results are uploaded to NASA's Applied Science and Technology Project Office Webpage.

The physiology of mangrove trees with changing climate

USGS Publications Warehouse

Lovelock, Catherine E.; Krauss, Ken W.; Osland, Michael J.; Reef, Ruth; Ball, Marilyn C.; Meinzer, Frederick C.; Niinemets, Ülo

2016-01-01

Mangrove forests grow on saline, periodically flooded soils of the tropical and subtropical coasts. The tree species that comprise the mangrove are halophytes that have suites of traits that confer differing levels of tolerance of salinity, aridity, inundation and extremes of temperature. Here we review how climate change and elevated levels of atmospheric CO2 will influence mangrove forests. Tolerance of salinity and inundation in mangroves is associated with the efficient use of water for photosynthetic carbon gain which unpins anticipated gains in productivity with increasing levels of CO2. We review evidence of increases in productivity with increasing CO2, finding that enhancements in growth appear to be similar to trees in non-mangrove habitats and that gains in productivity with elevated CO2 are likely due to changes in biomass allocation. High levels of trait plasticity are observed in some mangrove species, which potentially facilitates their responses to climate change. Trait plasticity is associated with broad tolerance of salinity, aridity, low temperatures and nutrient availability. Because low temperatures and aridity place strong limits on mangrove growth at the edge of their current distribution, increasing temperatures over time and changing rainfall patterns are likely to have an important influence on the distribution of mangroves. We provide a global analysis based on plant traits and IPCC scenarios of changing temperature and aridity that indicates substantial global potential for mangrove expansion.

Temperature and Salinity Effects on Quantitative Raman Spectroscopic Analysis of Dissolved Volatiles Concentration in Geofluids

NASA Astrophysics Data System (ADS)

Wu, X.; Lu, W.

2017-12-01

The concentration detection of the volatiles such as CH4 and CO2 in the hydrothermal systems and fluid inclusions is critical for understanding the fluxes of volatiles from mantle to crust and atmosphere. In-situ Raman spectroscopy has been developed successfully in laboratory, fluid inclusions and submarine environment because of its non-destructive and non-contact advantages. For improving the ability of detecting different species quantitatively by in-situ Raman spectroscopy in the extreme environment, such as the hydrothermal system and fluid inclusion, we studied the temperature- and salinity-dependence of Raman scattering cross section (RSCS) of the water OH stretching band at temperatures from 20 to 300 oC under 30 MPa. This is important because the water is often used as internal standard in the Raman quantitative application. Based on our previous study of NaCl-H2O system, we made further investigation on the CaCl2-H2O system. Our results revealed that the cation shows negligible effect on the RSCS of water OH stretching band, while the cations seems to have more obvious different effect on the structure of water within high temperatures. Besides the NaCl-CH4-H2O system, we also take the CO2-H2O system into account. Further conclusion can be made that the variation of the Raman quantitative factor (QF) (both PAR/mCH4 and PAR/mCO2) with the temperature and salinity is mainly caused by the temperature- and Cl- concentration-dependence of the relative RSCS of the water OH stretching band. If the Raman quantitative factor at ambient condition still being used, the RSCS of the water OH stretching band would induce about 47%, 34% and 29% error for the determined concentration of dissolved CH4 or CO2 (in mol/kg·H2O) by in-situ Raman spectroscopy for 0 m Cl-, 3 m Cl- and 5 m Cl- aqueous system when the temperature increases from 20 to 300 oC, respectively. Considering the wide range of the temperature and salinity in hydrothermal systems and fluid inclusions, the following equation can be used to calculate the relative QF at different temperatures and salinity referencing to the 0 m Cl- aqueous solution at 20 oC: QF(T, salinity)/QF(20 oC, 0 m Cl-)=k(T-20 oC)+b, where a=-0.0035× mCl-1/2+0.00168, b=-0.03× mCl-+1;

Acute toxicity of 4-nitrophenol, 2,4-dinitrophenol, terbufos and trichlorfon to grass shrimp (Palaemonetes spp.) and sheepshead minnows (Cyprinodon variegatus) as affected by salinity and temperature

USGS Publications Warehouse

Brecken-Folse, J. A.; Mayer, F.L.; Pedigo, L.E.; Marking, L.L.

1994-01-01

The toxicities of two industrial chemicals (4-nitrophenol and 2,4-dinitrophenol) and two organophosphate insecticides (terbufos and trichlorfon) to juvenile grass shrimp (Palaemonetes spp.) and sheepshead minnows (Cyprinodon vanegatus) were determined by static, 96-h toxicity tests in a factorial design with 12 combinations of salinity and temperature (15, 20, 25, 30ppt x 17, 22, 27°C). Concentrations of the toxicants, including bioconcentradon, were determined as appropriate by gas or liquid chromatography and the use of 14C-labeled compounds. The 96-h LC50s for 4-nitrophenol ranged from 12 to 31 mg/L and for 2,4-dinitrophenol from 13 to 50 mg/L. Toxicity decreased as salinity increased for 4-nitrophenol and both test organisms. Toxicity decreased as salinity increased for 2,4-dinitrophenol and sheepshead minnows, but toxicity to grass shrimp increased as salinity increased. Toxicity decreased with increased temperature for grass shrimp exposed to 2,4-dinitrophenol and sheepshead minnows exposed to 4-nitrophenol, increased with temperature for sheepshead minnows exposed to 2,4-dinitrophenol, and no change was observed for grass shrimp exposed to 4-nitrophenol. Bioconcentration of phenols in both test organisms increased as concentration increased. The 96-h LC50s for terbufos ranged from 3.4 to 6.6 μg/L and for trichlorfon from 6.3 to 19,300 μg/L. Terbufos and trichlorfon toxicity to grass shrimp and sheepshead minnows increased with increased temperature. BCFs for terbufos were greater in sheepshead minnows than grass shrimp, but were reversed for trichlorfon.

Seawater-overwash impacts on freshwater-lens water supplies of low-lying oceanic islands: example from Roi-Namur Island, Kwajalein Atoll, Republic of the Marshall Islands

NASA Astrophysics Data System (ADS)

Voss, C. I.; Gingerich, S. B.

2015-12-01

Low-lying oceanic islands host thin freshwater lenses subject to long-term aquifer salinization by seawater overwash. The lens is often the sole-source water supply for inhabitants. As maximum elevation for these islands is only a few meters above sea level, overwash can occur during high tides and storm surges. Sea level rise due to climate change will make overwash events even more common. The thin freshwater lenses, a few meters thick, are underlain by seawater, so pumping must be done carefully, often with horizontal skimming wells. Even a small amount of downward seawater infiltration from an overwash event can render the water supply non-potable. Where permeability is high, seawater infiltrates quickly, but seawater that infiltrates lower-permeability zones may remain for many months causing groundwater to remain non-potable, leaving residents without a reliable freshwater source. Initial post-overwash salinization is driven by the higher density of the invading saltwater, which sinks and mixes into the fresher water in potentially-complex patterns determined by: distribution of flooding and post-flood ponding, locations of permeable paths, and the inherently complex flow fields generated when fluid of higher density overlies lower-density fluid. The flow patterns cannot generally be measured or predicted in detail. This study develops basic understanding of overwash salinization processes impacting water supply on low-level islands, using a rare example of a monitored seawater overwash event that occurred in December 2008 at Roi-Namur Island in Kwajalein Atoll, Republic of the Marshall Islands, in which the salinity evolution of well water was measured. Due to typical lack of field data on such islands, a set of plausible alternative simulation-model descriptions of the hydrogeology and overwash event are created for analysis of the monitored salinization and recovery. Despite inability to know the 'true and complete' description of the event and the hydrogeology, the alternative models provide a range of possible evolutions of aquifer salinity. This allows identification of the controls on the rate and extent of initial salinization and of salinity persistence, which can be used as a basis for development of strategies to manage groundwater resources on low-lying islands.

Na/Ca Ratio in Large Benthic Foraminifera as a Novel Proxy for Past Ocean Calcium

NASA Astrophysics Data System (ADS)

Rosenthal, Y.; Hauzer, H.; Evans, D.; Erez, J.

2017-12-01

Culture experiments with Operculina ammonoides (a large symbiont bearing benthic foraminifer and an extant relative of the Eocene Nummulites) were carried out varying seawater [Ca], temperature and salinity. The main results of these experiments are: 1. Na/Ca in these foraminifera shells varies with the Na/Ca ratio in the seawater 2. Na/Ca shows small, non-systematic variations with temperature (22-28 ºC) that are within our analytical precision. 3. Na/Ca in the shells show very low changes, increasing linearly with salinity. The sensitivity to salinity is very low compared to that caused by changes of Na/Ca in seawater. Over the seawater experimental range of Na/Ca (10-18 mM), a change of 5 ppt salinity induced a slight Na/Ca increase comparable to the analytical error for Na, or that caused by temperature. Initial reconstructions of seawater [Ca], based on these calibrations, generally agree well with previous models and reconstructions confirming that seawater [Ca] concentrations were substantially higher during the early-mid Cenozoic than today.

Nitrogen removal via nitrite from seawater contained sewage.

PubMed

Peng, Yongzhen; Yu, De-Shuang; Liang, Dawei; Zhu, Guibing

2004-01-01

Under the control of both pH and the concentration of free ammonia (FA), the nitrification-denitrification via nitrite pathway was accomplished in SBR to achieve enhanced biological nitrogen removal from seawater contained wastewater, which is used to flush toilet, under relatively high salinity. Several parameters including salinity, temperature, pH, and NH4+-N loading rate were studied to evaluate their effects. The results indicate that at different salinity the nitrogen removal efficiency is relative to ammonia-nitrogen loading rate. The nitrogen removal efficiency reaches above 90% when the NH4+-N loading does not exceed 0.15 kg NH4+-N/kg MLSS d. With the salinity increasing, the ammonia-nitrogen loading rate should be lowered to obtain high removal efficiency. The evaluation of temperature effect shows that nitrogen removal efficiency is promoted twice when reaction temperature is elevated from 20 to 30 degrees C. Moderately high pH in the range of 7.5-8.5 has advantage to achieve effective nitrification-denitrification via nitrite, the process of which is caused by the selective inhibition of free ammonia (FA).

Regional studies of dolomites and their included fluids: recognizing multiple chemically distinct fluids during the complex diagenetic history of Lower Carboniferous (Mississippian) rocks of the Irish Zn-Pb ore field

NASA Astrophysics Data System (ADS)

Johnson, Aaron W.; Shelton, Kevin L.; Gregg, Jay M.; Somerville, Ian D.; Wright, Wayne R.; Nagy, Zsolt R.

2009-05-01

This study provides a regional framework within which studies of ore-related dolomite and dolomite cements may be placed. Fluid inclusion data indicate the presence of three distinct fluids following early dolomitization: 1) a ubiquitous low-temperature, higher salinity fluid found in saddle dolomite; 2) a low-temperature, lower salinity fluid limited to sub-Waulsortian and Waulsortian carbonates; and 3) a higher temperature, lower salinity fluid found in Waulsortian and supra-Waulsortian rocks. Similar fluids have been reported in ore-associated minerals and postmineralization dolomite (Type 1) and in ore-stage carbonates and sphalerite (Types 2 and 3). The halogen geochemistry of included fluids indicates genesis from evaporated seawater. Type 1 fluids are enriched in chloride relative to bromide, reflecting a component of salinity derived via dissolution of halite or from dehydration of seawater. These data suggest that dolomitization and mineralization of Mississippian rocks in the Midlands requires both regionally extensive and localized fluid flow.

