Sample records for sea salt components

  1. Frost flowers and sea-salt aerosols over seasonal sea-ice areas in northwestern Greenland during winter-spring

    NASA Astrophysics Data System (ADS)

    Hara, Keiichiro; Matoba, Sumito; Hirabayashi, Motohiro; Yamasaki, Tetsuhide

    2017-07-01

    Sea salts and halogens in aerosols, frost flowers, and brine play an important role in atmospheric chemistry in polar regions. Simultaneous sampling and observations of frost flowers, brine, and aerosol particles were conducted around Siorapaluk in northwestern Greenland during December 2013 to March 2014. Results show that water-soluble frost flower and brine components are sea-salt components (e.g., Na+, Cl-, Mg2+, K+, Ca2+, Br-, and iodine). Concentration factors of sea-salt components of frost flowers and brine relative to seawater were 1.14-3.67. Sea-salt enrichment of Mg2+, K+, Ca2+, and halogens (Cl-, Br-, and iodine) in frost flowers is associated with sea-salt fractionation by precipitation of mirabilite and hydrohalite. High aerosol number concentrations correspond to the occurrence of higher abundance of sea-salt particles in both coarse and fine modes, and blowing snow and strong winds. Aerosol number concentrations, particularly in coarse mode, are increased considerably by release from the sea-ice surface under strong wind conditions. Sulfate depletion by sea-salt fractionation was found to be limited in sea-salt aerosols because of the presence of non-sea-salt (NSS) SO42-. However, coarse and fine sea-salt particles were found to be rich in Mg. Strong Mg enrichment might be more likely to proceed in fine sea-salt particles. Magnesium-rich sea-salt particles might be released from the surface of snow and slush layer (brine) on sea ice and frost flowers. Mirabilite-like and ikaite-like particles were identified only in aerosol samples collected near new sea-ice areas. From the field evidence and results from earlier studies, we propose and describe sea-salt cycles in seasonal sea-ice areas.

  2. Sea Salt vs. Table Salt: What's the Difference?

    MedlinePlus

    ... Nutrition and healthy eating What's the difference between sea salt and table salt? Answers from Katherine Zeratsky, R.D., L.D. The main differences between sea salt and table salt are in their taste, ...

  3. Sea-Salt Aerosol Forecasts Compared with Wave and Sea-Salt Measurements in the Open Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Kishcha, P.; Starobinets, B.; Bozzano, R.; Pensieri, S.; Canepa, E.; Nickovie, S.; di Sarra, A.; Udisti, R.; Becagli, S.; Alpert, P.

    2012-03-01

    Sea-salt aerosol (SSA) could influence the Earth's climate acting as cloud condensation nuclei. However, there were no regular measurements of SSA in the open sea. At Tel-Aviv University, the DREAM-Salt prediction system has been producing daily forecasts of 3-D distribution of sea-salt aerosol concentrations over the Mediterranean Sea (http://wind.tau.ac.il/saltina/ salt.html). In order to evaluate the model performance in the open sea, daily modeled concentrations were compared directly with SSA measurements taken at the tiny island of Lampedusa, in the Central Mediterranean. In order to further test the robustness of the model, the model performance over the open sea was indirectly verified by comparing modeled SSA concentrations with wave height measurements collected by the ODAS Italia 1 buoy and the Llobregat buoy. Model-vs.-measurement comparisons show that the model is capable of producing realistic SSA concentrations and their day-today variations over the open sea, in accordance with observed wave height and wind speed.

  4. Whitecaps, sea-salt aerosols, and climate

    NASA Astrophysics Data System (ADS)

    Anguelova, Magdalena Dimitrova

    Oceanic whitecaps are the major source of sea-salt aerosols. Because these aerosols are dominant in remote marine air, they control the radiative properties of the clean background atmosphere by scattering sunlight, changing cloud properties and lifetime, and providing media for chemical reactions. Including sea-salt effects in climate models improves predictions, but simulating their generation is first necessary. To make the sea-salt generation function currently used in climate models more relevant for aerosol investigations, this study proposes two modifications. First, the conventional relation between whitecap coverage, W, and the 10-meter wind speed, U10, used in typical generation functions is expanded to include additional factors that affect whitecaps and sea-salt aerosol formation. Second, the sea-salt generation function is extended to smaller sizes; sea-salt aerosol with initial radii from 0.4 to 20 mum can now be modeled. To achieve these goals, this thesis develops a new method for estimating whitecap coverage on a global scale using satellite measurements of the brightness temperature of the ocean surface. Whitecap coverage evaluated with this method incorporates the effects of atmospheric stability, sea-surface temperature, salinity, wind fetch, wind duration, and the amount of surface-active material. Assimilating satellite-derived values for whitecap coverage in the sea-salt generation function incorporates the effects of all environmental factors on sea-salt production and predicts realistic sea-salt aerosol loadings into the atmosphere. An extensive database of whitecap coverage and sea-salt aerosol fluxes has been compiled with the new method and is used to investigate their spatial and temporal characteristics. The composite effect of all environmental factors suggests a more uniform latitudinal distribution of whitecaps and sea-salt aerosols than that predicted from wind speed alone. The effect of sea-surface temperature, TS, is

  5. Maritime Aerosol Network as a Component of AERONET - a Useful Tool for Evaluation of the Global Sea-Salt Aerosol Distribution

    NASA Astrophysics Data System (ADS)

    Smirnov, A.; Holben, B. N.; Kinne, S.; Nelson, N. B.; Stenchikov, G. L.; Broccardo, S. P.; Sowers, D.; Lobecker, E.; Ondrusek, M.; Zielinski, T. P.; Gray, L. M.; Frouin, R.; Radionov, V. F.; Smyth, T. J.; Zibordi, G.; Heller, M. I.; Slabakova, V.; Krüger, K.; Reid, E. A.; Istomina, L.; Vandermeulen, R. A.; O'Neill, N. T.; Levy, G.; Giles, D. M.; Slutsker, I.; Sorokin, M. G.; Eck, T. F.

    2016-02-01

    Sea-salt aerosol plays an important role in radiation balance and chemistry of marine atmosphere. Sea-salt production depends on various factors. There is a significant uncertainty in the parametrization of the sea-salt production and budget. Ship-based aerosol optical depth (AOD) measurements can be used as an important validation tool for various global models and in-situ measurements. The paper presents the current status of the Maritime Aerosol Network (MAN) which is a component of Aerosol Robotic Network. Since 2006 over 300 cruises were completed and data archive of more than 5500 measurement days is accessible at http://aeronet.gsfc.nasa.gov/new_web/maritime_aerosol_network.html . AOD measurements from ships of opportunity complemented island-based AERONET measurements and provided important reference points for satellite retrieved and modelled AOD climatology over the oceans. The program exemplifies mutually beneficial international, multi-agency effort in atmospheric aerosol optical studies over the oceans.

  6. On the origin of salt in the Caspian Sea

    NASA Astrophysics Data System (ADS)

    Esin, Nikolay; Esin, Nikolay V.; Yanko-Hombach, Valentina

    2017-04-01

    A very serious problem associated with the evolution of the Caspian Sea, is the appearance of salt in it with a chemical composition that is different from the ocean salt (Svitoch, 2014). There are several hypotheses proposed to explain the specified properties. In each of them states that the salt entered the sea from the Arctic or Indian oceans or from the Mediterranean Sea, and then it was subsequently reworked by numerous evaporations. But they do not explain the mechanism of salt accumulation in the Caspian lowlands and its chemical composition changes. In recent years, our studies have shown that after Paratethys disconnecting from the Mediterranean Sea the transgressions of the Black and Caspian seas occurred as a result of periodic melting of the continental ice. The flow of water through the mountain range from the Black Sea to the Mediterranean Sea led to the formation of the Bosphorus Strait. The erosive lowering of the river bed flowing out of the Black Sea is gradually lowered limit of the possible filling of the seas Paratethys descendants. A mathematical reconstruction of the Sarmatian Sea in current relief showed that the theoretical contours of the sea very well coincide with the contours obtained according to the natural geological research. This shows that over the past 14 million years the significant changes in the landscape of the Black Sea-Caspian lowlands in the whole did not happen. The results allow creating a new understanding of the dynamics of the coasts and seas levels, and the origin of salt in the Caspian Sea. In our opinion the oceanic salt in the Caspian Sea remained since Paratethys connection with the Mediterranean Sea. As a result of tectonic processes of the Alps formation there was a gradual separation of the Paratethys from the Mediterranean Sea. As a result of negative freshwater balance the water in the Caspian depression evaporated with continuous (some time) inflow of salt water from the ocean. Thus, water evaporated and

  7. Investigations of novel unsaturated bile salts of male sea lamprey as potential chemical cues

    USGS Publications Warehouse

    Johnson, Nicholas S.; Yun, Sang-Seon; Li, Weiming

    2014-01-01

    Sulfated bile salts function as chemical cues that coordinate reproduction in sea lamprey, Petromyzon marinus. 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) is the most abundant known bile salt released by sexually mature male sea lampreys and attracts ovulated females. However, previous studies showed that the male-produced pheromone consists of unidentified components in addition to 3kPZS. Here, analysis of water conditioned with mature male sea lampreys indicated the presence of 4 oxidized, unsaturated compounds with molecular weights of 466 Da, 468 Da, and 2 of 470 Da. These compounds were not detectable in water conditioned with immature male sea lampreys. By using mass spectrometry, 4 A-ring unsaturated sulfated bile salts were tentatively identified from male washings as 2 4-ene, a 1-ene, and a 1,4-diene analogs. These were synthesized to determine if they attracted ovulated female sea lampreys to spawning nests in natural streams. One of the novel synthetic bile salts, 3 keto-1-ene PZS, attracted ovulated females to the point of application at a concentration of 10-12 M. This study reveals the structural diversity of bile salts in sea lamprey, some of which have been demonstrated to be pheromonal cues.

  8. An Investigation of the Radiative Effects and Climate Feedbacks of Sea Ice Sources of Sea Salt Aerosol

    NASA Astrophysics Data System (ADS)

    Horowitz, H. M.; Alexander, B.; Bitz, C. M.; Jaegle, L.; Burrows, S. M.

    2017-12-01

    In polar regions, sea ice is a major source of sea salt aerosol through lofting of saline frost flowers or blowing saline snow from the sea ice surface. Under continued climate warming, an ice-free Arctic in summer with only first-year, more saline sea ice in winter is likely. Previous work has focused on climate impacts in summer from increasing open ocean sea salt aerosol emissions following complete sea ice loss in the Arctic, with conflicting results suggesting no net radiative effect or a negative climate feedback resulting from a strong first aerosol indirect effect. However, the radiative forcing from changes to the sea ice sources of sea salt aerosol in a future, warmer climate has not previously been explored. Understanding how sea ice loss affects the Arctic climate system requires investigating both open-ocean and sea ice sources of sea-salt aerosol and their potential interactions. Here, we implement a blowing snow source of sea salt aerosol into the Community Earth System Model (CESM) dynamically coupled to the latest version of the Los Alamos sea ice model (CICE5). Snow salinity is a key parameter affecting blowing snow sea salt emissions and previous work has assumed constant regional snow salinity over sea ice. We develop a parameterization for dynamic snow salinity in the sea ice model and examine how its spatial and temporal variability impacts the production of sea salt from blowing snow. We evaluate and constrain the snow salinity parameterization using available observations. Present-day coupled CESM-CICE5 simulations of sea salt aerosol concentrations including sea ice sources are evaluated against in situ and satellite (CALIOP) observations in polar regions. We then quantify the present-day radiative forcing from the addition of blowing snow sea salt aerosol with respect to aerosol-radiation and aerosol-cloud interactions. The relative contributions of sea ice vs. open ocean sources of sea salt aerosol to radiative forcing in polar regions is

  9. Feasibility of laser-induced breakdown spectroscopy (LIBS) for classification of sea salts.

    PubMed

    Tan, Man Minh; Cui, Sheng; Yoo, Jonghyun; Han, Song-Hee; Ham, Kyung-Sik; Nam, Sang-Ho; Lee, Yonghoon

    2012-03-01

    We have investigated the feasibility of laser-induced breakdown spectroscopy (LIBS) as a fast, reliable classification tool for sea salts. For 11 kinds of sea salts, potassium (K), magnesium (Mg), calcium (Ca), and aluminum (Al), concentrations were measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the LIBS spectra were recorded in the narrow wavelength region between 760 and 800 nm where K (I), Mg (I), Ca (II), Al (I), and cyanide (CN) band emissions are observed. The ICP-AES measurements revealed that the K, Mg, Ca, and Al concentrations varied significantly with the provenance of each salt. The relative intensities of the K (I), Mg (I), Ca (II), and Al (I) peaks observed in the LIBS spectra are consistent with the results using ICP-AES. The principal component analysis of the LIBS spectra provided the score plot with quite a high degree of clustering. This indicates that classification of sea salts by chemometric analysis of LIBS spectra is very promising. Classification models were developed by partial least squares discriminant analysis (PLS-DA) and evaluated. In addition, the Al (I) peaks enabled us to discriminate between different production methods of the salts. © 2012 Society for Applied Spectroscopy

  10. Sea salts as a potential source of food spoilage fungi.

    PubMed

    Biango-Daniels, Megan N; Hodge, Kathie T

    2018-02-01

    Production of sea salt begins with evaporation of sea water in shallow pools called salterns, and ends with the harvest and packing of salts. This process provides many opportunities for fungal contamination. This study aimed to determine whether finished salts contain viable fungi that have the potential to cause spoilage when sea salt is used as a food ingredient by isolating fungi on a medium that simulated salted food with a lowered water activity (0.95 a w ). The viable filamentous fungi from seven commercial salts were quantified and identified by DNA sequencing, and the fungal communities in different salts were compared. Every sea salt tested contained viable fungi, in concentrations ranging from 0.07 to 1.71 colony-forming units per gram of salt. In total, 85 fungi were isolated representing seven genera. One or more species of the most abundant genera, Aspergillus, Cladosporium, and Penicillium was found in every salt. Many species found in this study have been previously isolated from low water activity environments, including salterns and foods. We conclude that sea salts contain many fungi that have potential to cause food spoilage as well as some that may be mycotoxigenic. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Changes in Sea Salt Emissions Enhance ENSO Variability

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

    Yang, Yang; Russell, Lynn M.; Lou, Sijia

    Two 150-year pre-industrial simulations with and without interactive sea salt emissions from the Community Earth System Model (CESM) are performed to quantify the interactions between sea salt emissions and El Niño–Southern Oscillation (ENSO). Variations in sea salt emissions over the tropical Pacific Ocean are affected by changing wind speed associated with ENSO variability. ENSO-induced interannual variations in sea salt emissions result in decreasing (increasing) aerosol optical depth (AOD) by 0.03 over the equatorial central-eastern (western) Pacific Ocean during El Niño events compared to those during La Niña events. These changes in AOD further increase (decrease) radiative fluxes into the atmospheremore » by +0.2 W m -2 (-0.4 W m -2) over the tropical eastern (western) Pacific. Thereby, sea surface temperature increases (decreases) by 0.2–0.4 K over the tropical eastern (western) Pacific Ocean during El Niño compared to La Niña events and enhances ENSO variability by 10%. The increase in ENSO amplitude is a result of systematic heating (cooling) during the warm (cold) phase, of ENSO in the eastern Pacific. Interannual variations in sea salt emissions then produce the anomalous ascent (subsidence) over the equatorial eastern (western) Pacific between El Niño and La Niña events, which is a result of heating anomalies. Due to variations in sea salt emissions, the convective precipitation is enhanced by 0.6–1.2 mm day -1 over the tropical central-eastern Pacific Ocean and weakened by 0.9–1.5 mm day -1 over the Maritime Continent during El Niño compared to La Niña events, enhancing the precipitation variability over the tropical Pacific.« less

  12. Salt marsh persistence is threatened by predicted sea-level rise

    NASA Astrophysics Data System (ADS)

    Crosby, Sarah C.; Sax, Dov F.; Palmer, Megan E.; Booth, Harriet S.; Deegan, Linda A.; Bertness, Mark D.; Leslie, Heather M.

    2016-11-01

    Salt marshes buffer coastlines and provide critical ecosystem services from storm protection to food provision. Worldwide, these ecosystems are in danger of disappearing if they cannot increase elevation at rates that match sea-level rise. However, the magnitude of loss to be expected is not known. A synthesis of existing records of salt marsh elevation change was conducted in order to consider the likelihood of their future persistence. This analysis indicates that many salt marshes did not keep pace with sea-level rise in the past century and kept pace even less well over the past two decades. Salt marshes experiencing higher local sea-level rise rates were less likely to be keeping pace. These results suggest that sea-level rise will overwhelm most salt marshes' capacity to maintain elevation. Under the most optimistic IPCC emissions pathway, 60% of the salt marshes studied will be gaining elevation at a rate insufficient to keep pace with sea-level rise by 2100. Without mitigation of greenhouse gas emissions this potential loss could exceed 90%, which will have substantial ecological, economic, and human health consequences.

  13. Fourier transform near-infrared spectroscopy application for sea salt quality evaluation.

    PubMed

    Galvis-Sánchez, Andrea C; Lopes, João Almeida; Delgadillo, Ivonne; Rangel, António O S S

    2011-10-26

    Near-infrared (NIR) spectroscopy in diffuse reflectance mode was explored with the objective of discriminating sea salts according to their quality type (traditional salt vs "flower of salt") and geographical origin (Atlantic vs Mediterranean). Sea salts were also analyzed in terms of Ca(2+), Mg(2+), K(+), alkalinity, and sulfate concentrations to support spectroscopic results. High concentrations of Mg(2+) and K(+) characterized Atlantic samples, while a high Ca(2+) content was observed in traditional sea salts. A partial least-squares discriminant analysis model considering the 8500-7500 cm(-1) region permitted the discrimination of salts by quality types. The regions 4650-4350 and 5900-5500 cm(-1) allowed salts classification according to their geographical origin. It was possible to classify correctly 85.3 and 94.8% of the analyzed samples according to the salt type and to the geographical origin, respectively. These results demonstrated that NIR spectroscopy is a suitable and very efficient tool for sea salt quality evaluation.

  14. Process evaluation of sea salt aerosol concentrations at remote marine locations

    NASA Astrophysics Data System (ADS)

    Struthers, H.; Ekman, A. M.; Nilsson, E. D.

    2011-12-01

    Sea salt, an important natural aerosol, is generated by bubbles bursting at the surface of the ocean. Sea salt aerosol contributes significantly to the global aerosol burden and radiative budget and are a significant source of cloud condensation nuclei in remote marine areas (Monahan et al., 1986). Consequently, changes in marine aerosol abundance is expected to impact on climate forcing. Estimates of the atmospheric burden of sea salt aerosol mass derived from chemical transport and global climate models vary greatly both in the global total and the spatial distribution (Texor et al. 2006). This large uncertainty in the sea salt aerosol distribution in turn contributes to the large uncertainty in the current estimates of anthropogenic aerosol climate forcing (IPCC, 2007). To correctly attribute anthropogenic climate change and to veraciously project future climate, natural aerosols including sea salt must be understood and accurately modelled. In addition, the physical processes that determine the sea salt aerosol concentration are susceptible to modification due to climate change (Carslaw et al., 2010) which means there is the potential for feedbacks within the climate/aerosol system. Given the large uncertainties in sea salt aerosol modelling, there is an urgent need to evaluate the process description of sea salt aerosols in global models. An extremely valuable source of data for model evaluation is the long term measurements of PM10 sea salt aerosol mass available from a number of remote marine observation sites around the globe (including the GAW network). Sea salt aerosol concentrations at remote marine locations depend strongly on the surface exchange (emission and deposition) as well as entrainment or detrainment to the free troposphere. This suggests that the key parameters to consider in any analysis include the sea surface water temperature, wind speed, precipitation rate and the atmospheric stability. In this study, the sea salt aerosol observations

  15. Simulating Emission and Chemical Evolution of Coarse Sea-Salt Particles in the Community Multiscale Air Quality (CMAQ) Model

    EPA Science Inventory

    Chemical processing of sea-salt particles in coastal environments significantly impacts concentrations of particle components and gas-phase species and has implications for human exposure to particulate matter and nitrogen deposition to sensitive ecosystems. Emission of sea-sal...

  16. Optical Modeling of Sea Salt Aerosols: The Effects of Nonsphericity and Inhomogeneity

    NASA Astrophysics Data System (ADS)

    Bi, Lei; Lin, Wushao; Wang, Zheng; Tang, Xiaoyun; Zhang, Xiaoyu; Yi, Bingqi

    2018-01-01

    The nonsphericity and inhomogeneity of marine aerosols (sea salts) have not been addressed in pertinent radiative transfer calculations and remote sensing studies. This study investigates the optical properties of nonspherical and inhomogeneous sea salts using invariant imbedding T-matrix simulations. Dry sea salt aerosols are modeled based on superellipsoidal geometries with a prescribed aspect ratio and roundness parameter. Wet sea salt particles are modeled as coated superellipsoids, as spherical particles with a superellipsoidal core, and as homogeneous spheres depending on the level of relative humidity. Aspect ratio and roundness parameters are found to be critical to interpreting the linear depolarization ratios (LDRs) of NaCl crystals from laboratory measurements. The optimal morphology parameters of NaCl necessary to reproduce the measurements are found to be consistent with data gleaned from an electron micrograph. The LDRs of wet sea salts are computed based on inhomogeneous models and compared with the measured data from ground-based LiDAR. The dependence of the LDR on relative humidity is explicitly considered. The increase in the LDR with relative humidity at the initial phase of deliquescence is attributed to both the size increase and the inhomogeneity effect. For large humidity values, the LDR substantially decreases because the overall particle shape becomes more spherical and the inhomogeneity effect in a particle on the LDR is suppressed for submicron sea salts. However, the effect of inhomogeneity on optical properties is pronounced for coarse-mode sea salts. These findings have important implications for atmospheric radiative transfer and remote sensing involving sea salt aerosols.

  17. Interannual to decadal climate variability of sea salt aerosols in the coupled climate model CESM1.0: Climate variability of sea salt aerosols

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

    Xu, Li; Pierce, David W.; Russell, Lynn M.

    This study examines multi-year climate variability associated with sea salt aerosols and their contribution to the variability of shortwave cloud forcing (SWCF) using a 150-year simulation for pre-industrial conditions of the Community Earth System Model version 1.0 (CESM1). The results suggest that changes in sea salt and related cloud and radiative properties on interannual timescales are dominated by the ENSO cycle. Sea salt variability on longer (interdecadal) timescales is associated with low-frequency Pacific ocean variability similar to the interdecadal Pacific Oscillation (IPO), but does not show a statistically significant spectral peak. A multivariate regression suggests that sea salt aerosol variabilitymore » may contribute to SWCF variability in the tropical Pacific, explaining up to 25-35% of the variance in that region. Elsewhere, there is only a small aerosol influence on SWCF through modifying cloud droplet number and liquid water path that contributes to the change of cloud effective radius and cloud optical depth (and hence cloud albedo), producing a multi-year aerosol-cloud-wind interaction.« less

  18. Revising the hygroscopicity of inorganic sea salt particles

    PubMed Central

    Zieger, P.; Väisänen, O.; Corbin, J. C.; Partridge, D. G.; Bastelberger, S.; Mousavi-Fard, M.; Rosati, B.; Gysel, M.; Krieger, U. K.; Leck, C.; Nenes, A.; Riipinen, I.; Virtanen, A.; Salter, M. E.

    2017-01-01

    Sea spray is one of the largest natural aerosol sources and plays an important role in the Earth’s radiative budget. These particles are inherently hygroscopic, that is, they take-up moisture from the air, which affects the extent to which they interact with solar radiation. We demonstrate that the hygroscopic growth of inorganic sea salt is 8–15% lower than pure sodium chloride, most likely due to the presence of hydrates. We observe an increase in hygroscopic growth with decreasing particle size (for particle diameters <150 nm) that is independent of the particle generation method. We vary the hygroscopic growth of the inorganic sea salt within a general circulation model and show that a reduced hygroscopicity leads to a reduction in aerosol-radiation interactions, manifested by a latitudinal-dependent reduction of the aerosol optical depth by up to 15%, while cloud-related parameters are unaffected. We propose that a value of κs=1.1 (at RH=90%) is used to represent the hygroscopicity of inorganic sea salt particles in numerical models. PMID:28671188

  19. Seasonal variation of fractionated sea-salt particles on the Antarctic coast

    NASA Astrophysics Data System (ADS)

    Hara, K.; Osada, K.; Yabuki, M.; Yamanouchi, T.

    2012-09-01

    Aerosol sampling was conducted at Syowa Station, Antarctica (coastal station) in 2004-2006. SO42-depletion by mirabilite precipitation was identified from April through November. The fractionated sea-salt particles were distributed in ultrafine- coarse modes. Molar ratios of Mg2+/Na+ and K+/Na+ were higher than in bulk seawater ratio during winter-spring. The Mg2+/Na+ ratio in aerosols greatly exceeded the upper limit in the case only with mirabilite precipitation. The temperature dependence of Mg2+/Na+ ratio strongly suggested that higher ratios of Mg2+/Na+ and K+/Na+ were associated with sea-salt fractionation by precipitation of mirabilite at -9°C, hydrohalite at ca. -23°C and other salts such as ikaite at ca. -5°C and gypsum at ca. -22°C during winter-spring. Mg-salts with lower deliquescence relative humidity can be enriched gradually in the fractionated sea-salt particles. Results suggests that sea-salt fractionation can alter aerosol hygroscopicity and atmospheric chemistry in polar regions.

  20. Potential sea salt aerosol sources from frost flowers in the pan-Arctic region

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

    Xu, Li; Russell, Lynn M.; Burrows, Susannah M.

    In order to better represent observed wintertime aerosol concentrations at Barrow, Alaska, we implemented an observationally-based parameterization for estimating sea salt production from frost flowers in the Community Earth System Model (CESM). In this work, we evaluate the potential influence of this sea salt source on the pan-Arctic (60ºN-90ºN) climate. Results show that frost flower salt emissions substantially increase the modeled surface sea salt aerosol concentration in the winter months when new sea ice and frost flowers are present. The parameterization reproduces both the magnitude and seasonal variation of the observed submicron sea salt aerosol concentration at surface in Barrowmore » during winter much better than the standard CESM simulation without a frost-flower salt particle source. Adding these frost flower salt particle emissions increases aerosol optical depth by 10% and results in a small cooling at surface. The increase in salt particle mass concentrations of a factor of 8 provides nearly two times the cloud condensation nuclei concentration, as well as 10% increases in cloud droplet number and 40% increases in liquid water content near coastal regions adjacent to continents. These cloud changes reduce longwave cloud forcing by 3% and cause a small surface warming, increasing the downward longwave flux at the surface by 2 W m-2 in the pan-Arctic under the present-day climate.« less

  1. The distribution and utility of sea-level indicators in Eurasian sub-Arctic salt marshes (White Sea, Russia).

    NASA Astrophysics Data System (ADS)

    Nikitina, Daria; Kemp, Andrew; Horton, Benjamin; Van, Christopher; Potapova, Marina; Culver, Stephen; Repkina, Tatyana; Hill, David

    2017-04-01

    We investigated the utility of foraminifera, diatoms and bulk-sediment geochemistry (δ13C and parameters measured by RockEval pyrolysis) as sea-level indicators in Eurasian sub-Arctic salt marshes. At three salt marshes in Dvina Bay (White Sea, Russia), we collected surface sediment samples along transects sequentially crossing sub-tidal, tidal-flat, salt-marsh and Taiga forest environments. Foraminifera formed bipartite assemblages, where elevations below mean high higher water (MHHW) were dominated by Miliammina spp. and elevations between MHHW and the highest occurrence of foraminifera were dominated by Jadammina macrescens and Balticammina pseudomacrescens. Both assemblages existed on all three transects and we conclude that foraminifera are sea-level indicators in Eurasian sub-Arctic salt marshes. Five, high-diversity groups of diatoms were identified and they displayed geographic variability among the study sites (<15 km apart). RockEval pyrolysis and δ13C measurements recognized two groups (clastic-dominated environments below MHHW and organic-rich environments above MHHW). Since one group included sub-tidal elevations and the other supra-tidal elevations, we conclude that the measured geochemical parameters do not meet the criteria for being stand-alone sea-level indicators. Core JT2012 captured a regressive sediment sequence of clastic, tidal-flat sediment overlain by salt-marsh organic silt and freshwater peat. The salt-marsh sediment accumulated at 2804 ± 52 years BP years before present and preserved foraminifera (J. macrescens and B. pseudomacrescens) with a high degree of analogy to modern assemblages indicating that relative sea level was 2.60 ± 0.47 m above present at this time. Diatoms confirm that marine influence decreased through time, but the lack of analogy between modern and core assemblages limits their utility as sea-level indicators in this setting.

  2. Stratigraphic response of salt marshes to slow rates of sea-level change

    NASA Astrophysics Data System (ADS)

    Daly, J.; Bell, T.