Effects of temperature, salinity, light intensity, and pH on the eicosapentaenoic acid production of Pinguiococcus pyrenoidosus

NASA Astrophysics Data System (ADS)

Sang, Min; Wang, Ming; Liu, Jianhui; Zhang, Chengwu; Li, Aifen

2012-06-01

The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The fatty acid composition was assayed by gas chromatography-mass spectrometry, which indicated that the main fatty acids were C14:0, C16:0 and EPA. The highest EPA percentage 20.83% of total fatty acids was obtained at 20°C with the temperature being set at 20, 24, and 28°C. Under different salinities and light intensities, the highest percentages of total polyunsaturated fatty acids (PUFAs) and EPA were 17.82% and 31.37% of total fatty acids, respectively, which were achieved at salinity 30 and 100 μmol photon m-2s-1 illumination. The highest percentages of total PUFAs and EPA were 38.75% and 23.13% of total fatty acids, respectively, which were reached at an initial pH of 6 with the test range being from 5.0 to 9.0.

Lateral baroclinic forcing enhances sediment transport from shallows to channel in an estuary

USGS Publications Warehouse

Lacy, Jessica R.; Gladding, Steve; Brand, Andreas; Collignon, Audric; Stacey, Mark

2014-01-01

We investigate the dynamics governing exchange of sediment between estuarine shallows and the channel based on field measurements at eight stations spanning the interface between the channel and the extensive eastern shoals of South San Francisco Bay. The study site is characterized by longitudinally homogeneous bathymetry and a straight channel, with friction more important than the Coriolis forcing. Data were collected for 3 weeks in the winter and 4 weeks in the late summer of 2009, to capture a range of hydrologic and meteorologic conditions. The greatest sediment transport from shallows to channel occurred during a pair of strong, late-summer wind events, with westerly winds exceeding 10 m/s for more than 24 h. A combination of wind-driven barotropic return flow and lateral baroclinic circulation caused the transport. The lateral density gradient was produced by differences in temperature and suspended sediment concentration (SSC). During the wind events, SSC-induced vertical density stratification limited turbulent mixing at slack tides in the shallows, increasing the potential for two-layer exchange. The temperature- and SSC-induced lateral density gradient was comparable in strength to salinity-induced gradients in South Bay produced by seasonal freshwater inflows, but shorter in duration. In the absence of a lateral density gradient, suspended sediment flux at the channel slope was directed towards the shallows, both in winter and during summer sea breeze conditions, indicating the importance of baroclinically driven exchange to supply of sediment from the shallows to the channel in South San Francisco Bay and systems with similar bathymetry.

Response of the mesozooplankton community of the St Lucia estuary, South Africa, to a mouth-opening event during an extended drought

NASA Astrophysics Data System (ADS)

Jerling, Hendrik L.; Vivier, Leon; Cyrus, Digby P.

2010-03-01

Mesozooplankton samples were collected between March 2005 and November 2008 in St Lucia, the largest estuarine lake system in South Africa. St Lucia experienced an extended period of drought before and during the present study. This drought led to natural closing of the estuary mouth as a result of flood-tide marine sediment deposition in 2002. In March 2007 the mouth was washed open by exceptionally high tidal and wave conditions. This resulted in an influx of a large volume of seawater. The mouth closed again in August 2007. Before opening of the mouth salinities in the Estuary were below 10 and large parts of North Lake dried up while South Lake retained a relatively stable waterbody with salinities between 10 and 30. When the mouth opened seawater flooded the system and salinities changed to about 35. After the mouth had closed again in August 2007 salinities increased in the lakes and decreased in the Estuary. The mesozooplankton community was dominated by copepods during all sampling sessions, especially by the estuarine calanoids Pseudodiaptomus stuhlmanni and Acartia natalensis. Mean mesozooplankton densities were significantly higher in South Lake before the mouth opened in March 2007. While zooplankton density decreased when the mouth opened species richness increased with the influx of coastal marine species, especially in the Estuary. Overall zooplankton densities declined progressively as salinity increased to hypersaline levels after mouth closure. Multivariate analyses supported significant differences between the lakes and the Estuary in terms of mesozooplankton community composition. Taxa mostly responsible for the similarities within and dissimilarity between sections of the system were the copepods P. stuhlmanni and A. natalensis with the meroplankton, crab zoeae and mollusc larvae, also contributing significantly after the mouth-opening event.

[Effects of Suaeda glauca planting and straw mulching on soil salinity dynamics and desalination in extremely heavy saline soil of coastal areas.

PubMed

Zhang, Jiao; Cui, Shi You; Feng, Zhi Xiang

2018-05-01

To elucidate the seasonal variations in soil salinity and its driving factors, and to explore the effects of planting Suaeda glauca and straw mulching on soil desalination and salinity controlling, a field experiment was conducted in extremely heavy saline soil of coastal areas in Rudong, Jiangsu Province. There were four treatments: control (bare land, CK), planting S. glauca (PS), straw mulching A (at 15 t·hm -2 , SM-A), straw mulching 2A (at 30 t·hm -2 , SM-2A). Climate factors (including rainfall, atmospheric temperature, sunshine duration, and atmospheric evaporation) and soil salinity dynamic changes were determined from May 2014 to May 2015. Results showed that: (1) The seasonal variation of soil salinity was obvious in the bare ground (CK), with the lowest (8.69 g·kg -1 ) during June-August and the highest (26.66 g·kg -1 ) during September-December. The changes of soil salinity in topsoil (0-20 cm) were more intense than that in sub-topsoil (20-40 cm), with the changes in sub-topsoil having somewhat time lag compared the topsoil. (2) Soil salinity in CK treatment had a significantly linear correlation with the cumulative rainfall and evaporation-precipitation ratio of the fifteen-day before sampling. The results from multifactor and interphase analysis indicated that the increases of rainfall would promote soil desalinization. The rise of atmospheric temperature could exacerbate soil salt accumulation in surface soil. The interaction between rainfall and atmospheric temperature would have a positive effect on soil salt accumulation. (3) PS treatment did not alter the seasonal variation in soil salinity, but it reduced soil salinity in topsoil. (4) In SM-A and SM-2A treatments, the relationship of soil desalinization rate (%, Y) and treatment time (days, X) was expressed as Logistic curve equation. Moreover, the soil desalination rate was over 95.0% in the topsoil after 90-100 days of straw mul-ching treatment and was over 92.0% in sub-topsoil after 120 days of straw mulching treatment. The soil salinity in SM-A and SM-2A treatments fluctuated below 0.60 g·kg -1 and 1.00 g·kg -1 , respectively in topsoil and sub-topsoil. Considering the desalination and economic costs, a suitable amount of straw mulching (such as 15 t·hm -2 ) before rainy season was recommended, which would promote the soil desalinization and reclamation in extremely heavy saline soil of coastal areas.

P-T composition and evolution of paleofluids in the Paleoproterozoic Mag Hill IOCG system, Contact Lake belt, Northwest Territories, Canada

NASA Astrophysics Data System (ADS)

Somarin, A. Karimzadeh; Mumin, A. Hamid

2014-02-01

The Echo Bay stratovolcano complex and Contact Lake Belt of the Great Bear Magmatic Zone, Northwest Territories, host a series of coalescing Paleoproterozoic hydrothermal systems that affected an area of several hundred square kilometers. They were caused by intrusion of synvolcanic diorite-monzodioritic plutons into andesitic host rocks, producing several characteristic hydrothermal assemblages. They include early and proximal albite, magnetite-actinolite-apatite, and potassic (K-feldspar) alteration, followed by more distal hematite, phyllic (quartz-sericite-pyrite), and propylitic (chlorite-epidote-carbonate±sericite±albite±quartz) alteration, and finally by late-stage polymetallic epithermal veins. These alteration types are characteristic of iron oxide copper-gold deposits, however, with distal and lower-temperature assemblages similar to porphyry Cu systems. Magnetite-actinolite-apatite alteration formed from high temperature (up to 560 °C) fluids with average salinity of 12.8 wt% NaCl equivalent. The prograde propylitic and phyllic alteration stages are associated with fluids with temperatures varying from 80 to 430 °C and a wide salinity range (0.5-45.6 wt% NaCl equivalent). Similarly, wide fluid temperature (104-450 °C) and salinity (4.2-46.1 wt% NaCl equivalent) ranges are recorded for the phyllic alteration. This was followed by Cu-Ag-U-Zn-Co-Pb sulfarsenide mineralization in late-stage epithermal veins formed at shallow depths and temperatures from 270 °C to as low as 105 °C. The polymetallic veins precipitated from high salinity (mean 30 wt% NaCl equivalent) dense fluids (1.14 g/cm3) with a vapor pressure of 3.8 bars, typical of epithermal conditions. Fluid inclusion evidence indicates that mixed fluids with evolving physicochemical properties were responsible for the formation of the alteration assemblages and mineralization at Mag Hill. An early high temperature, moderate salinity, and magmatic fluid was subsequently modified variably by boiling, mixing with cooler low-salinity meteoric water, and simple cooling. The evidence is consistent with emplacement of the source plutons and stocks into an epithermal environment within ~1 km of surface. This generated near-surface high-temperature alteration in a dynamic hydrothermal system that collapsed (telescoped) resulting in widespread evidence of boiling and epithermal mineralization superimposed on earlier stages of alteration.

Salinization owing to evaporation from bare-soil surfaces and its influences on the evaporation

NASA Astrophysics Data System (ADS)

Shimojimaa, Eiichi; Yoshioka, Ryuma; Tamagawa, Ichiro

1996-04-01

To investigate the relationship between evaporation and salinization, the surfaces of three columns of uniform porous materials, desert dune sand, silica sand and glass beads, respectively, were exposed to a temperature-, humidity- and/or wind-speed-controlled ambient atmosphere. For the dune sand, chemicals such as Na +, Ca 2+, Cl - and SO 42-, dissolved mainly from CaSO 4, Na 2SO 4, CaCO 3 and NaC1 in the sand particles, caused marked salinization near the top surface. Slow dissolution of Na 2SO 4 and CaSO 4 influenced the development of concentration profiles for SO 42- and Na + markedly for months after the beginning of the experiment, while the profile of Cl - was not affected directly, because dissolution of NaCl was rapid. Concentration profiles of Cl - for the glass beads and for the silica sand columns filled with a high concentration of NaCI solution of (10 4 mg1 -1 for Cl -), were analysed similarly. Experimental results suggested that the vapour flux in a dry soil became larger because of the increase in the gradient of the vapour density caused by greater chemical enrichment near the top surface compared with that at the evaporation surface. The vapour flux also became smaller as the gradient of the vapour density decreased, owing to the markedly enriched evaporation surface. In the experiment with glass beads, filled with the NaCl solution, solute crystallization (4-10 mm thick) was observed. For the dune sand, only when a turbulent airflow was applied did a crust (a few millimetres in thickness) form entirely on the top surface. Such deposition led to a reduction in the flux of water vapour as the permeable cross-sectional area decreased. The resistance to transfer increased three to ten times for the glass beads but only by 30% for the dune sand. The lower increase for the dune sand may be due to penetration of the applied airflow into cracks in the crust.

Aquarius Salinity Retrieval Algorithm: Final Pre-Launch Version

NASA Technical Reports Server (NTRS)

Wentz, Frank J.; Le Vine, David M.

2011-01-01

This document provides the theoretical basis for the Aquarius salinity retrieval algorithm. The inputs to the algorithm are the Aquarius antenna temperature (T(sub A)) measurements along with a number of NCEP operational products and pre-computed tables of space radiation coming from the galaxy and sun. The output is sea-surface salinity and many intermediate variables required for the salinity calculation. This revision of the Algorithm Theoretical Basis Document (ATBD) is intended to be the final pre-launch version.