    2006-12-01

    Conventional models of salt-marsh development show an idealized spatial relationship between salt-marsh floral and foraminiferal zones, where the landward margin of the marsh gradually migrates inland in response to sea-level rise. This model predicts that transgression will result in persistent and possibly expanded salt marshes at the surface, depending on a variety of factors including sediment supply, hydrologic conditions, tidal range, and rate of sea-level rise. However, in areas with abundant sediment supply and slow rates of sea- level rise, the extent of back-barrier salt marshes may decline over time as the barrier-spits mature. Sea level around the northeast coast of Newfoundland is rising at a very slow rate during the late Holocene (<0.5 mm/yr). Sandy barrier-spits and tombolos are common coastal features, but salt marshes are rare. The generalized stratigraphy of dutch cores collected in back-barrier settings in this region is a surface layer of sphagnum peat with abundant woody roots, underlain by sedge-dominated peat that transitions gradually to a thin layer of Juncus sp. peat with agglutinated foraminifera, dominantly Jadammina macrescens and Balticammina pseudomacrescens. These basal peats are interpreted as salt-marsh peats, characterized by the presence of foraminifera that are absent in overlying peat units. This sequence indicates that salt marshes developed in back-barrier environments during the initial stages of barrier progradation, then gradually transitioned to environments increasingly dominated by freshwater flora. These transitions are interpreted to reflect the progradation of the spit, decreased tidal exchange in the back-barrier, and increased influence of freshwater streams discharging into the back-barrier setting. Decreased marine influence on the back-barrier environment leads to a floral and faunal shift associated with a regressive stratigraphy in an area experiencing sea-level rise. For studies of Holocene sea-level change

  3. Year-round records of bulk and size-segregated aerosol composition in central Antarctica (Concordia site) - Part 1: Fractionation of sea-salt particles

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Preunkert, Susanne; Wolff, Eric; Weller, Rolf; Jourdain, Bruno; Wagenbach, Dietmar

    2017-11-01

    Multiple year-round records of bulk and size-segregated composition of aerosol were obtained at the inland site of Concordia located at Dome C in East Antarctica. In parallel, sampling of acidic gases on denuder tubes was carried out to quantify the concentrations of HCl and HNO3 present in the gas phase. These time series are used to examine aerosol present over central Antarctica in terms of chloride depletion relative to sodium with respect to freshly emitted sea-salt aerosol as well as depletion of sulfate relative to sodium with respect to the composition of seawater. A depletion of chloride relative to sodium is observed over most of the year, reaching a maximum of ˜ 20 ng m-3 in spring when there are still large sea-salt amounts and acidic components start to recover. The role of acidic sulfur aerosol and nitric acid in replacing chloride from sea-salt particles is here discussed. HCl is found to be around twice more abundant than the amount of chloride lost by sea-salt aerosol, suggesting that either HCl is more efficiently transported to Concordia than sea-salt aerosol or re-emission from the snow pack over the Antarctic plateau represents an additional significant HCl source. The size-segregated composition of aerosol collected in winter (from 2006 to 2011) indicates a mean sulfate to sodium ratio of sea-salt aerosol present over central Antarctica of 0.16 ± 0.05, suggesting that, on average, the sea-ice and open-ocean emissions equally contribute to sea-salt aerosol load of the inland Antarctic atmosphere. The temporal variability of the sulfate depletion relative to sodium was examined at the light of air mass backward trajectories, showing an overall decreasing trend of the ratio (i.e., a stronger sulfate depletion relative to sodium) when air masses arriving at Dome C had traveled a longer time over sea ice than over open ocean. The findings are shown to be useful to discuss sea-salt ice records extracted at deep drilling sites located inland

  4. Variability of sea salts in ice and firn cores from Fimbul Ice Shelf, Dronning Maud Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Paulina Vega, Carmen; Isaksson, Elisabeth; Schlosser, Elisabeth; Divine, Dmitry; Martma, Tõnu; Mulvaney, Robert; Eichler, Anja; Schwikowski-Gigar, Margit

    2018-05-01

    Major ions were analysed in firn and ice cores located at Fimbul Ice Shelf (FIS), Dronning Maud Land - DML, Antarctica. FIS is the largest ice shelf in the Haakon VII Sea, with an extent of approximately 36 500 km2. Three shallow firn cores (about 20 m deep) were retrieved in different ice rises, Kupol Ciolkovskogo (KC), Kupol Moskovskij (KM), and Blåskimen Island (BI), while a 100 m long core (S100) was drilled near the FIS edge. These sites are distributed over the entire FIS area so that they provide a variety of elevation (50-400 m a.s.l.) and distance (3-42 km) to the sea. Sea-salt species (mainly Na+ and Cl-) generally dominate the precipitation chemistry in the study region. We associate a significant sixfold increase in median sea-salt concentrations, observed in the S100 core after the 1950s, to an enhanced exposure of the S100 site to primary sea-salt aerosol due to a shorter distance from the S100 site to the ice front, and to enhanced sea-salt aerosol production from blowing salty snow over sea ice, most likely related to the calving of Trolltunga occurred during the 1960s. This increase in sea-salt concentrations is synchronous with a shift in non-sea-salt sulfate (nssSO42-) toward negative values, suggesting a possible contribution of fractionated aerosol to the sea-salt load in the S100 core most likely originating from salty snow found on sea ice. In contrast, there is no evidence of a significant contribution of fractionated sea salt to the ice-rises sites, where the signal would be most likely masked by the large inputs of biogenic sulfate estimated for these sites. In summary, these results suggest that the S100 core contains a sea-salt record dominated by the proximity of the site to the ocean, and processes of sea ice formation in the neighbouring waters. In contrast, the ice-rises firn cores register a larger-scale signal of atmospheric flow conditions and a less efficient transport of sea-salt aerosols to these sites. These findings are a

  5. Can salt marshes survive sea level rise ?

    NASA Astrophysics Data System (ADS)

    Tambroni, N.; Seminara, G.

    2008-12-01

    Stability of salt marshes is a very delicate issue depending on the subtle interplay among hydrodynamics, morphodynamics and ecology. In fact, the elevation of the marsh platform depends essentially on three effects: i) the production of soil associated with sediments resuspended by tidal currents and wind waves in the adjacent tidal flats, advected to the marsh and settling therein; ii) production of organic sediments by the salt marsh vegetation; iii) soil 'loss' driven by sea level rise and subsidence. In order to gain insight into the mechanics of the process, we consider a schematic configuration consisting of a salt marsh located at the landward end of a tidal channel connected at the upstream end with a tidal sea, under different scenarios of sea level rise. We extend the simple 1D model for the morphodynamic evolution of a tidal channel formulated by Lanzoni and Seminara (2002, Journal of Geophysical Research-Oceans, 107, C1) allowing for sediment resuspension in the channel and vegetation growth in the marsh using the depth dependent model of biomass productivity of Spartina proposed by Morris et al. (2002, Ecology, 83, pp. 2869 - 2877). We first focus on the case of a tide dominated salt marsh neglecting wind driven sediment resuspension in the shoal. Results show that the production of biomass plays a crucial role on salt marsh stability and, provided productivity is high enough, it may turn out to be sufficient to counteract the effects of sea level rise even in the absence of significant supply of mineral sediments. The additional effect of wind resuspension is then introduced. Note that the wind action is twofold: on one hand, it generates wind waves the amplitude of which is strongly dependent on shoal depth and wind fetch; on the other hand, it generates currents driven by the surface setup induced by the shear stress acting on the free surface. Here, each contribution is analysed separately. Results show that the values of bottom stress induced by

  6. Continuous Flow Hygroscopicity-Resolved Relaxed Eddy Accumulation (Hy-Res REA) Method of Measuring Size-Resolved Sea-Salt Particle Fluxes

    NASA Astrophysics Data System (ADS)

    Meskhidze, N.; Royalty, T. M.; Phillips, B.; Dawson, K. W.; Petters, M. D.; Reed, R.; Weinstein, J.; Hook, D.; Wiener, R.

    2017-12-01

    The accurate representation of aerosols in climate models requires direct ambient measurement of the size- and composition-dependent particle production fluxes. Here we present the design, testing, and analysis of data collected through the first instrument capable of measuring hygroscopicity-based, size-resolved particle fluxes using a continuous-flow Hygroscopicity-Resolved Relaxed Eddy Accumulation (Hy-Res REA) technique. The different components of the instrument were extensively tested inside the US Environmental Protection Agency's Aerosol Test Facility for sea-salt and ammoniums sulfate particle fluxes. The new REA system design does not require particle accumulation, therefore avoids the diffusional wall losses associated with long residence times of particles inside the air collectors of the traditional REA devices. The Hy-Res REA system used in this study includes a 3-D sonic anemometer, two fast-response solenoid valves, two Condensation Particle Counters (CPCs), a Scanning Mobility Particle Sizer (SMPS), and a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). A linear relationship was found between the sea-salt particle fluxes measured by eddy covariance and REA techniques, with comparable theoretical (0.34) and measured (0.39) proportionality constants. The sea-salt particle detection limit of the Hy-Res REA flux system is estimated to be 6x105 m-2s-1. For the conditions of ammonium sulfate and sea-salt particles of comparable source strength and location, the continuous-flow Hy-Res REA instrument was able to achieve better than 90% accuracy of measuring the sea-salt particle fluxes. In principle, the instrument can be applied to measure fluxes of particles of variable size and distinct hygroscopic properties (i.e., mineral dust, black carbon, etc.).

  7. Enrichment of Mineral Dust Storm Particles with Sea Salt Elements - Using bulk and Single Particle Analyses

    NASA Astrophysics Data System (ADS)

    Mamane, Y.; Perrino, C.; Yossef, O.

    2009-12-01

    Mineral aerosol emitted from African and Asian deserts plays an important role in the atmosphere. During their long-range transport, the physical and chemical properties of mineral dust particles change due to heterogeneous reactions with trace gases, coagulation with other particles, and in-cloud processing. These processes affect the optical and hygroscopic properties of dust particles, and in general influencing the physics and chemistry of the atmosphere. Four African and Arabian dust storm episodes affecting the East Mediterranean Coast in the spring of 2006 have been characterized, to determine if atmospheric natural dust particles are enriched with sea salt and anthropogenic pollution. Particle samplers included PM10 and manual dichotomous sampler that collected fine and coarse particles. Three sets of filters were used: Teflon filters for gravimetric, elemental and ionic analyses; Pre-fired Quartz-fiber filters for elemental and organic carbon; and Nuclepore filters for scanning electron microscopy analysis. Computer-controlled scanning electron microscopy (Philips XL 30 ESEM) was used to analyze single particle, for morphology, size and chemistry of selected filter samples. A detailed chemical and microscopical characterization has been performed for the particles collected during dust event days and during clear days. The Saharan and Arabian air masses increased significantly the daily mass concentrations of the coarse and the fine particle fractions. Carbonates, mostly as soil calcites mixed with dolomites, and silicates are the major components of the coarse fraction, followed by sea salt particles. In addition, the levels of anthropogenic heavy metals and sea salt elements registered during the dust episode were considerably higher than levels recorded during clear days. Sea salt elements contain Na and Cl, and smaller amounts of Mg, K, S and Br. Cl ranges from 300 to 5500 ng/m3 and Na from 100 to almost 2400 ng/m3. The Cl to Na ratio on dusty days in

  8. The Dead Sea Mud and Salt: A Review of Its Characterization, Contaminants, and Beneficial Effects

    NASA Astrophysics Data System (ADS)

    Bawab, Abeer Al; Bozeya, Ayat; Abu-Mallouh, Saida; Abu Irmaileh, Basha'er; Daqour, Ismail; Abu-Zurayk, Rund A.

    2018-02-01

    The Dead Sea has been known for its therapeutic and cosmetic properties. The unique climatic conditions in the Dead Sea area make it a renowned site worldwide for the field of climatotherapy, which is a natural approach for the provision of medications for many human diseases including unusual exclusive salt composition of the water, a special natural mud, thermal mineral springs, solar irradiation, oxygen-rich and bromine-rich haze. This review focuses on the physical, chemical, and biological characteristics of the Dead Sea mud and salts, in addition to their contaminants, allowing this review to serve as a guide to interested researchers to their risks and the importance of treatment. Beneficial effects of Dead Sea mud and salts are discussed in terms of therapy and cosmetics. Additional benefits of both Dead Sea mud and salts are also discussed, such as antimicrobial action of the mud in relation to its therapeutic properties, and the potency of mud and salts to be a good medium for the growth of a halophilic unicellular algae, used for the commercial production of β-carotene Dunaliella.

  9. Modelling and Caracterisation of sea salt aerosols during ChArMEx-ADRIMED campaign in Ersa

    NASA Astrophysics Data System (ADS)

    Claeys, Marine; Roberts, Greg; Mallet, Marc; Sciare, Jean; Arndt, Jovanna; Mihalopoulos, Nikos

    2015-04-01

    During ChArMEx-ADRIMED campaign (June and July 2013), aerosol particles measurements were conducted in Ersa (600 m asl), Cap Corsica. The in-situ instrumentation allowed to characterize sea salt aerosols (SSA) by their physico-chemical and optical properties and their size distribution. This study concentrates particularly on a period of a few days where the concentration of sea salt aerosols was higher. The chemistry results indicate that the SSA measured during this period were mostly aged. The comparison of the number size distributions of air masses allow to determine the SSA size mode. These data are used to evaluate the sea salt aerosol emission scheme implemented in the regional scale Meso-Nh model. A new emission scheme based on available source fonctions is tested for different sea state conditions to evaluate the direct radiative impact of sea salt aerosols over the Mediterranean basin.

  10. Individual aerosol particles in and below clouds along a Mt. Fuji slope: Modification of sea-salt-containing particles by in-cloud processing

    NASA Astrophysics Data System (ADS)

    Ueda, S.; Hirose, Y.; Miura, K.; Okochi, H.

    2014-02-01

    Sizes and compositions of atmospheric aerosol particles can be altered by in-cloud processing by absorption/adsorption of gaseous and particulate materials and drying of aerosol particles that were formerly activated as cloud condensation nuclei. To elucidate differences of aerosol particles before and after in-cloud processing, aerosols were observed along a slope of Mt. Fuji, Japan (3776 m a.s.l.) during the summer in 2011 and 2012 using a portable laser particle counter (LPC) and an aerosol sampler. Aerosol samples for analyses of elemental compositions were obtained using a cascade impactor at top-of-cloud, in-cloud, and below-cloud altitudes. To investigate composition changes via in-cloud processing, individual particles (0.5-2 μm diameter) of samples from five cases (days) collected at different altitudes under similar backward air mass trajectory conditions were analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer. For most cases (four cases), most particles at all altitudes mainly comprised sea salts: mainly Na with some S and/or Cl. Of those, in two cases, sea-salt-containing particles with Cl were found in below-cloud samples, although sea-salt-containing particles in top-of-cloud samples did not contain Cl. This result suggests that Cl in the sea salt was displaced by other cloud components. In the other two cases, sea-salt-containing particles on samples at all altitudes were without Cl. However, molar ratios of S to Na (S/Na) of the sea-salt-containing particles of top-of-cloud samples were higher than those of below-cloud samples, suggesting that sulfuric acid or sulfate was added to sea-salt-containing particles after complete displacement of Cl by absorption of SO2 or coagulation with sulfate. The additional volume of sulfuric acid in clouds for the two cases was estimated using the observed S/Na values of sea-salt-containing particles. The estimation revealed that size changes by in

  11. Size Distribution of Sea-Salt Emissions as a Function of Relative Humidity

    NASA Astrophysics Data System (ADS)

    Zhang, K. M.; Knipping, E. M.; Wexler, A. S.; Bhave, P. V.; Tonnesen, G. S.

    2004-12-01

    Here we introduced a simple method for correcting sea-salt particle-size distributions as a function of relative humidity. Distinct from previous approaches, our derivation uses particle size at formation as the reference state rather than dry particle size. The correction factors, corresponding to the size at formation and the size at 80% RH, are given as polynomial functions of local relative humidity which are straightforward to implement. Without major compromises, the correction factors are thermodynamically accurate and can be applied between 0.45 and 0.99 RH. Since the thermodynamic properties of sea-salt electrolytes are weakly dependent on ambient temperature, these factors can be regarded as temperature independent. The correction factor w.r.t. to the size at 80% RH is in excellent agreement with those from Fitzgerald's and Gerber's growth equations; while the correction factor w.r.t. the size at formation has the advantage of being independent of dry size and relative humidity at formation. The resultant sea-salt emissions can be used directly in atmospheric model simulations at urban, regional and global scales without further correction. Application of this method to several common open-ocean and surf-zone sea-salt-particle source functions is described.

  12. Synchrotron X-ray fluorescence spectroscopy of salts in natural sea ice

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

    Obbard, Rachel W.; Lieb-Lappen, Ross M.; Nordick, Katherine V.

    We describe the use of synchrotron-based X-ray fluorescence spectroscopy to examine the microstructural location of specific elements, primarily salts, in sea ice. This work was part of an investigation of the location of bromine in the sea ice-snowpack-blowing snow system, where it plays a part in the heterogeneous chemistry that contributes to tropospheric ozone depletion episodes. We analyzed samples at beamline 13-ID-E of the Advanced Photon Source at Argonne National Laboratory. Using an 18 keV incident energy beam, we produced elemental maps of salts for sea ice samples from the Ross Sea, Antarctica. The distribution of salts in sea icemore » depends on ice type. In our columnar ice samples, Br was located in parallel lines spaced roughly 0.5 mm apart, corresponding to the spacing of lamellae in the skeletal region during initial ice growth. The maps revealed concentrations of Br in linear features in samples from all but the topmost and bottommost depths. For those samples, the maps revealed rounded features. Calibration of the Br elemental maps showed bulk concentrations to be 5–10 g/m 3, with concentrations ten times larger in the linear features. Through comparison with horizontal thin sections, we could verify that these linear features were brine sheets or layers.« less

  13. Synchrotron X-ray fluorescence spectroscopy of salts in natural sea ice

    DOE PAGES

    Obbard, Rachel W.; Lieb-Lappen, Ross M.; Nordick, Katherine V.; ...

    2016-10-23

    We describe the use of synchrotron-based X-ray fluorescence spectroscopy to examine the microstructural location of specific elements, primarily salts, in sea ice. This work was part of an investigation of the location of bromine in the sea ice-snowpack-blowing snow system, where it plays a part in the heterogeneous chemistry that contributes to tropospheric ozone depletion episodes. We analyzed samples at beamline 13-ID-E of the Advanced Photon Source at Argonne National Laboratory. Using an 18 keV incident energy beam, we produced elemental maps of salts for sea ice samples from the Ross Sea, Antarctica. The distribution of salts in sea icemore » depends on ice type. In our columnar ice samples, Br was located in parallel lines spaced roughly 0.5 mm apart, corresponding to the spacing of lamellae in the skeletal region during initial ice growth. The maps revealed concentrations of Br in linear features in samples from all but the topmost and bottommost depths. For those samples, the maps revealed rounded features. Calibration of the Br elemental maps showed bulk concentrations to be 5–10 g/m 3, with concentrations ten times larger in the linear features. Through comparison with horizontal thin sections, we could verify that these linear features were brine sheets or layers.« less

  14. On the evaluation of global sea-salt aerosol models at coastal/orographic sites

    NASA Astrophysics Data System (ADS)

    Spada, M.; Jorba, O.; Pérez García-Pando, C.; Janjic, Z.; Baldasano, J. M.

    2015-01-01

    Sea-salt aerosol global models are typically evaluated against concentration observations at coastal stations that are unaffected by local surf conditions and thus considered representative of open ocean conditions. Despite recent improvements in sea-salt source functions, studies still show significant model errors in specific regions. Using a multiscale model, we investigated the effect of high model resolution (0.1° × 0.1° vs. 1° × 1.4°) upon sea-salt patterns in four stations from the University of Miami Network: Baring Head, Chatam Island, and Invercargill in New Zealand, and Marion Island in the sub-antarctic Indian Ocean. Normalized biases improved from +63.7% to +3.3% and correlation increased from 0.52 to 0.84. The representation of sea/land interfaces, mesoscale circulations, and precipitation with the higher resolution model played a major role in the simulation of annual concentration trends. Our results recommend caution when comparing or constraining global models using surface concentration observations from coastal stations.

  15. Irreversible and reversible components in the genesis of hypertension by sodium chloride (salt).

    PubMed

    Tekol, Yalcin

    2008-01-01

    Despite the abundant studies and overwhelming evidences demonstrating the essential role of salt (sodium chloride) for developing "essential" hypertension (EH), the controversies about salt-hypertension (HT) relations are still continuing. One of important mistakes in this topic is assuming that the HT-producing effect of salt is reversible. The present paper explains the complex nature of salt-HT relations. The deduction was made basing on the studies which investigate the relations between salt and HT. Animal experiments show that HT-producing effect of salt contains irreversible and reversible components. The existence of irreversible component manifests itself in this way: the blood pressure (BP) does not recede to the natural values despite removing of salt exposure. The proportion of BP decreasing after salt exposure termination belongs to the reversible component. Available evidences indicate that the irreversible component is developed in utero, during suckling and, generally, in prepubertal period secondary to salt exposure, however, if the salt exposure extends over more than one period, the HT may be intensified. The consequences of salt exposure during early life of human beings have not been investigated as detailed as in experimental animals, however, there are some clinical trials and epidemiological observations indicating that, similar to experimental animals, irreversible and reversible components are also developed in man during the genesis of HT. By the introduction of irreversible and reversible components notion, some obscured items on salt-HT relations can be clarified. For example, some intervention studies could not find dramatic relations between salt and HT, because these interventions modify only the reversible component, but irreversible component remains unchanged. As a result, salt exposure is detrimental for each period of life. For eradication of HT, it is prerequisite to prevent all individuals (especially pregnant or lactating

  16. SIZE DISTRIBUTION OF SEA-SALT EMISSIONS AS A FUNCTION OF RELATIVE HUMIDITY

    EPA Science Inventory

    This note presents a straightforward method to correct sea-salt-emission particle-size distributions according to local relative humidity. The proposed method covers a wide range of relative humidity (0.45 to 0.99) and its derivation incorporates recent laboratory results on sea-...

  17. Freshwater lake to salt-water sea causing widespread hydrate dissociation in the Black Sea.

    PubMed

    Riboulot, Vincent; Ker, Stephan; Sultan, Nabil; Thomas, Yannick; Marsset, Bruno; Scalabrin, Carla; Ruffine, Livio; Boulart, Cédric; Ion, Gabriel

    2018-01-09

    Gas hydrates, a solid established by water and gas molecules, are widespread along the continental margins of the world. Their dynamics have mainly been regarded through the lens of temperature-pressure conditions. A fluctuation in one of these parameters may cause destabilization of gas hydrate-bearing sediments below the seafloor with implications in ocean acidification and eventually in global warming. Here we show throughout an example of the Black Sea, the world's most isolated sea, evidence that extensive gas hydrate dissociation may occur in the future due to recent salinity changes of the sea water. Recent and forthcoming salt diffusion within the sediment will destabilize gas hydrates by reducing the extension and thickness of their thermodynamic stability zone in a region covering at least 2800 square kilometers which focus seepages at the observed sites. We suspect this process to occur in other world regions (e.g., Caspian Sea, Sea of Marmara).

  18. A study of the sea-salt chemistry using size-segregated aerosol measurements at coastal Antarctic station Neumayer

    NASA Astrophysics Data System (ADS)

    Teinilä, K.; Frey, A.; Hillamo, R.; Tülp, H. C.; Weller, R.

    2014-10-01

    Aerosol chemical and physical properties were measured in 2010 at Neumayer research station, Antarctica. Samples for chemical analysis (ion chromatography) were collected using a Teflon/Nylon filter combination (TNy) sampler, and with a multi stage low pressure impactor (SDI). Particle number concentration was measured continuously with a Grimm OPC optical particle counter. Total particle number concentration varied largely throughout the year, and the highest number concentrations for particles larger than 0.3 μm were observed simultaneously with the highest sea salt concentrations. About 50% of the sea salt aerosol mass was found in the submicron size range. Below 0.2 μm of particle aerodynamic diameter the contribution of sea salt aerosols was negligible. Further analysis showed that sea salt aerosols had undergone physico-chemical processes, either during the transportation, or during their formation. High degree of chloride depletion was observed during austral summer, when the presence of acidic gases exhibit their characteristic seasonal maximum. Apart from chloride depletion, excess chloride relating to sodium was also detected in one SDI sample, indicating actually a sodium depletion by mirabilite formation on freshly formed sea ice areas. Analysis of selected episodes showed that the concentration of sea salt particles, their modal structure, and their chemical composition is connected with their source areas, their formation mechanisms, and local transport history.

  19. Self-accelerated development of salt karst during flash floods along the Dead Sea Coast, Israel

    NASA Astrophysics Data System (ADS)

    Avni, Yoav; Lensky, Nadav; Dente, Elad; Shviro, Maayan; Arav, Reuma; Gavrieli, Ittai; Yechieli, Yoseph; Abelson, Meir; Lutzky, Hallel; Filin, Sagi; Haviv, Itai; Baer, Gidon

    2016-01-01

    We document and analyze the rapid development of a real-time karst system within the subsurface salt layers of the Ze'elim Fan, Dead Sea, Israel by a multidisciplinary study that combines interferometric synthetic aperture radar and light detection and ranging measurements, sinkhole mapping, time-lapse camera monitoring, groundwater level measurements and chemical and isotopic analyses of surface runoff and groundwater. The >1 m/yr drop of Dead Sea water level and the subsequent change in the adjacent groundwater system since the 1960s resulted in flushing of the coastal aquifer by fresh groundwater, subsurface salt dissolution, gradual land subsidence and formation of sinkholes. Since 2010 this process accelerated dramatically as flash floods at the Ze'elim Fan were drained by newly formed sinkholes. During and immediately after these flood events the dissolution rates of the subsurface salt layer increased dramatically, the overlying ground surface subsided, a large number of sinkholes developed over short time periods (hours to days), and salt-saturated water resurged downstream. Groundwater flow velocities increased by more than 2 orders of magnitudes compared to previously measured velocities along the Dead Sea. The process is self-accelerating as salt dissolution enhances subsidence and sinkhole formation, which in turn increase the ponding areas of flood water and generate additional draining conduits to the subsurface. The rapid terrain response is predominantly due to the highly soluble salt. It is enhanced by the shallow depth of the salt layer, the low competence of the newly exposed unconsolidated overburden and the moderate topographic gradients of the Ze'elim Fan.

  20. Microplastic Pollution in Table Salts from China.

    PubMed

    Yang, Dongqi; Shi, Huahong; Li, Lan; Li, Jiana; Jabeen, Khalida; Kolandhasamy, Prabhu

    2015-11-17

    Microplastics have been found in seas all over the world. We hypothesize that sea salts might contain microplastics, because they are directly supplied by seawater. To test our hypothesis, we collected 15 brands of sea salts, lake salts, and rock/well salts from supermarkets throughout China. The microplastics content was 550-681 particles/kg in sea salts, 43-364 particles/kg in lake salts, and 7-204 particles/kg in rock/well salts. In sea salts, fragments and fibers were the prevalent types of particles compared with pellets and sheets. Microplastics measuring less than 200 μm represented the majority of the particles, accounting for 55% of the total microplastics, and the most common microplastics were polyethylene terephthalate, followed by polyethylene and cellophane in sea salts. The abundance of microplastics in sea salts was significantly higher than that in lake salts and rock/well salts. This result indicates that sea products, such as sea salts, are contaminated by microplastics. To the best of our knowledge, this is the first report on microplastic pollution in abiotic sea products.

  1. High temperature reaction between sea salt deposit and (U,Zr)O2 simulated corium debris

    NASA Astrophysics Data System (ADS)

    Takano, Masahide; Nishi, Tsuyoshi

    2013-11-01

    In order to clarify the possible impacts of seawater injection on the chemical and physical state of the corium debris formed in the severe accident at Fukushima Daiichi Nuclear Power Plants, the high temperature reaction between sea salt deposit and (U,Zr)O2 simulated corium debris (sim-debris) was examined in the temperature range from 1088 to 1668 K. A dense layer of calcium and sodium uranate formed on the surface of a sim-debris pellet at 1275 K under airflow, with the thickness of over 50 μm. When the oxygen partial pressure is low, calcium is likely to dissolve into the cubic sim-debris phase to form solid solution (Ca,U,Zr)O2+x. The diffusion depth was 5-6 μm from the surface, subjected to 1275 K for 12 h. The crystalline MgO remains affixed on the surface as the main residue of salt components. A part of it can also dissolve into the sim-debris.

  2. Rhode Island Salt Marshes: Elevation Capital and Resilience to Sea Level Rise

    EPA Science Inventory

    Tidal salt marsh is especially sensitive to deterioration due to the effects of accelerated sea level rise when combined with other anthropogenically linked stressors, including crab herbivory, changes in tidal hydrology, nutrient loading, dam construction, changes in temperature...

  3. 20 Years of sea-levels, accretion, and vegetation on two Long Island Sound salt marshes

    EPA Science Inventory

    The long-term 1939-2013 rate of RSLR (Relative Sea-Level Rise) at the New London, CT tide gauge is ~2.6 mm/yr, near the maximum rate of salt marsh accretion reported in eastern Long Island Sound salt marshes. Consistent with recent literature RSLR at New London has accelerated si...

  4. Inventory and protection of salt marshes from risks of sea-level rise at Acadia National Park, Maine

    USGS Publications Warehouse

    Dudley, Robert W.; Nielsen, Martha G.

    2011-01-01

    Recent U.S. Geological Survey (USGS) climate studies in the northeastern United States have shown substantial evidence of climate-related changes during the last 100 years, including earlier snowmelt runoff, decreasing occurrence of river ice, and decreasing winter snowpack. These studies related to climate change are being expanded to include investigation of coastal wetlands that might be at risk from sealevel rise. Coastal wetlands, particularly salt marshes, are important ecosystems that provide wildlife nursery and breeding habitat, migratory bird habitat, water quality enhancement, and shoreline erosion control. The USGS is investigating salt marshes in Acadia National Park with the goal of determining which salt marshes may be threatened by sea-level rise and which salt marshes may be able to adapt to sea-level rise by migrating into adjacent low-lying lands.