The salinity gradient power generating system integrated into the seawater desalination system

NASA Astrophysics Data System (ADS)

Zhu, Yongqiang; Wang, Wanjun; Cai, Bingqian; Hao, Jiacheng; Xia, Ruihua

2017-01-01

Seawater desalination is an important way to solve the problem of fresh water shortage. Low energy efficiency and high cost are disadvantages existing in seawater desalination. With huge reserve and the highest energy density among different types of marine energy, salinity gradient energy has a bright application prospect. The promotion of traditional salinity gradient power generating systems is hindered by its low efficiency and specific requirements on site selection. This paper proposes a salinity gradient power generating system integrated into the seawater desalination system which combines the salinity gradient power generating system and the seawater desalination system aiming to remedy the aforementioned deficiency and could serve as references for future seawater desalination and salinity gradient energy exploitation. The paper elaborates on the operating principles of the system, analyzes the detailed working process, and estimates the energy output and consumption of the system. It is proved that with appropriate design, the energy output of the salinity gradient power generating system can satisfy the demand of the seawater desalination system.

The Effect of Different Feed and Stocking Densities on Growth And Survival Rate Of Blue Swimming Crablets (Portunus pelagicus)

NASA Astrophysics Data System (ADS)

Ariyati, R. W.; Rejeki, S.; Bosma, R. H.

2018-02-01

Blue swimming crab is targeted by commercial fisheries because of the high economic value, good taste, and attractive colors. As a result, the stock is overexploited and fisherman catch market also juveniles. The most sustainable solution would be to stop fishing for commercial trade and to culture this crab from brood to market size. This study aimed to find the best feed and stocking density for the on-growing of crablets. In 20 tanks juvenile crabs with a carapace width±1 cm were stocked in three densities; 40, 60 and 80 crablets / m2, and fed ad-libitum twice a day with either trash fish or pellets of shrimp feed, for 8 weeks. The circular (ᴓ 1.6 m x 1 m) tanks with 1 m3 of water were aerated, and temperature, salinity, dissolved oxygen and pH recorded daily. In the end, growth and survival rates were determined. In general, feeding the crablets at a density of 40 m-2 gave the highest growth. For crablest fed with pellets, the density of 40 m-2 gave significantly better growth than 80 m-2. The crablets at a density 40 m-2 having a fish diet with the density 40 m-2 grew better than 60 and 80 m-2. There was no significant difference between fed used among different densities. The lower densities resulted in higher survival, either on crablets fed with pellets or fish. But, crablets fed the fish diet and cultured in the lowest density (40 m-2) had the highest survival rate.

Comparison of the Effects of Environmental Parameters on the Growth Variability of Vibrio parahaemolyticus Coupled with Strain Sources and Genotypes Analyses.

PubMed

Liu, Bingxuan; Liu, Haiquan; Pan, Yingjie; Xie, Jing; Zhao, Yong

2016-01-01

Microbial growth variability plays an important role on food safety risk assessment. In this study, the growth kinetic characteristics corresponding to maximum specific growth rate (μmax) of 50 V. parahaemolyticus isolates from different sources and genotypes were evaluated at different temperatures (10, 20, 30, and 37°C) and salinity (0.5, 3, 5, 7, and 9%) using the automated turbidimetric system Bioscreen C. The results demonstrated that strain growth variability increased as the growth conditions became more stressful both in terms of temperature and salinity. The coefficient of variation (CV) of μmax for temperature was larger than that for salinity, indicating that the impact of temperature on strain growth variability was greater than that of salinity. The strains isolated from freshwater aquatic products had more conspicuous growth variations than those from seawater. Moreover, the strains with tlh (+) /tdh (+) /trh (-) exhibited higher growth variability than tlh (+) /tdh (-) /trh (-) or tlh (+) /tdh (-) /trh (+), revealing that gene heterogeneity might have possible relations with the growth variability. This research illustrates that the growth environments, strain sources as well as genotypes have impacts on strain growth variability of V. parahaemolyticus, which can be helpful for incorporating strain variability in predictive microbiology and microbial risk assessment.

Hydrophysical correlation and water mass indication of optical physiological parameters of picophytoplankton in Prydz Bay during autumn 2008.

PubMed

Zhang, Fang; Ma, Yuxin; Lin, Ling; He, Jianfeng

2012-12-01

Flow cytometry (FCM) is efficient in detecting both abundance and optical physiological parameters including cell size and cellular carbon content-side scatter (SSC), carotenoids-green and orange fluorescence (FL1 and FL2), and red fluorescence-chlorophylls (FL3) can be obtained by FCM. The utilization of these physiological parameters in indicating water masses in Prydz Bay was investigated for the first time. Picophytoplankton were very sensitive to hydrophysical changes and present distinct characteristics of water masses: Picophytoplankton in water closer to the Amery Ice Shelf were more affected by salinity than by temperature, while temperature became more important than salinity the nearer the picophytoplankton were to the deep sea. The picophytoplankton dealt with declines in light by increasing the size of cells, which increase the fixation of carbon. This can also be increased by high temperature and salinity. Pure water masses can increase the content of chlorophylls and cellular carbon. Generally, the distributions of all the five parameters at upper water depths were less affected by temperature and salinity than by water masses; and these parameters can be as indicators to Summer Surface Water (SSW), Winter Water (WW) and Continental Shelf Water (CSW). Copyright © 2012 Elsevier B.V. All rights reserved.

World Ocean Database and the Global Temperature and Salinity Profile Program Database: Synthesis of historical and near real-time ocean profile data

NASA Astrophysics Data System (ADS)

Boyer, T.; Sun, L.; Locarnini, R. A.; Mishonov, A. V.; Hall, N.; Ouellet, M.

2016-02-01

The World Ocean Database (WOD) contains systematically quality controlled historical and recent ocean profile data (temperature, salinity, oxygen, nutrients, carbon cycle variables, biological variables) ranging from Captain Cooks second voyage (1773) to this year's Argo floats. The US National Centers for Environmental Information (NCEI) also hosts the Global Temperature and Salinity Profile Program (GTSPP) Continuously Managed Database (CMD) which provides quality controlled near-real time ocean profile data and higher level quality controlled temperature and salinity profiles from 1990 to present. Both databases are used extensively for ocean and climate studies. Synchronization of these two databases will allow easier access and use of comprehensive regional and global ocean profile data sets for ocean and climate studies. Synchronizing consists of two distinct phases: 1) a retrospective comparison of data in WOD and GTSPP to ensure that the most comprehensive and highest quality data set is available to researchers without the need to individually combine and contrast the two datasets and 2) web services to allow the constantly accruing near-real time data in the GTSPP CMD and the continuous addition and quality control of historical data in WOD to be made available to researchers together, seamlessly.

Comparison of the Effects of Environmental Parameters on the Growth Variability of Vibrio parahaemolyticus Coupled with Strain Sources and Genotypes Analyses

PubMed Central

Liu, Bingxuan; Liu, Haiquan; Pan, Yingjie; Xie, Jing; Zhao, Yong

2016-01-01

Microbial growth variability plays an important role on food safety risk assessment. In this study, the growth kinetic characteristics corresponding to maximum specific growth rate (μmax) of 50 V. parahaemolyticus isolates from different sources and genotypes were evaluated at different temperatures (10, 20, 30, and 37°C) and salinity (0.5, 3, 5, 7, and 9%) using the automated turbidimetric system Bioscreen C. The results demonstrated that strain growth variability increased as the growth conditions became more stressful both in terms of temperature and salinity. The coefficient of variation (CV) of μmax for temperature was larger than that for salinity, indicating that the impact of temperature on strain growth variability was greater than that of salinity. The strains isolated from freshwater aquatic products had more conspicuous growth variations than those from seawater. Moreover, the strains with tlh+/tdh+/trh− exhibited higher growth variability than tlh+/tdh−/trh− or tlh+/tdh−/trh+, revealing that gene heterogeneity might have possible relations with the growth variability. This research illustrates that the growth environments, strain sources as well as genotypes have impacts on strain growth variability of V. parahaemolyticus, which can be helpful for incorporating strain variability in predictive microbiology and microbial risk assessment. PMID:27446034

Hydrologic Data Summary for the Northeast Creek/Fresh Meadow Estuary, Acadia National Park, Maine, 2000-2001

USGS Publications Warehouse

Caldwell, James M.; Culbertson, Charles W.

2007-01-01

The U.S. Geological Survey, in cooperation with the National Park Service, collected data in Northeast Creek estuary, Mt. Desert Island, Maine, to establish baseline water-quality conditions including estuarine nutrient concentrations. Five sampling sites in Northeast Creek were established and monitored continuously for temperature and specific conductance during May to November, 2000 and 2001. Stream stage, which was affected by ocean tidal dynamics, was recorded at the most downstream site and at one upstream site. Discrete water samples for nutrient concentrations were collected biweekly during May to November, 2000 and 2001, at the five sampling sites, and an additional site seaward of the estuary mouth. Results indicated that the salinity regime of Northeast Creek estuary is dynamic and highly regulated by strong seasonal variations in freshwater runoff, as well as limited seawater exchange caused by a constriction at the bridge, at the downstream end of the estuary. Oligohaline conditions (0.5-5 practical salinity units) occasionally extend to the estuary mouth. During other periods oligohaline and mesohaline (5-20 practical salinity units) conditions exist in some areas of the estuary; polyhaline/marine (20-35 practical salinity units) conditions occasionally exist near the mouth. A saltwater wedge in the bottom water, due to density stratification, was observed to migrate upstream as fresh surface-water inputs diminished during the onset of summer low-flow conditions. Although specific conductance ranged widely at most sites because of tidal influences, other water-quality constituents, including nutrient and chlorophyll-a concentrations, exhibited seasonal distribution patterns in which maximum levels generally occurred in early to mid-summer and again in the fall over both field seasons.

The influence of spatially and temporally varying oceanographic conditions on meroplanktonic metapopulations

NASA Astrophysics Data System (ADS)

Botsford, L. W.; Moloney, C. L.; Hastings, A.; Largier, J. L.; Powell, T. M.; Higgins, K.; Quinn, J. F.

We synthesize the results of several modelling studies that address the influence of variability in larval transport and survival on the dynamics of marine metapopulations distributed along a coast. Two important benthic invertebrates in the California Current System (CCS), the Dungeness crab and the red sea urchin, are used as examples of the way in which physical oceanographic conditions can influence stability, synchrony and persistence of meroplanktonic metapopulations. We first explore population dynamics of subpopulations and metapopulations. Even without environmental forcing, isolated local subpopulations with density-dependence can vary on time scales roughly twice the generation time at high adult survival, shifting to annual time scales at low survivals. The high frequency behavior is not seen in models of the Dungeness crab, because of their high adult survival rates. Metapopulations with density-dependent recruitment and deterministic larval dispersal fluctuate in an asynchronous fashion. Along the coast, abundance varies on spatial scales which increase with dispersal distance. Coastwide, synchronous, random environmental variability tends to synchronize these metapopulations. Climate change could cause a long-term increase or decrease in mean larval survival, which in this model leads to greater synchrony or extinction respectively. Spatially managed metapopulations of red sea urchins go extinct when distances between harvest refugia become greater than the scale of larval dispersal. All assessments of population dynamics indicate that metapopulation behavior in general dependes critically on the temporal and spatial nature of larval dispersal, which is largely determined by physical oceanographic conditions. We therfore explore physical influences on larval dispersal patterns. Observed trends in temperature and salinity applied to laboratory-determined responses indicate that natural variability in temperature and salinity can lead to variability in larval development period on interannual (50%), intra-annual (20%) and latitudinal (200%) scales. Variability in development period significantly influences larval survival and, thus, net transport. Larval drifters that undertake diel vertical migration in a primitive equation model of coastal circulation (SPEM) demonstrate the importance of vertical migration in determining horizontal transport. Empirically derived estimates of the effects of wind forcing on larval transport of vertically migrating larvae (wind drift when near the surface and Ekman transport below the surface) match cross-shelf distributions in 4 years of existing larval data. We use a one-dimensional advection-diffusion model, which includes intra-annual timing of cross-shelf flows in the CCS, to explore the combined effects on settlement: (1) temperature- and salinity-dependent development and survival rates and (2) possible horizontal transport due to vertical migration of crab larvae. Natural variability in temperature, wind forcing, and the timing of the spring transition can cause the observed variability in recruitment. We conclude that understanding the dynamics of coastally distributed metapopulations in response to physically-induced variability in larval dispersal will be a critical step in assessing the effects of climate change on marine populations.