  5. Rheological characterization of hair shampoo in the presence of dead sea salt.

    PubMed

    Abu-Jdayil, B; Mohameed, H A; Sa'id, M; Snobar, T

    2004-02-01

    In Jordan, a growing industry has been established to produce different types of Dead Sea (DS) cosmetics that have DS salt (contains mainly NaCl, KCl, and MgCl(2)) in their formulas. In this work, the effect of DS salt on the rheology of hair shampoo containing the sodium lauryl ether sulfate as a main active matter was studied. The effects of DS salt and active matter concentration, and the temperature and time of salt mixing, on the rheological properties of hair shampoo were investigated. The salt-free shampoo showed a Newtonian behavior at 'low active matter' (LAM) and shear thinning at 'high active matter' (HAM). The presence of DS salt changed the rheological behavior of LAM shampoo from Newtonian (for the salt-free shampoo) to shear thinning. On the other hand, the behavior of HAM shampoo switched from shear thinning to Newtonian behavior in the presence of high concentration of DS salt. The addition of DS salt increased the apparent viscosity of shampoo to reach a maximum value that corresponded to a salt concentration of 1.5 wt.%. Further addition of DS salt led to a decrease in the shampoo viscosity to reach a value less than that of the salt-free sample at high salt concentration. Changing the mixing temperature (25-45 degrees C) and mixing time (15-120 min) of DS salt with shampoo has no significant influence on the rheological behavior. However, the mixing process increased the apparent viscosity of salt-free shampoo. The power law model fitted well the flow curves of hair shampoo with and without DS salt.

  6. EFFECTS OF CHRONIC EXCESS SALT FEEDING

    PubMed Central

    Dahl, Lewis K.; Heine, Martha

    1961-01-01

    Female rats were fed diets containing either excess sea salt or excess sodium chloride for periods up to 14 months. The hypertension produced by sea salt was more pronounced than that caused by sodium chloride alone, although the average amount of sodium chloride contained in the sea salt feeding was slightly less. The ions involved in this incremental effect of sea salt were not identified. PMID:13719314

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

    USGS Publications Warehouse

    Langevin, Christian D.; Zygnerski, Michael

    2013-01-01

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

  8. Atmospheric fate of oil matter adsorbed on sea salt particles under UV light

    NASA Astrophysics Data System (ADS)

    Vaitilingom, M.; Avij, P.; Huang, H.; Valsaraj, K. T.

    2014-12-01

    The presence of liquid petroleum hydrocarbons at the sea water surface is an important source of marine pollution. An oil spill in sea-water will most likely occur due to an involuntary accident from tankers, offshore platforms, etc. However, a large amount of oil is also deliberately spilled in sea-water during the clean-out process of tank vessels (e.g. for the Mediterranean Sea, 490,000 tons/yr). Moreover, the pollution caused by an oil spill does not only affect the aquatic environment but also is of concern for the atmospheric environment. A portion of the oil matter present at the sea-water surface is transported into the atmosphere viaevaporation and adsorption at the surface of sea spray particles. Few studies are related to the presence of oil matter in airborne particles resulting from their adsorption on sea salt aerosols. We observed that the non-volatile oil matter was adsorbed at the surface of sea-salt crystals (av. size of 1.1 μm). Due to their small size, these particles can have a significant residence time in the atmosphere. The hydrocarbon matter adsorbed at the surface of these particles can also be transformed by catalyzers present in the atmosphere (i.e. UV, OH, O3, ...). In this work, we focused on the photo-oxidation rates of the C16 to C30alkanes present in these particles. We utilized a bubble column reactor, which produced an abundance of small sized bubbles. These bubbles generated droplets upon bursting at the air-salt water interface. These droplets were then further dried up and lifted to the top of the column where they were collected as particles. These particles were incubated in a controlled reactor in either dark conditions or under UV-visible light. The difference of alkane content analyzed by GC-MS between the particles exposed to UV or the particles not exposed to UV indicated that up to 20% in mass was lost after 20 min of light exposure. The degradation kinetics varied for each range of alkanes (C16-20, C21-25, C26

  9. Linking hygroscopicity and the surface microstructure of model inorganic salts, simple and complex carbohydrates, and authentic sea spray aerosol particles.

    PubMed

    Estillore, Armando D; Morris, Holly S; Or, Victor W; Lee, Hansol D; Alves, Michael R; Marciano, Meagan A; Laskina, Olga; Qin, Zhen; Tivanski, Alexei V; Grassian, Vicki H

    2017-08-09

    Individual airborne sea spray aerosol (SSA) particles show diversity in their morphologies and water uptake properties that are highly dependent on the biological, chemical, and physical processes within the sea subsurface and the sea surface microlayer. In this study, hygroscopicity data for model systems of organic compounds of marine origin mixed with NaCl are compared to data for authentic SSA samples collected in an ocean-atmosphere facility providing insights into the SSA particle growth, phase transitions and interactions with water vapor in the atmosphere. In particular, we combine single particle morphology analyses using atomic force microscopy (AFM) with hygroscopic growth measurements in order to provide important insights into particle hygroscopicity and the surface microstructure. For model systems, a range of simple and complex carbohydrates were studied including glucose, maltose, sucrose, laminarin, sodium alginate, and lipopolysaccharides. The measured hygroscopic growth was compared with predictions from the Extended-Aerosol Inorganics Model (E-AIM). It is shown here that the E-AIM model describes well the deliquescence transition and hygroscopic growth at low mass ratios but not as well for high ratios, most likely due to a high organic volume fraction. AFM imaging reveals that the equilibrium morphology of these single-component organic particles is amorphous. When NaCl is mixed with the organics, the particles adopt a core-shell morphology with a cubic NaCl core and the organics forming a shell similar to what is observed for the authentic SSA samples. The observation of such core-shell morphologies is found to be highly dependent on the salt to organic ratio and varies depending on the nature and solubility of the organic component. Additionally, single particle organic volume fraction AFM analysis of NaCl : glucose and NaCl : laminarin mixtures shows that the ratio of salt to organics in solution does not correspond exactly for

  10. Integrating biomass, sulphate and sea-salt aerosol responses into a microphysical chemical parcel model: implications for climate studies.

    PubMed

    Ghosh, S; Smith, M H; Rap, A

    2007-11-15

    Aerosols are known to influence significantly the radiative budget of the Earth. Although the direct effect (whereby aerosols scatter and absorb solar and thermal infrared radiation) has a large perturbing influence on the radiation budget, the indirect effect (whereby aerosols modify the microphysical and hence the radiative properties and amounts of clouds) poses a greater challenge to climate modellers. This is because aerosols undergo chemical and physical changes while in the atmosphere, notably within clouds, and are removed largely by precipitation. The way in which aerosols are processed by clouds depends on the type, abundance and the mixing state of the aerosols concerned. A parametrization with sulphate and sea-salt aerosol has been successfully integrated within the Hadley Centre general circulation model (GCM). The results of this combined parametrization indicate a significantly reduced role, compared with previous estimates, for sulphate aerosol in cloud droplet nucleation and, consequently, in indirect radiative forcing. However, in this bicomponent system, the cloud droplet number concentration, N(d) (a crucial parameter that is used in GCMs for radiative transfer calculations), is a smoothly varying function of the sulphate aerosol loading. Apart from sea-salt and sulphate aerosol particles, biomass aerosol particles are also present widely in the troposphere. We find that biomass smoke can significantly perturb the activation and growth of both sulphate and sea-salt particles. For a fixed salt loading, N(d) increases linearly with modest increases in sulphate and smoke masses, but significant nonlinearities are observed at higher non-sea-salt mass loadings. This non-intuitive N(d) variation poses a fresh challenge to climate modellers.

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

    PubMed

    Langevin, Christian D; Zygnerski, Michael

    2013-01-01

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

  12. Internally mixed sea salt, soot, and sulfates at Macao, a coastal city in South China.

    PubMed

    Li, Weijun; Shao, Longyi; Shen, Rongrong; Yang, Shusheng; Wang, Zhishi; Tang, Uwa

    2011-11-01

    Direct observation of the mixing state of aerosol particles in a coastal urban city is critical to understand atmospheric processing and hygroscopic growth in humid air. Morphology, composition, and mixing state of individual aerosol particles from Macao, located south of the Pearl River Delta (PRD) and 100 km west of Hong Kong, were investigated using scanning electron microscopy (SEM) and transmission electron microscopy coupled with energy-dispersive X-ray spectrometry (TEM/EDX). SEM images show that soot and roughly spherical particles are prevalent in the samples. Based on the compositions of individual aerosol particles, aerosol particles with roughly spherical shape are classified into coarse Na-rich and fine S-rich particles. TEM/EDX indicates that each Na-rich particle consists of a Na-S core and NaNO3 shell. Even in the absence of heavy pollution, the marine sea salt particles were completely depleted in chloride, and Na-related sulfates and nitrates were enriched in Macao air. The reason could be that SO2 from the polluted PRD and ships in the South China Sea and NO2 from vehicles in the city sped up the chlorine depletion in sea salt through heterogeneous reactions. Fresh soot particles from vehicular emissions mainly occur near curbside. However, there are many aged soot particles in the sampling site surrounded by main roads 200 to 400 m away, suggesting that the fresh soot likely underwent a quick aging. Overall, secondary nitrates and sulfates internally mixed with soot and sea salt particles can totally change their surface hygroscopicity in coastal cities.

  13. Enhanced MFC power production and struvite recovery by the addition of sea salts to urine.

    PubMed

    Merino-Jimenez, Irene; Celorrio, Veronica; Fermin, David J; Greenman, John; Ieropoulos, Ioannis

    2017-02-01

    Urine is an excellent fuel for electricity generation in Microbial Fuel Cells (MFCs), especially with practical implementations in mind. Moreover, urine has a high content in nutrients which can be easily recovered. Struvite (MgNH 4 PO 4 ·6H 2 O) crystals naturally precipitate in urine, but this reaction can be enhanced by the introduction of additional magnesium. In this work, the effect of magnesium additives on the power output of the MFCs and on the catholyte generation is evaluated. Several magnesium sources including MgCl 2 , artificial sea water and a commercially available sea salts mixture for seawater preparation (SeaMix) were mixed with real fresh human urine in order to enhance struvite precipitation. The supernatant of each mixture was tested as a feedstock for the MFCs and it was evaluated in terms of power output and catholyte generation. The commercial SeaMix showed the best performance in terms of struvite precipitation, increasing the amount of struvite in the solid collected from 21% to 94%. Moreover, the SeaMix increased the maximum power performance of the MFCs by over 10% and it also changed the properties of the catholyte collected by increasing the pH, conductivity and the concentration of chloride ions. These results demonstrate that the addition of sea-salts to real urine is beneficial for both struvite recovery and electricity generation in MFCs. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Anthropogenic contamination of tap water, beer, and sea salt

    PubMed Central

    2018-01-01

    Plastic pollution has been well documented in natural environments, including the open waters and sediments within lakes and rivers, the open ocean and even the air, but less attention has been paid to synthetic polymers in human consumables. Since multiple toxicity studies indicate risks to human health when plastic particles are ingested, more needs to be known about the presence and abundance of anthropogenic particles in human foods and beverages. This study investigates the presence of anthropogenic particles in 159 samples of globally sourced tap water, 12 brands of Laurentian Great Lakes beer, and 12 brands of commercial sea salt. Of the tap water samples analyzed, 81% were found to contain anthropogenic particles. The majority of these particles were fibers (98.3%) between 0.1–5 mm in length. The range was 0 to 61 particles/L, with an overall mean of 5.45 particles/L. Anthropogenic debris was found in each brand of beer and salt. Of the extracted particles, over 99% were fibers. After adjusting for particles found in lab blanks for both salt and beer, the average number of particles found in beer was 4.05 particles/L with a range of 0 to 14.3 particles/L and the average number of particles found in each brand of salt was 212 particles/kg with a range of 46.7 to 806 particles/kg. Based on consumer guidelines, our results indicate the average person ingests over 5,800 particles of synthetic debris from these three sources annually, with the largest contribution coming from tap water (88%). PMID:29641556

  15. The Use of a Sea Salt-based Spray for Diabetic Foot Ulcers: A Novel Concept.

    PubMed

    Pougatsch, David A; Rader, Andrew; Rogers, Lee C

    2017-02-01

    Several patients present to wound healing specialists seeking a natural or alternative medical approach to their wounds. The purpose of this prospective, case-cohort study of 10 patients was to evaluate the use of Oceanzyme Wound Care Spray (Ocean Aid, Inc, Boynton Beach, FL) in improving healing in diabetic foot ulcers during a 12-week period. This product contains water purified by reverse osmosis, coral reef sea salt, lysozyme, and sodium benzoate. The primary endpoint was wound closure, and secondary endpoints were infection rate and wound area reduction. Overall, 2 patients healed, 2 withdrew, and the remaining 6 had an average of 73% reduction in wound area. While more study is needed, the use of this sea salt-based spray may provide a viable alternative for patients seeking a natural therapy for their wound care.

  16. Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes.

    PubMed

    Ge, Zhen-Ming; Wang, Heng; Cao, Hao-Bin; Zhao, Bin; Zhou, Xiao; Peltola, Heli; Cui, Li-Fang; Li, Xiu-Zhen; Zhang, Li-Quan

    2016-06-23

    The impacts of sea-level rise (SLR) on coastal ecosystems have attracted worldwide attention in relation to global change. In this study, the salt marsh model for the Yangtze Estuary (SMM-YE, developed in China) and the Sea Level Affecting Marshes Model (SLAMM, developed in the U.S.) were used to simulate the effects of SLR on the coastal salt marshes in eastern China. The changes in the dominant species in the plant community were also considered. Predictions based on the SLAMM indicated a trend of habitat degradation up to 2100; total salt marsh habitat area continued to decline (4-16%) based on the low-level scenario, with greater losses (6-25%) predicted under the high-level scenario. The SMM-YE showed that the salt marshes could be resilient to threats of SLR through the processes of accretion of mudflats, vegetation expansion and sediment trapping by plants. This model predicted that salt marsh areas increased (3-6%) under the low-level scenario. The decrease in the total habitat area with the SMM-YE under the high-level scenario was much lower than the SLAMM prediction. Nevertheless, SLR might negatively affect the salt marsh species that are not adapted to prolonged inundation. An adaptive strategy for responding to changes in sediment resources is necessary in the Yangtze Estuary.

  17. Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes

    NASA Astrophysics Data System (ADS)

    Ge, Zhen-Ming; Wang, Heng; Cao, Hao-Bin; Zhao, Bin; Zhou, Xiao; Peltola, Heli; Cui, Li-Fang; Li, Xiu-Zhen; Zhang, Li-Quan

    2016-06-01

    The impacts of sea-level rise (SLR) on coastal ecosystems have attracted worldwide attention in relation to global change. In this study, the salt marsh model for the Yangtze Estuary (SMM-YE, developed in China) and the Sea Level Affecting Marshes Model (SLAMM, developed in the U.S.) were used to simulate the effects of SLR on the coastal salt marshes in eastern China. The changes in the dominant species in the plant community were also considered. Predictions based on the SLAMM indicated a trend of habitat degradation up to 2100; total salt marsh habitat area continued to decline (4-16%) based on the low-level scenario, with greater losses (6-25%) predicted under the high-level scenario. The SMM-YE showed that the salt marshes could be resilient to threats of SLR through the processes of accretion of mudflats, vegetation expansion and sediment trapping by plants. This model predicted that salt marsh areas increased (3-6%) under the low-level scenario. The decrease in the total habitat area with the SMM-YE under the high-level scenario was much lower than the SLAMM prediction. Nevertheless, SLR might negatively affect the salt marsh species that are not adapted to prolonged inundation. An adaptive strategy for responding to changes in sediment resources is necessary in the Yangtze Estuary.

  18. Sea water in coastal aquifers

    USGS Publications Warehouse

    Cooper, Hilton Hammond

    1964-01-01

    Investigations in the coastal part of the Biscayne aquifer, a highly productive aquifer of limestone and sand in the Miami area, Florida, show that the salt-water front is dynamically stable as much as 8 miles seaward of the position computed according to the Ghyben-Herzberg principle. This discrepancy results, at least in part, from the fact that the salt water in the Biscayne aquifer is not static, as explanations of the dynamic balance commonly assume. Cross sections showing lines of equal fresh-water potential indicate that during periods of heavy recharge, the fresh-water head is high enough to cause the fresh water, the salt water, and the zone of diffusion between them to move seaward. When the fresh-water head is low, salt water in the lower part of the aquifer intrudes inland, but some of the diluted sea water in the zone of diffusion continues to flow seaward. Thus, salt water circulates inland from the floor of the sea through the lower part of the aquifer becoming progressively diluted with fresh water to a line along which there is no horizontal component of flow, after which it moves upward and returns to the sea. This cyclic flow is demonstrated by a flow net which is constructed by the use of horizontal gradients determined from the low-head equipotential diagram. The flow net shows that about seven-eights of the total discharge at the shoreline originates as fresh water in inland parts of the aquifer. The remaining one-eighth represents a return of sea water entering the aquifer through the floor of the sea.

  19. Year-round records of sea salt, gaseous, and particulate inorganic bromine in the atmospheric boundary layer at coastal (Dumont d'Urville) and central (Concordia) East Antarctic sites

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Yang, Xin; Preunkert, Susanne; Theys, Nicolas

    2016-01-01

    Multiple year-round records of bulk and size-segregated compositions of aerosol were obtained at the coastal Dumont d'Urville (DDU) and inland Concordia sites located in East Antarctica. They document the sea-salt aerosol load and composition including, for the first time in Antarctica, the bromide depletion of sea-salt aerosol relative to sodium with respect to seawater. In parallel, measurements of bromide trapped in mist chambers and denuder tubes were done to investigate the concentrations of gaseous inorganic bromine species. These data are compared to simulations done with an off-line chemistry transport model, coupled with a full tropospheric bromine chemistry scheme and a process-based sea-salt production module that includes both sea-ice-sourced and open-ocean-sourced aerosol emissions. Observed and simulated sea-salt concentrations sometime differ by up to a factor of 2 to 3, particularly at DDU possibly due to local wind pattern. In spite of these discrepancies, both at coastal and inland Antarctica, the dominance of sea-ice-related processes with respect to open ocean emissions for the sea-salt aerosol load in winter is confirmed. For summer, observations and simulations point out sea salt as the main source of gaseous inorganic bromine species. Investigations of bromide in snow pit samples do not support the importance of snowpack bromine emissions over the Antarctic Plateau. To evaluate the overall importance of the bromine chemistry over East Antarctica, BrO simulations were also discussed with respect data derived from GOME-2 satellite observations over Antarctica.

  20. Salt marsh as a coastal filter for the oceans: changes in function with experimental increases in nitrogen loading and sea-level rise.

    PubMed

    Nelson, Joanna L; Zavaleta, Erika S

    2012-01-01

    Coastal salt marshes are among Earth's most productive ecosystems and provide a number of ecosystem services, including interception of watershed-derived nitrogen (N) before it reaches nearshore oceans. Nitrogen pollution and climate change are two dominant drivers of global-change impacts on ecosystems, yet their interacting effects at the land-sea interface are poorly understood. We addressed how sea-level rise and anthropogenic N additions affect the salt marsh ecosystem process of nitrogen uptake using a field-based, manipulative experiment. We crossed simulated sea-level change and ammonium-nitrate (NH(4)NO(3))-addition treatments in a fully factorial design to examine their potentially interacting effects on emergent marsh plants in a central California estuary. We measured above- and belowground biomass and tissue nutrient concentrations seasonally and found that N-addition had a significant, positive effect on a) aboveground biomass, b) plant tissue N concentrations, c) N stock sequestered in plants, and d) shoot:root ratios in summer. Relative sea-level rise did not significantly affect biomass, with the exception of the most extreme sea-level-rise simulation, in which all plants died by the summer of the second year. Although there was a strong response to N-addition treatments, salt marsh responses varied by season. Our results suggest that in our site at Coyote Marsh, Elkhorn Slough, coastal salt marsh plants serve as a robust N trap and coastal filter; this function is not saturated by high background annual N inputs from upstream agriculture. However, if the marsh is drowned by rising seas, as in our most extreme sea-level rise treatment, marsh plants will no longer provide the ecosystem service of buffering the coastal ocean from eutrophication.

  1. Salt Marsh as a Coastal Filter for the Oceans: Changes in Function with Experimental Increases in Nitrogen Loading and Sea-Level Rise

    PubMed Central

    Nelson, Joanna L.; Zavaleta, Erika S.

    2012-01-01

    Coastal salt marshes are among Earth's most productive ecosystems and provide a number of ecosystem services, including interception of watershed-derived nitrogen (N) before it reaches nearshore oceans. Nitrogen pollution and climate change are two dominant drivers of global-change impacts on ecosystems, yet their interacting effects at the land-sea interface are poorly understood. We addressed how sea-level rise and anthropogenic N additions affect the salt marsh ecosystem process of nitrogen uptake using a field-based, manipulative experiment. We crossed simulated sea-level change and ammonium-nitrate (NH4NO3)-addition treatments in a fully factorial design to examine their potentially interacting effects on emergent marsh plants in a central California estuary. We measured above- and belowground biomass and tissue nutrient concentrations seasonally and found that N-addition had a significant, positive effect on a) aboveground biomass, b) plant tissue N concentrations, c) N stock sequestered in plants, and d) shoot:root ratios in summer. Relative sea-level rise did not significantly affect biomass, with the exception of the most extreme sea-level-rise simulation, in which all plants died by the summer of the second year. Although there was a strong response to N-addition treatments, salt marsh responses varied by season. Our results suggest that in our site at Coyote Marsh, Elkhorn Slough, coastal salt marsh plants serve as a robust N trap and coastal filter; this function is not saturated by high background annual N inputs from upstream agriculture. However, if the marsh is drowned by rising seas, as in our most extreme sea-level rise treatment, marsh plants will no longer provide the ecosystem service of buffering the coastal ocean from eutrophication. PMID:22879873

  2. Vertical Redistribution of Ocean Salt Content

    NASA Astrophysics Data System (ADS)

    Liang, X.; Liu, C.; Ponte, R. M.; Piecuch, C. G.

    2017-12-01

    Ocean salinity is an important proxy for change and variability in the global water cycle. Multi-decadal trends have been observed in both surface and subsurface salinity in the past decades, and are usually attributed to the change in air-sea freshwater flux. Although air-sea freshwater flux, a major component of the global water cycle, certainly contributes to the change in surface and upper ocean salinity, the salt redistribution inside the ocean can affect the surface and upper ocean salinity as well. Also, the mechanisms controlling the surface and upper ocean salinity changes likely depend on timescales. Here we examined the ocean salinity changes as well as the contribution of the vertical redistribution of salt with a 20-year dynamically consistent and data-constrained ocean state estimate (ECCO: Estimating Circulation and Climate of the Ocean). A decrease in the spatial mean upper ocean salinity and an upward salt flux inside the ocean were observed. These findings indicate that over 1992-2011, surface freshwater fluxes contribute to the decrease in spatial mean upper ocean salinity and are partly compensated by the vertical redistribution of salt inside the ocean. Between advection and diffusion, the two major processes determining the vertical exchange of salt, the advective term at different depths shows a downward transport, while the diffusive term is the dominant upward transport contributor. These results suggest that the salt transport in the ocean interior should be considered in interpreting the observed surface and upper ocean salinity changes, as well as inferring information about the changes in the global water cycle.

  3. Direct observation of nitrate and sulfate formations from mineral dust and sea-salts using low- Z particle electron probe X-ray microanalysis

    NASA Astrophysics Data System (ADS)

    Hwang, HeeJin; Ro, Chul-Un

    In the present work, it is demonstrated that a single particle analytical technique, named low- Z particle electron probe X-ray microanalysis, is a practically useful tool for the study of heterogeneous reactions of mineral dust and sea-salts when this analytical technique was applied to a sample collected during an Asian Dust storm event. The technique does not require a special treatment of sample to identify particles reacted in the air. Also, quantitative chemical speciation of reacted particles can provide concrete information on what chemical reaction, if any, occurred for individual particles. Among overall 178 analyzed particles, the number of reacted particles is 81 and heterogeneous chemical reactions mostly occurred on CaCO 3 mineral dust (54 particles) and sea-salts (26 particles). Several observations made for the Asian Dust sample in the present work are: (1) CaCO 3 species almost completely reacted to produce mostly Ca(NO 3) 2 species, and CaSO 4 to a much lesser extent. (2) When reacted particles contain CaSO 4, almost all of them are internally mixed with nitrate. (3) Reacted CaCO 3 particles seem to contain moisture when they were collected. (4) Some reacted CaCO 3 particles have unreacted mineral species, such as aluminosilicates, iron oxide, SiO 2, etc., in the core region. (5) All sea-salt particles are observed to have reacted in the air. Some of them were recrystallized in the air before being collected and they are observed as crystalline NaNO 3 particles. (6) Many sea-salts were collected as water drops, and some of them were fractionally recrystallized on Ag collecting substrate. When sea-salts were not recrystallized on the substrate, they are found as particles internally mixed with NaNO 3 and Mg(NO 3) 2, and in some cases SO 4 and Cl species as additional anions.

  4. Response of salt marsh and mangrove wetlands to changes in atmospheric CO2, climate, and sea-level

    USGS Publications Warehouse

    Mckee, Karen L.; Rogers, Kerrylee; Saintilan, Neil; Middleton, Beth A.

    2012-01-01

    Coastal salt marsh and mangrove ecosystems are particularly vulnerable to changes in atmospheric CO2 concentrations and associated climate and climate-induced changes. We provide a review of the literature detailing theoretical predictions and observed responses of coastal wetlands to a range of climate change stressors, including CO2, temperature, rainfall, and sea-level rise. This review incorporates a discussion of key processes controlling responses in different settings and thresholds of resilience derived from experimental and observational studies. We specifically consider the potential and observed effects on salt marsh and mangrove vegetation of changes in (1) elevated [CO2] on physiology, growth, and distribution; (2) temperature on distribution and diversity; (3) rainfall and salinity regimes on growth and competitive interactions; and (4) sea level on geomorphological, hydrological, and biological processes.

  5. Comparing salt tolerance of beet cultivars and their halophytic ancestor: consequences of domestication and breeding programmes

    PubMed Central

    Rozema, Jelte; Cornelisse, Danny; Zhang, Yuancheng; Li, Hongxiu; Bruning, Bas; Katschnig, Diana; Broekman, Rob; Ji, Bin; van Bodegom, Peter

    2015-01-01

    Salt tolerance of higher plants is determined by a complex set of traits, the timing and rate of evolution of which are largely unknown. We compared the salt tolerance of cultivars of sugar beet and their ancestor, sea beet, in hydroponic studies and evaluated whether traditional domestication and more recent breeding have changed salt tolerance of the cultivars relative to their ancestor. Our comparison of salt tolerance of crop cultivars is based on values of the relative growth rate (RGR) of the entire plant at various salinity levels. We found considerable salt tolerance of the sea beet and slightly, but significantly, reduced salt tolerance of the sugar beet cultivars. This indicates that traditional domestication by selection for morphological traits such as leaf size, beet shape and size, enhanced productivity, sugar content and palatability slightly affected salt tolerance of sugar beet cultivars. Salt tolerance among four sugar beet cultivars, three of which have been claimed to be salt tolerant, did not differ. We analysed the components of RGR to understand the mechanism of salt tolerance at the whole-plant level. The growth rate reduction at higher salinity was linked with reduced leaf area at the whole-plant level (leaf area ratio) and at the individual leaf level (specific leaf area). The leaf weight fraction was not affected by increased salinity. On the other hand, succulence and leaf thickness and the net assimilation per unit of leaf area (unit leaf rate) increased in response to salt treatment, thus partially counteracting reduced capture of light by lower leaf area. This compensatory mechanism may form part of the salt tolerance mechanism of sea beet and the four studied sugar beet cultivars. Together, our results indicate that domestication of the halophytic ancestor sea beet slightly reduced salt tolerance and that breeding for improved salt tolerance of sugar beet cultivars has not been effective. PMID:25492122

  6. Carbon burial and storage in tropical salt marshes under the influence of sea level rise.

    PubMed

    Ruiz-Fernández, A C; Carnero-Bravo, V; Sanchez-Cabeza, J A; Pérez-Bernal, L H; Amaya-Monterrosa, O A; Bojórquez-Sánchez, S; López-Mendoza, P G; Cardoso-Mohedano, J G; Dunbar, R B; Mucciarone, D A; Marmolejo-Rodríguez, A J

    2018-07-15

    Coastal vegetated habitats can be important sinks of organic carbon (C org ) and mitigate global warming by sequestering significant quantities of atmospheric CO 2 and storing sedimentary C org for long periods, although their C org burial and storage capacity may be affected by on-going sea level rise and human intervention. Geochemical data from published 210 Pb-dated sediment cores, collected from low-energy microtidal coastal wetlands in El Salvador (Jiquilisco Bay) and in Mexico (Salada Lagoon; Estero de Urias Lagoon; Sian Ka'an Biosphere Reserve) were revisited to assess temporal changes (within the last 100years) of C org concentrations, storage and burial rates in tropical salt marshes under the influence of sea level rise and contrasting anthropization degree. Grain size distribution was used to identify hydrodynamic changes, and δ 13 C to distinguish terrigenous sediments from those accumulated under the influence of marine transgression. Although the accretion rate ranges in all sediment records were comparable, C org concentrations (0.2-30%), stocks (30-465Mgha -1 , by extrapolation to 1m depth), and burial rates (3-378gm -2 year -1 ) varied widely within and among the study areas. However, in most sites sea level rise decreased C org concentrations and stocks in sediments, but increased C org burial rates. Lower C org concentrations were attributed to the input of reworked marine particles, which contribute with a lower amount of C org than terrigenous sediments; whereas higher C org burial rates were driven by higher mass accumulation rates, influenced by increased flooding and human interventions in the surroundings. C org accumulation and long-term preservation in tropical salt marshes can be as high as in mangrove or temperate salt marsh areas and, besides the reduction of C org stocks by ongoing sea level rise, the disturbance of the long-term buried C org inventories might cause high CO 2 releases, for which they must be protected as a part of

  7. The spectral albedo of sea ice and salt crusts on the tropical ocean of Snowball Earth: 1. Laboratory measurements

    NASA Astrophysics Data System (ADS)

    Light, Bonnie; Carns, Regina C.; Warren, Stephen G.