Interacting stressors and the potential for adaptation in a changing world: responses of populations and individuals

PubMed Central

French, Susannah S.; Brodie, Edmund D.

2017-01-01

To accurately predict the impact of environmental change, it is necessary to assay effects of key interacting stressors on vulnerable organisms, and the potential resiliency of their populations. Yet, for the most part, these critical data are missing. We examined the effects of two common abiotic stressors predicted to interact with climate change, salinity and temperature, on the embryonic survival and development of a model freshwater vertebrate, the rough-skinned newt (Taricha granulosa) from different populations. We found that salinity and temperature significantly interacted to affect newt embryonic survival and development, with the negative effects of salinity most pronounced at temperature extremes. We also found significant variation among, and especially within, populations, with different females varying in the performance of their eggs at different salinity–temperature combinations, possibly providing the raw material for future natural selection. Our results highlight the complex nature of predicting responses to climate change in space and time, and provide critical data towards that aim. PMID:28680662

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui

NASA Astrophysics Data System (ADS)

Dirghangi, Sitindra S.; Pagani, Mark

2013-10-01

We studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen isotope composition (D/H) of water, temperature, and salinity. Cultures were grown on three substrates: succinate, pyruvate and glycerol with known hydrogen isotope compositions, and in water with different hydrogen isotopic compositions. All culture series grown on a particular substrate show strong correlations between δDarchaeol and δDwater. However, correlations are distinctly different for cultures grown on different substrates. Our results indicate that the metabolic pathway of substrate exerts a fundamental influence on the δD value of lipids, likely by influencing the D/H composition of NADPH (nicotinamide adenine dinucleotide phosphate), the reducing agent that contributes hydrogen to carbon atoms during lipid biosynthesis. Temperature and salinity have smaller, but similar effects on δDlipid, primarily due to the way temperature and salinity influence growth rate, as well as temperature effects on the activity of enzymes.

Modification of ocean-estuary salt fluxes by density-driven advection of a headland eddy

NASA Astrophysics Data System (ADS)

Fram, J. P.; Stacey, M. T.

2005-05-01

Scalar exchange between San Francisco Bay and the coastal ocean is examined using shipboard observations made across the Golden Gate Channel. Ocean-estuary exchange is often described as a combination of two independent types of mechanisms: density-driven exchange such as gravitational circulation and tidal asymmetries such as tidal trapping. In this study we found that exchange is also governed by an interaction between these mechanisms. Tidally trapped eddies created in shallow shoals are mixed into the main channel earlier in the tidal cycle during the rainy season because the eddies are pushed seaward by gravitational circulation. This interaction increases the tidally averaged dispersive salt flux into the bay. The study consists of experiments during each of three 'seasons': winter/spring runoff (March 2002), summer upwelling (July 2003), and fall relaxation (October 2002). Within each experiment, transects across the channel were repeated approximately every 12 minutes for 25 hours during both spring tide and the following neap tide. Velocity was measured from a boat-mounted ADCP. Scalar concentrations were measured from a tow-yoed SeaSciences Acrobat. Salinity exchange over each spring-neap cycle is quantified with harmonic analysis. Harmonic results are decomposed into flux mechanisms using temporal and spatial correlations. The temporal correlation of cross-sectional averaged salinity and velocity (tidal pumping flux) is the largest part of the dispersive flux of salinity into the bay. From the tidal pumping portion of the dispersive flux, it is shown that there is less exchange than was found in earlier studies. Furthermore, tidal pumping flux scales strongly with flow due to density-driven movement of tidally trapped eddies and density-driven increases in ebb-flood frictional phasing. Complex bathymetry makes salinity exchange scale differently with flow than would be expected from simple tidal pumping and gravitational circulation models.

Microstructure and corrosion behaviour in biological environments of the new forged low-Ni Co-Cr-Mo alloys.

PubMed

Hiromoto, Sachiko; Onodera, Emi; Chiba, Akihiko; Asami, Katsuhiko; Hanawa, Takao

2005-08-01

Corrosion behaviour and microstructure of developed low-Ni Co-29Cr-(6, 8)Mo (mass%) alloys and a conventional Co-29Cr-6Mo-1Ni alloy (ASTM F75-92) were investigated in saline solution (saline), Hanks' solution (Hanks), and cell culture medium (E-MEM + FBS). The forging ratios of the Co-29Cr-6Mo alloy were 50% and 88% and that of the Co-29Cr-8Mo alloy was 88%. Ni content in the air-formed surface oxide film of the low-Ni alloys was under the detection limit of XPS. The passive current densities of the low-Ni alloys were of the same order of magnitude as that of the ASTM alloy in all the solutions. The passive current densities of all the alloys did not significantly change with the inorganic ions and the biomolecules. The anodic current densities in the secondary passive region of the low-Ni alloys were lower than that of the ASTM alloy in the E-MEM + FBS. Consequently, the low-Ni alloys are expected to show as high corrosion resistance as the ASTM alloy. On the other hand, the passive current density of the Co-29Cr-6Mo alloy with a forging ratio of 50% was slightly lower than that with a forging ratio of 88% in the saline. The refining of grains by further forging causes the increase in the passive current density of the low-Ni alloy.

Anthropogenic Influence on the Changes of the Subtropical Gyre Circulation in the South Pacific in the 20th Century

NASA Astrophysics Data System (ADS)

Albrecht, F.; Pizarro, O.; Montecinos, A.

2016-12-01

The subtropical ocean gyre in the South Pacific is a large scale wind-driven ocean circulation, including the Peru-Chile Current, the westward South Equatorial Current, the East Australian Current, and the eastward South Pacific Current. Large scale ocean circulations play an essential role in the climate of the Earth over long and short term time scales.In the recent years a spin-up of this circulation has been recognized analyzing observations of sea level, temperature and salinity profiles, sea surface temperature and wind. Until now it is not clear whether this spin-up is decadal variability or whether it is a long-term trend introduced by anthropogenic forcing. This study aims to analyze whether and how anthropogenic forcing influences the position and the strength of the gyre in the 20th century. To determine that, yearly means of different variables of an ensemble of CMIP5 models are analyzed. The experiments 'historical' and 'historicalNat' are examined. The 'historical' experiment simulates the climate of the 20th century and the 'historicalNat' experiment covers the same time period, but only includes natural forcings. Comparing the outcomes of these two experiments is supposed to give information about the anthropogenic influence on the subtropical gyre of the South Pacific.The main variable we analyze is sea level change. This is directly related to the gyre circulation. The center of the gyre is characterized by a high pressure zone (high sea level) and the temporal and spatial variability of the sea level height field gives information about changes in the gyre circulation. The CMIP5 databank includes steric and dynamic sea level changes. Steric sea level, that is the contribution of temperature and salinity of the water, describes the major contribution to regional sea level change with respect to the global mean. Density changes contract or expand the water, which also changes the sea surface height. This does not only occur at the surface, but at all layers in the ocean. Sea level change thus integrates ocean variability throughout the depth of the ocean. Sea level simulations of the different experiments are compared using long-term trends, multi-year anomalies and EOF-Analysis. Changes in temperature and salinity in the deeper ocean are used to describe the development of the gyre below the surface.

Distribution and Habitat Associations of Billfish and Swordfish Larvae across Mesoscale Features in the Gulf of Mexico

PubMed Central

Rooker, Jay R.; Simms, Jeff R.; Wells, R. J. David; Holt, Scott A.; Holt, G. Joan; Graves, John E.; Furey, Nathan B.

2012-01-01

Ichthyoplankton surveys were conducted in surface waters of the northern Gulf of Mexico (NGoM) over a three-year period (2006–2008) to determine the relative value of this region as early life habitat of sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida), and swordfish (Xiphias gladius). Sailfish were the dominant billfish collected in summer surveys, and larvae were present at 37.5% of the stations sampled. Blue marlin and white marlin larvae were present at 25.0% and 4.6% of the stations sampled, respectively, while swordfish occurred at 17.2% of the stations. Areas of peak production were detected and maximum density estimates for sailfish (22.09 larvae 1000 m−2) were significantly higher than the three other species: blue marlin (9.62 larvae 1000 m−2), white marlin (5.44 larvae 1000 m−2), and swordfish (4.67 larvae 1000 m−2). The distribution and abundance of billfish and swordfish larvae varied spatially and temporally, and several environmental variables (sea surface temperature, salinity, sea surface height, distance to the Loop Current, current velocity, water depth, and Sargassum biomass) were deemed to be influential variables in generalized additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and swordfish larvae, with densities typically higher in frontal zones or areas proximal to the Loop Current. Habitat suitability of all four species was strongly linked to physicochemical attributes of the water masses they inhabited, and observed abundance was higher in slope waters with lower sea surface temperature and higher salinity. Our results highlight the value of the NGoM as early life habitat of billfishes and swordfish, and represent valuable baseline data for evaluating anthropogenic effects (i.e., Deepwater Horizon oil spill) on the Atlantic billfish and swordfish populations. PMID:22509277

Distribution and habitat associations of billfish and swordfish larvae across mesoscale features in the Gulf of Mexico.

PubMed

Rooker, Jay R; Simms, Jeff R; Wells, R J David; Holt, Scott A; Holt, G Joan; Graves, John E; Furey, Nathan B

2012-01-01

Ichthyoplankton surveys were conducted in surface waters of the northern Gulf of Mexico (NGoM) over a three-year period (2006-2008) to determine the relative value of this region as early life habitat of sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida), and swordfish (Xiphias gladius). Sailfish were the dominant billfish collected in summer surveys, and larvae were present at 37.5% of the stations sampled. Blue marlin and white marlin larvae were present at 25.0% and 4.6% of the stations sampled, respectively, while swordfish occurred at 17.2% of the stations. Areas of peak production were detected and maximum density estimates for sailfish (22.09 larvae 1000 m(-2)) were significantly higher than the three other species: blue marlin (9.62 larvae 1000 m(-2)), white marlin (5.44 larvae 1000 m(-2)), and swordfish (4.67 larvae 1000 m(-2)). The distribution and abundance of billfish and swordfish larvae varied spatially and temporally, and several environmental variables (sea surface temperature, salinity, sea surface height, distance to the Loop Current, current velocity, water depth, and Sargassum biomass) were deemed to be influential variables in generalized additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and swordfish larvae, with densities typically higher in frontal zones or areas proximal to the Loop Current. Habitat suitability of all four species was strongly linked to physicochemical attributes of the water masses they inhabited, and observed abundance was higher in slope waters with lower sea surface temperature and higher salinity. Our results highlight the value of the NGoM as early life habitat of billfishes and swordfish, and represent valuable baseline data for evaluating anthropogenic effects (i.e., Deepwater Horizon oil spill) on the Atlantic billfish and swordfish populations.