    2016-07-01

    The ice-albedo feedback mechanism likely contributed to global glaciation during the Snowball Earth events of the Neoproterozoic era (1 Ga to 544 Ma). This feedback results from the albedo contrast between sea ice and open ocean. Little is known about the optical properties of some of the possible surface types that may have been present, including sea ice that is both snow-free and cold enough for salts to precipitate within brine inclusions. A proxy surface for such ice was grown in a freezer laboratory using the single salt NaCl and kept below the eutectic temperature (-21.2°C) of the NaCl-H2O binary system. The resulting ice cover was composed of ice and precipitated hydrohalite crystals (NaCl · 2H2O). As the cold ice sublimated, a thin lag-deposit of salt formed on the surface. To hasten its growth in the laboratory, the deposit was augmented by addition of a salt-enriched surface crust. Measurements of the spectral albedo of this surface were carried out over 90 days as the hydrohalite crust thickened due to sublimation of ice, and subsequently over several hours as the crust warmed and dissolved, finally resulting in a surface with puddled liquid brine. The all-wave solar albedo of the subeutectic crust is 0.93 (in contrast to 0.83 for fresh snow and 0.67 for melting bare sea ice). Incorporation of these processes into a climate model of Snowball Earth will result in a positive salt-albedo feedback operating between -21°C and -36°C.

  8. Exploring mechanisms of compaction in salt-marsh sediments using Common Era relative sea-level reconstructions

    NASA Astrophysics Data System (ADS)

    Brain, Matthew J.; Kemp, Andrew C.; Hawkes, Andrea D.; Engelhart, Simon E.; Vane, Christopher H.; Cahill, Niamh; Hill, Troy D.; Donnelly, Jeffrey P.; Horton, Benjamin P.

    2017-07-01

    Salt-marsh sediments provide precise and near-continuous reconstructions of Common Era relative sea level (RSL). However, organic and low-density salt-marsh sediments are prone to compaction processes that cause post-depositional distortion of the stratigraphic column used to reconstruct RSL. We compared two RSL reconstructions from East River Marsh (Connecticut, USA) to assess the contribution of mechanical compression and biodegradation to compaction of salt-marsh sediments and their subsequent influence on RSL reconstructions. The first, existing reconstruction ('trench') was produced from a continuous sequence of basal salt-marsh sediment and is unaffected by compaction. The second, new reconstruction is from a compaction-susceptible core taken at the same location. We highlight that sediment compaction is the only feasible mechanism for explaining the observed differences in RSL reconstructed from the trench and core. Both reconstructions display long-term RSL rise of ∼1 mm/yr, followed by a ∼19th Century acceleration to ∼3 mm/yr. A statistically-significant difference between the records at ∼1100 to 1800 CE could not be explained by a compression-only geotechnical model. We suggest that the warmer and drier conditions of the Medieval Climate Anomaly (MCA) resulted in an increase in sediment compressibility during this time period. We adapted the geotechnical model by reducing the compressive strength of MCA sediments to simulate this softening of sediments. 'Decompaction' of the core reconstruction with this modified model accounted for the difference between the two RSL reconstructions. Our results demonstrate that compression-only geotechnical models may be inadequate for estimating compaction and post-depositional lowering of susceptible organic salt-marsh sediments in some settings. This has important implications for our understanding of the drivers of sea-level change. Further, our results suggest that future climate changes may make salt

  9. Sea-salt injections into the low-latitude marine boundary layer: The transient response in three Earth system models

    NASA Astrophysics Data System (ADS)

    Alterskjær, Kari; Kristjánsson, Jón Egill; Boucher, Olivier; Muri, Helene; Niemeier, Ulrike; Schmidt, Hauke; Schulz, Michael; Timmreck, Claudia

    2013-11-01

    proposed mechanisms for counteracting global warming through solar radiation management is the deliberate injection of sea salt acting via marine cloud brightening and the direct effect of sea-salt aerosols. In this study, we show results from multidecadal simulations of such sea-salt climate engineering (SSCE) on top of the RCP4.5 emission scenario using three Earth system models. As in the proposed "G3" experiment of the Geoengineering Model Intercomparison Project, SSCE is designed to keep the top-of-atmosphere radiative forcing at the 2020 level for 50 years. SSCE is then turned off and the models run for another 20 years, enabling an investigation of the abrupt warming associated with a termination of climate engineering ("termination effect"). As in former idealized studies, the climate engineering in all three models leads to a significant suppression of evaporation from low-latitude oceans and reduced precipitation over low-latitude oceans as well as in the storm-track regions. Unlike those studies, however, we find in all models enhanced evaporation, cloud formation, and precipitation over low-latitude land regions. This is a response to the localized cooling over the low-latitude oceans imposed by the SSCE design. As a result, the models obtain reduced aridity in many low-latitude land regions as well as in southern Europe. Terminating the SSCE leads to a rapid near-surface temperature increase, which, in the Arctic, exceeds 2 K in all three models within 20 years after SSCE has ceased. In the same period September Arctic sea ice cover shrinks by over 25%.

  10. Synthesis of zwitterionic salts of pyridinium-Meldrum acid and barbiturate through unique four-component reactions.

    PubMed

    Wang, Qi-Fang; Hui, Li; Hou, Hong; Yan, Chao-Guo

    2010-03-08

    An efficient synthetic procedure for the preparation of the unusual charge-separated pyridinium-Meldrum acid and N,N-dimethylbarbiturate acid zwitterionic salts was developed though a unique one-pot four-component reaction involving pyridine, aromatic aldehyde, Meldrum acid or N,N-dimethylbarbituric acid, and p-nitrobenzyl bromide in acetonitrile. By varying combinations of four components involving nitrogen-containing heterocycles, we conveniently established reactive alpha-halomethylene compounds, aldehydes and beta-dicarbonyl compounds a library of zwitterionic salts.

  11. Pharmacological actions and therapeutic applications of Salvia miltiorrhiza depside salt and its active components.

    PubMed

    Wu, Wen-yu; Wang, Yi-ping

    2012-09-01

    Salvia miltiorrhiza, a traditional medical herb known as danshen, has been widely used in China to improve blood circulation, relieve blood stasis, and treat coronary heart disease. S miltiorrhiza depside salt is a novel drug recently developed at the Shanghai Institute of Materia Medica; it contains magnesium lithospermate B (MLB) and its analogs, rosmarinic acid (RA) and lithospermic acid (LA), as active components. The drug has been used in the clinic to improve blood circulation and treat coronary heart disease. The pharmacological effects of the depside salt from S miltiorrhiza and its components have been extensively investigated. Experimental studies have demonstrated that magnesium lithospermate B possesses a variety of biological activities, especially protective effects in the cardiovascular system such as attenuation of atherosclerosis and protection against myocardial ischemia-reperfusion injury. Rosmarinic acid and lithospermic acid also show beneficial effects on the cardiovascular system. This paper reviews the recent findings regarding the mechanisms underlying the pharmacological actions of the active components of S miltiorrhiza depside salt, based on published works and our own observations.

  12. Arctic Sea Salt Aerosol from Blowing Snow and Sea Ice Surfaces - a Missing Natural Source in Winter

    NASA Astrophysics Data System (ADS)

    Frey, M. M.; Norris, S. J.; Brooks, I. M.; Nishimura, K.; Jones, A. E.

    2015-12-01

    Atmospheric particles in the polar regions consist mostly of sea salt aerosol (SSA). SSA plays an important role in regional climate change through influencing the surface energy balance either directly or indirectly via cloud formation. SSA irradiated by sunlight also releases very reactive halogen radicals, which control concentrations of ozone, a pollutant and greenhouse gas. However, models under-predict SSA concentrations in the Arctic during winter pointing to a missing source. It has been recently suggested that salty blowing snow above sea ice, which is evaporating, to be that source as it may produce more SSA than equivalent areas of open ocean. Participation in the 'Norwegian Young Sea Ice Cruise (N-ICE 2015)' on board the research vessel `Lance' allowed to test this hypothesis in the Arctic sea ice zone during winter. Measurements were carried out from the ship frozen into the pack ice North of 80º N during February to March 2015. Observations at ground level (0.1-2 m) and from the ship's crows nest (30 m) included number concentrations and size spectra of SSA (diameter range 0.3-10 μm) as well as snow particles (diameter range 50-500 μm). During and after blowing snow events significant SSA production was observed. In the aerosol and snow phase sulfate is fractionated with respect to sea water, which confirms sea ice surfaces and salty snow, and not the open ocean, to be the dominant source of airborne SSA. Aerosol shows depletion in bromide with respect to sea water, especially after sunrise, indicating photochemically driven release of bromine. We discuss the SSA source strength from blowing snow in light of environmental conditions (wind speed, atmospheric turbulence, temperature and snow salinity) and recommend improved model parameterisations to estimate regional aerosol production. N-ICE 2015 results are then compared to a similar study carried out previously in the Weddell Sea during the Antarctic winter.

  13. Contamination of table salts from Turkey with microplastics.

    PubMed

    Gündoğdu, Sedat

    2018-05-01

    Microplastics (MPs) pollution has become a problem that affects all aquatic, atmospheric and terrestial environments in the world. In this study, we looked into whether MPs in seas and lakes reach consumers through table salt. For this purpose, we obtained 16 brands of table salts from the Turkish market and determined their MPs content with microscopic and Raman spectroscopic examination. According to our results, the MP particle content was 16-84 item/kg in sea salt, 8-102 item/kg in lake salt and 9-16 item/kg in rock salt. The most common plastic polymers were polyethylene (22.9%) and polypropylene (19.2%). When the amounts of MPs and the amount of salt consumed by Turkish consumers per year are considered together, if they consume sea salt, lake salt or rock salt, they consume 249-302, 203-247 or 64-78 items per year, respectively. This is the first time this concerning level of MPs content in table salts in the Turkish market has been reported.

  14. Relationships between lake-level changes and water and salt budgets in the Dead Sea during extreme aridities in the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Kiro, Yael; Goldstein, Steven L.; Garcia-Veigas, Javier; Levy, Elan; Kushnir, Yochanan; Stein, Mordechai; Lazar, Boaz

    2017-04-01

    Thick halite intervals recovered by the Dead Sea Deep Drilling Project cores show evidence for severely arid climatic conditions in the eastern Mediterranean during the last three interglacials. In particular, the core interval corresponding to the peak of the last interglacial (Marine Isotope Stage 5e or MIS 5e) contains ∼30 m of salt over 85 m of core length, making this the driest known period in that region during the late Quaternary. This study reconstructs Dead Sea lake levels during the salt deposition intervals, based on water and salt budgets derived from the Dead Sea brine composition and the amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of dissolved Na+ and Cl- accumulates during wetter intervals. Based on the compositions of Dead Sea brines from pore waters and halite fluid inclusions, we estimate that ∼12-16 cm of halite precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg2+ concentration increases and the Na+/Cl- ratio decreases in the lake. Our calculations indicate major lake-level drops of ∼170 m from lake levels of 320 and 310 m below sea level (mbsl) down to lake levels of ∼490 and ∼480 mbsl, during MIS 5e and the Holocene, respectively. These lake levels are much lower than typical interglacial lake levels of around 400 mbsl. These lake-level drops occurred as a result of major decreases in average fresh water runoff, to ∼40% of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ∼600 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average. The halite intervals include

  15. Research on the Fatigue Flexural Performance of RC Beams Attacked by Salt Spray

    NASA Astrophysics Data System (ADS)

    Mao, Jiang-hong; Xu, Fang-yuan; Jin, Wei-liang; Zhang, Jun; Wu, Xi-xi; Chen, Cai-sheng

    2018-04-01

    The fatigue flexural performance of RC beams attacked by salt spray was studied. A testing method involving electro osmosis, electrical accelerated corrosion and salt spray was proposed. This corrosion process method effectively simulates real-world salt spray and fatigue loading exerted by RC components on sea bridges. Four RC beams that have different stress amplitudes were tested. It is found that deterioration by corrosion and fatigue loading reduces the fatigue life of the RC and decreases the ability of deformation. The fatigue life and deflection ability could be reduced by increasing the stress amplitude and the corrosion duration time. The test result demonstrates that this experimental method can couple corrosion deterioration and fatigue loading reasonably. This procedure may be applied to evaluate the fatigue life and concrete durability of RC components located in a natural salt spray environment.

  16. [Analysis on component difference in Citrus reticulata before and after being processed with salt by UPLC-Q-TOF/MS].

    PubMed

    Zeng, Rui; Fu, Juan; Wu, La-Bin; Huang, Lin-Fang

    2013-07-01

    To analyze components of Citrus reticulata and salt-processed C. reticulata by ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and compared the changes in components before and after being processed with salt. Principal component analysis (PCA) and partial least squares discriminant analysis (OPLS-DA) were adopted to analyze the difference in fingerprint between crude and processed C. reticulata, showing increased content of eriocitrin, limonin, nomilin and obacunone increase in salt-processed C. reticulata. Potential chemical markers were identified as limonin, obacunone and nomilin, which could be used for distinguishing index components of crude and processed C. reticulata.

  17. Estimates of future inundation of salt marshes in response to sea-level rise in and around Acadia National Park, Maine

    USGS Publications Warehouse

    Nielsen, Martha G.; Dudley, Robert W.

    2013-01-01

    Salt marshes are ecosystems that provide many important ecological functions in the Gulf of Maine. The U.S. Geological Survey investigated salt marshes in and around Acadia National Park from Penobscot Bay to the Schoodic Peninsula to map the potential for landward migration of marshes using a static inundation model of a sea-level rise scenario of 60 centimeters (cm; 2 feet). The resulting inundation contours can be used by resource managers to proactively adapt to sea-level rise by identifying and targeting low-lying coastal areas adjacent to salt marshes for conservation or further investigation, and to identify risks to infrastructure in the coastal zone. For this study, the mapping of static inundation was based on digital elevation models derived from light detection and ranging (LiDAR) topographic data collected in October 2010. Land-surveyed control points were used to evaluate the accuracy of the LiDAR data in the study area, yielding a root mean square error of 11.3 cm. An independent accuracy assessment of the LiDAR data specific to salt-marsh land surfaces indicated a root mean square error of 13.3 cm and 95-percent confidence interval of ± 26.0 cm. LiDAR-derived digital elevation models and digital color aerial photography, taken during low tide conditions in 2008, with a pixel resolution of 0.5 meters, were used to identify the highest elevation of the land surface at each salt marsh in the study area. Inundation contours for 60-cm of sea-level rise were delineated above the highest marsh elevation for each marsh. Confidence interval contours (95-percent,± 26.0 cm) were delineated above and below the 60-cm inundation contours, and artificial structures, such as roads and bridges, that may present barriers to salt-marsh migration were mapped. This study delineated 114 salt marshes totaling 340 hectares (ha), ranging in size from 0.11 ha (marshes less than 0.2 ha were mapped only if they were on Acadia National Park property) to 52 ha, with a median

  18. A Continuous Flow Diffusion Chamber Study of Sea Salt Particles Acting as Cloud Seeds: Deliquescence, Ice Nucleation and Sublimation

    NASA Astrophysics Data System (ADS)

    Kong, X.; Wolf, M. J.; Garimella, S.; Roesch, M.; Cziczo, D. J.

    2016-12-01

    Sea Salt Aerosols (SSA) are abundant in the atmosphere, and important to the Earth's chemistry and energy budget. However, the roles of sea salts in the context of cloud formation are still poorly understood, which is partially due to the complexity of the water-salt phase diagram. At ambient temperatures, even well below 0°C, SSA deliquesces at sub-water saturated conditions. Since the ratio of the partial pressure over ice versus super-cooled water continuously declines with decreasing temperatures, it is interesting to consider if SSA continues to deliquesce under a super-saturated condition of ice, or if particles act as depositional ice nuclei when a critical supersaturation is reached. Some recent studies suggest hydrated NaCl and simulated sea salt might deliquesce between -35°C to -44°C, and below that deposition freezing becomes possible. Deliquesced droplets can subsequently freeze via the immersion or homogenous freezing mode, depending on if the deliquescence processes is complete. After the droplets or ice particles are formed, it is also interesting to consider how the different processes influence physical properties after evaporation or sublimation. This data is important for climate modeling that includes bromine burst observed in Antarctica, which is hypothesized to be relevant to the sublimation of blowing snow particles. In this study we use a SPectrometer for Ice Nuclei (SPIN; DMT, Inc., Boulder, CO) to perform experiments over a wide range of temperature and RH conditions to quantify deliquescence, droplet formation and ice nucleation. The formation of droplets and ice particles is detected by an advanced Optical Particle Counter (OPC) and the liquid/solid phases are distinguished by a machine learning method based on laser scattering and polarization data. Using an atomizer, four different sea salt samples are generated: pure NaCl and MgCl2 solutions, synthetic seawater, and natural seawater. Downstream of the SPIN chamber, a Pumped

  19. Unraveling the hydrocarbon charge potential of the Nordkapp Basin, Barents Sea: An integrated approach to reduce exploration risk in complex salt basins

    NASA Astrophysics Data System (ADS)

    Schenk, Oliver; Shtukert, Olga; Bishop, Andrew; Kornpihl, Kristijan; Milne, Graham

    2014-05-01

    The Nordkapp Basin, Barents Sea, is an intra-continental syn-rift basin containing many complex salt structures. The salt is late-Carboniferous to Early Permian in age, with regional extension in the Triassic initiating the salt movement resulting in formation of sub- and mini-basins with significant subsidence (especially in the northeastern part of the basin). Subsequent tectonic phases allowed growth and distortion of salt diapirs that were later affected by uplift and erosion during Tertiary resulting in the formation of salt-related traps in Triassic and Lower Jurassic strata. During Plio-Pleistocene, glacial erosion removed additional Mesozoic and Cenozoic strata. This basin is regarded as a frontier salt province. A small hydrocarbon discovery (Pandora well) in the southwestern part of the basin points to the presence several functioning petroleum systems. The primary play type is related to salt traps below overhangs. Such structures are however, very difficult to image with conventional seismic techniques due to i) generation of multiples from sea floor and top of shallow salt bodies and ii) seismic shadow zones within the salt (possibly resulting from shale and carbonate stringers) which cause severe diffractions so that prospective areas adjacent to the salt remain elusive. Arctic exploration is expensive and the ability to focus on the highest potential targets is essential. A unique solution to this challenging subsurface Arctic environment was developed by integrating petroleum system modeling with full azimuth broadband seismic acquisition and processing. This integrated approach allows intelligent location of seismic surveys over structures which have the maximum chance of success of hydrocarbon charge. Petroleum system modeling was conducted for four seismic sections. Salt was reconstructed according to the diapiric evolution presented in Nilsen et al. (1995) and Koyi et al. (1995). Episodes of major erosion were assigned to Tertiary (tectonic) and

  20. Sea ice melting in the marginal ice zone.

    USGS Publications Warehouse

    Josberger, E.G.

    1983-01-01

    The heat and salt flux boundary conditions together with the freezing curve relationship are a necessary component of any ice- sea water thermodynamic model. A neutral two-layer oceanic planetary boundary layer model that incorporates these boundary conditions is used. The results are discussed. -from Author

  1. Synthesis of Quinolines through Three-Component Cascade Annulation of Aryl Diazonium Salts, Nitriles, and Alkynes.

    PubMed

    Wang, Hao; Xu, Qian; Shen, Sheng; Yu, Shouyun

    2017-01-06

    An efficient and rapid synthesis of multiply substituted quinolines is described. This method is enabled by a three-component cascade annulation of readily available aryl diazonium salts, nitriles, and alkynes. This reaction is catalyst- and additive-free. Various aryl diazonium salts, nitriles, and alkynes can participate in this transformation, and the yields are up to 83%.

  2. Albedo of cold sea ice with precipitated salt on the tropical ocean of Snowball Earth: field measurements and laboratory experiments

    NASA Astrophysics Data System (ADS)

    Light, B.; Black, T.; Carns, R.; Brandt, R.; Dadic, R.; Warren, S.

    2012-04-01

    During the initial freezing of the tropical ocean on Snowball Earth, the first ice to form would be sea ice, which contains salt within liquid brine inclusions. At temperatures below -23 C, significant amounts of salt begin to crystallize within the brine inclusions. These crystals scatter light, increasing the ice albedo. The most abundant salt is hydrohalite, NaCl.2H2O. A dry tropical atmosphere promoting ice surface sublimation would cause a salt crust to be left on the surface as a lag deposit. Such a high-albedo surface could be crucial during the snowball initiation. These processes must be considered when assigning albedos to sea ice in a climate model of Snowball Earth. Precipitation of salt within brine inclusions was observed on windswept bare ice of McMurdo Sound at the coast of Antarctica (78 S) in late winter. Consequently the albedo was higher at lower temperature. The precipitation process exhibited hysteresis, with hydrohalite precipitating at about -30 C and dissolving at about -23 C. The causes of the hysteresis are being investigated in laboratory experiments; they may involve biological macromolecules. Nowhere on the modern Earth does sea ice undergo sublimation at low temperatures for long enough to develop a salt crust before the summer melt begins, so this process is being investigated in our laboratory. A 1000-liter tank is used to grow artificial sea ice, and a system has been built to measure its albedo. A diffusely reflecting hemispherical dome of diameter 1.2 m is placed on top of the tank and illuminated from within. The interior of the dome illuminates the ice surface as well as serving as a platform for detecting the incident and backscattered radiance fields. The diffusely reflecting surfaces of the ice and the dome make it straightforward to estimate incoming and reflected irradiance as angular integrals of the radiance measurements. The albedo of the bare, cold (below -23 C) ice is 0.8 at visible wavelengths, decreasing toward the

  3. Meta-omic analyses of Baltic Sea cyanobacteria: diversity, community structure and salt acclimation.

    PubMed

    Celepli, Narin; Sundh, John; Ekman, Martin; Dupont, Chris L; Yooseph, Shibu; Bergman, Birgitta; Ininbergs, Karolina

    2017-02-01

    Cyanobacteria are important phytoplankton in the Baltic Sea, an estuarine-like environment with pronounced north to south gradients in salinity and nutrient concentrations. Here, we present a metagenomic and -transcriptomic survey, with subsequent analyses targeting the genetic identity, phylogenetic diversity, and spatial distribution of Baltic Sea cyanobacteria. The cyanobacterial community constituted close to 12% of the microbial population sampled during a pre-bloom period (June-July 2009). The community was dominated by unicellular picocyanobacteria, specifically a few highly abundant taxa (Synechococcus and Cyanobium) with a long tail of low abundance representatives, and local peaks of bloom-forming heterocystous taxa. Cyanobacteria in the Baltic Sea differed genetically from those in adjacent limnic and marine waters as well as from cultivated and sequenced picocyanobacterial strains. Diversity peaked at brackish salinities 3.5-16 psu, with low N:P ratios. A shift in community composition from brackish to marine strains was accompanied by a change in the repertoire and expression of genes involved in salt acclimation. Overall, the pre-bloom cyanobacterial population was more genetically diverse, widespread and abundant than previously documented, with unicellular picocyanobacteria being the most abundant clade along the entire Baltic Sea salinity gradient. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. DEVELOPING INDICATORS OF SALT MARSH HEALTH

    EPA Science Inventory

    We relate plant zonation in salt marshes to key ecosystem services such as erosion control and wildlife habitat. Ten salt marshes in Narragansett Bay, with similar geological bedrock and sea exchange, were identified to examine plant zonation. Sub-watersheds adjacent to the salt ...

  5. Long term effect of a modified hydrodynamic at a lagoon inlet on the salt marsh ability to keep pace with sea level rise.

    NASA Astrophysics Data System (ADS)

    Carniello, L.; Nordio, G.; D'Alpaos, A.; Silvestri, S.

    2016-12-01

    In a context of global increase of mean sea level, the fate of salt marshes relates to their ability of keeping pace with relative sea level rise (SLR) and depends on the external sediment supply and organic soil production. Detecting the vertical sinking of salt marshes is a difficult task being the process characterized by time scales of tens to hundreds of years. Thanks to the availability of historical maps of the Venice lagoon, we reconstructed the reduction of salt mash areas that occurred in the northern part of the lagoon in the last two centuries. In this period, anthropic interventions played a crucial role in promoting the disappearance of vast marsh surfaces in the inner lagoon, while the marshes closer to the inlet remained fairly stable. Using a 2D numerical model we investigated the hydrodynamic behavior of different ancient lagoon configurations analyzing the effect of i) the construction of the jetties at the Lido inlet in 1882-1892 and ii) the removal of reed barriers that protected a fish farm area in the same period. Our results show that the deepening of the inlet induced by the construction of the jetties had a positive feedback on the vertical accretion of the salt marshes close to the inlet by lowering the local mean sea level and increasing the tidal amplitude. This effect contrasted the eustatic SLR for more than 30 years, allowing these marshes to increase their height with respect to the local mean sea level. On the contrary, the salt marshes far from the inlet could not take the same rapid advantage of this effect due to tidal wave dissipation characterizing tide propagation in shallow basins. Elevation of inner marshes is low due to the small tidal excursion, making these marshes extremely vulnerable to changes in sediment supply and SLR. We show that the removal of reed barriers used by ancient Venetians to create fish farms in the inner lagoon may have reduced the sediments available to the marshes thus contributing to their drowning.

  6. A universal salt model based on under-ground precipitation of solid salts due to supercritical water `out-salting'

    NASA Astrophysics Data System (ADS)

    Rueslåtten, H.; Hovland, M. T.

    2010-12-01

    One of the common characteristics of planets Earth and Mars is that both host water (H2O) and large accumulations of salt. Whereas Earth’s surface-environment can be regarded as ‘water-friendly’ and ‘salt hostile’, the reverse can be said for the surface of Mars. This is because liquid water is stable on Earth, and the atmosphere transports humidity around the globe, whereas on planet Mars, liquid water is unstable, rendering the atmosphere dry and, therefore, ‘salt-friendly’. The riddle as to how the salt accumulated in various locations on those two planets, is one of long-lasting and great debate. The salt accumulations on Earth are traditionally termed ‘evaporites’, meaning that they formed as a consequence of the evaporation of large masses of seawater. How the accumulations on Mars formed is much harder to explain, as an ocean only existed briefly. Although water molecules and OH-groups may exist in abundance in bound form (crystal water, adsorbed water, etc.), the only place where free water is expected to be stable on Mars is within underground faults, fractures, and crevices. Here it likely occurs as brine or in the form of ice. Based on these conditions, a key to understanding the accumulation of large deposits of salt on both planets is linked to how brines behave in the subsurface when pressurized and heated beyond their supercritical point. At depths greater than about 3 km (P>300 bars) water will no longer boil in a steam phase. Rather, it becomes supercritical and will attain the phase of supercritical water vapor (SCRIW) with a specific gravity of typically 0.3 g/cm3. An important characteristic of SCRIW is its inability to dissolve the common sea salts. The salt dissolved in the brines will therefore precipitate as solid particles when brines (seawater on the Earth) move into the supercritical P&T-domain (T>400°C, P>300 bars). Numerical modeling of a hydrothermal system in the Atlantis II Deep of the Red Sea indicates that a

  7. Community solar salt production in Goa, India

    PubMed Central

    2012-01-01

    Traditional salt farming in Goa, India has been practised for the past 1,500 years by a few communities. Goa’s riverine estuaries, easy access to sea water and favourable climatic conditions makes salt production attractive during summer. Salt produced through this natural evaporation process also played an important role in the economy of Goa even during the Portuguese rule as salt was the chief export commodity. In the past there were 36 villages involved in salt production, which is now reduced to 9. Low income, lack of skilled labour, competition from industrially produced salt, losses incurred on the yearly damage of embankments are the major reasons responsible for the reduction in the number of salt pans. Salt pans (Mithagar or Mithache agor) form a part of the reclaimed waterlogged khazan lands, which are also utilised for aquaculture, pisciculture and agriculture. Salt pans in Goa experience three phases namely, the ceased phase during monsoon period of June to October, preparatory phase from December to January, and salt harvesting phase, from February to June. After the monsoons, the salt pans are prepared manually for salt production. During high tide, an influx of sea water occurs, which enters the reservoir pans through sluice gates. The sea water after 1–2 days on attaining a salinity of approximately 5ºBé, is released into the evaporator pans and kept till it attains a salinity of 23 - 25ºBé. The brine is then released to crystallizer pans, where the salt crystallises out 25 - 27ºBé and is then harvested. Salt pans form a unique ecosystem where succession of different organisms with varying environmental conditions occurs. Organisms ranging from bacteria, archaea to fungi, algae, etc., are known to colonise salt pans and may influence the quality of salt produced. The aim of this review is to describe salt farming in Goa’s history, importance of salt production as a community activity, traditional method of salt production and the

  8. Community solar salt production in Goa, India.

    PubMed

    Mani, Kabilan; Salgaonkar, Bhakti B; Das, Deepthi; Bragança, Judith M

    2012-12-01

    Traditional salt farming in Goa, India has been practised for the past 1,500 years by a few communities. Goa's riverine estuaries, easy access to sea water and favourable climatic conditions makes salt production attractive during summer. Salt produced through this natural evaporation process also played an important role in the economy of Goa even during the Portuguese rule as salt was the chief export commodity. In the past there were 36 villages involved in salt production, which is now reduced to 9. Low income, lack of skilled labour, competition from industrially produced salt, losses incurred on the yearly damage of embankments are the major reasons responsible for the reduction in the number of salt pans.Salt pans (Mithagar or Mithache agor) form a part of the reclaimed waterlogged khazan lands, which are also utilised for aquaculture, pisciculture and agriculture. Salt pans in Goa experience three phases namely, the ceased phase during monsoon period of June to October, preparatory phase from December to January, and salt harvesting phase, from February to June. After the monsoons, the salt pans are prepared manually for salt production. During high tide, an influx of sea water occurs, which enters the reservoir pans through sluice gates. The sea water after 1-2 days on attaining a salinity of approximately 5ºBé, is released into the evaporator pans and kept till it attains a salinity of 23 - 25ºBé. The brine is then released to crystallizer pans, where the salt crystallises out 25 - 27ºBé and is then harvested.Salt pans form a unique ecosystem where succession of different organisms with varying environmental conditions occurs. Organisms ranging from bacteria, archaea to fungi, algae, etc., are known to colonise salt pans and may influence the quality of salt produced.The aim of this review is to describe salt farming in Goa's history, importance of salt production as a community activity, traditional method of salt production and the biota

  9. Modeling and Evaluation of the Global Sea-Salt Aerosol Distribution: Sensitivity to Emission Schemes and Resolution Effects at Coastal/Orographic Sites

    NASA Technical Reports Server (NTRS)

    Spada, M.; Jorba, O.; Perez Garcia-Pando, C.; Janjic, Z.; Baldasano, J. M.