Factors Influencing Spatial and Annual Variability in Eelgrass (Zostera marina L.) Meadows in Willapa Bay, Washington, and Coos Bay, Oregon, Estuaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thom, Ronald M.; Borde, Amy B.; Rumrill, Steven

2003-08-01

Environmental factors that influence annual variability and spatial differences in eelgrass meadows (Zostera marina L.) were examined within Willapa Bay, WA, and Coos Bay, OR, over a period of 4 years (1998-2001). A suite of eelgrass metrics were recorded annually at field sites that spanned the estuarine gradient from the marine-dominated to mesohaline regions. Growth of eelgrass plants was also monitored on a monthly basis within Sequim Bay, WA. Both the spatial cover and density of Z. marina were positively correlated with estuarine salinity and inversely correlated with temperature of the tideflat sediment. Experimental evidence verified that optimal eelgrass growthmore » occurred at highest salinities and relatively low temperatures. Eelgrass density, biomass, and the incident of flowering plants all increased substantially in Willapa Bay, and less so in Coos Bay, over the duration of the study. Warmer winters and cooler summers associated with the transition from El Ni?o to La Ni?a ocean conditions during the study period were correlated with the increase in eelgrass abundance and flowering. Anthropogenic factors (e.g., disturbance and erosion by vessel wakes and recreational shellfishing activities) may have contributed to spatial variability. Our findings indicate that large-scale changes in climate and nearshore ocean conditions can exert a strong regional influence on eelgrass abundance, which can vary annually by as much as 700% in Willapa Bay. Lower levels of variability observed in Coos Bay may be due to the stronger and more direct influence of the nearshore Pacific Ocean. We conclude that climate variation may have profound effects on the abundance and distribution of eelgrass meadows throughout the Pacific Northwest, and we anticipate that ocean conditions will emerge as a primary driving force for living estuarine resources and ecological processes that are associated with Z. marina beds within the landscape of these estuarine tidal basins.« less

A zonally averaged, three-basin ocean circulation model for climate studies

NASA Astrophysics Data System (ADS)

Hovine, S.; Fichefet, T.

1994-09-01

A two-dimensional, three-basin ocean model suitable for long-term climate studies is developed. The model is based on the zonally averaged form of the primitive equations written in spherical coordinates. The east-west density difference which arises upon averaging the momentum equations is taken to be proportional to the meridional density gradient. Lateral exchanges of heat and salt between the basins are explicitly resolved. Moreover, the model includes bottom topography and has representations of the Arctic Ocean and of the Weddell and Ross seas. Under realistic restoring boundary conditions, the model reproduces the global conveyor belt: deep water is formed in the Atlantic between 60 and 70°N at a rate of about 17 Sv (1 Sv=106 m3 s-1) and in the vicinity of the Antarctic continent, while the Indian and Pacific basins show broad upwelling. Superimposed on this thermohaline circulation are vigorous wind-driven cells in the upper thermocline. The simulated temperature and salinity fields and the computed meridional heat transport compare reasonably well with the observational estimates. When mixed boundary conditions (i.e., a restoring condition on sea-surface temperature and flux condition on sea-surface salinity) are applied, the model exhibits an irregular behavior before reaching a steady state characterized by self-sustained oscillations of 8.5-y period. The conveyor-belt circulation always results at this stage. A series of perturbation experiments illustrates the ability of the model to reproduce different steady-state circulations under mixed boundary conditions. Finally, the model sensitivity to various factors is examined. This sensitivity study reveals that the bottom topography and the presence of a submarine meridional ridge in the zone of the Drake Passage play a crucial role in determining the properties of the model bottom-water masses. The importance of the seasonality of the surface forcing is also stressed.

Thermohaline circulation in the Gulf of California

NASA Astrophysics Data System (ADS)

Bray, N. A.

1988-05-01

The Gulf of California, a narrow, semienclosed sea, is the only evaporative basin of the Pacific Ocean. As a result of evaporative forcing, salinities in the gulf are 1 to 2 ‰ higher than in the adjacent Pacific at the same latitude. This paper examines the thermohaline structure of the gulf and the means by which thermohaline exchange between the Pacific and the gulf occurs, over time scales of months to years. In addition to evaporative forcing, air-sea heat fluxes and momentum fluxes are important to thermohaline circulation in the gulf. From observations presented here, it appears that the gulf gains heat from the atmosphere on an annual average, unlike the Mediterranean and Red seas, which have comparable evaporative forcing. As a result, outflow from the gulf tends to be less dense than inflow from the Pacific. Winds over the gulf change direction with season, blowing northward in summer and southward in winter. This same seasonal pattern appears in near-surface transports averaged across the gulf. The thermohaline circulation, then, consists of outflow mostly between about 50 m and 250 m, inflow mostly between 250 m and 500 m, and a surface layer in which the direction of transport changes with seasonal changes in the large-scale winds. Using hydrographic observations from a section across the central gulf, total transport in or out of the northern gulf is estimated to be 0.9 Sv, heat gain from the atmosphere is estimated to be 20 to 50 W m-2, and evaporation is estimated to be 0.95 m yr-1. These estimates are annual averages, based on cruises from several years. Seasonal variations in thermohaline structure in the gulf are also examined and found to dominate the variance in temperature and density in the top 500 m of the water column. Salinity has little seasonal variability but does exhibit more horizontal variablility than temperature or density. Major year-to-year variations in thermohaline structure may be attributable to El Niño-Southern Oscillation events.

Tropical Pacific sea surface salinity variability derived from SMOS data: Comparison with in-situ observations.

NASA Astrophysics Data System (ADS)

Ballabrera, Joaquim; Hoareau, Nina; Umbert, Marta; Martínez, Justino; Turiel, Antonio

2013-04-01

Prediction of El Niño/Southern Oscillation (ENSO), and its relation with global climate anomalies, continues to be an important research effort in short-term climate forecasting. This task has become even more challenging as researchers are becoming more and more convinced that there is not a single archetypical El Niño (or La Niña) pattern, but several. During some events (called now Standard or East Pacific), the largest temperature anomalies are located at the eastern part of the Pacific. However, during some of the most recent events, the largest anomalies are restricted to the central part of the Pacific Ocean, and are now called Central Pacific or Modoki (a Japanese word for "almost") events. Although the role of salinity in operational ENSO forecasting was initially neglected (in contrast with temperature, sea level, or surface winds), recent studies have shown that salinity does play a role in the preconditioning of ENSO. Moreover, some researchers suggest that sea surface salinity might play a role (through the modulation of the western Pacific barrier layer) to favor the Standard or the Modoki nature of each event. Sea Surface Salinity maps are being operationally generated from microwave (L-band, 1.4 Ghz) brightness temperature maps. The L-band frequency was chosen because is the optimal one for ocean salinity measurements. However, after three years of satellite data, it has been found that noise in brightness temperatures (due to natural and artificial sources) is larger than expected. Moreover, the retrieval of SSS information requires special care because of the low sensitivity of the brightness temperature to SSS: from 0.2-0.8 K per salinity unit. Despite of all these facts, current accuracy of SS maps ranges from 0.2-0.4, depending on the processing level and the region being considered. We present here our study about the salinity variability in the tropical Pacific Ocean from the 9-day, 0.25 bins salinity maps derived from the SMOS reprocessing campaign released to the SMOS user community on March 2011. During the period under study, the equatorial Pacific has been in a quasi-continuous La Niña state. During the cold phases of ENSO, positive anomalies of SSS are expected with the largest anomalous values in the western warm-fresh pool. The anomalies derived from the SMOS data do indeed display a positive anomaly. The persistence of the feature, its geographical pattern, the time modulation of the anomaly amplitude indicate, and its resemblance with in situ observations indicate this novel observation technology is currently able to capture seasonal and interannual signatures of climate interest.

Halophilic Bacteria as a Source of Novel Hydrolytic Enzymes

PubMed Central

de Lourdes Moreno, María; Pérez, Dolores; García, María Teresa; Mellado, Encarnación

2013-01-01

Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. The halotolerance of many enzymes derived from halophilic bacteria can be exploited wherever enzymatic transformations are required to function under physical and chemical conditions, such as in the presence of organic solvents and extremes in temperature and salt content. In recent years, different screening programs have been performed in saline habitats in order to isolate and characterize novel enzymatic activities with different properties to those of conventional enzymes. Several halophilic hydrolases have been described, including amylases, lipases and proteases, and then used for biotechnological applications. Moreover, the discovery of biopolymer-degrading enzymes offers a new solution for the treatment of oilfield waste, where high temperature and salinity are typically found, while providing valuable information about heterotrophic processes in saline environments. In this work, we describe the results obtained in different screening programs specially focused on the diversity of halophiles showing hydrolytic activities in saline and hypersaline habitats, including the description of enzymes with special biochemical properties. The intracellular lipolytic enzyme LipBL, produced by the moderately halophilic bacterium Marinobacter lipolyticus, showed advantages over other lipases, being an enzyme active over a wide range of pH values and temperatures. The immobilized LipBL derivatives obtained and tested in regio- and enantioselective reactions, showed an excellent behavior in the production of free polyunsaturated fatty acids (PUFAs). On the other hand, the extremely halophilic bacterium, Salicola marasensis sp. IC10 showing lipase and protease activities, was studied for its ability to produce promising enzymes in terms of its resistance to temperature and salinity. PMID:25371331

Pre-stack full-waveform inversion of multichannel seismic data to retrieve thermohaline ocean structure. Application to the Gulf of Cadiz (SW Iberia).

NASA Astrophysics Data System (ADS)

Dagnino, Daniel; Jiménez Tejero, Clara-Estela; Meléndez, Adrià; Gras, Clàudia; Sallarès, Valentí; Ranero, César R.

2016-04-01

This work demonstrates the feasibility to retrieve high-resolution models of oceanic physical parameters by means of 2D adjoint-state full-waveform inversion (FWI). The proposed method is applied to pre-stack multi-channel seismic (MCS) data acquired in the Gulf of Cadiz (SW Iberia) in the framework of the EU GO (Geophysical Oceanography) project in 2006. We first design and apply a specific data processing flow that allows reducing data noise without modifying trace amplitudes. This step is shown to be essential to obtain accurate results due to the low signal-to-noise ratio (SNR) of water layer reflections, which are typically three-to-four orders of magnitude weaker than those in solid earth. Second, we propose new techniques to improve the inversion results by reducing the artefacts appearing in the gradient and misfit as a consequence of the low SNR. We use a weight and filter operator to focus in the regions where the gradient is reliable. The source wavelet is then inverted together with the sound speed. We demonstrate the efficiency of the proposed method and inversion strategy retrieving a 2D sound speed model along a 50 km-long MCS profile collected in the Gulf of Cadiz during the GO experiment. In this region, the Mediterranean outflow entrains the Atlantic waters, creating a salinity complex thermohaline structure that can be measured by a difference in acoustic impedance. The inverted sound speed model have a resolution of 75m for the horizontal direction, which is two orders of magnitude better than the models obtained using conventional, probe-based oceanographic techniques. In a second step, temperature and salinity are derived from the sound speed by minimizing the difference between the inverted and the theoretical sound speed estimated using the thermodynamic equation of seawater (TEOS-10 software). To apply the TEOS-10 we first calculate a linear-fitting between temperature and salinity using regional data from the National Oceanic and Atmospheric Administration (NOAA) compilation. Pressure is calculated from latitude and depth. In the final step, salinity is calculated using the Temperature-Salinity relation and the previously estimated temperature. The comparison of the inverted temperature, salinity model with measures from XBT and CTD probes deployed simultaneously to the MCS data acquisition shows that the accuracy of the inverted models is ˜0.15°C for temperature and ˜0.1psu for salinity.

Influence of Temperature on the Colloidal Stability of Polymer-Coated Gold Nanoparticles in Cell Culture Media.

PubMed

Zyuzin, Mikhail V; Honold, Tobias; Carregal-Romero, Susana; Kantner, Karsten; Karg, Matthias; Parak, Wolfgang J

2016-04-06

The temperature-dependence of the hydrodynamic diameter and colloidal stability of gold-polymer core-shell particles with temperature-sensitive (poly(N-isopropylacrylamide)) and temperature-insensitive shells (polyallylaminine hydrochloride/polystyrensulfonate, poly(isobutylene-alt-maleic anhydride)-graft-dodecyl) are investigated in various aqueous media. The data demonstrate that for all nanoparticle agglomeration, i.e., increase in effective nanoparticle size, the presence of salts or proteins in the dispersion media has to be taken into account. Poly(N-isopropylacrylamide) coated nanoparticles show a reversible temperature-dependent increase in size above the volume phase transition of the polymer shell when they are dispersed in phosphate buffered saline or in media containing protein. In contrast, the nanoparticles coated with temperature-insensitive polymers show a time-dependent increase in size in phosphate buffered saline or in medium containing protein. This is due to time-dependent agglomeration, which is particularly strong in phosphate buffered saline, and induces a time-dependent, irreversible increase in the hydrodynamic diameter of the nanoparticles. This demonstrates that one has to distinguish between temperature- and time-induced agglomerations. Since the size of nanoparticles regulates their uptake by cells, temperature-dependent uptake of thermosensitive and non-thermosensitive nanoparticles by cells lines is compared. No temperature-specific difference between both types of nanoparticles could be observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photobleaching of chromophoric dissolved organic matter (CDOM) in the Yangtze River estuary: kinetics and effects of temperature, pH, and salinity.

PubMed

Song, Guisheng; Li, Yijie; Hu, Suzheng; Li, Guiju; Zhao, Ruihua; Sun, Xin; Xie, Huixiang

2017-06-21

The kinetics and temperature-, pH- and salinity-dependences of photobleaching of chromophoric dissolved organic matter (CDOM) in the Yangtze River estuary (YRE) were evaluated using laboratory solar-simulated irradiation and compared to those of Suwannee River humic substances (SRHSs). Nearly all CDOM in water at the head of the estuary (headwater herein) was photobleachable in both summer and winter, while significant fractions of CDOM (13-29%) were resistant to photobleaching in saltier waters. The photobleaching rate constant in the headwater was 25% higher in summer than that in winter. The absorbed photon-based photobleaching efficiency (PE) increased with temperature following the linear Arrhenius equation. For a 20 °C increase in temperature, PE increased by ∼45% in the headwater and by 70-81% in the saltier waters. PE for YRE samples exhibited minima at pH from 6 to 7 and increased with both lower and higher pH values, contrasting the consistent increase in PE with pH shown by SRHSs. No consistent effect of salinity on PE was observed for both SRHSs and YRE samples. Photobleaching increased the spectral slope coefficient between 275 nm and 295 nm in summer, consistent with the behavior of SRHSs, but decreased it in winter, implying a difference in the molecular composition of chromophores between the two seasons. Temperature, salinity, and pH modified the photoalteration of the spectral shape but their effects varied spatially and seasonally. This study demonstrates that CDOM quality, temperature, and pH should be incorporated into models involving quantification of photobleaching.

Characterization and Correction of Aquarius Long Term Calibration Drift Using On-Earth Brightness Temperature Refernces

NASA Technical Reports Server (NTRS)

Brown, Shannon; Misra, Sidharth

2013-01-01

The Aquarius/SAC-D mission was launched on June 10, 2011 from Vandenberg Air Force Base. Aquarius consists of an L-band radiometer and scatterometer intended to provide global maps of sea surface salinity. One of the main mission objectives is to provide monthly global salinity maps for climate studies of ocean circulation, surface evaporation and precipitation, air/sea interactions and other processes. Therefore, it is critical that any spatial or temporal systematic biases be characterized and corrected. One of the main mission requirements is to measure salinity with an accuracy of 0.2 psu on montly time scales which requires a brightness temperature stability of about 0.1K, which is a challenging requirement for the radiometer. A secondary use of the Aquarius data is for soil moisture applications, which requires brightness temperature stability at the warmer end of the brightness temperature dynamic range. Soon after launch, time variable drifts were observed in the Aquarius data compared to in-situ data from ARGO and models for the ocean surface salinity. These drifts could arise from a number of sources, including the various components of the retrieval algorithm, such as the correction for direct and reflected galactic emission, or from the instrument brightness temperature calibration. If arising from the brightness temperature calibration, they could have gain and offset components. It is critical that the nature of the drifts be understood before a suitable correction can be implemented. This paper describes the approach that was used to detect and characterize the components of the drift that were in the brightness temperature calibration using on-Earth reference targets that were independent of the ocean model.

Multiproxy evidence of Holocene climate variability from estuarine sediments, eastern North America

USGS Publications Warehouse

Cronin, T. M.; Thunell, R.; Dwyer, G.S.; Saenger, C.; Mann, M.E.; Vann, C.; Seal, R.R.

2005-01-01

We reconstructed paleoclimate patterns from oxygen and carbon isotope records from the fossil estuarine benthic foraminifera Elphidium and Mg/ Ca ratios from the ostracode Loxoconcha from sediment cores from Chesapeake Bay to examine the Holocene evolution of North Atlantic Oscillation (NAO)-type climate variability. Precipitation-driven river discharge and regional temperature variability are the primary influences on Chesapeake Bay salinity and water temperature, respectively. We first calibrated modern ??18 Owater to salinity and applied this relationship to calculate trends in paleosalinity from the ??18 Oforam, correcting for changes in water temperature estimated from ostracode Mg /Ca ratios. The results indicate a much drier early Holocene in which mean paleosalinity was ???28 ppt in the northern bay, falling ???25% to ???20 ppt during the late Holocene. Early Holocene Mg/Ca-derived temperatures varied in a relatively narrow range of 13?? to 16??C with a mean temperature of 14.2??C and excursions above 16??C; the late Holocene was on average cooler (mean temperature of 12.8??C). In addition to the large contrast between early and late Holocene regional climate conditions, multidecadal (20-40 years) salinity and temperature variability is an inherent part of the region's climate during both the early and late Holocene, including the Medieval Warm Period and Little Ice Age. These patterns are similar to those observed during the twentieth century caused by NAO-related processes. Comparison of the midlatitude Chesapeake Bay salinity record with tropical climate records of Intertropical Convergence Zone fluctuations inferred from the Cariaco Basin titanium record suggests an anticorrelation between precipitation in the two regions at both millennial and centennial timescales. Copyright 2005 by the American Geophysical Union.

Invasive Marine and Estuarine Animals of the Pacific Northwest and Alaska

DTIC Science & Technology

2005-09-01

or never be realized at all depending on the characteristics of the individual species and the conditions into which it is introduced. Figure 1...including rocky intertidal, unvegetated intertidal and subtidal mud and sand, salt marsh, and seagrass. Capable of tolerating a wide range of salinity ...and temperature, it prefers mesohaline to polyhaline salinities (10-30 ppt) and temperatures between 3 and 26 °C (Grosholz and Ruiz 2002). The green

A Community Terrain-Following Ocean Modeling System (ROMS)

DTIC Science & Technology

2015-09-30

funded NOPP project titled: Toward the Development of a Coupled COAMPS-ROMS Ensemble Kalman filter and adjoint with a focus on the Indian Ocean and the...surface temperature and surface salinity daily averages for 31-Jan-2014. Similarly, Figure 3 shows the sea surface height averaged solution for 31-Jan... temperature (upper panel; Celsius) and surface salinity (lower panel) for 31-Jan-2014. The refined solution for the Hudson Canyon grid is overlaid on

Improved perfusion system for bipolar radiofrequency ablation of liver: preliminary findings from a computer modeling study.

PubMed

Berjano, Enrique J; Burdío, Fernando; Navarro, Ana C; Burdío, José M; Güemes, Antonio; Aldana, Oscar; Ros, Paloma; Sousa, Ramón; Lozano, Ricardo; Tejero, Eloy; de Gregorio, Miguel A

2006-10-01

Current systems for radiofrequency ablation of liver tumors are unable to consistently treat tumors larger than 3 cm in diameter with a single electrode in a single application. One of the strategies for enlarging coagulation zone dimensions is to infuse saline solutions into the tissue through the active electrodes. Nevertheless, the uncontrolled and undirected diffusion of boiling saline into the tissue has been associated with irregular coagulation zones and severe complications, mainly due to reflux of saline along the electrode path. In order to improve the perfusion bipolar ablation method, we hypothesized that the creation of small monopolar coagulation zones adjacent to the bipolar electrodes and previous to the saline infusion would create preferential paths for the saline to concentrate on the targeted coagulation zone. Firstly, we conducted ex vivo experiments in order to characterize the monopolar coagulation zones. We observed that they are practically impermeable to the infused saline. On the basis of this finding, we built theoretical models and conducted computer simulations to assess the feasibility of our hypothesis. Temperature distributions during bipolar ablations with and without previous monopolar coagulation zones were obtained. The results showed that in the case of monopolar coagulation zones the temperature of the tissue took longer to reach 100 degrees C. Since this temperature value is related to rise of impedance, and the time necessary for this process is directly related to the volume of the coagulation zone, our results suggest that monopolar sealing would allow larger coagulation zones to be created. Future experimental studies should confirm this benefit.

Low-Reynolds-number swimming at pycnoclines.

PubMed

Doostmohammadi, Amin; Stocker, Roman; Ardekani, Arezoo M

2012-03-06

Microorganisms play pivotal functions in the trophic dynamics and biogeochemistry of aquatic ecosystems. Their concentrations and activities often peak at localized hotspots, an important example of which are pycnoclines, where water density increases sharply with depth due to gradients in temperature or salinity. At pycnoclines organisms are exposed to different environmental conditions compared to the bulk water column, including reduced turbulence, slow mass transfer, and high particle and predator concentrations. Here we show that, at an even more fundamental level, the density stratification itself can affect microbial ecology at pycnoclines, by quenching the flow signature, increasing the energetic expenditure, and stifling the nutrient uptake of motile organisms. We demonstrate this through numerical simulations of an archetypal low-Reynolds-number swimmer, the "squirmer." We identify the Richardson number--the ratio of buoyancy forces to viscous forces--as the fundamental parameter that quantifies the effects of stratification. These results demonstrate an unexpected effect of buoyancy on low-Reynolds-number swimming, potentially affecting a broad range of abundant organisms living at pycnoclines in oceans and lakes.

Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea.

PubMed

Lozano-Cortés, Diego F; Berumen, Michael L

2016-04-30

Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north-south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pore-water and epibenthic exposures in contaminated sediments using embryos of two estuarine fish species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jelinski, J.A.; Anderson, S.L.

1995-12-31

The authors` objectives were to determine the feasibility of using embryos of two fish species, Menidia beryllina and Atherinops affinis, in estuarine sediment toxicity tests at ambient temperatures and salinities, and to compare pore-water and sediment water interface corer (SWIC) exposure techniques using these same species. The ultimate goal is to determine whether these pore-water and SWIC methods can be used in in situ exposure studies. Sediment samples were collected at both a reference and contaminated site at the Mare Island Naval Shipyard in San Francisco Bay. Pore-water testes were conducted using methods developed in the laboratory, and SWIC testsmore » were conducted using a modification of B. Anderson et al. Salinity and temperature tolerance experiments revealed that M. beryllina embryos can tolerate temperatures between 160 C and 240 C and salinities of 10 ppt to 25 ppt, whereas A. affinis has a temperature range between 160 C and 200 C. Comparisons between pore-water and SWIC exposures at a reference site within MINSY showed no significant difference in hatching success. However, hatching success in SWIC exposures was significantly lower than pore-water exposures at a previously characterized contaminated site. In conclusion, both M. beryllina and A. affinis embryos may be useful for sediment and in situ toxicity testing in estuarine environments. Their wide temperature and salinity tolerances allow for minimal test manipulations, and M. beryllina showed excellent hatching success in reference sediments for both types of exposures.« less

Phase relations and adiabats in boiling seafloor geothermal systems

USGS Publications Warehouse

Bischoff, J.L.; Pitzer, Kenneth S.