    2013-01-01

    One of the major sources of uncertainty in model estimates of the global sea-salt aerosol distribution is the emission parameterization. We evaluate a new sea-salt aerosol life cycle module coupled to the online multi-scale chemical transport model NMMB/BSC-CTM. We compare 5 year global simulations using five state-of-the-art sea-salt open-ocean emission schemes with monthly averaged coarse aerosol optical depth (AOD) from selected AERONET sun photometers, surface concentration measurements from the University of Miami's Ocean Aerosol Network, and measurements from two NOAA/PMEL cruises (AEROINDOEX and ACE1). Model results are highly sensitive to the introduction of sea-surface-temperature (SST)-dependent emissions and to the accounting of spume particles production. Emission ranges from 3888 teragrams per year to 8114 teragrams per year, lifetime varies between 7.3 hours and 11.3 hours, and the average column mass load is between 5.0 teragrams and 7.2 teragrams. Coarse AOD is reproduced with an overall correlation of around 0.5 and with normalized biases ranging from +8.8 percent to +38.8 percent. Surface concentration is simulated with normalized biases ranging from minus 9.5 percent to plus 28 percent and the overall correlation is around 0.5. Our results indicate that SST-dependent emission schemes improve the overall model performance in reproducing surface concentrations. On the other hand, they lead to an overestimation of the coarse AOD at tropical latitudes, although it may be affected by uncertainties in the comparison due to the use of all-sky model AOD, the treatment of water uptake, deposition and optical properties in the model and/or an inaccurate size distribution at emission.

  10. Basement inheritance and salt tectonics in the SE Barents Sea: Insights from new potential field data

    NASA Astrophysics Data System (ADS)

    Gernigon, L.; Broenner, M.; Dumais, M. A.; Gradmann, S.; Grønlie, A.; Nasuti, A.; Roberts, D.

    2017-12-01

    The tectonic evolution of the former `grey zone' between Russia and Norway has so far remained poorly constrained due to a lack of geophysical data. In 2014, we carried out a new aeromagnetic survey (BASAR-14) in the southern part of the new Norwegian offshore territory. Caledonian and Timanian structures, highlighted by the new potential field data, dominate the basement patterns and have exerted a strong influence on the structure and development of the overlying basins and basement highs. Clearly associated with NW-SE-oriented Timanian trends, the Tiddlybanken Basin represents an atypical sag basin that developed at the southern edge of the Fedynsky High. Regional extension and rapid sedimentation initiated the salt tectonics in the Barents Sea in the Early Triassic. Some of the pillows became diapiric during the Early Triassic and rejuvenated during subsequent Jurassic-Tertiary episodes of regional extension and/or compression. At present, quite a few large diapiric salt domes along the Nordkapp and Tiddlybanken basins are relatively shallow, locally reaching the seabed and thus show a clear bathymetric and magnetic signature. Quantitative modelling along 2D seismic transects was also carried out to constrain the structural and basement composition of the study area. The predominant NE-SW Mesozoic trend of the Nordkapp Basin represents a major crustal hinge zone between the Finnmark Platform, poorly affected by major crustal deformation, and the Bjarmeland Platform where Late Palaeozoic rifting controlled the widespread accumulation of salt deposits in Late Carboniferous-Early Permian time. The entire structure and segmentation of the Nordkapp Basin have been influenced by the inherited basement configuration highlighted by the new aeromagnetic data. Both the Nordkapp and the Tiddlybanken basins appear to lie at the edge of a peculiar thick and rigid crustal feature that coincides with a highly magnetic region. The abrupt termination of the eastern Nordkapp

  11. The role of elevation, relative sea-level history and vegetation transition in determining carbon distribution in Spartina alterniflora dominated salt marshes

    NASA Astrophysics Data System (ADS)

    Kulawardhana, Ranjani W.; Feagin, Rusty A.; Popescu, Sorin C.; Boutton, Thomas W.; Yeager, Kevin M.; Bianchi, Thomas S.

    2015-03-01

    Spartina alterniflora salt marshes are among the most productive ecosystems on earth, and represent a substantial global carbon sink. Understanding the spatial heterogeneity in the distribution of both above- and below-ground carbon in these wetland ecosystems is especially important considering their potential in carbon sequestration projects, as well as for conservation efforts in the context of a changing climate and rising sea-level. Through the use of extensive field sampling and remote sensing data (Light Detection and Ranging - LiDAR, and aerial images), we sought to map and explain how vegetation biomass and soil carbon are related to elevation and relative sea-level change in a S. alterniflora dominated salt marsh on Galveston Island, Texas. The specific objectives of this study were to: 1) understand the relationship between elevation and the distribution of salt marsh vegetation percent cover, plant height, plant density, above-and below-ground biomass, and carbon, and 2) evaluate the temporal changes in relative sea-level history, vegetation transitions, and resulting changes in the patterns of soil carbon distribution. Our results indicated a clear zonation of terrain and vegetation characteristics (i.e., height, cover and biomass). In the soil profile, carbon concentrations and bulk densities showed significant and abrupt change at a depth of ∼10-15 cm. This apparent transition in the soil characteristics coincided temporally with a transformation of the land cover, as driven by a rapid increase in relative sea-level around this time at the sample locations. The amounts of soil carbon stored in recently established S. alterniflora intertidal marshes were significantly lower than those that have remained in situ for a longer period of time. Thus, in order to quantify and predict carbon in coastal wetlands, and also to understand the heterogeneity in the spatial distribution of carbon stocks, it is essential to understand not only the elevation, the

  12. Nutrient enrichment and precipitation changes do not enhance resiliency of salt marshes to sea level rise in the Northeastern U.S.

    EPA Science Inventory

    In the U.S. Northeast, salt marshes are exceptionally vulnerable to the effects of accelerated sea level rise as compensatory mechanisms relying on positive feedbacks between inundation and sediment deposition are insufficient to counter inundation increases in low turbidity tida...

  13. STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER, AND BY FATTY ACIDS, MINERAL ACIDS, AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER

    PubMed Central

    Allison, J. B.; Cole, William H.

    1934-01-01

    1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water. 2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water. 3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH2 groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value. 4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water. 5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response. 6. Stimulation by sodium chloride, nitrate

  14. [Principal component analysis and cluster analysis of inorganic elements in sea cucumber Apostichopus japonicus].

    PubMed

    Liu, Xiao-Fang; Xue, Chang-Hu; Wang, Yu-Ming; Li, Zhao-Jie; Xue, Yong; Xu, Jie

    2011-11-01

    The present study is to investigate the feasibility of multi-elements analysis in determination of the geographical origin of sea cucumber Apostichopus japonicus, and to make choice of the effective tracers in sea cucumber Apostichopus japonicus geographical origin assessment. The content of the elements such as Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Hg and Pb in sea cucumber Apostichopus japonicus samples from seven places of geographical origin were determined by means of ICP-MS. The results were used for the development of elements database. Cluster analysis(CA) and principal component analysis (PCA) were applied to differentiate the sea cucumber Apostichopus japonicus geographical origin. Three principal components which accounted for over 89% of the total variance were extracted from the standardized data. The results of Q-type cluster analysis showed that the 26 samples could be clustered reasonably into five groups, the classification results were significantly associated with the marine distribution of the sea cucumber Apostichopus japonicus samples. The CA and PCA were the effective methods for elements analysis of sea cucumber Apostichopus japonicus samples. The content of the mineral elements in sea cucumber Apostichopus japonicus samples was good chemical descriptors for differentiating their geographical origins.

  15. Fractal-like thickness and topography of the salt layer in a pillows province of the southern North Sea

    NASA Astrophysics Data System (ADS)

    Hernandez Maya, K.; Mitchell, N. C.; Huuse, M.

    2017-12-01

    Salt topography and thickness variations are important for testing theories of how halokinetic deformation proceeds. The ability to predict thickness variations of salt at small scale is also important for reservoir evaluations, as breach of the salt layer can lead to loss of petroleum fluids and can be difficult to evaluate from seismic reflection data. Relevant to these issues, we here report analysis of data on salt layer topography and thickness from the southern North Sea, where the salt is organized into pillows. These data were derived by the Geological Survey of the Netherlands (TNO) from industry 3D seismic reflection data combined with a dense network of well information. Highs and lows in the topography of the upper salt interface occur spaced over a variety of lengthscales. Power spectral analysis of the interface topography reveals a simple inverse power law relationship between power spectral density and spatial wave number. The relationship suggests that the interface is a self-affine fractal with a fractal dimension of 2.85. A similar analysis of the salt layer thickness also suggests a fractal-like power law. Whereas the layer thickness power law is unsurprising as the underlying basement topography dominates the thickness and it also has a fractal-like power spectrum, the salt topography is not so easily explained as not all the basement faults are overlaid by salt pillows, instead some areas of the dataset salt thinning overlies faults. We consider instead whether a spatially varied loading of the salt layer may have caused this fractal-like geometry. Varied density and thickness of overburdening layers seem unlikely causes, as thicknesses of layers and their reflectivities do not vary sympathetically with the topography of the interface. The composition of the salt layer varies with the relative proportions of halite and denser anhydrite and other minerals. Although limited in scope and representing the mobilized salt layer, the information from

  16. Influence of different salting processes on the evolution of the volatile metabolites of vacuum-packed fillets of farmed and wild sea bass (Dicentrarchus labrax) stored under refrigeration conditions: a study by SPME-GC/MS.

    PubMed

    Vidal, Natalia P; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

    2017-02-01

    Fish shelf-life extension is a topic of great interest. In this study the behaviour of salted and unsalted farmed and wild European sea bass (Dicentrarchus labrax) fillets during storage was analysed through the evolution of their volatile metabolites. Farmed and wild sea bass fillets were brine-salted for 15 or 75 min, or dry-salted, vacuum-packed and stored at 4 °C for up to 1 month, and their headspaces were studied by Solid Phase Micro extraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). At the same storage time, unsalted wild fillets contained, in general, a higher number and abundance of volatile compounds coming from microbiological or endogenous enzymatic activity than unsalted farmed ones. The more intense the salting, the lower the number and abundance of microbiological spoilage metabolites, especially in wild samples. The appearance of oxidation metabolites only in dry-salted wild samples evidences that this kind of salting provokes a certain oxidation in these samples. The better performance of farmed than wild fillets suggests that salted farmed fillets, vacuum-packed and stored under refrigeration conditions, could be a successful alternative to diversify the presence of sea bass in the market. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Steric sea level change in the Bay of Bengal: investigating the most variable component of sea level change

    NASA Astrophysics Data System (ADS)

    Uebbing, Bernd; Kusche, Jürgen; Rietbroek, Roelof; Shum, Ck

    2015-04-01

    Regional sea level change is influenced by contributions from mass sources, like melting of glaciers and the ice-sheets in Greenland and Antarctica, as well as steric contributions from changes in temperature and salinity of the oceans. Radar altimetry indicates a sea level trend in the Bay of Bengal of about 6 mm- yr over the time period of 2002-2014, which is significantly larger than the global mean trend. Here, we explain 80% of this rise by steric contributions and 20% by mass-related contributions. The increased rise of sea level in the Bay of Bengal threatens the coastal vulnerability of the surrounding countries like Bangladesh, where this effect is exacerbated in combination with land subsidence of the very low lying coastal areas. The BanD-AID (Bangladesh Delta: Assessment of the Causes of Sea-level Rise Hazards and Integrated Development of Predictive Modeling Towards Mitigation and Adaptation) project tries to assess the current and future sea level rise and its impacts on the people living in the threatened coastal areas. As a part of this, it is necessary to analyze the different mass and steric contributors to the total sea level rise to aid in the prediction of future risks. We use data from radar altimetry and the GRACE mission to separate the total sea level rise into contributions from mass sources and steric changes. In our approach, temporal GRACE gravity data and Jason-1 and -2 along track altimetry data are fitted to time invariant spatial patterns (fingerprints) to avoid problems with GRACE resolution, filtering, geocenter and related issues. Our results show that in the Bay of Bengal the steric component is influenced by annual and interannual phenomena and, at the same time, it is significantly larger compared to the individual mass contributions, which show a linear and relatively stable behavior over time. We validate the steric component of our inversion by comparing it to independent steric estimates from 4-D gridded temperature and

  18. Salt dissolution and sinkhole formation: Results of laboratory experiments

    NASA Astrophysics Data System (ADS)

    Oz, Imri; Eyal, Shalev; Yoseph, Yechieli; Ittai, Gavrieli; Elad, Levanon; Haim, Gvirtzman

    2016-10-01

    The accepted mechanism for the formation of thousands of sinkholes along the coast of the Dead Sea suggests that their primary cause is dissolution of a salt layer by groundwater undersaturated with respect to halite. This is related to the drop in the Dead Sea level, which caused a corresponding drop of the freshwater-saltwater interface, resulting in fresher groundwater replacing the brines that were in contact with the salt layer. In this study we used physical laboratory experiments to examine the validity of this mechanism by reproducing the full dynamic natural process and to examine the impact of different hydrogeological characteristics on this process. The experimental results show surface subsidence and sinkhole formation. The stratigraphic configurations of the aquifer, together with the mechanical properties of the salt layer, determine the dynamic patterns of the sinkhole formation (instantaneous versus gradual formation). Laboratory experiments were also used to study the potential impact of future stratification in the Dead Sea, if and when the "Red Sea-Dead Sea Canal" project is carried out, and the Dead Sea level remains stable. The results show that the dissolution rates are slower by 1 order of magnitude in comparison with a nonstratified saltwater body, and therefore, the processes of salt dissolution and sinkhole formation will be relatively restrained under these conditions.

  19. Bile Salt-like Dienones Having a Novel Skeleton or a Rare Substitution Pattern Function as Chemical Cues in Adult Sea Lamprey.

    PubMed

    Li, Ke; Scott, Anne M; Brant, Cory O; Fissette, Skye D; Riedy, Joseph J; Hoye, Thomas R; Li, Weiming

    2017-09-01

    Two novel sulfated bile salt-like dienones, featuring either a unique, rearranged side chain or a rare cis-11,12-diol on the steroidal C-ring, herein named petromyzene A (1) and B (2), respectively, were isolated from water conditioned with spawning male sea lamprey (Petromyzon marinus; a jawless vertebrate animal). The structures of these natural products were elucidated by mass spectrometry and NMR spectroscopy. Petromyzenes A and B exhibited high olfactory potency for adult sea lamprey and strong behavioral attraction for spawning females.

  20. The Early Gulf of Mexico as a Subaerial Basin Below Sea Level (SABSEL) Basin. Evidence from Stratigraphy and Facies of Luanne salt, Norphlet sandstone and Smackover Brown Dense Formations.

    NASA Astrophysics Data System (ADS)

    Cassidy, M. M.

    2016-12-01

    Many workers recognize that large salt deposits form in post-rift sag basins which were subaerial and susceptible to rapid flooding from adjacent oceansl. I have termed these basins "subaerial basins below sea level" or "SABSEL" basins. A key marker of SABSEL basins are terrestrial sediments immediately overlain by deepwater sediments with no transition. Desert deposits -including Aeolian dunes- are preserved in the adiabatically heated depression. Dunes are not eroded by transgressing seas but are drowned by rising water as in a bath tub. They maintain their shape. Deepwater marine black shales or limestones drape the dunes. The Southern North sea is an example. Above the original marine shale over the dunes are evaporites. Winds descending into the basin were heated by adiabatic compression providing the very hot air need to allow survival of potassium salts. A similar situation was probably active during the Messinian salinity crisis in the Mediterranean basin, and the opening of the South Atlantic. In the Gulf of Mexico (GOM) a desert is on the Louann salt. Here the sea invaded the lows first to deposit the salt overlying tilted fault blocks of the opening basin, as in the Afar Triangle of Africa. In the GOM entry to the west fed in sea water, then closed. The Norphlet desert formed. Streams carried sands to the basin to be spread by winds where they willed, not limited to sand entry areas. Upon deposition their original weight depressed the salt. Seismic shows depressions in the salt but the dunes are high at the top Norphlet, forming distinctive small "eyes" at the top salt. The 600 foot dunes are draped by deep water dolomitic finely laminated organic rich black/ brown shale, the Brown Dense Facies of the Smackover formation. The lack of reworking of the dunes found by detailed seismic is distinctive of deposition in a SABSEL basin. The overlap of terrestrial sediments by deep water deposition is good evidence of sudden flooding. In summary this vertical

  1. A systematic technique for the sequential restoration of salt structures

    NASA Astrophysics Data System (ADS)

    Rowan, Mark G.

    1993-12-01

    A method is described for the sequential restoration of cross sections in areas of salt tectonics where deformation is confined to the salt and higher layers. The subsurface geometry evolves with time through the interaction of various processes: sedimentation, compaction, isostatic adjustment, thermal subsidence (if present), faulting, and salt withdrawal/ diapirism. The technique systematically calculates and removes the effects of each of these processes during specified time intervals defined by the interpreted horizons. It makes no assumptions about salt kinematics and generally results in the area of the salt layer changing through time. The method is described for restoration of extensional terranes, but it is also suitable for areas of contractional salt tectonics with only minor modifications. After converting an interpreted seismic profile to depth, the top layer is stripped off and the underlying section is decompacted according to standard porosity-depth functions. A deep baseline, unaffected by compaction or deformation, is used to restore any isostatic compensation or thermal subsidence. Isostasy is calculated according to the Airy model, and differential sedimentary loading across a section is shown to be approximately balanced by changes in salt thickness so that the load is evenly distributed. After these processes have been reversed, the resulting geometry and the seismic data are used to create the sea-floor template for structural restoration. Fault offsets are removed and the layers down to the top salt are restored to this template, while the base salt remains fixed. The resulting space between the restored top salt and the fixed base salt defines the restored salt geometry. In addition, the difference between the sea-floor template and a fixed sea level provides a measure of the change in water depth (ignoring eustatic changes in sea level). The technique is applied to an interpreted seismic profile from the eastern Green Canyon/Ewing Bank

  2. Heterogeneous Ice Nucleation Ability of NaCl and Sea Salt Aerosol Particles at Cirrus Temperatures

    NASA Astrophysics Data System (ADS)

    Wagner, Robert; Kaufmann, Julia; Möhler, Ottmar; Saathoff, Harald; Schnaiter, Martin; Ullrich, Romy; Leisner, Thomas

    2018-03-01

    In situ measurements of the composition of heterogeneous cirrus ice cloud residuals have indicated a substantial contribution of sea salt in sampling regions above the ocean. We have investigated the heterogeneous ice nucleation ability of sodium chloride (NaCl) and sea salt aerosol (SSA) particles at cirrus cloud temperatures between 235 and 200 K in the Aerosol Interaction and Dynamics in the Atmosphere aerosol and cloud chamber. Effloresced NaCl particles were found to act as ice nucleating particles in the deposition nucleation mode at temperatures below about 225 K, with freezing onsets in terms of the ice saturation ratio, Sice, between 1.28 and 1.40. Above 225 K, the crystalline NaCl particles deliquesced and nucleated ice homogeneously. The heterogeneous ice nucleation efficiency was rather similar for the two crystalline forms of NaCl (anhydrous NaCl and NaCl dihydrate). Mixed-phase (solid/liquid) SSA particles were found to act as ice nucleating particles in the immersion freezing mode at temperatures below about 220 K, with freezing onsets in terms of Sice between 1.24 and 1.42. Above 220 K, the SSA particles fully deliquesced and nucleated ice homogeneously. Ice nucleation active surface site densities of the SSA particles were found to be in the range between 1.0 · 1010 and 1.0 · 1011 m-2 at T < 220 K. These values are of the same order of magnitude as ice nucleation active surface site densities recently determined for desert dust, suggesting a potential contribution of SSA particles to low-temperature heterogeneous ice nucleation in the atmosphere.

  3. Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics

    USGS Publications Warehouse

    Al-Zoubi, A.; ten Brink, Uri S.

    2001-01-01

    Regional extension of a brittle overburden and underlying salt causes differential loading that is thought to initiate the rise of reactive diapirs below and through regions of thin overburden. We present a modern example of a large salt diapir in the Dead Sea pull-apart basin, the Lisan diapir, which we believe was formed during the Quaternary due to basin transtension and subsidence. Using newly released seismic data that are correlated to several deep wells, we determine the size of the diapir to be 13 x 10 km. its maximum depth 7.2 km. and its roof 125 m below the surface. From seismic stratigraphy, we infer that the diapir started rising during the early to middle Pleistocene as this section of the basin underwater rapid subsidence and significant extension of the overburden. During the middle to late Pleistocene, the diapir pierced through the extensionally thinned overburden, as indicated by rim synclines, which attest to rapid salt withdrawal from the surrounding regions. Slight positive topography above the diapir and shallow folded horizons indicate that it is still rising intermittently. The smaller Sedom diapir, exposed along the western bounding fault of the basin is presently rising and forms a 200 m-high ridge. Its initiation is explained by localized E-W extension due monoclinal draping over the edge of a rapidly subsiding basin during the early to middle Pleistocene, and its continued rise by lateral squeezing due to continued rotation of the Amazyahu diagonal fault. 

  4. Atmospheric salt deposition in a tropical mountain rainforest at the eastern Andean slopes of south Ecuador - Pacific or Atlantic origin?

    NASA Astrophysics Data System (ADS)

    Makowski Giannoni, Sandro; Trachte, Katja; Rollenbeck, Ruetger; Lehnert, Lukas; Fuchs, Julia; Bendix, Joerg

    2016-08-01

    Sea salt (NaCl) has recently been proven to be of the utmost importance for ecosystem functioning in Amazon lowland forests because of its impact on herbivory, litter decomposition and, thus, carbon cycling. Sea salt deposition should generally decline as distance from its marine source increases. For the Amazon, a negative east-west gradient of sea salt availability is assumed as a consequence of the barrier effect of the Andes Mountains for Pacific air masses. However, this generalized pattern may not hold for the tropical mountain rainforest in the Andes of southern Ecuador. To analyse sea salt availability, we investigated the deposition of sodium (Na+) and chloride (Cl-), which are good proxies of sea spray aerosol. Because of the complexity of the terrain and related cloud and rain formation processes, sea salt deposition was analysed from both, rain and occult precipitation (OP) along an altitudinal gradient over a period between 2004 and 2009. To assess the influence of easterly and westerly air masses on the deposition of sodium and chloride over southern Ecuador, sea salt aerosol concentration data from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis data set and back-trajectory statistical methods were combined. Our results, based on deposition time series, show a clear difference in the temporal variation of sodium and chloride concentration and Na+ / Cl- ratio in relation to height and exposure to winds. At higher elevations, sodium and chloride present a higher seasonality and the Na+ / Cl- ratio is closer to that of sea salt. Medium- to long-range sea salt transport exhibited a similar seasonality, which shows the link between our measurements at high elevations and the sea salt synoptic transport. Although the influence of the easterlies was predominant regarding the atmospheric circulation, the statistical analysis of trajectories and hybrid receptor models revealed a stronger impact of the north equatorial Atlantic, Caribbean

  5. Remote-sensing-based analysis of landscape change in the desiccated seabed of the Aral Sea--a potential tool for assessing the hazard degree of dust and salt storms.

    PubMed

    Löw, F; Navratil, P; Kotte, K; Schöler, H F; Bubenzer, O

    2013-10-01

    With the recession of the Aral Sea in Central Asia, once the world's fourth largest lake, a huge new saline desert emerged which is nowadays called the Aralkum. Saline soils in the Aralkum are a major source for dust and salt storms in the region. The aim of this study was to analyze the spatio-temporal land cover change dynamics in the Aralkum and discuss potential implications for the recent and future dust and salt storm activity in the region. MODIS satellite time series were classified from 2000-2008 and change of land cover was quantified. The Aral Sea desiccation accelerated between 2004 and 2008. The area of sandy surfaces and salt soils, which bear the greatest dust and salt storm generation potential increased by more than 36 %. In parts of the Aralkum desalinization of soils was found to take place within 4-8 years. The implication of the ongoing regression of the Aral Sea is that the expansion of saline surfaces will continue. Knowing the spatio-temporal dynamics of both the location and the surface characteristics of the source areas for dust and salt storms allows drawing conclusions about the potential hazard degree of the dust load. The remote-sensing-based land cover assessment presented in this study could be coupled with existing knowledge on the location of source areas for an early estimation of trends in shifting dust composition. Opportunities, limits, and requirements of satellite-based land cover classification and change detection in the Aralkum are discussed.

  6. Insight into Generation and Evolution of Sea-Salt Aerosols from Field Measurements in Diversified Marine and Coastal Atmospheres

    PubMed Central

    Feng, Limin; Shen, Hengqing; Zhu, Yujiao; Gao, Huiwang; Yao, Xiaohong

    2017-01-01

    This report focuses on studying generation and/or evolution of sea-salt aerosols (SSA) on basis of measurements in the Northwest Pacific Ocean (NWPO), the marginal seas of China, at sea-beach sites and a semi-urban coastal site in 2012–2015. From measurements in the NWPO, we obtained the smallest generation function of the super-micron SSA mass ([MSSA]) by the local wind comparing to those previously reported. Vessel-caused wave-breaking was found to greatly enhance generation of SSA and increase [MSSA], which was subject to non-natural generation of SSA. However, naturally enhanced generation of SSA was indeed observed in the marginal seas and at the sea-beach site. The two enhancement mechanisms may explain the difference among this and previous studies. Size distributions of super-micron SSA exhibited two modes, i.e., 1–2 μm mode and ~5 μm mode. The 1–2 μm mode of SSA was enhanced more and comparable to the ~5 μm mode under the wind speed >7 m/s. However, the smaller mode SSA was largely reduced from open oceans to sea-beach sites with reducing wind speed. The two super-micron modes were comparable again at a semi-urban coastal site, suggesting that the smaller super-micron mode SSA may play more important roles in atmospheres. PMID:28120906

  7. A synthesized mating pheromone component increases adult sea lamprey (Petromyzon marinus) trap capture in management scenarios

    USGS Publications Warehouse

    Johnson, Nicholas S.; Siefkes, Michael J.; Wagner, C. Michael; Dawson, Heather; Wang, Huiyong; Steeves, Todd; Twohey, Michael; Li, Weiming

    2013-01-01

    Application of chemical cues to manipulate adult sea lamprey (Petromyzon marinus) behavior is among the options considered for new sea lamprey control techniques in the Laurentian Great Lakes. A male mating pheromone component, 7a,12a,24-trihydroxy-3-one-5a-cholan-24-sulfate (3kPZS), lures ovulated female sea lamprey upstream into baited traps in experimental contexts with no odorant competition. A critical knowledge gap is whether this single pheromone component influences adult sea lamprey behavior in management contexts containing free-ranging sea lampreys. A solution of 3kPZS to reach a final in-stream concentration of 10-12 mol·L-1 was applied to eight Michigan streams at existing sea lamprey traps over 3 years, and catch rates were compared between paired 3kPZS-baited and unbaited traps. 3kPZS-baited traps captured significantly more sexually immature and mature sea lampreys, and overall yearly trapping efficiency within a stream averaged 10% higher during years when 3kPZS was applied. Video analysis of a trap funnel showed that the likelihood of sea lamprey trap entry after trap encounter was higher when the trap was 3kPZS baited. Our approach serves as a model for the development of similar control tools for sea lamprey and other aquatic invaders.

  8. Early evolution of salt structures in north Louisiana salt basin

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

    Lobao, J.J.; Pilger, R.H. Jr.

    1986-05-01

    Several salt diapirs and pillows in southern and central north Louisiana have been studied using approximately 355 mi (570 km) of seismic reflection data and information from 57 deep well holes. Using seismic profiles with deep well-hole data is the most advantageous method to document regional salt tectonism through time. The following conclusions were reached on diapirism in the North Louisiana Salt basin. (1) The diapiric event began early (early Coahuilan) in the southern and central part of the basin, and later (late Coahuilan to Comanchean) in the northern part. (2) The initial diapiric event is much more abrupt andmore » intense in the southern and central diapirs when compared with the later diapiric event in the northern diapirs. (3) Regional depocenter shifting, relative sea level, local erosion with salt extrusion, and rapid depositional loading of sediments are the major controls on diapirism in the basin.« less

  9. A Krill's Eye View: Sea Ice Microstructure and Microchemistry

    NASA Astrophysics Data System (ADS)

    Obbard, R. W.; Lieb-Lappen, R.

    2015-12-01

    Sea ice plays important roles in the marine ecosystem and our environment, and a detailed understanding of all aspects of its microstructure is especially important in this time of changing climate. For many months of the year, the ice forms a permeable barrier between Polar oceans and the atmosphere, and as it freezes and melts, its microstructure evolves and changes in ways that affect other parts of that system. Sea ice also provides a microhabitat that is an important part of the marine ecosystem, but much remains to be learned about it on this scale. In material terms, sea ice is multiphase and very close to its melting point, and these properties make its microstructure particularly complex and dynamic, as well as challenging and interesting to study. We use a combination of analytical methods to achieve a very detailed understanding of sea ice microstructure - specifically the morphology and distribution of ice crystals and brine channels. Overall porosity affects freeboard, emissivity, and optical and mechanical properties, but pore connectivity is critical to gas and fluid transport, salt flux to polar oceans, the transfer of halogens to the boundary layer troposphere, and the transport of nutrients and pollutants to microorganisms. When sea ice forms, salts are expelled from newly formed ice crystals and concentrated on grain boundaries and in brine pockets and channels. We use synchrotron-based X-ray fluorescence spectroscopy (SXRF) and scanning electron microscope-based energy dispersive spectroscopy (EDS) to map the location in two dimensions of several important salt components in sea ice: SXRF for bromine, chlorine, potassium, calcium and iron, EDS for these as well as some lighter elements such as sodium, magnesium, and silicon. We use X-ray microcomputed tomography (microCT) to produce three-dimensional models of brine channels and to study changes in brine network topology due to warming and cooling. Both microCT and optical thin sections provide

  10. Recent Trends in Bird Abundance on Rhode Island Salt Marshes

    EPA Science Inventory

    Salt marsh habitat is under pressure from development on the landward side, and sea level rise from the seaward side. The resulting loss of habitat is potentially disastrous for salt marsh dependent species. To assess the population status of three species of salt marsh dependent...

  11. Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla.

    PubMed

    Sørensen, Sune Riis; Butts, Ian Anthony Ernest; Munk, Peter; Tomkiewicz, Jonna

    2016-02-01

    Improper activation and swelling of in vitro produced eggs of European eel, Anguilla anguilla, has been shown to negatively affect embryonic development and hatching. We investigated this phenomenon by examining the effects of salinity and sea salt type on egg dimensions, cell cleavage patterns and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30-40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion diameters reached maximal values of 1642 ± 8 μm at 35 psu. A positive relationship was found between egg neutral buoyancy and activation salinity. Nine salt types were investigated as activation and incubation media. Five of these types induced a substantial perivitelline space (PVS), leading to large egg sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic composition of the media when rearing fish eggs and further studies are encouraged.

  12. The street children of Manila are affected by early-in-life periodontal infection: description of a treatment modality: sea salt.

    PubMed

    Michel, J F; Michel, M G; Nadan, J; Nowzari, H

    2013-01-01

    Thousands of street children of Manila are affected by early-in-life oral infection. The aim of the present investigation was to evaluate the effectiveness of a sea-salt mouthrinse solution in street children of Manila affected by mild to severe forms of periodontal disease. These children were all in need of special protection: abandoned, abused, exploited, neglected, orphaned, poor. During 3 oral-health missions in 2003, 2004 and 2005, 617 abandoned children (5 to 13 year-old), received oral examination at a non-sectarian child-caring institution in Metro Manila (Virlanie Foundation) by calibrated examiners. A treatment based on what could be done was proposed: 1. Teaching of a precise tooth brushing technique with sea-salt, controlled and reinforced every two days for one week by calibrated health educators, 2. The application of sea-salt water mouthrinse (2.5 gram in 20 ml). Periodontal measurements were repeated at the end of each mission. All children returned to child-caring institution for the followup examinations. In 2003, 10 male and 11 female (n=21) were diagnosed with aggressive periodontitis. In 2009 and 2010, none was affected by aggressive periodontitis. For all patients, the gingival index decreased from 1.08 at the first mission to 1.04 at the end of the second mission and 0.98 at the end of the third mission. The periodontal index decreased from 1.33 at the first mission to 0.98 at the second mission and 0.92 at the last mission. The present investigation confirms that prevention and early diagnosis can result in success with minimum cost. The provided oral health program empowered street children in the most desperate circumstances to be educated and become self-reliant, independent, and responsible. We propose here an antimicrobial approach which has a high degree of efficacy and tolerability, and can be implemented in virtually all parts of the world using low-cost resources.

  13. Plant salt-tolerance mechanisms

    DOE PAGES

    Deinlein, Ulrich; Stephan, Aaron B.; Horie, Tomoaki; ...

    2014-06-01

    Crop performance is severely affected by high salt concentrations in soils. To engineer more salt-tolerant plants it is crucial to unravel the key components of the plant salt-tolerance network. Here we review our understanding of the core salt-tolerance mechanisms in plants. Recent studies have shown that stress sensing and signaling components can play important roles in regulating the plant salinity stress response. We also review key Na+ transport and detoxification pathways and the impact of epigenetic chromatin modifications on salinity tolerance. In addition, we discuss the progress that has been made towards engineering salt tolerance in crops, including marker-assisted selectionmore » and gene stacking techniques. We also identify key open questions that remain to be addressed in the future.« less

  14. Extreme Dead Sea drying event during the last interglacial from the ICDP Dead Sea Deep Drill Core

    NASA Astrophysics Data System (ADS)

    Goldstein, S.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.

    2012-04-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes in a deep and a shallow site extending to ~450 meters. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments are an archive of the evolving climatic conditions. During glacials the sediments comprise intervals of marl (aragonite, gypsum and detritus) and during interglacials they are salts and marls. We estimate that the deep site core spans ~200 kyr (to early MIS 7). A dramatic discovery is a ~40 cm interval of rounded pebbles at ~235 m below the lake floor, the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the runoff. GCM models indicate a more arid future in the region. The core shows that the runoff nearly stopped during a past warm period without human intervention.

  15. Multiple functions of a multi-component mating pheromone in sea lamprey Petromyzon marinus

    USGS Publications Warehouse

    Johnson, N.S.; Yun, S.-S.; Buchinger, T.J.; Li, W.

    2012-01-01

    The role of the C24 sulphate in the mating pheromone component, 7α,12α,24-trihydroxy-5α-cholan-3-one 24-sulphate (3kPZS), to specifically induce upstream movement in ovulated female sea lampreys Petromyzon marinus was investigated. 7α,12α-dihydroxy-5α-cholan-3-one 24-oic acid (3kACA), a structurally similar bile acid released by spermiated males, but lacking the C24 sulphate ester, was tested in bioassays at concentrations between 10−11 and 10−14 molar (M). 3kACA did not induce upstream movement in females or additional reproductive behaviours. In contrast, spermiated male washings induced upstream movement, prolonged retention on a nest and induced an array of nesting behaviours. Differential extraction and elution by solid-phase extraction resins showed that components other than 3kPZS + 3kACA are necessary to retain females on nests and induce nest cleaning behaviours. All pheromone components, including components in addition to 3kPZS + 3kACA that retain females and induce nest cleaning behaviours were released from the anterior region of the males, as had been reported for 3kPZS. It is concluded that the sea lamprey male mating pheromone has multiple functions and is composed of multiple components.

  16. Natural versus human control on subsurface salt dissolution and development of thousands of sinkholes along the Dead Sea coast

    NASA Astrophysics Data System (ADS)

    Abelson, Meir; Yechieli, Yoseph; Baer, Gidon; Lapid, Gil; Behar, Nicole; Calvo, Ran; Rosensaft, Marcelo

    2017-06-01

    One of the most hazardous results of the human-induced Dead Sea (DS) shrinkage is the formation of more than 6000 sinkholes over the last 25 years. The DS shrinkage caused eastward retreat of underground brine replaced by fresh groundwater, which in turn dissolved a subsurface salt layer, to generate cavities and collapse sinkholes. The areal growth rate of sinkhole clusters is considered the most pertinent proxy for sinkholes development. Analysis of light detection and ranging, digital elevation models, and interferometric synthetic aperture radar allows translation of the areal growth rate to a salt dissolution rate of the salt layer, revealing two peaks in the history of the salt dissolution rate. These peaks cannot be attributed to the decline of the DS level. Instead, we show that they are related to long-term variations of precipitation in the groundwater source region, the Judea Mountains, and the delayed response of the aquifer system between the mountains and the DS rift. This response is documented by groundwater levels and salinity variations. We thus conclude that while the DS level decline is the major trigger for sinkholes formation, the rainfall variations more than 30 km to the west dominate their evolution rate. The influence of increasing rainfall in the Judea Mountains reaches the DS at a typical time lag of 4 years, and the resulting increase in the salt dissolution rate lags by a total time of 5-6 years.

  17. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

    PubMed

    Takahashi, Masateru; Takahashi, Etsuko; Joudeh, Luay I; Marini, Monica; Das, Gobind; Elshenawy, Mohamed M; Akal, Anastassja; Sakashita, Kosuke; Alam, Intikhab; Tehseen, Muhammad; Sobhy, Mohamed A; Stingl, Ulrich; Merzaban, Jasmeen S; Di Fabrizio, Enzo; Hamdan, Samir M

    2018-01-24

    The deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein's surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of KOD DNA polymerase.-Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

  18. High-value components and bioactives from sea cucumbers for functional foods--a review.

    PubMed

    Bordbar, Sara; Anwar, Farooq; Saari, Nazamid

    2011-01-01

    Sea cucumbers, belonging to the class Holothuroidea, are marine invertebrates, habitually found in the benthic areas and deep seas across the world. They have high commercial value coupled with increasing global production and trade. Sea cucumbers, informally named as bêche-de-mer, or gamat, have long been used for food and folk medicine in the communities of Asia and Middle East. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as Vitamin A, Vitamin B1 (thiamine), Vitamin B2 (riboflavin), Vitamin B3 (niacin), and minerals, especially calcium, magnesium, iron and zinc. A number of unique biological and pharmacological activities including anti-angiogenic, anticancer, anticoagulant, anti-hypertension, anti-inflammatory, antimicrobial, antioxidant, antithrombotic, antitumor and wound healing have been ascribed to various species of sea cucumbers. Therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives especially triterpene glycosides (saponins), chondroitin sulfates, glycosaminoglycan (GAGs), sulfated polysaccharides, sterols (glycosides and sulfates), phenolics, cerberosides, lectins, peptides, glycoprotein, glycosphingolipids and essential fatty acids. This review is mainly designed to cover the high-value components and bioactives as well as the multiple biological and therapeutic properties of sea cucumbers with regard to exploring their potential uses for functional foods and nutraceuticals.

  19. High-Value Components and Bioactives from Sea Cucumbers for Functional Foods—A Review

    PubMed Central

    Bordbar, Sara; Anwar, Farooq; Saari, Nazamid

    2011-01-01

    Sea cucumbers, belonging to the class Holothuroidea, are marine invertebrates, habitually found in the benthic areas and deep seas across the world. They have high commercial value coupled with increasing global production and trade. Sea cucumbers, informally named as bêche-de-mer, or gamat, have long been used for food and folk medicine in the communities of Asia and Middle East. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as Vitamin A, Vitamin B1 (thiamine), Vitamin B2 (riboflavin), Vitamin B3 (niacin), and minerals, especially calcium, magnesium, iron and zinc. A number of unique biological and pharmacological activities including anti-angiogenic, anticancer, anticoagulant, anti-hypertension, anti-inflammatory, antimicrobial, antioxidant, antithrombotic, antitumor and wound healing have been ascribed to various species of sea cucumbers. Therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array of bioactives especially triterpene glycosides (saponins), chondroitin sulfates, glycosaminoglycan (GAGs), sulfated polysaccharides, sterols (glycosides and sulfates), phenolics, cerberosides, lectins, peptides, glycoprotein, glycosphingolipids and essential fatty acids. This review is mainly designed to cover the high-value components and bioactives as well as the multiple biological and therapeutic properties of sea cucumbers with regard to exploring their potential uses for functional foods and nutraceuticals. PMID:22072996

  20. Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

    NASA Astrophysics Data System (ADS)

    Yi, Liang; Chen, Yanping

    2013-04-01

    Future anthropogenic sea-level rise and its impact on coastal regions is an important issue facing human civilizations. Due to the short nature of the instrumental record of sea-level change, development of proxies for sea-level change prior to the advent of instrumental records is essential to reconstruct long-term background sea-level changes on local, regional and global scales. Two of the most widely used approaches for past sea-level changes are: (1) exploitation of dated geomorphologic features such as coastal sands (e.g. Mauz and Hassler, 2000), salt marsh (e.g. Madsen et al., 2007), terraces (e.g. Chappell et al., 1996), and other coastal sediments (e.g. Zong et al., 2003); and (2) sea-level transfer functions based on faunal assemblages such as testate amoebae (e.g. Charman et al., 2002), foraminifera (e.g. Chappell and Shackleton, 1986; Horton, 1997), and diatoms (e.g. Horton et al., 2006). While a variety of methods has been developed to reconstruct palaeo-changes in sea level, many regions, including the Bohai Sea, China, still lack detailed relative sea-level curves extending back to the Pleistocene (Yi et al., 2012). For example, coral terraces are absent in the Bohai Sea, and the poor preservation of faunal assemblages makes development of a transfer function for a relative sea-level reconstruction unfeasible. In contrast, frequent alternations between transgression and regression has presumably imprinted sea-level change on the grain size distribution of Bohai Sea sediments, which varies from medium silt to coarse sand during the late Quaternary (IOCAS, 1985). Advantages of grainsize-based relative sea-level transfer function approaches are that they require smaller sample sizes, allowing for replication, faster measurement and higher spatial or temporal resolution at a fraction of the cost of detail micro-palaeontological analysis (Yi et al., 2012). Here, we employ numerical methods to partition sediment grain size using a combined database of

  1. Improvement of seawater salt quality by hydro-extraction and re-crystallization methods

    NASA Astrophysics Data System (ADS)

    Sumada, K.; Dewati, R.; Suprihatin

    2018-01-01

    Indonesia is one of the salt producing countries that use sea water as a source of raw materials, the quality of salt produced is influenced by the quality of sea water. The resulting average salt quality contains 85-90% NaCl. The Indonesian National Standard (SNI) for human salt’s consumption sodium chloride content is 94.7 % (dry base) and for industrial salt 98,5 %. In this study developed the re-crystallization without chemical and hydro-extraction method. The objective of this research to choose the best methods based on efficiency. The results showed that re-crystallization method can produce salt with NaCl content 99,21%, while hydro-extraction method content 99,34 % NaCl. The salt produced through both methods can be used as a consumption and industrial salt, Hydro-extraction method is more efficient than re-crystallization method because re-crystallization method requires heat energy.

  2. Resistance of Silicon Nitride Turbine Components to Erosion and Hot Corrosion/oxidation Attack

    NASA Technical Reports Server (NTRS)

    Strangmen, Thomas E.; Fox, Dennis S.

    1994-01-01

    Silicon nitride turbine components are under intensive development by AlliedSignal to enable a new generation of higher power density auxiliary power systems. In order to be viable in the intended applications, silicon nitride turbine airfoils must be designed for survival in aggressive oxidizing combustion gas environments. Erosive and corrosive damage to ceramic airfoils from ingested sand and sea salt must be avoided. Recent engine test experience demonstrated that NT154 silicon nitride turbine vanes have exceptional resistance to sand erosion, relative to superalloys used in production engines. Similarly, NT154 silicon nitride has excellent resistance to oxidation in the temperature range of interest - up to 1400 C. Hot corrosion attack of superalloy gas turbine components is well documented. While hot corrosion from ingested sea salt will attack silicon nitride substantially less than the superalloys being replaced in initial engine applications, this degradation has the potential to limit component lives in advanced engine applications. Hot corrosion adversely affects the strength of silicon nitride in the 850 to 1300 C range. Since unacceptable reductions in strength must be rapidly identified and avoided, AlliedSignal and the NASA Lewis Research Center have pioneered the development of an environmental life prediction model for silicon nitride turbine components. Strength retention in flexure specimens following 1 to 3300 hour exposures to high temperature oxidation and hot corrosion has been measured and used to calibrate the life prediction model. Predicted component life is dependent upon engine design (stress, temperature, pressure, fuel/air ratio, gas velocity, and inlet air filtration), mission usage (fuel sulfur content, location (salt in air), and times at duty cycle power points), and material parameters. Preliminary analyses indicate that the hot corrosion resistance of NT154 silicon nitride is adequate for AlliedSignal's initial engine

  3. Observations of brine plumes below melting Arctic sea ice

    NASA Astrophysics Data System (ADS)

    Peterson, Algot K.

    2018-02-01

    In sea ice, interconnected pockets and channels of brine are surrounded by fresh ice. Over time, brine is lost by gravity drainage and flushing. The timing of salt release and its interaction with the underlying water can impact subsequent sea ice melt. Turbulence measurements 1 m below melting sea ice north of Svalbard reveal anticorrelated heat and salt fluxes. From the observations, 131 salty plumes descending from the warm sea ice are identified, confirming previous observations from a Svalbard fjord. The plumes are likely triggered by oceanic heat through bottom melt. Calculated over a composite plume, oceanic heat and salt fluxes during the plumes account for 6 and 9 % of the total fluxes, respectively, while only lasting in total 0.5 % of the time. The observed salt flux accumulates to 7.6 kg m-2, indicating nearly full desalination of the ice. Bulk salinity reduction between two nearby ice cores agrees with accumulated salt fluxes to within a factor of 2. The increasing fraction of younger, more saline ice in the Arctic suggests an increase in desalination processes with the transition to the new Arctic.

  4. Salting effects on protein components in aqueous NaCl and urea solutions: toward understanding of urea-induced protein denaturation.

    PubMed

    Li, Weifeng; Zhou, Ruhong; Mu, Yuguang

    2012-02-02

    The mechanism of urea-induced protein denaturation is explored through studying the salting effect of urea on 14 amino acid side chain analogues, and N-methylacetamide (NMA) which mimics the protein backbone. The solvation free energies of the 15 molecules were calculated in pure water, aqueous urea, and NaCl solutions. Our results show that NaCl displays strong capability to salt out all 15 molecules, while urea facilitates the solvation (salting-in) of all the 15 molecules on the other hand. The salting effect is found to be largely enthalpy-driven for both NaCl and urea. Our observations can explain the higher stability of protein's secondary and tertiary structures in typical salt solutions than that in pure water. Meanwhile, urea's capability to better solvate protein backbone and side-chain components can be extrapolated to explain protein's denaturation in aqueous urea solution. Urea salts in molecules through direct binding to solute surface, and the strength is linearly dependent on the number of heavy atoms of solute molecules. The van der Waals interactions are found to be the dominant force, which challenges a hydrogen-bonding-driven mechanism proposed previously.

  5. Variability and change of sea level and its components in the Indo-Pacific region during the altimetry era

    NASA Astrophysics Data System (ADS)

    Wu, Quran; Zhang, Xuebin; Church, John A.; Hu, Jianyu

    2017-03-01

    Previous studies have shown that regional sea level exhibits interannual and decadal variations associated with the modes of climate variability. A better understanding of those low-frequency sea level variations benefits the detection and attribution of climate change signals. Nonetheless, the contributions of thermosteric, halosteric, and mass sea level components to sea level variability and trend patterns remain unclear. By focusing on signals associated with dominant climate modes in the Indo-Pacific region, we estimate the interannual and decadal fingerprints and trend of each sea level component utilizing a multivariate linear regression of two adjoint-based ocean reanalyses. Sea level interannual, decadal, and trend patterns primarily come from thermosteric sea level (TSSL). Halosteric sea level (HSSL) is of regional importance in the Pacific Ocean on decadal time scale and dominates sea level trends in the northeast subtropical Pacific. The compensation between TSSL and HSSL is identified in their decadal variability and trends. The interannual and decadal variability of temperature generally peak at subsurface around 100 m but that of salinity tend to be surface-intensified. Decadal temperature and salinity signals extend deeper into the ocean in some regions than their interannual equivalents. Mass sea level (MassSL) is critical for the interannual and decadal variability of sea level over shelf seas. Inconsistencies exist in MassSL trend patterns among various estimates. This study highlights regions where multiple processes work together to control sea level variability and change. Further work is required to better understand the interaction of different processes in those regions.

  6. Resistance of Coatings for Boiler Components of Waste-to-Energy Plants to Salt Melts Containing Copper Compounds

    NASA Astrophysics Data System (ADS)

    Galetz, Mathias Christian; Bauer, Johannes Thomas; Schütze, Michael; Noguchi, Manabu; Cho, Hiromitsu

    2013-06-01

    The accelerating effect of heavy metal compounds on the corrosive attack of boiler components like superheaters poses a severe problem in modern waste-to-energy plants (WTPs). Coatings are a possible solution to protect cheap, low alloyed steel substrates from heavy metal chloride and sulfate salts, which have a relatively low melting point. These salts dissolve many alloys, and therefore often are the limiting factor as far as the lifetime of superheater tubes is concerned. In this work the corrosion performance under artificial salt deposits of different coatings, manufactured by overlay welding, thermal spraying of self-fluxing as well as conventional systems was investigated. The results of our studies clearly demonstrate the importance of alloying elements such as molybdenum or silicon. Additionally, the coatings have to be dense and of a certain thickness in order to resist the corrosive attack under these severe conditions.

  7. Relationship between the Bering Strait Throughflow and Salinity in the Bering Sea in an Atmosphere-Ocean-Ice Coupled Model

    NASA Astrophysics Data System (ADS)

    Kawai, Y.; Osafune, S.; Masuda, S.; Komuro, Y.

    2016-12-01

    The relationship between the volumetric transport of the Bering Strait throughflow (BTF) and sea surface salinity (SSS) in the Bering Sea was investigated using an atmosphere-ocean-ice coupled model, MIROC4h, which includes an eddy-permitting ocean model. The MIROC4h simulated well the seasonal cycle of BTF transport, although it overestimated the transport compared with previous studies. The interannual variations of SSS in the Bering Sea were correlated with those of BTF transport: SSS in the northwestern Bering Sea was high when BTF transport was large. The SSS anomaly associated with the BTF anomaly became evident from late autumn to spring, and SSS lagged behind the BTF by a few months. The BTF transport was strongly correlated with the SSH in the eastern Bering Sea, the southwestern Chukchi Sea, and the East Siberian Sea. The low SSH along the Russian coast in the Arctic Ocean was uncorrelated with the high SSH in the Bering Sea. The Arctic SSH affected BTF transport and the SSS in the northwestern Bering Sea independently of the SSH in the Bering Sea. We evaluated the salt budget in the northwestern Bering Sea, including Anadyr Bay. When the BTF transport in October-March was large, the horizontal convergence of salt increased and sea-ice melting decreased; both changes contributed to the increase of salinity. In contrast, evaporation-minus-precipitation and the residual component had the opposite effect. The sea-ice retreat was closely related to meridional wind anomalies that also raised the SSH in the eastern Bering Sea. Changes in upper-layer currents caused by the southerly wind anomalies in the Bering Sea contributed to the increase of the horizontal convergence of salt. In addition, the SSH anomalies in the Arctic Ocean independently affected the currents in the Bering Strait and the northwestern Bering Sea, perhaps through the propagation of shelf waves, which also led to salinization.

  8. Sea level reconstructions from altimetry and tide gauges using independent component analysis

    NASA Astrophysics Data System (ADS)

    Brunnabend, Sandra-Esther; Kusche, Jürgen; Forootan, Ehsan

    2017-04-01

    Many reconstructions of global and regional sea level rise derived from tide gauges and satellite altimetry used the method of empirical orthogonal functions (EOF) to reduce noise, improving the spatial resolution of the reconstructed outputs and investigate the different signals in climate time series. However, the second order EOF method has some limitations, e.g. in the separation of individual physical signals into different modes of sea level variations and in the capability to physically interpret the different modes as they are assumed to be orthogonal. Therefore, we investigate the use of the more advanced statistical signal decomposition technique called independent component analysis (ICA) to reconstruct global and regional sea level change from satellite altimetry and tide gauge records. Our results indicate that the used method has almost no influence on the reconstruction of global mean sea level change (1.6 mm/yr from 1960-2010 and 2.9 mm/yr from 1993-2013). Only different numbers of modes are needed for the reconstruction. Using the ICA method is advantageous for separating independent climate variability signals from regional sea level variations as the mixing problem of the EOF method is strongly reduced. As an example, the modes most dominated by the El Niño-Southern Oscillation (ENSO) signal are compared. Regional sea level changes near Tianjin, China, Los Angeles, USA, and Majuro, Marshall Islands are reconstructed and the contributions from ENSO are identified.

  9. Processes controlling surface, bottom and lateral melt of Arctic sea ice in a state of the art sea ice model.

    PubMed

    Tsamados, Michel; Feltham, Daniel; Petty, Alek; Schroeder, David; Flocco, Daniela

    2015-10-13

    We present a modelling study of processes controlling the summer melt of the Arctic sea ice cover. We perform a sensitivity study and focus our interest on the thermodynamics at the ice-atmosphere and ice-ocean interfaces. We use the Los Alamos community sea ice model CICE, and additionally implement and test three new parametrization schemes: (i) a prognostic mixed layer; (ii) a three equation boundary condition for the salt and heat flux at the ice-ocean interface; and (iii) a new lateral melt parametrization. Recent additions to the CICE model are also tested, including explicit melt ponds, a form drag parametrization and a halodynamic brine drainage scheme. The various sea ice parametrizations tested in this sensitivity study introduce a wide spread in the simulated sea ice characteristics. For each simulation, the total melt is decomposed into its surface, bottom and lateral melt components to assess the processes driving melt and how this varies regionally and temporally. Because this study quantifies the relative importance of several processes in driving the summer melt of sea ice, this work can serve as a guide for future research priorities. © 2015 The Author(s).

  10. Holocene sea-level changes in the Falkland Islands

    NASA Astrophysics Data System (ADS)

    Newton, Tom; Gehrels, Roland; Daley, Tim; Long, Antony; Bentley, Mike

    2014-05-01

    In many locations in the southern hemisphere, relative sea level (RSL) reached its maximum position during the middle Holocene. This highstand is used by models of glacial isostatic adjustment (GIA) to constrain the melt histories of the large ice sheets, particularly Antarctica. In this paper we present the first Holocene sea-level record from the Falkland Islands (Islas Malvinas), an archipelago located on the Patagonian continental shelf about 500 km east of mainland South America at a latitude of ca. 52 degrees. Unlike coastal locations in southernmost South America, Holocene sea-level data from the Falklands are not influenced by tectonics, local ice loading effects and large tidal ranges such that GIA and ice-ocean mass flux are the dominant drivers of RSL change. Our study site is a salt marsh located in Swan Inlet in East Falkland, around 50 km southwest of Stanley. This is the largest and best developed salt marsh in the Falkland Islands. Cores were collected in 2005 and 2013. Lithostratigraphic analyses were complemented by analyses of foraminifera, testate amoebae and diatoms to infer palaeoenvironments. The bedrock, a Permian black shale, is overlain by grey-brown organic salt-marsh clay, up to 90 cm thick, which, in a landward direction, is replaced by freshwater organic sediments. Overlying these units are medium-coarse sands with occasional pebbles, up to 115 cm thick, containing tidal flat foraminifera. The sandy unit is erosively overlain by a grey-brown organic salt-marsh peat which extends up to the present surface. Further away from the sea this unit is predominantly of freshwater origin. Based on 13 radiocarbon dates we infer that prior to ~9.5 ka sea level was several metres below present. Under rising sea levels a salt marsh developed which was suddenly drowned around 8.4 ka, synchronous with a sea-level jump known from northern hemisphere locations. Following the drowning, RSL rose to its maximum position around 7 ka, less than 0.5 m above

  11. Ecophysiological response of native and exotic salt marsh vegetation to waterlogging and salinity: Implications for the effects of sea-level rise.

    PubMed

    Li, Shi-Hua; Ge, Zhen-Ming; Xie, Li-Na; Chen, Wei; Yuan, Lin; Wang, Dong-Qi; Li, Xiu-Zhen; Zhang, Li-Quan

    2018-02-05

    The ecophysiological characteristics of native Phragmites australis and exotic Spartina alterniflora grown under waterlogging and salinity were investigated to explore their adaptation potential to sea level rise. The seasonal course of phenotypic traits, photosynthetic activity and chlorophyll fluorescence parameters of P. australis did not change remarkably under shallow flooding, whereas these variables were sensitive to increasing salinity. Waterlogging exacerbated the negative effects of salinity on shoot growth and photosynthetic activity of P. australis, and the combined stresses led to an absence of tassel and reproductive organs. By contrast, S. alterniflora performed well under both stresses and showed an obvious adaptation of salt secretion with increasing salinity. Light salinity was the optimal condition for S. alterniflora, and the tassel growth, chlorophyll content and fluorescence characters under moderate stresses did not differ notably. The Na + and Cl - concentrations in leaves of both species increased, and the K + content decreased in response to salinity. Under moderate and high saline levels, the ion concentrations in S. alterniflora were maintained at relatively consistent levels with increased salt secretion. We expect the degradation of P. australis and further colonization of S. alterniflora under prolonged flooding and saltwater intrusion from sea level rise on the coastline of China.

  12. Seasonal variation in chromophoric dissolved organic matter and relationships among fluorescent components, absorption coefficients and dissolved organic carbon in the Bohai Sea, the Yellow Sea and the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhu, Wen-Zhuo; Zhang, Hong-Hai; Zhang, Jing; Yang, Gui-Peng

    2018-04-01

    The absorption coefficient and fluorescent components of chromophoric dissolved organic matter (CDOM) in the Bohai Sea (BS), Yellow Sea (YS), and East China Sea (ECS) in spring and autumn were analyzed in this study. Excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC) identified three components, namely, humic-like C1, tyrosine-like C2 and tryptophan-like C3. The seasonal variations in the vertical patterns of the CDOM absorption coefficient (aCDOM(355)) and fluorescent components were influenced by the seasonal water mass except for the terrestrial input. The relationship between aCDOM(355) and dissolved organic matter (DOC) was attributed to their own mixing behavior. The correlation of the fluorescent components with DOC was disturbed by other non-conservative processes during the export of CDOM to the open ocean. The different chemical compositions and origins of DOC and CDOM led to variability in carbon-specific CDOM absorption (a*CDOM(355)) and fluorescent component ratios (ICn/IC1). The relationship between a*CDOM(355) and aCDOM(355) demonstrated that dissolved organic matter (DOM) in the BS, but not in the ECS, highly contributed non-absorbing DOC to the total DOC concentration. The photodegradation of dominant terrestrially derived CDOM in the ECS contributed to the positive relationship between a*CDOM(355) and ICn/IC1. By contrast, the abundant autochthonous CDOM in the YS was negatively correlated with ICn/IC1 in autumn. Our established box models showed that water exchange is a potentially important source of the aromatic components in the BS, YS, and ECS. Hence, the seasonal variations in water exchange might contribute to the variability of CDOM chemical composition in the BS, YS, and ECS, and significantly influence the structure and function of their ecosystems.