1985-01-01

Observations of large salinity variations and vent temperatures in the range of 380-400??C suggest that boiling or two-phase separation may be occurring in some seafloor geothermal systems. Consideration of flow rates and the relatively small differences in density between vapors and liquids at the supercritical pressures at depth in these systems suggests that boiling is occurring under closed-system conditions. Salinity and temperature of boiling vents can be used to estimate the pressure-temperature point in the subsurface at which liquid seawater first reached the two-phase boundary. Data are reviewed to construct phase diagrams of coexisting brines and vapors in the two-phase region at pressures corresponding to those of the seafloor geothermal systems. A method is developed for calculating the enthalpy and entropy of the coexisting mixtures, and results are used to construct adiabats from the seafloor to the P-T two-phase boundary. Results for seafloor vents discharging at 2300 m below sea level indicate that a 385??C vent is composed of a brine (7% NaCl equivalent) in equilibrium with a vapor (0.1% NaCl). Brine constitutes 45% by weight of the mixture, and the fluid first boiled at approximately 1 km below the seafloor at 415??C, 330 bar. A 400??C vent is primarily vapor (88 wt.%, 0.044% NaCl) with a small amount of brine (26% NaCl) and first boiled at 2.9 km below the seafloor at 500??C, 520 bar. These results show that adiabatic decompression in the two-phase region results in dramatic cooling of the fluid mixture when there is a large fraction of vapor. ?? 1985.

The role of hydrothermal processes in the granite-hosted Zr, Y, REE deposit at Strange Lake, Quebec/Labrador: Evidence from fluid inclusions

NASA Astrophysics Data System (ADS)

Salvi, Stefano; Williams-Jones, Anthony E.

1990-09-01

The Strange Lake Zr, Y, REE, Nb, and Be deposit is hosted by a small, high-level, Late-Proterozoic peralkaline granite stock that intruded into high-grade metamorphic gneisses on the Quebec-Labrador border. The stock is extensively altered. Early alteration is manifested by the replacement of arfvedsonite with aegirine. Later alteration involved Ca-Na exchange. Zr, Ti, Y, REEs, Nb, and Be are concentrated in Ca-bearing minerals that, together with quartz, commonly pseudomorph Na-bearing minerals. Fluid inclusions in pseudomorphs comprise several distinct types: high-salinity (13 to 24 wt% NaCl eq.), Ca-rich aqueous inclusions that homogenize to liquid between 135 and 195°C; mixed aqueousmethane inclusions; methane inclusions; and solid-bearing inclusions. Aqueous-methane inclusions represent heterogeneous entrapment of immiscible high-salinity aqueous liquid and methane. Bastnäsite (tentatively identified by SEM analysis) occurs as a daughter mineral. Other daughter or trapped minerals include a Y, HREE-bearing mineral, possibly gagarinite, and hematite, galena, sphalerite, fluorite, pyrochlore, kutnahorite (?), and griceite (?). The first three inclusion types also occur in quartz in pegmatites and veins together with lower-temperature, lower-salinity, Na-dominated aqueous inclusions. The entrapment temperature inferred for the aqueous inclusions from microthermometry and the Na-K-Ca geothermometer range from 155 to 195°C for the higher-salinity inclusions and 100 to 165°C for the low-salinity inclusions. A model is proposed in which the intrusion of a peralkaline granite to high crustal levels initiated a ground/formational water-dominated hydrothermal system in adjacent gabbroic, calc-silicate, and graphitic gneisses. Reaction of the high-salinity, Ca-rich liquid with the graphitic gneisses led to the production of an immiscible methane gas. Subsequent interaction of this liquid with the granite led to extensive replacement of sodic minerals by calcium analogues at temperatures of less than 200°C. Some time after the onset of Ca metasomatism the high-salinity liquid mixed with a Ca-poor, low-salinity, low-temperature liquid that had leached F and rare metals from the granite. Yttrium and REE mineral deposition occurred as a result of the decreased ligand concentration that accompanied fluorite deposition during mixing of the Ca-rich and Ca-poor aqueous liquids.

Increased Accuracy in the Measurement of the Dielectric Constant of Seawater at 1.413 GHz

NASA Technical Reports Server (NTRS)

Zhou, Y.; Lang R.; Drego, C.; Utku, C.; LeVine, D.

2012-01-01

This paper describes the latest results for the measurements of the dielectric constant at 1.413 GHz by using a resonant cavity technique. The purpose of these measurements is to develop an accurate relationship for the dependence of the dielectric constant of sea water on temperature and salinity which is needed by the Aquarius inversion algorithm to retrieve salinity. Aquarius is the major instrument on the Aquarius/SAC-D observatory, a NASA/CONAE satellite mission launched in June of20ll with the primary mission of measuring global sea surface salinity to an accuracy of 0.2 psu. Aquarius measures salinity with a 1.413 GHz radiometer and uses a scatterometer to compensate for the effects of surface roughness. The core part of the seawater dielectric constant measurement system is a brass microwave cavity that is resonant at 1.413 GHz. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The change of resonance frequency and the cavity Q value are used to determine the real and imaginary parts of the dielectric constant of seawater introduced into the thin tube. Measurements are automated with the help of software developed at the George Washington University. In this talk, new results from measurements made since September 2010 will be presented for salinities 30, 35 and 38 psu with a temperature range of O C to 350 C in intervals of 5 C. These measurements are more accurate than earlier measurements made in 2008 because of a new method for measuring the calibration constant using methanol. In addition, the variance of repeated seawater measurements has been reduced by letting the system stabilize overnight between temperature changes. The new results are compared to the Kline Swift and Meissner Wentz model functions. The importance of an accurate model function will be illustrated by using these model functions to invert the Aquarius brightness temperature to get the salinity values. The salinity values will be compared to co-located in situ data collected by Argo buoys.

Anomalous pH-Dependent Nanofluidic Salinity Gradient Power.

PubMed

Yeh, Li-Hsien; Chen, Fu; Chiou, Yu-Ting; Su, Yen-Shao

2017-12-01

Previous studies on nanofluidic salinity gradient power (NSGP), where energy associated with the salinity gradient can be harvested with ion-selective nanopores, all suggest that nanofluidic devices having higher surface charge density should have higher performance, including osmotic power and conversion efficiency. In this manuscript, this viewpoint is challenged and anomalous counterintuitive pH-dependent NSGP behaviors are reported. For example, with equal pH deviation from its isoelectric point (IEP), the nanopore at pH < IEP is shown to have smaller surface charge density but remarkably higher NSGP performance than that at pH > IEP. Moreover, for sufficiently low pH, the NSGP performance decreases with lowering pH (increasing nanopore charge density). As a result, a maximum osmotic power density as high as 5.85 kW m -2 can be generated along with a conversion efficiency of 26.3% achieved for a single alumina nanopore at pH 3.5 under a 1000-fold concentration ratio. Using the rigorous model with considering the surface equilibrium reactions on the pore wall, it is proved that these counterintuitive surface-charge-dependent NSGP behaviors result from the pH-dependent ion concentration polarization effect, which yields the degradation in effective concentration ratio across the nanopore. These findings provide significant insight for the design of next-generation, high-performance NSGP devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Different Saline-Alkaline Conditions on the Characteristics of Phytoplankton Communities in the Lakes of Songnen Plain, China

PubMed Central

Zang, Shuying; Fan, Yawen; Ye, Huaxiang

2016-01-01

Many lakes located in the Songnen Plain of China exhibit a high saline-alkaline level. 25 lakes in the Songnen Plain were selected as research objects in this study. Water samples in these lakes were collected from June to August in 2008. Total Dissolved Solids (TDS) and Total Alkalinity (TA) were measured to assess the saline-alkaline level, and partial canonical correspondence analysis (CCA) was conducted as well. The results show that the majority of these lakes in the study area could be categorized into HCO3−-Na+-I type. According to the TDS assessment, of the total 25 lakes, there are 14 for freshwater, 7 for brackish water and 4 for saltwater; and the respective range of TA was from 0.98 to 40.52. The relationship between TA and TDS indicated significant linear relationship (R2 = 0.9292) in the HCO3−-Na+-I type lakes in the Songnen Plain. There was a general trend that cell density, genera richness and taxonomic diversity decreased with the increase of saline-alkaline gradient, whereas a contrary trend was observed for the proportion of dominant species. When the TDS values were above 3×103mg/L and the TA values were above 15mg/L, there was a significant reduction in cell density, genera richness and biodiversity, and their corresponding values were respectively below 10×106 (ind/L), 15 and approximately 2.5. Through the partial canonical correspondence analysis (CCA), 10.7% of the genera variation was explained by pure saline-alkaline variables. Cyclotella meneghiniana, Melosira ambigua and Melosira granulate were found to become the dominant species in most of these lakes, which indicated that there may be rather wide saline-alkaline niches for common dominant species. About one-quarters of the genera which have certain tolerance to salinity and alkalinity preferred to live in the regions with relatively higher saline-alkaline levels in this study. PMID:27749936

Abundance and distribution of Vibrio cholerae, V. parahaemolyticus, and V. vulnificus following a major freshwater intrusion into the Mississippi Sound.

PubMed

Griffitt, Kimberly J; Grimes, D Jay

2013-04-01

In response to a major influx of freshwater to the Mississippi Sound following the opening of the Bonnet Carre Spillway, water samples were collected from three sites along the Mississippi shoreline to assess the impact of altered salinity on three pathogenic Vibrio species. Salinity readings across the affected area during the 2011 sample period ranged from 1.4 to 12.9 ppt (mean = 7.0) and for the 2012 sample period from 14.1 to 23.6 ppt (mean = 19.8). Analyses of the data collected in 2011 showed a reduction in densities of Vibrio parahaemolyticus and Vibrio vulnificus with a concurrent increase of Vibrio cholerae numbers, with V. cholerae becoming the only Vibrio detected once salinity readings dropped to 6 ppt. Follow-up samples taken in 2012 after recovery of the salinity in the sound showed that the relative densities of the three pathogenic vibrios had reverted back to normal levels. This study shows that although the spillway was open but a few weeks and the effects were therefore time limited, the Mississippi River water had a profound, if temporary, effect on Vibrio ecology in the Mississippi Sound.

Do copepods inhabit hypersaline waters worldwide? A short review and discussion

NASA Astrophysics Data System (ADS)

Anufriieva, Elena V.

2015-11-01

A small number of copepod species have adapted to an existence in the extreme habitat of hypersaline water. 13 copepod species have been recorded in the hypersaline waters of Crimea (the largest peninsula in the Black Sea with over 50 hypersaline lakes). Summarizing our own and literature data, the author concludes that the Crimean extreme environment is not an exception: copepod species dwell in hypersaline waters worldwide. There are at least 26 copepod species around the world living at salinity above 100; among them 12 species are found at salinity higher than 200. In the Crimea Cletocamptus retrogressus is found at salinity 360×10-3 (with a density of 1 320 individuals/m3) and Arctodiaptomus salinus at salinity 300×10-3 (with a density of 343 individuals/m3). Those species are probably the most halotolerant copepod species in the world. High halotolerance of osmoconforming copepods may be explained by exoosmolyte consumption, mainly with food. High tolerance to many factors in adults, availability of resting stages, and an opportunity of long-distance transportation of resting stages by birds and/or winds are responsible for the wide geographic distribution of these halophilic copepods.