  13. Air-sea Forcing and Thermohaline Changes In The Ross Sea.

    NASA Astrophysics Data System (ADS)

    Fusco, G.; Budillon, G.

    Heat exchanges between sea and atmosphere from 1986 to 2000 in the Ross Sea (Antarctica) were computed from climatological data obtained from the European Centre for Medium Range Weather Forecasts. They have been related with the thermo- haline changes observed during 5 hydrological surveys performed between the austral summer 1994-1995 and 2000-2001 in the western sector of the Ross Sea. The esti- mated heat fluxes show extremely strong spatial and temporal variability over all the Ross Sea. As can be expected the largest heat losses occur between May and August, while during the period November-February the heat budget becomes positive. In the first six years of the investigated period the heat loss is very strong with its maximum about 166 Wm-2; while during the period 1992-2000 the yearly heat losses are the lowest. Thermohaline changes in the surface layer (upper pycnocline) of the western Ross Sea follow the expected seasonal pattern of warming and freshening from the be- ginning to the end of the austral summer. The heating changes are substantially lower than the estimated heat supplied by the atmosphere during the summer, which under- lines the importance in this season of the advective component carried by the currents in the total heat budget of this area. The year to year differences are about one or two orders of magnitude smaller than the seasonal changes in the surface layer. In the in- termediate and deep layers, the summer heat and salt variability is of the same order as or one order higher than from one summer to the next. Moreover a freshening of the near bottom layer has been observed, it is consistent with the High Salinity Shelf Water salinity decrease recently detected in the Ross Sea.

  14. Microbial life in the Lake Medee, the largest deep-sea salt-saturated formation

    NASA Astrophysics Data System (ADS)

    Yakimov, Michail M.; La Cono, Violetta; Slepak, Vladlen Z.; La Spada, Gina; Arcadi, Erika; Messina, Enzo; Borghini, Mireno; Monticelli, Luis S.; Rojo, David; Barbas, Coral; Golyshina, Olga V.; Ferrer, Manuel; Golyshin, Peter N.; Giuliano, Laura

    2013-12-01

    Deep-sea hypersaline anoxic lakes (DHALs) of the Eastern Mediterranean represent some of the most hostile environments on our planet. We investigated microbial life in the recently discovered Lake Medee, the largest DHAL found to-date. Medee has two unique features: a complex geobiochemical stratification and an absence of chemolithoautotrophic Epsilonproteobacteria, which usually play the primary role in dark bicarbonate assimilation in DHALs interfaces. Presumably because of these features, Medee is less productive and exhibits reduced diversity of autochthonous prokaryotes in its interior. Indeed, the brine community almost exclusively consists of the members of euryarchaeal MSBL1 and bacterial KB1 candidate divisions. Our experiments utilizing cultivation and [14C]-assimilation, showed that these organisms at least partially rely on reductive cleavage of osmoprotectant glycine betaine and are engaged in trophic cooperation. These findings provide novel insights into how prokaryotic communities can adapt to salt-saturated conditions and sustain active metabolism at the thermodynamic edge of life.

  15. Anthropocene Survival of Southern New England’s Salt Marshes

    EPA Science Inventory

    In southern New England, salt marshes are exceptionally vulnerable to the impacts of accelerated sea level rise. Regional rates of sea level rise have been as much as 50 % greater than the global average over past decades, a more than fourfold increase over late Holocene backgrou...

  16. Platyamoeba pseudovannellida n. sp., a naked amoeba with wide salt tolerance isolated from the Salton Sea, California.

    PubMed

    Hauer, G; Rogerson, A; Anderson, O R

    2001-01-01

    A new species of naked amoeba, Platyamoeba pseudovannellida n.sp., is described on the basis of light microscopic and fine structural features. The amoeba was isolated from the Salton Sea, California, from water at a salinity of ca. 44%. Locomotive amoebae occasionally had a spatulate outline and floating cells had radiating pseudopodia, sometimes with pointed tips. Both these features are reminiscent of the genus Vannella. However, the surface coat (glycocalyx) as revealed by TEM indicates that this is a species of Platyamoeba. Although salinity was not used as a diagnostic feature, this species was found to have remarkable tolerance to fluctuating salinity levels, even when changes were rapid. Amoebae survived over the range 0 per thousand to 150 per thousand salt and grew within the range 0 per thousand to 138 per thousand salt. The generation time of cells averaged 29 h and was not markedly affected by salt concentration. This is longer than expected for an amoeba of this size and suggests a high energetic cost of coping with salinity changes. The morphology of cells changed with increasing salinity: at 0 per thousand cells were flattened and active and at the other extreme (138 per thousand) amoebae were wrinkled and domed and cell movement was very slow. At the ultrastructural level, the cytoplasm of cells grown at high salinity (98 per thousand was considerably denser than that of cells reared at 0 per thousand.

  17. Impacts of Multiple Stressors on Southern New England Salt Marshes

    EPA Science Inventory

    In the Northeastern U.S., salt marsh area is in decline. Low sediment supply combined with regionally high rates of sea level rise mean that future salt marsh survival depends primarily on biomass production and organic matter accumulation, which are impacted by high nutrient lo...

  18. Assessing sea wave and spray effects on Marine Boundary Layer structure

    NASA Astrophysics Data System (ADS)

    Stathopoulos, Christos; Galanis, George; Patlakas, Platon; Kallos, George

    2017-04-01

    Air sea interface is characterized by several mechanical and thermodynamical processes. Heat, moisture and momentum exchanges increase the complexity in modeling the atmospheric-ocean system. Near surface atmospheric levels are subject to sea surface roughness and sea spray. Sea spray fluxes can affect atmospheric stability and induce microphysical processes such as sea salt particle formation and condensation/evaporation of water in the boundary layer. Moreover, presence of sea spray can alter stratification over the ocean surface with further insertion of water vapor. This can lead to modified stability conditions and to wind profiles that deviate significantly from the logarithmic approximation. To model these effects, we introduce a fully coupled system consisting of the mesoscale atmospheric model RAMS/ICLAMS and the wave model WAM. The system encompasses schemes for ocean surface roughness, sea salt aerosols and droplet thermodynamic processes and handles sea salt as predictive quantity. Numerical experiments using the developed atmospheric-ocean system are performed over the Atlantic and Mediterranean shoreline. Emphasis is given to the quantification of the improvement obtained in the description of the marine boundary layer, particularly in its lower part as well as in wave characteristics.

  19. Coagulation mechanism of salt solution-extracted active component in Moringa oleifera seeds.

    PubMed

    Okuda, T; Baes, A U; Nishijima, W; Okada, M

    2001-03-01

    This study focuses on the coagulation mechanism by the purified coagulant solution (MOC-SC-PC) with the coagulation active component extracted from M. oleifera seeds using salt solution. The addition of MOC-SC-PC tap water formed insoluble matters. This formation was responsible for kaolin coagulation. On the other hand, insoluble matters were not formed when the MOC-SC-PC was added into distilled water. The formation was affected by Ca2+ or other bivalent cations which may connect each molecule of the active coagulation component in MOC-SC-PC and form a net-like structure. The coagulation mechanism of MOC-SC-PC seemed to be an enmeshment of Kaolin by the insoluble matters with the net-like structure. In case of Ca2+ ion (bivalent cations), at least 0.2 mM was necessary for coagulation at 0.3 mgC l-1 dose of MOC-SC-PC. Other coagulation mechanisms like compression of double layer, interparticle bridging or charge neutralization were not responsible for the coagulation by MOC-SC-PC.

  20. Constraining Aerosol Optical Models Using Ground-Based, Collocated Particle Size and Mass Measurements in Variable Air Mass Regimes During the 7-SEAS/Dongsha Experiment

    NASA Technical Reports Server (NTRS)

    Bell, Shaun W.; Hansell, Richard A.; Chow, Judith C.; Tsay, Si-Chee; Wang, Sheng-Hsiang; Ji, Qiang; Li, Can; Watson, John G.; Khlystov, Andrey

    2012-01-01

    During the spring of 2010, NASA Goddard's COMMIT ground-based mobile laboratory was stationed on Dongsha Island off the southwest coast of Taiwan, in preparation for the upcoming 2012 7-SEAS field campaign. The measurement period offered a unique opportunity for conducting detailed investigations of the optical properties of aerosols associated with different air mass regimes including background maritime and those contaminated by anthropogenic air pollution and mineral dust. What appears to be the first time for this region, a shortwave optical closure experiment for both scattering and absorption was attempted over a 12-day period during which aerosols exhibited the most change. Constraints to the optical model included combined SMPS and APS number concentration data for a continuum of fine and coarse-mode particle sizes up to PM2.5. We also take advantage of an IMPROVE chemical sampler to help constrain aerosol composition and mass partitioning of key elemental species including sea-salt, particulate organic matter, soil, non sea-salt sulphate, nitrate, and elemental carbon. Our results demonstrate that the observed aerosol scattering and absorption for these diverse air masses are reasonably captured by the model, where peak aerosol events and transitions between key aerosols types are evident. Signatures of heavy polluted aerosol composed mostly of ammonium and non sea-salt sulphate mixed with some dust with transitions to background sea-salt conditions are apparent in the absorption data, which is particularly reassuring owing to the large variability in the imaginary component of the refractive indices. Extinctive features at significantly smaller time scales than the one-day sample period of IMPROVE are more difficult to reproduce, as this requires further knowledge concerning the source apportionment of major chemical components in the model. Consistency between the measured and modeled optical parameters serves as an important link for advancing remote

  1. Extreme drying event in the Dead Sea basin during MIS5 from the ICDP Dead Sea Deep Drill Core

    NASA Astrophysics Data System (ADS)

    Goldstein, S. L.; Stein, M.; Ben-Avraham, Z.; Agnon, A.; Ariztegui, D.; Brauer, A.; Haug, G. H.; Ito, E.; Kitagawa, H.; Torfstein, A.; Yasuda, Y.; The Icdp-Dsddp Scientific Party

    2011-12-01

    The ICDP funded Dead Sea Deep Drilling Project (DSDDP) recovered the longest and most complete paleo-environmental record in the Middle East, drilling holes of ~450 and ~350 meters in length in deep (~300 m below the lake level) and shallow sites (~3 mbll) respectively. The Dead Sea expands during the glacials and contracts during interglacials, and the sediments comprise a geological archive of the evolving environmental conditions (e.g. rains, floods, dust-storms, droughts). Dead Sea sediments include inorganic aragonite, allowing for dating by U-series (e.g. Haase-Schramm et al. GCA 2004). The deep site cores were opened and described in June 2011. The cores are composed mainly of alternating intervals of marl (aragonite, gypsum and detritus) during glacials, and salts and marls during interglacials. From this stratigraphy we estimate that the deep site core spans ~200 kyr (to the boundary of MIS 6 and 7). A dramatic discovery is a ~40 cm thick interval of partly rounded pebbles at ~235 m below the lake floor. This is the only clean pebbly unit in the entire core. It appears to be a beach layer, near the deepest part of the Dead Sea, lying above ~35 meters of mainly salt. If it is a beach layer, it implies an almost complete dry-down of the paleo-Dead Sea. The pebble layer lies within the last interglacial interval. Our initial attempt to more precisely estimate the age of the possible dry down shows an intriguing correlation between the salt-mud stratigraphy of the Dead Sea core and the oxygen isotope record of Soreq Cave, whereby excursions to light oxygen in the speleothems correspond to periods of salt deposition. Through this comparison, we estimate that the possible dry down occurred during MIS 5e. The occurrence of ~35 meters of mainly salt along with the pebble layer demonstrates a severe dry interval during MIS 5. This observation has implications for the Middle East today, where the Dead Sea level is dropping as all the countries in the area use the

  2. The flushing and exchange of the South China Sea derived from salt and mass conservation

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Bye, John A. T.; You, Yuzhu; Bao, Xianwen; Wu, Dexing

    2010-07-01

    In this paper, we use two kinds of hydrographic data, historical cruise data, Array for Real-time Geostrophic Oceanography (Argo) float data, and atmospheric data to study the water exchange between the South China Sea (SCS) and the Pacific Ocean through the Luzon Strait. The annual mean distributions of temperature and salinity at five different levels in the SCS and the adjacent Pacific Ocean are presented, which indicate the occurrence of active water exchange through the Luzon Strait. The flushing and exchange of the SCS are then determined by the application of salt and mass conservation in a multi-layered thermohaline system, using an estimate of the net rainfall obtained from reanalysis data. The results show that the annual mean flushing time is 44±8 months with an inflow rate of 11±2 Sv (1 Sv=10 6 m 3 s -1), part of which recirculates at a deeper level through the Luzon Strait, the remainder (6±2 Sv) forming the SCS throughflow. The diffusive influx of salt is also estimated and accounts for about 10% of the total influx, and hence advection dominates over diffusion in the water exchange through the Luzon Strait. The seasonal cycle of exchange shows a maximum in autumn and winter of about twice the annual mean rate.

  3. New iodide-based molten salt systems for high temperature molten salt batteries

    NASA Astrophysics Data System (ADS)

    Fujiwara, Syozo; Kato, Fumio; Watanabe, Syouichiro; Inaba, Minoru; Tasaka, Akimasa

    Novel multi-component molten salt systems containing iodides, LiF-LiBr-LiI, LiF-NaBr-LiI, and LiF-LiCl-LiBr-LiI, were investigated for use as electrolytes in high temperature molten salt batteries to improve the discharge rate-capability. The iodide-based molten salts showed higher ionic conductivity (∼3 S cm -1 at 500 °C) than conventional LiCl-KCl, and had low enough melting points (below 400 °C) that can be used in practical high temperature molten salt batteries. The iodide-based salts showed instability at temperatures higher than 280 °C in dried air. The decomposition mechanism of iodide-based molten salts was discussed, and it was found that elimination of oxygen from the environment is effective to stabilize the iodide-based molten salts at high temperatures.

  4. Chemical characteristics, deposition fluxes and source apportionment of precipitation components in the Jiaozhou Bay, North China

    NASA Astrophysics Data System (ADS)

    Xing, Jianwei; Song, Jinming; Yuan, Huamao; Li, Xuegang; Li, Ning; Duan, Liqin; Qu, Baoxiao; Wang, Qidong; Kang, Xuming

    2017-07-01

    To systematically illustrate the chemical characteristics, deposition fluxes and potential sources of the major components in precipitation, 49 rainwater and snow water samples were collected in the Jiaozhou Bay from June 2015 to May 2016. We determined the pH, electric conductivity (EC) and the concentrations of main ions (Na+, K+, Ca2 +, Mg2 +, NH4+, SO42 -, NO3-, Cl- and F-) as well as analyzed their source contributions and atmospheric transport. The results showed that the precipitation samples were severely acidified with an annual volume-weighted mean (VWM) pH of 4.77. The frequency of acid precipitation (pH < 5.6) reached up to 71.4%, and the mean EC value was relatively higher at 64.9 μS cm- 1, all of which suggested a higher atmospheric pollution level over the Jiaozhou Bay. Surprisingly, NH4+ (40.4%), which is higher than Ca2 + (29.3%), is the dominant species of cations, which is different from that in most areas of China. SO42 - was the most abundant anions, and accounted for 41.6% of the total anions. The wet deposition fluxes of sulfur (S) was 12.98 kg ha- 1 yr- 1. Rainfall, emission intensity and long-range transport of natural and anthropogenic pollutants together control the concentrations and wet deposition fluxes of chemical components in the precipitation. Non-sea-salt SO42 - and NO3- were the primary acid components while NH4+ and non-sea-salt Ca2 + were the dominating neutralizing constituents. The comparatively lower rainwater concentration of Ca2 + in the Jiaozhou Bay than that in other regions in Northern China likely to be a cause for the strong acidity of precipitation. Based on the combined enrichment factor and correlation analysis, the integrated contributions of sea-salt, crustal and anthropogenic sources to the total ions of precipitation were estimated to be 28.7%, 14.5% and 56.8%, respectively. However, the marine source fraction of SO42 - may be underestimated as the contribution from marine phytoplankton was neglected

  5. Iatrogenic salt poisoning in captive sandhill cranes

    USGS Publications Warehouse

    Franson, J.C.; Sileo, L.; Fleming, W.J.

    1981-01-01

    Salt poisoning developed in captive sandhill cranes (Grus canadensis) when sea salt was added to normal drinking water to produce a sodium chloride concentration of 1%. Two of 18 cranes died and 2 were euthanatized when moribund. Muscle weakness, paresis, dyspnea, and depression were observed. Brain and serum sodium, serum uric acid,:and plasma osmolality values were abnormally high. Lesions were those of visceral gout, renal tubular necrosis, nephrosis, and skeletal muscle.necrosis.

  6. Tropical vegetation evidence for rapid sea level changes associated with Heinrich Events

    NASA Astrophysics Data System (ADS)

    González, Catalina; Dupont, Lydie M.

    2010-03-01

    A Cariaco Basin pollen record shows the development of tropical salt marshes during marine isotope stage 3. Rapid and abrupt expansions of salt marsh vegetation in tropical South America are associated with north Atlantic Heinrich Events stadials (HE-stadials). Intervals of salt marsh expansion have an internal structure, which consists of a recurrent alternation of species that starts with pollen increments of Chenopodiaceae, that are followed by increments of grasses, and subsequently by increments of Cyperaceae. This pattern suggests a successional process that is determined by the close relationship between sea-level and plant community dynamics. The salt tolerant Chenopodiaceae, indicate hypersaline intertidal environments, which were most likely promoted by extremely dry atmospheric conditions. Rapid sea-level rise characterizes the onset of HE-stadials, causing the continued recruitment of pioneer species, which are the only ones tolerating rapid rates of disturbance. Once sea-level rise decelerates, marsh plants are able to trap and stabilize sediments, favouring the establishment of more competitive species. These results add to the scarce knowledge on the dynamics of tropical salt marsh ecosystems, and provide independent paleoclimatic evidence on sea-level changes following Antarctic climate variability.

  7. Experimental evaluation of atmospheric effects on radiometric measurements using the EREP of Skylab. [Salton Sea and Great Salt Lake

    NASA Technical Reports Server (NTRS)

    Chang, D. T. (Principal Investigator); Isaacs, R. G.

    1975-01-01

    The author has identified the following significant results. Test sites were located near the Great Salt Lake and the Salton Sea. Calculations were performed for a set of atmospheric models corresponding to the test sites, in addition to standard models for summer and winter midlatitude atmospheres with respective integrated water vapor amount of 2.4 g/sq cm and 0.9 g/sq cm. Each atmosphere was found to contain an average amount of continental aerosol. Computations were valid for high solar elevation angles. Atmospheric attenuation quantities were computed in addition to simulated EREP S192 radiances.

  8. Constraints on the thermosteric component of Last Interglacial sea level

    NASA Astrophysics Data System (ADS)

    Shackleton, S. A.; Severinghaus, J. P.; Petrenko, V. V.; Dyonisius, M.; Hmiel, B.

    2016-12-01

    With global temperatures 1 to 2°C above preindustrial, but sea level exceeding current levels by upwards of 8 meters, the Last Interglacial (LIG) period at 125 ka may provide valuable insight into Earth system constraints under future global warming. The relative contributions of thermal expansion and ice sheet loss to sea level rise over this period are of particular interest in seeking to improve sea level projections in the upcoming decades and beyond. Here we quantify this thermosteric component from a reconstruction of global ocean temperature over the LIG from atmospheric noble gases trapped in glacial ice. With no major sources or sinks outside of the ocean-atmosphere system, the relative changes in the atmospheric content of krypton, xenon, and nitrogen reflect changes in ocean gas storage. This storage is primarily governed by solubility and ocean temperature, making dKr/N2, dXe/N2­, and dXe/Kr unique tracers of globally integrated oceanic heat content. However, processes within the firn can fractionate these gases, and firn effects on these tracers must be removed to derive an ocean temperature. We present high precision measurements of these gas ratios along with isotopes of argon, krypton, and xenon in firn air withdrawn from the snowpack at Summit, Greenland. We use these isotopes to identify sources of fractionation within the firn and quantify their effects on the noble gas tracers, enabling a reconstruction of Last Interglacial ocean temperature.

  9. Study of salt transport processes in Delaware Bay

    USGS Publications Warehouse

    Walters, Roy

    1992-01-01

    The study described here is a subset of a broader climate-related study, and is focused primarily on salinity intrusion into Delaware Bay and River. Given changes in freshwater discharge into the Delaware River as determined from the larger study, and given probable sea level rise estimates, the purpose here is to calculate the distribution of salinity within Delaware Bay and River. The approach adopted for this study is composed of two parts: an analysis of existing physical data in order to derive a basic understanding of the salt dynamics, and numerical simulation of future conditions based on this analysis. There are two important constraints in the model used: it must resolve the spatial scales important to the salt dynamics, and it must be sufficiently efficient to allow extensive sensitivity studies. This has led to the development of a 3D model that uses harmonic decomposition in time and irregular finite elements in space. All nonlinear terms are retained in the governing equations, including quadratic bottom stress, advection, and wave transport (continuity nonlinearity). These equations are coupled to the advection-diffusion equation for salt so that density gradient forcing is included in the momentum equations. Although this study is still in progress, the model has reproduced sea level variations and the 3D structure of tidal and residual currents very well. In addition, the study has addressed the effects of a 1-meter rise in mean sea level on hydrodynamics of the study area. Current work is focused on salt dynamics.

  10. Conjecture of plume components in hydrothermal sea area

    NASA Astrophysics Data System (ADS)

    Noda, K., IV; Aoyama, C.

    2017-12-01

    Investigation at Southern Okinawa Trough, western Kume Island, and Tokara Islands was performed from June 26 to July 12, 2016, as a part of Japan's cross ministerial Strategic Innovation Promotion Program (SIP) for a complete understanding of active hydrothermal vents. In this investigation, water column sonar data was obtained using multi-beam sonar (EM122) onboard YOKOSUKA (Japan Agency for Marine-Earth Science and Technology) and methane plumes were alsp monitored (YK16-07). Multi-beam sonar is an acoustic instrument used to measure submarine topography, and in this investigation, plumes were observed to successfully regenerate the data. It also became clear that volume backscattering strength (SV) of plumes varies, depending on the area where they are settled. On the other hand, components of plumes are still unknown. In this study, acoustic data obtained from YK16-07 will be reviewed using analytical software (echo view 7) to calculate volume backscattering strength (SV) of plumes. Likewise, multi-beam sonar (EM122) onboard DAIICHI KAIYOMARU (KAIYO ENGINEERING CO., LTD) was used to collect acoustic data. This already known data of methane plume from Sea of Japan will be analyzed using echo view 7. By comparing these data, plume components will be examined from plume size.

  11. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Salt Lake City, Utah, will host the 2002 Winter Olympic Games. The city is located on the southeastern shore of the Great Salt Lake and sits to the west of the Wasatch Mountains, which rise more than 3,500 meters (10,000 feet) above sea level. The city was first settled in 1847 by pioneers seeking relief from religious persecution. Today Salt Lake City, the capital of Utah, is home to more than 170,000 residents. This true-color image of Salt Lake City was acquired by the Enhanced Thematic Mapper Plus (ETM+), flying aboard Landsat 7, on May 26, 2000. The southeastern tip of the Great Salt Lake is visible in the upper left of the image. The furrowed green and brown landscape running north-south is a portion of the Wasatch Mountains, some of which are snow-capped (white pixels). The greyish pixels in the center of the image show the developed areas of the city. A number of water reservoirs can be seen east of the mountain range. Salt Lake City International Airport is visible on the northwestern edge of the city. About 20 miles south of the airport is the Bingham Canyon Copper Mine (tan pixels), the world's largest open pit excavation. See also this MODIS image of Utah. Image courtesy NASA Landsat7 Science Team and USGS Eros Data Center

  12. Salt Acclimation of Cyanobacteria and Their Application in Biotechnology

    PubMed Central

    Pade, Nadin; Hagemann, Martin

    2014-01-01

    The long evolutionary history and photo-autotrophic lifestyle of cyanobacteria has allowed them to colonize almost all photic habitats on Earth, including environments with high or fluctuating salinity. Their basal salt acclimation strategy includes two principal reactions, the active export of ions and the accumulation of compatible solutes. Cyanobacterial salt acclimation has been characterized in much detail using selected model cyanobacteria, but their salt sensing and regulatory mechanisms are less well understood. Here, we briefly review recent advances in the identification of salt acclimation processes and the essential genes/proteins involved in acclimation to high salt. This knowledge is of increasing importance because the necessary mass cultivation of cyanobacteria for future use in biotechnology will be performed in sea water. In addition, cyanobacterial salt resistance genes also can be applied to improve the salt tolerance of salt sensitive organisms, such as crop plants. PMID:25551682

  13. Mechanism of deep-sea fish α-actin pressure tolerance investigated by molecular dynamics simulations.

    PubMed

    Wakai, Nobuhiko; Takemura, Kazuhiro; Morita, Takami; Kitao, Akio

    2014-01-01

    The pressure tolerance of monomeric α-actin proteins from the deep-sea fish Coryphaenoides armatus and C. yaquinae was compared to that of non-deep-sea fish C. acrolepis, carp, and rabbit/human/chicken actins using molecular dynamics simulations at 0.1 and 60 MPa. The amino acid sequences of actins are highly conserved across a variety of species. The actins from C. armatus and C. yaquinae have the specific substitutions Q137K/V54A and Q137K/L67P, respectively, relative to C. acrolepis, and are pressure tolerant to depths of at least 6000 m. At high pressure, we observed significant changes in the salt bridge patterns in deep-sea fish actins, and these changes are expected to stabilize ATP binding and subdomain arrangement. Salt bridges between ATP and K137, formed in deep-sea fish actins, are expected to stabilize ATP binding even at high pressure. At high pressure, deep-sea fish actins also formed a greater total number of salt bridges than non-deep-sea fish actins owing to the formation of inter-helix/strand and inter-subdomain salt bridges. Free energy analysis suggests that deep-sea fish actins are stabilized to a greater degree by the conformational energy decrease associated with pressure effect.

  14. Mechanism of Deep-Sea Fish α-Actin Pressure Tolerance Investigated by Molecular Dynamics Simulations

    PubMed Central

    Wakai, Nobuhiko; Takemura, Kazuhiro; Morita, Takami; Kitao, Akio

    2014-01-01

    The pressure tolerance of monomeric α-actin proteins from the deep-sea fish Coryphaenoides armatus and C. yaquinae was compared to that of non-deep-sea fish C. acrolepis, carp, and rabbit/human/chicken actins using molecular dynamics simulations at 0.1 and 60 MPa. The amino acid sequences of actins are highly conserved across a variety of species. The actins from C. armatus and C. yaquinae have the specific substitutions Q137K/V54A and Q137K/L67P, respectively, relative to C. acrolepis, and are pressure tolerant to depths of at least 6000 m. At high pressure, we observed significant changes in the salt bridge patterns in deep-sea fish actins, and these changes are expected to stabilize ATP binding and subdomain arrangement. Salt bridges between ATP and K137, formed in deep-sea fish actins, are expected to stabilize ATP binding even at high pressure. At high pressure, deep-sea fish actins also formed a greater total number of salt bridges than non-deep-sea fish actins owing to the formation of inter-helix/strand and inter-subdomain salt bridges. Free energy analysis suggests that deep-sea fish actins are stabilized to a greater degree by the conformational energy decrease associated with pressure effect. PMID:24465747

  15. North Atlantic sea-level variability during the last millennium

    NASA Astrophysics Data System (ADS)

    Gehrels, Roland; Long, Antony; Saher, Margot; Barlow, Natasha; Blaauw, Maarten; Haigh, Ivan; Woodworth, Philip

    2014-05-01

    Climate modelling studies have demonstrated that spatial and temporal sea-level variability observed in North Atlantic tide-gauge records is controlled by a complex array of processes, including ice-ocean mass exchange, freshwater forcing, steric changes, changes in wind fields, and variations in the speed of the Gulf Stream. Longer records of sea-level change, also covering the pre-industrial period, are important as a 'natural' and long-term baseline against which to test model performance and to place recent and future sea-level changes and ice-sheet change into a long-term context. Such records can only be reliably and continuously reconstructed from proxy methods. Salt marshes are capable of recording decimetre-scale sea-level variations with high precision and accuracy. In this paper we present four new high-resolution proxy records of (sub-) decadal sea-level variability reconstructed from salt-marsh sediments in Iceland, Nova Scotia, Maine and Connecticut that span the past 400 to 900 years. Our records, based on more than 100 new radiocarbon analyses, Pb-210 and Cs-137 measurements as well as other biological and geochemical age markers, together with hundreds of new microfossil observations from contemporary and fossil salt marshes, capture not only the rapid 20th century sea-level rise, but also small-scale (decimetre, multi-decadal) sea-level fluctuations during preceding centuries. We show that in Iceland three periods of rapid sea-level rise are synchronous with the three largest positive shifts of the reconstructed North Atlantic Oscillation (NAO) index. Along the North American east coast we compare our data with salt-marsh records from New Jersey, North Carolina and Florida and observe a trend of increased pre-industrial sea-level variability from south to north (Florida to Nova Scotia). Mass changes and freshwater forcing cannot explain this pattern. Based on comparisons with instrumental sea-level data and modelling studies we hypothesise that

  16. Contributions of the atmosphere-land and ocean-sea ice model components to the tropical Atlantic SST bias in CESM1

    NASA Astrophysics Data System (ADS)

    Song, Z.; Lee, S. K.; Wang, C.; Kirtman, B. P.; Qiao, F.