Improved statistical method for temperature and salinity quality control

NASA Astrophysics Data System (ADS)

Gourrion, Jérôme; Szekely, Tanguy

2017-04-01

Climate research and Ocean monitoring benefit from the continuous development of global in-situ hydrographic networks in the last decades. Apart from the increasing volume of observations available on a large range of temporal and spatial scales, a critical aspect concerns the ability to constantly improve the quality of the datasets. In the context of the Coriolis Dataset for ReAnalysis (CORA) version 4.2, a new quality control method based on a local comparison to historical extreme values ever observed is developed, implemented and validated. Temperature, salinity and potential density validity intervals are directly estimated from minimum and maximum values from an historical reference dataset, rather than from traditional mean and standard deviation estimates. Such an approach avoids strong statistical assumptions on the data distributions such as unimodality, absence of skewness and spatially homogeneous kurtosis. As a new feature, it also allows addressing simultaneously the two main objectives of an automatic quality control strategy, i.e. maximizing the number of good detections while minimizing the number of false alarms. The reference dataset is presently built from the fusion of 1) all ARGO profiles up to late 2015, 2) 3 historical CTD datasets and 3) the Sea Mammals CTD profiles from the MEOP database. All datasets are extensively and manually quality controlled. In this communication, the latest method validation results are also presented. The method has already been implemented in the latest version of the delayed-time CMEMS in-situ dataset and will be deployed soon in the equivalent near-real time products.

Rapid fluctuations in flow and water-column properties in Asan Bay, Guam: implications for selective resilience of coral reefs in warming seas

USGS Publications Warehouse

Storlazzi, Curt D.; Field, Michael E.; Cheriton, Olivia M.; Presto, M.K.; Logan, J.B.

2013-01-01

Hydrodynamics and water-column properties were investigated off west-central Guam from July 2007 through January 2008. Rapid fluctuations, on time scales of 10s of min, in currents, temperature, salinity, and acoustic backscatter were observed to occur on sub-diurnal frequencies along more than 2 km of the fore reef but not at the reef crest. During periods characterized by higher sea-surface temperatures (SSTs), weaker wind forcing, smaller ocean surface waves, and greater thermal stratification, rapid decreases in temperature and concurrent rapid increases in salinity and acoustic backscatter coincided with onshore-directed near-bed currents and offshore-directed near-surface currents. During the study, these cool-water events, on average, lasted 2.3 h and decreased the water temperature 0.57 °C, increased the salinity 0.25 PSU, and were two orders of magnitude more prevalent during the summer season than the winter. During the summer season when the average satellite-derived SST anomaly was +0.63 °C, these cooling events, on average, lowered the temperature 1.14 °C along the fore reef but only 0.11 °C along the reef crest. The rapid shifts appear to be the result of internal tidal bores pumping cooler, more saline, higher-backscatter oceanic water from depths >50 m over cross-shore distances of 100 s of m into the warmer, less saline waters at depths of 20 m and shallower. Such internal bores appear to have the potential to buffer shallow coral reefs from predicted increases in SSTs by bringing cool, offshore water to shallow coral environments. These cooling internal bores may also provide additional benefits to offset stress such as supplying food to thermally stressed corals, reducing stress due to ultraviolet radiation and/or low salinity, and delivering coral larvae from deeper reefs not impacted by surface thermal stress. Thus, the presence of internal bores might be an important factor locally in the resilience of select coral reefs facing increased thermal stress.

Rapid fluctuations in flow and water-column properties in Asan Bay, Guam: implications for selective resilience of coral reefs in warming seas

NASA Astrophysics Data System (ADS)

Storlazzi, C. D.; Field, M. E.; Cheriton, O. M.; Presto, M. K.; Logan, J. B.

2013-12-01

Hydrodynamics and water-column properties were investigated off west-central Guam from July 2007 through January 2008. Rapid fluctuations, on time scales of 10s of min, in currents, temperature, salinity, and acoustic backscatter were observed to occur on sub-diurnal frequencies along more than 2 km of the fore reef but not at the reef crest. During periods characterized by higher sea-surface temperatures (SSTs), weaker wind forcing, smaller ocean surface waves, and greater thermal stratification, rapid decreases in temperature and concurrent rapid increases in salinity and acoustic backscatter coincided with onshore-directed near-bed currents and offshore-directed near-surface currents. During the study, these cool-water events, on average, lasted 2.3 h and decreased the water temperature 0.57 °C, increased the salinity 0.25 PSU, and were two orders of magnitude more prevalent during the summer season than the winter. During the summer season when the average satellite-derived SST anomaly was +0.63 °C, these cooling events, on average, lowered the temperature 1.14 °C along the fore reef but only 0.11 °C along the reef crest. The rapid shifts appear to be the result of internal tidal bores pumping cooler, more saline, higher-backscatter oceanic water from depths >50 m over cross-shore distances of 100 s of m into the warmer, less saline waters at depths of 20 m and shallower. Such internal bores appear to have the potential to buffer shallow coral reefs from predicted increases in SSTs by bringing cool, offshore water to shallow coral environments. These cooling internal bores may also provide additional benefits to offset stress such as supplying food to thermally stressed corals, reducing stress due to ultraviolet radiation and/or low salinity, and delivering coral larvae from deeper reefs not impacted by surface thermal stress. Thus, the presence of internal bores might be an important factor locally in the resilience of select coral reefs facing increased thermal stress.

Pressure and Temperature Changes in In Vitro Applications with the Laser and Their Implications for Middle Ear Surgery

PubMed Central

Schwab, Burkard; Kontorinis, Georgios

2010-01-01

Background. The purpose of this study was to evaluate the thermal and pressure effects using a Titan Sapphire chirped-pulse amplifier system configured to deliver ultrashort pulses of 180 femtoseconds (fs) in an inner ear model. Materials and Methods. Temperature increases and heat exchange processes in the fluid (physiological saline) were examined in a calorically and physiologically approximated cochlea model for applying laser parameters effective in the creation of footplate perforations. Results. In the effective energy density range, the highest temperature increases achieved with the Carbon dioxide (CO2) laser were about 11 degrees C. The lowest temperature maxima were 6 degrees C with the Er:YAG laser (Yttrium-Aluminum-Oxide doted with Erbium3+-ions) and <5 degrees C with the femtosecond laser. Comparison of the laser-induced pressure with the limit graph published by Pfander indicated that the use of the fs laser is unobjectionable for fluences <1 J/cm2. Conclusions. Our investigations demonstrated that the application of the fs laser in middle ear surgery presents a new and promising addition to the range of ultrashort wavelength lasers used for this purpose. PMID:20953354

Brine Migration from a Flooded Salt Mine in the Genesee Valley, Livingston County, New York: Geochemical Modeling and Simulation of Variable-Density Flow

USGS Publications Warehouse

Yager, Richard M.; Misut, Paul E.; Langevin, Christian D.; Parkhurst, David L.

2009-01-01

The Retsof salt mine in upstate New York was flooded from 1994 to 1996 after two roof collapses created rubble chimneys in overlying bedrock that intersected a confined aquifer in glacial sediments. The mine now contains about 60 billion liters of saturated halite brine that is slowly being displaced as the weight of overlying sediments causes the mine cavity to close, a process that could last several hundred years. Saline water was detected in the confined aquifer in 2002, and a brine-mitigation project that includes pumping followed by onsite desalination was implemented in 2006 to prevent further migration of saline water from the collapse area. A study was conducted by the U.S. Geological Survey using geochemical and variable-density flow modeling to determine sources of salinity in the confined aquifer and to assess (1) processes that control movement and mixing of waters in the collapse area, (2) the effect of pumping on salinity, and (3) the potential for anhydrite dissolution and subsequent land subsidence resulting from mixing of waters induced by pumping. The primary source of salinity in the collapse area is halite brine that was displaced from the flooded mine and transported upward by advection and dispersion through the rubble chimneys and surrounding deformation zone. Geochemical and variable-density modeling indicate that salinity in the upper part of the collapse area is partly derived from inflow of saline water from bedrock fracture zones during water-level recovery (January 1996 through August 2006). The lateral diversion of brine into bedrock fracture zones promoted the upward migration of mine water through mixing with lower density waters. The relative contributions of mine water, bedrock water, and aquifer water to the observed salinity profile within the collapse area are controlled by the rates of flow to and from bedrock fracture zones. Variable-density simulations of water-level recovery indicate that saline water has probably not migrated beyond the collapse area, while simulations of pumping indicate that further upward migration of brine and saline water is now prevented by groundwater withdrawals under the brine-mitigation project. Geochemical modeling indicates that additional land subsidence as a result of anhydrite dissolution in the collapse area is not a concern, as long as the rate of brine pumping is less than the rate of upward flow of brine from the flooded mine. The collapse area above the flooded salt mine is within a glacially scoured bedrock valley that is filled with more than 150 meters of glacial drift. A confined aquifer at the bottom of the glacial sediments (referred to as the lower confined aquifer, or LCA) was the source of most of the water that flooded the mine. Two rubble chimneys that formed above the roof collapses in 1994 hydraulically connect the flooded mine to the LCA through 180 meters of sedimentary rock. From 1996 through 2006, water levels in the aquifer system recovered and the brine-displacement rate ranged from 4.4 to 1.6 liters per second, as estimated from land-surface subsidence above the mine. A zone of fracturing within the bedrock (the deformation zone) formed around the rubble chimneys as rock layers sagged toward the mine cavity after the roof collapses. Borehole geophysical surveys have identified three saline-water-bearing fracture zones in the bedrock: at stratigraphic contacts between the Onondaga and Bertie Limestones (O/B-FZ) and the Bertie Limestone and the Camillus Shale (B/C-FZ), and in the Syracuse Formation (Syr-FZ). The only outlets for brine displaced from the mine are through the rubble chimneys, but some of the brine could be diverted laterally into fracture zones in the rocks that lie between the mine and the LCA. Inverse geochemical models developed using PHREEQC indicate that halite brine in the flooded mine is derived from a mixture of freshwater from the LCA (81 percent), saline water from bedrock fracture zones (16 per

Assessing the Impact of Topography on Groundwater Salinization Due to Storm Surge Inundation

NASA Astrophysics Data System (ADS)

Yu, X.; Yang, J.; Graf, T.; Koneshloo, M.; O'Neal, M. A.; Michael, H. A.

2015-12-01

The sea-level rise and increase in the frequency and intensity of coastal storms due to climate change are likely to exacerbate adverse effects of storm surges on low-lying coastal areas. The landward flow of water during storm surges introduces salt to surficial coastal aquifers and threatens groundwater resources. Coastal topography (e.g. ponds, dunes, canals) likely has a strong impact on overwash and salinization processes, but is generally highly simplified in modeling studies. To understand the topographic impacts on groundwater salinization, we modeled overwash and variable-density groundwater flow and salt transport in 3D using the fully coupled surface and subsurface numerical simulator, HydroGeoSphere. The model simulates the coastal aquifer as an integrated system considering processes such as overland flow, coupled surface and subsurface exchange, variably saturated flow, and variable-density flow. To represent various coastal landscape types, we started with realistic coastal topography from Delaware, USA, and then generated synthetic fields with differing shore-perpendicular connectivity and surface depressions. The groundwater salinization analysis suggested that the topographic connectivity promoting overland flow controls the volume of aquifer that is salinized. In contrast, depression storage of surface water mainly controls the time for infiltrated salt to flush from the aquifer. The results indicate that for a range of synthetic conditions, topography increases the flushing time of salt by 20-300% relative to an equivalent "simple slope" in which topographic variation is absent. Our study suggests that topography have a significant impact on overwash salinization, with important implications for land management at local scales and groundwater vulnerability assessment at regional to global scales.