    2016-02-01

    In order to identify and quantify intrinsic errors in the atmosphere-land and ocean-sea ice model components of the Community Earth System Model version 1 (CESM1) and their contributions to the tropical Atlantic sea surface temperature (SST) bias in CESM1, we propose a new method of diagnosis and apply it to a set of CESM1 simulations. Our analyses of the model simulations indicate that both the atmosphere-land and ocean-sea ice model components of CESM1 contain large errors in the tropical Atlantic. When the two model components are fully coupled, the intrinsic errors in the two components emerge quickly within a year with strong seasonality in their growth rates. In particular, the ocean-sea ice model contributes significantly in forcing the eastern equatorial Atlantic warm SST bias in early boreal summer. Further analysis shows that the upper thermocline water underneath the eastern equatorial Atlantic surface mixed layer is too warm in a stand-alone ocean-sea ice simulation of CESM1 forced with observed surface flux fields, suggesting that the mixed layer cooling associated with the entrainment of upper thermocline water is too weak in early boreal summer. Therefore, although we acknowledge the potential importance of the westerly wind bias in the western equatorial Atlantic and the low-level stratus cloud bias in the southeastern tropical Atlantic, both of which originate from the atmosphere-land model, we emphasize here that solving those problems in the atmosphere-land model alone does not resolve the equatorial Atlantic warm bias in CESM1.

  17. Uncovering a Salt Giant. Deep-Sea Record of Mediterranean Messinian Events (DREAM) multi-phase drilling project

    NASA Astrophysics Data System (ADS)

    Camerlenghi, Angelo; Aoisi, Vanni; Lofi, Johanna; Hübscher, Christian; deLange, Gert; Flecker, Rachel; Garcia-Castellanos, Daniel; Gorini, Christian; Gvirtzman, Zohar; Krijgsman, Wout; Lugli, Stefano; Makowsky, Yizhaq; Manzi, Vinicio; McGenity, Terry; Panieri, Giuliana; Rabineau, Marina; Roveri, Marco; Sierro, Francisco Javier; Waldmann, Nicolas

    2014-05-01

    related to the MSC event. Several proposal ideas also emerged to support the Multi-phase drilling project concept: Salt tectonics and fluids, Deep stratigraphic and crustal drilling in the Gulf of Lion (deriving from the GOLD drilling project), Deep stratigraphic and crustal drilling in the Ionian Sea, Deep Biosphere, Sapropels, and the Red Sea. A second MagellanPlus workshop held in January 2014 in Paris (France), has proceeded a step further towards the drafting of the Multi-phase Drilling Project and a set of pre-proposals for submission to IODP.

  18. Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

    DOE PAGES

    Turchi, Craig S.; Vidal, Judith; Bauer, Matthew

    2018-03-14

    This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO 2) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

  19. Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

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

    Turchi, Craig S.; Vidal, Judith; Bauer, Matthew

    This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO 2) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

  20. Numerical models of salt marsh evolution: ecological, geomorphic, and climatic factors

    USGS Publications Warehouse

    Fagherazzi, Sergio; Kirwan, Matthew L.; Mudd, Simon M.; Guntenspergen, Glenn R.; Temmerman, Stijn; D'Alpaos, Andrea; van de Koppel, Johan; Rybczyk, John; Reyes, Enrique; Craft, Chris; Clough, Jonathan

    2012-01-01

    Salt marshes are delicate landforms at the boundary between the sea and land. These ecosystems support a diverse biota that modifies the erosive characteristics of the substrate and mediates sediment transport processes. Here we present a broad overview of recent numerical models that quantify the formation and evolution of salt marshes under different physical and ecological drivers. In particular, we focus on the coupling between geomorphological and ecological processes and on how these feedbacks are included in predictive models of landform evolution. We describe in detail models that simulate fluxes of water, organic matter, and sediments in salt marshes. The interplay between biological and morphological processes often produces a distinct scarp between salt marshes and tidal flats. Numerical models can capture the dynamics of this boundary and the progradation or regression of the marsh in time. Tidal channels are also key features of the marsh landscape, flooding and draining the marsh platform and providing a source of sediments and nutrients to the marsh ecosystem. In recent years, several numerical models have been developed to describe the morphogenesis and long-term dynamics of salt marsh channels. Finally, salt marshes are highly sensitive to the effects of long-term climatic change. We therefore discuss in detail how numerical models have been used to determine salt marsh survival under different scenarios of sea level rise.

  1. Numerical models of salt marsh evolution: Ecological, geomorphic, and climatic factors

    USGS Publications Warehouse

    Fagherazzi, S.; Kirwan, M.L.; Mudd, S.M.; Guntenspergen, G.R.; Temmerman, S.; D'Alpaos, A.; Van De Koppel, J.; Rybczyk, J.M.; Reyes, E.; Craft, C.; Clough, J.

    2012-01-01

    Salt marshes are delicate landforms at the boundary between the sea and land. These ecosystems support a diverse biota that modifies the erosive characteristics of the substrate and mediates sediment transport processes. Here we present a broad overview of recent numerical models that quantify the formation and evolution of salt marshes under different physical and ecological drivers. In particular, we focus on the coupling between geomorphological and ecological processes and on how these feedbacks are included in predictive models of landform evolution. We describe in detail models that simulate fluxes of water, organic matter, and sediments in salt marshes. The interplay between biological and morphological processes often produces a distinct scarp between salt marshes and tidal flats. Numerical models can capture the dynamics of this boundary and the progradation or regression of the marsh in time. Tidal channels are also key features of the marsh landscape, flooding and draining the marsh platform and providing a source of sediments and nutrients to the marsh ecosystem. In recent years, several numerical models have been developed to describe the morphogenesis and long-term dynamics of salt marsh channels. Finally, salt marshes are highly sensitive to the effects of long-term climatic change. We therefore discuss in detail how numerical models have been used to determine salt marsh survival under different scenarios of sea level rise. Copyright 2012 by the American Geophysical Union.

  2. Spatiotemporal variation of Van der Burgh's coefficient in a salt plug estuary

    NASA Astrophysics Data System (ADS)

    Shaha, Dinesh Chandra; Cho, Yang-Ki; Kim, Bong Guk; Rafi Afruz Sony, M.; Rani Kundu, Sampa; Faruqul Islam, M.

    2017-09-01

    Salt water intrusion in estuaries is expected to become a serious global issue due to climate change. Van der Burgh's coefficient, K, is a good proxy for describing the relative contribution of tide-driven and gravitational (discharge-driven and density-driven) components of salt transport in estuaries. However, debate continues over the use of the K value for an estuary where K should be a constant, spatially varying, or time-independent factor for different river discharge conditions. In this study, we determined K during spring and neap tides in the dry (< 30 m-3 s-1) and wet (> 750 m-3 s-1) seasons in a salt plug estuary with an exponentially varying width and depth, to examine the relative contributions of tidal versus density-driven salt transport mechanisms. High-resolution salinity data were used to determine K. Discharge-driven gravitational circulation (K ˜ 0.8) was entirely dominant over tidal dispersion during spring and neap tides in the wet season, to the extent that salt transport upstream was effectively reduced, resulting in the estuary remaining in a relatively fresh state. In contrast, K increased gradually seaward (K ˜ 0.74) and landward (K ˜ 0.74) from the salt plug area (K ˜ 0.65) during the dry season, similar to an inverse and positive estuary, respectively. As a result, density-driven inverse gravitational circulation between the salt plug and the sea facilitates inverse estuarine circulation. On the other hand, positive estuarine circulation between the salt plug and the river arose due to density-driven positive gravitational circulation during the dry season, causing the upstream intrusion of high-salinity bottom water. Our results explicitly show that K varies spatially and depends on the river discharge. This result provides a better understanding of the distribution of hydrographic properties.

  3. Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan.

    PubMed

    Nakano, Takanori; Yokoo, Yoriko; Okumura, Masao; Jean, Seo-Ryong; Satake, Kenichi

    2012-11-01

    To elucidate the influence of airborne materials on the ecosystem of Japan's Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO(3) contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct (87)Sr/(86)Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81 % for Na, 83 % for Mg, 36 % for K, 32 % for Ca, and 33 % for Sr. The Sr value was comparable to the 28 % estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have (87)Sr/(86)Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China's loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima's ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils.

  4. Coastal aquifer groundwater dynamics and salt intrusion: Monitoring system of river Neretva delta

    NASA Astrophysics Data System (ADS)

    Srzić, Veljko; Vranješ, Mijo; Deković, Jure; Romić, Davor; Zovko, Monika; Milin, Marin

    2017-04-01

    River Neretva delta is located in southern part of Croatia and creates a complex surface- groundwater system influenced by tidal forces characteristic for Adriatic Sea and river Neretva whose discharge varies from 70 - 2700 m3/s over the year. From agricultural point of view, area is used widely for fruit production which implies existence and functionality of complex drainage system consisted of a net of lateral channels and pumping station plants with the capacity of app. 25 m3/s. Area of interest covers app 3500 ha and is bounded by river Neretva from North and Adriatic sea from West. Southern and eastern boundaries are dominantly karstic hills. Lover aquifer is confined with app depth of 65 m, made of fine gravel. Aquitard is a 15 m height layer of clay. Upper aquifer in unconfined with depth of app 10-20 m. Inside the area of interest there are 8 wells installed (each aquifer 4) measuring piezometric head on hourly/daily temporal scale. Sea level measurements are also made capturing for long term tidal oscillations. Discharge measurements are made few km downstream from hydropower plant Mostar (Bosnia and Herzegovina), while three meteorological stations for rainfall measurements are located at the area boundaries. Salt water concentration, pH and resistivity values have been measured locally, app 6 times per year for last 10 years. Results imply confined aquifer is dominantly influenced by the sea level while tidal effects are noticed 9 km upstream the river Neretva with delay of 9-12 minutes compared to sea level. Salt water cline inside the river is related to tidal effects and river discharge, with potential presence at distances of more than 15 km upstream from the sea. Salt water intrusion dominantly occurs through confined aquifer while vertical transport of salt is supposed to be enhanced by the effects of drainage system.

  5. The Contribution of Mangrove Expansion to Salt Marsh Loss on the Texas Gulf Coast

    PubMed Central

    Brody, Samuel D.; Louchouarn, Patrick

    2015-01-01

    Landscape-level shifts in plant species distribution and abundance can fundamentally change the ecology of an ecosystem. Such shifts are occurring within mangrove-marsh ecotones, where over the last few decades, relatively mild winters have led to mangrove expansion into areas previously occupied by salt marsh plants. On the Texas (USA) coast of the western Gulf of Mexico, most cases of mangrove expansion have been documented within specific bays or watersheds. Based on this body of relatively small-scale work and broader global patterns of mangrove expansion, we hypothesized that there has been a recent regional-level displacement of salt marshes by mangroves. We classified Landsat-5 Thematic Mapper images using artificial neural networks to quantify black mangrove (Avicennia germinans) expansion and salt marsh (Spartina alterniflora and other grass and forb species) loss over 20 years across the entire Texas coast. Between 1990 and 2010, mangrove area grew by 16.1 km2, a 74% increase. Concurrently, salt marsh area decreased by 77.8 km2, a 24% net loss. Only 6% of that loss was attributable to mangrove expansion; most salt marsh was lost due to conversion to tidal flats or water, likely a result of relative sea level rise. Our research confirmed that mangroves are expanding and, in some instances, displacing salt marshes at certain locations. However, this shift is not widespread when analyzed at a larger, regional level. Rather, local, relative sea level rise was indirectly implicated as another important driver causing regional-level salt marsh loss. Climate change is expected to accelerate both sea level rise and mangrove expansion; these mechanisms are likely to interact synergistically and contribute to salt marsh loss. PMID:25946132

  6. The contribution of mangrove expansion to salt marsh loss on the Texas Gulf Coast.

    PubMed

    Armitage, Anna R; Highfield, Wesley E; Brody, Samuel D; Louchouarn, Patrick

    2015-01-01

    Landscape-level shifts in plant species distribution and abundance can fundamentally change the ecology of an ecosystem. Such shifts are occurring within mangrove-marsh ecotones, where over the last few decades, relatively mild winters have led to mangrove expansion into areas previously occupied by salt marsh plants. On the Texas (USA) coast of the western Gulf of Mexico, most cases of mangrove expansion have been documented within specific bays or watersheds. Based on this body of relatively small-scale work and broader global patterns of mangrove expansion, we hypothesized that there has been a recent regional-level displacement of salt marshes by mangroves. We classified Landsat-5 Thematic Mapper images using artificial neural networks to quantify black mangrove (Avicennia germinans) expansion and salt marsh (Spartina alterniflora and other grass and forb species) loss over 20 years across the entire Texas coast. Between 1990 and 2010, mangrove area grew by 16.1 km(2), a 74% increase. Concurrently, salt marsh area decreased by 77.8 km(2), a 24% net loss. Only 6% of that loss was attributable to mangrove expansion; most salt marsh was lost due to conversion to tidal flats or water, likely a result of relative sea level rise. Our research confirmed that mangroves are expanding and, in some instances, displacing salt marshes at certain locations. However, this shift is not widespread when analyzed at a larger, regional level. Rather, local, relative sea level rise was indirectly implicated as another important driver causing regional-level salt marsh loss. Climate change is expected to accelerate both sea level rise and mangrove expansion; these mechanisms are likely to interact synergistically and contribute to salt marsh loss.

  7. Sea Level Driven Marsh Expansion in a Coupled Model of Marsh Erosion, Forest Retreat, and Human Impacts

    NASA Astrophysics Data System (ADS)

    Kirwan, M. L.; Walters, D. C.; Reay, W.; Carr, J.

    2016-12-01

    Salt marsh ecosystem services depend nonlinearly on wetland size and are threatened by sea level rise and coastal development. Here, we present a simple model of marsh migration into adjacent uplands, and couple it with existing models of seaward edge erosion and vertical soil accretion to explore how connectivity between adjacent ecosystems influences marsh size and response to sea level rise. We find that ecogeomorphic feedbacks tend to stabilize soil elevations relative to sea level rise so that changes in marsh size are determined mostly by the competition between ecological transitions at the upland boundary, and physical erosion at the seaward boundary. Salt marsh loss and natural flood protection is nearly inevitable under rapid sea level rise rates where topographic and anthropogenic barriers limit marsh migration into uplands. Where unconstrained by barriers, however, rates of marsh migration are much more sensitive to accelerated sea level rise than rates of edge erosion. Together, this behavior suggests a counterintuitive, natural tendency for marsh expansion with sea level rise, and emphasizes the disparity between coastal response to climate change with and without human intervention. Analysis of 19th century maps and modern photographs from the Chesapeake Bay region confirm that migration rates are more sensitive to sea level rise than erosion rate, and indicate that transgression has thus far allowed marshes to survive the fastest rates of relative sea level rise on the Atlantic Coast. This work suggests that the flux of organisms and sediment across adjacent ecosystems leads to an increase in system resilience that could not be inferred from studies that consider individual components of landscape change.

  8. Hydrogen production under salt stress conditions by a freshwater Rhodopseudomonas palustris strain.

    PubMed

    Adessi, Alessandra; Concato, Margherita; Sanchini, Andrea; Rossi, Federico; De Philippis, Roberto

    2016-03-01

    Hydrogen represents a possible alternative energy carrier to face the growing request for energy and the shortage of fossil fuels. Photofermentation for the production of H2 constitutes a promising way for integrating the production of energy with waste treatments. Many wastes are characterized by high salinity, and polluted seawater can as well be considered as a substrate. Moreover, the application of seawater for bacterial culturing is considered cost-effective. The aims of this study were to assess the capability of the metabolically versatile freshwater Rhodopseudomonas palustris 42OL of producing hydrogen on salt-containing substrates and to investigate its salt stress response strategy, never described before. R. palustris 42OL was able to produce hydrogen in media containing up to 3 % added salt concentration and to grow in media containing up to 4.5 % salinity without the addition of exogenous osmoprotectants. While the hydrogen production performances in absence of sea salts were higher than in their presence, there was no significant difference in performances between 1 and 2 % of added sea salts. Nitrogenase expression levels indicated that the enzyme was not directly inhibited during salt stress, but a regulation of its expression may have occurred in response to salt concentration increase. During cell growth and hydrogen production in the presence of salts, trehalose was accumulated as a compatible solute; it protected the enzymatic functionality against salt stress, thus allowing hydrogen production. The possibility of producing hydrogen on salt-containing substrates widens the range of wastes that can be efficiently used in production processes.

  9. A single-component multidrug transporter of the major facilitator superfamily is part of a network that protects E scherichia coli from bile salt stress

    PubMed Central

    Paul, Stephanie; Alegre, Kamela O; Holdsworth, Scarlett R; Rice, Matthew; Brown, James A; McVeigh, Paul; Kelly, Sharon M; Law, Christopher J

    2014-01-01

    Resistance to high concentrations of bile salts in the human intestinal tract is vital for the survival of enteric bacteria such as E scherichia coli. Although the tripartite AcrAB–TolC efflux system plays a significant role in this resistance, it is purported that other efflux pumps must also be involved. We provide evidence from a comprehensive suite of experiments performed at two different pH values (7.2 and 6.0) that reflect pH conditions that E . coli may encounter in human gut that MdtM, a single-component multidrug resistance transporter of the major facilitator superfamily, functions in bile salt resistance in E . coli by catalysing secondary active transport of bile salts out of the cell cytoplasm. Furthermore, assays performed on a chromosomal ΔacrB mutant transformed with multicopy plasmid encoding MdtM suggested a functional synergism between the single-component MdtM transporter and the tripartite AcrAB–TolC system that results in a multiplicative effect on resistance. Substrate binding experiments performed on purified MdtM demonstrated that the transporter binds to cholate and deoxycholate with micromolar affinity, and transport assays performed on inverted vesicles confirmed the capacity of MdtM to catalyse electrogenic bile salt/H+ antiport. PMID:24684269

  10. Aerosol observation using multi-wavelength Mie-Raman lidars of the Ad-Net and aerosol component analysis

    NASA Astrophysics Data System (ADS)

    Nishizawa, Tomoaki; Sugimoto, Nobuo; Shimizu, Atsushi; Uno, Itsushi; Hara, Yukari; Kudo, Rei

    2018-04-01

    We deployed multi-wavelength Mie-Raman lidars (MMRL) at three sites of the AD-Net and have conducted continuous measurements using them since 2013. To analyze the MMRL data and better understand the externally mixing state of main aerosol components (e.g., dust, sea-salt, and black carbon) in the atmosphere, we developed an integrated package of aerosol component retrieval algorithms, which have already been developed or are being developed, to estimate vertical profiles of the aerosol components. This package applies to the other ground-based lidar network data (e.g., EARLINET) and satellite-borne lidar data (e.g., CALIOP/CALIPSO and ATLID/EarthCARE) as well as the other lidar data of the AD-Net.

  11. Aral Sea in Uzbekastan seen from STS-59

    NASA Technical Reports Server (NTRS)

    1994-01-01

    View northeastward across Uzbekastan to the partly-ice-covered Aral Sea and Kazakhstan. The irrigated fan-delta of the Amu Darya extends from the right side of the photograph to end in extensive salt flats at the south end of the sea. The Aral was the fourth-largest inland sea or lake in the world, until diversion and over-use of the river water for irrigation led, in this arid climate, to the sea's decline.

  12. Spatially resolved micro-Raman observation on the phase separation of effloresced sea salt droplets.

    PubMed

    Xiao, Han-Shuang; Dong, Jin-Ling; Wang, Liang-Yu; Zhao, Li-Jun; Wang, Feng; Zhang, Yun-Hong

    2008-12-01

    We report on the investigation of the phase separation of individual seawater droplets in the efflorescence processes with the spatially resolved Raman system. Upon decreasing the relative humidity (RH), CaSO4.0.5H2O separated out foremost fromthe droplet atan unexpectedly high RH of approcimately 90%. Occasionally, CaSO4.2H2O substituted for CaSO4.O.5H2O crystallizing first at approximately 78% RH. Relatively large NaCI solids followed to crystallize at approximately 55% RH and led to the great loss of the solution. Then, the KMgCl3.6H2O crystallites separated out from the residual solutions, adjacentto NaCl at approximately 44% RH. Moreover, a shell structure of dried sea salt particle was found to form at low RHs, with the NaCl crystals in the core and minor supersaturated solutions covered with MgSO4 gel coating on the surface. Ultimately, the shielded solution partly effloresced into MgSO4 hydrates at very dry state (<5% RH).

  13. Centuries of human-driven change in salt marsh ecosystems.

    PubMed

    Gedan, K Bromberg; Silliman, B R; Bertness, M D

    2009-01-01

    Salt marshes are among the most abundant, fertile, and accessible coastal habitats on earth, and they provide more ecosystem services to coastal populations than any other environment. Since the Middle Ages, humans have manipulated salt marshes at a grand scale, altering species composition, distribution, and ecosystem function. Here, we review historic and contemporary human activities in marsh ecosystems--exploitation of plant products; conversion to farmland, salt works, and urban land; introduction of non-native species; alteration of coastal hydrology; and metal and nutrient pollution. Unexpectedly, diverse types of impacts can have a similar consequence, turning salt marsh food webs upside down, dramatically increasing top down control. Of the various impacts, invasive species, runaway consumer effects, and sea level rise represent the greatest threats to salt marsh ecosystems. We conclude that the best way to protect salt marshes and the services they provide is through the integrated approach of ecosystem-based management.

  14. High Spatial resolution remote sensing for salt marsh change detection on Fire Island National Seashore

    NASA Astrophysics Data System (ADS)

    Campbell, A.; Wang, Y.

    2017-12-01

    Salt marshes are under increasing pressure due to anthropogenic stressors including sea level rise, nutrient enrichment, herbivory and disturbances. Salt marsh losses risk the important ecosystem services they provide including biodiversity, water filtration, wave attenuation, and carbon sequestration. This study determines salt marsh change on Fire Island National Seashore, a barrier island along the south shore of Long Island, New York. Object-based image analysis was used to classifying Worldview-2, high resolution satellite, and topobathymetric LiDAR. The site was impacted by Hurricane Sandy in October of 2012 causing a breach in the Barrier Island and extensive overwash. In situ training data from vegetation plots were used to train the Random Forest classifier. The object-based Worldview-2 classification achieved an overall classification accuracy of 92.75. Salt marsh change for the study site was determined by comparing the 2015 classification with a 1997 classification. The study found a shift from high marsh to low marsh and a reduction in Phragmites on Fire Island. Vegetation losses were observed along the edge of the marsh and in the marsh interior. The analysis agreed with many of the trends found throughout the region including the reduction of high marsh and decline of salt marsh. The reduction in Phragmites could be due to the species shrinking niche between rising seas and dune vegetation on barrier islands. The complex management issues facing salt marsh across the United States including sea level rise and eutrophication necessitate very high resolution classification and change detection of salt marsh to inform management decisions such as restoration, salt marsh migration, and nutrient inputs.

  15. Study Orientation Ply of Fiberglass on Blade Salt Water Pump Windmill using Abaqus

    NASA Astrophysics Data System (ADS)

    Badruzzaman, B.; Sifa, A.

    2018-02-01

    Windmill is one tool to generate energy from wind energy is converted into energy motion, salt production process still using traditional process by utilizing windmill to move sea water to salt field With a windmill driven water system, a horizontal axis type windmill with an average windmill height of 3-4 m, with a potential wind speed of 5-9 m / s, the amount of blade used for salt water pumps as much as 4 blades, one of the main factor of the windmill component is a blade, blade designed for the needs of a salt water pump by using fiberglass material. On layer orientation 0°,30°,45°,60° and 90° with layer number 10 and layer thickness 2 mm, the purpose of this study was to determine the strength of fiberglass that was influenced by the orientation of the layer, and to determine the orientation of fiberglass layer before making. This method used Finite Element Analysis method using ABAQUS, with homogenous and heterogeneous layer parameters. The simulation result shows the difference in von misses value at an angle of 0°, 30°, 45°,60° homogeneous value is greater than heterogeneous value, whereas in orientation 90 heterogeneous values have value 1,689e9 Pa, greater than homogenous 90 orientation value of 1,296e9 Pa.

  16. Matrix partitioning and EOF/principal component analysis of Antarctic Sea ice brightness temperatures

    NASA Technical Reports Server (NTRS)

    Murray, C. W., Jr.; Mueller, J. L.; Zwally, H. J.

    1984-01-01

    A field of measured anomalies of some physical variable relative to their time averages, is partitioned in either the space domain or the time domain. Eigenvectors and corresponding principal components of the smaller dimensioned covariance matrices associated with the partitioned data sets are calculated independently, then joined to approximate the eigenstructure of the larger covariance matrix associated with the unpartitioned data set. The accuracy of the approximation (fraction of the total variance in the field) and the magnitudes of the largest eigenvalues from the partitioned covariance matrices together determine the number of local EOF's and principal components to be joined by any particular level. The space-time distribution of Nimbus-5 ESMR sea ice measurement is analyzed.

  17. Effects of Sea Level Rise and Coastal Marsh Transgression on Soil Organic Matter in a Chesapeake Bay Salt Marsh

    NASA Astrophysics Data System (ADS)

    Van Allen, R.; Schreiner, K. M.; Guntenspergen, G. R.

    2016-12-01

    Salt marsh, mangrove swamp, and seagrass bed ecosystems comprise a global carbon stock known as "blue carbon." While vegetated coastal ecosystems have a small global areal extent, their total carbon burial rates are comparable to global marine carbon burial rates. Under global climate change-induced sea level rise, the role of these systems in the global carbon cycle could change significantly. This study aims to develop a more complete view of how coastal marsh transgression into terrestrial upland environments impacts soil organic matter characteristics. A US Geological Survey study site in Blackwater National Wildlife Refuge on the eastern coast of Chesapeake Bay, Maryland was chosen for this study. This marsh has undergone transgression into adjacent upland forest as local relative sea level has risen, making it an ideal location to study the source and stability of organic matter underlying the shifting marsh-forest boundary. Peat cores and vegetation samples were collected from the study site in May 2015 and June 2016. Care was taken to sample marsh soils underlying a range of elevations and vegetation types from the intertidal zone through the transition to upland forest. Radiocarbon and lead-210 dating give age estimates for basal peat layers within the cores. Analysis of stable carbon isotopes in bulk soils in this site suggests a broad shift towards C4-dominated marsh vegetation. Finally, cupric oxide oxidation products of soil organic matter provide information about the changing molecular organic geochemistry of the marsh soils as sea level rises and the marsh transgresses. This represents a novel molecular-level study of the changing organic geochemistry of marsh soils with sea level rise and resulting vegetation changes.

  18. Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation

    NASA Astrophysics Data System (ADS)

    Yang, Qian; Dixon, Timothy H.; Myers, Paul G.; Bonin, Jennifer; Chambers, Don; van den Broeke, M. R.

    2016-01-01

    The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland's ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from Greenland using updated GRACE satellite data, present new flux estimates for heat and salt from the North Atlantic into the Labrador Sea and explain recent variations in LSW formation. We suggest that changes in LSW can be directly linked to recent freshening, and suggest a possible link to AMOC weakening.

  19. Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation

    PubMed Central

    Yang, Qian; Dixon, Timothy H.; Myers, Paul G.; Bonin, Jennifer; Chambers, Don; van den Broeke, M. R.; Ribergaard, Mads H.; Mortensen, John

    2016-01-01

    The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland's ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from Greenland using updated GRACE satellite data, present new flux estimates for heat and salt from the North Atlantic into the Labrador Sea and explain recent variations in LSW formation. We suggest that changes in LSW can be directly linked to recent freshening, and suggest a possible link to AMOC weakening. PMID:26796579

  20. Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation.

    PubMed

    Yang, Qian; Dixon, Timothy H; Myers, Paul G; Bonin, Jennifer; Chambers, Don; van den Broeke, M R

    2016-01-22

    The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland's ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from Greenland using updated GRACE satellite data, present new flux estimates for heat and salt from the North Atlantic into the Labrador Sea and explain recent variations in LSW formation. We suggest that changes in LSW can be directly linked to recent freshening, and suggest a possible link to AMOC weakening.

  1. Ceftriaxone-associated gallbladder sludge. Identification of calcium-ceftriaxone salt as a major component of gallbladder precipitate

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

    Park, H.Z.; Lee, S.P.; Schy, A.L.

    1991-06-01

    Ceftriaxone, a third-generation cephalosporin, is partially excreted into bile. With its clinical use, the formation of gallbladder sludge detected by ultrasonography has been reported. Four surgical specimens were examined and no gallstones were found. Instead, fine precipitates of 20-250 microns were present. Microscopically, there was a small number of cholesterol monohydrate crystals and bilirubin granules among an abundant amount of granular-crystalline material that was not morphologically cholesterol monohydrate crystals. The chemical composition of the precipitates (n = 4) was determined. There was a small amount of cholesterol (1.7% +/- 0.8%) and bilirubin (13.9% +/- 0.74%). The major component of themore » precipitate was a residue. On further analysis using thin-layer chromatography, high-performance liquid chromatography, and electron microprobe analysis, the residue was identified as a calcium salt of ceftriaxone. The residue also had identical crystal morphology and chromatographic elution profile as authentic calcium-ceftriaxone standards. It is concluded that ceftriaxone, after excretion and being concentrated in the gallbladder bile, can form a precipitate. The major constituent has been identified as a ceftriaxone-calcium salt.« less

  2. Subgrid Modeling Geomorphological and Ecological Processes in Salt Marsh Evolution

    NASA Astrophysics Data System (ADS)

    Shi, F.; Kirby, J. T., Jr.; Wu, G.; Abdolali, A.; Deb, M.

    2016-12-01

    Numerical modeling a long-term evolution of salt marshes is challenging because it requires an extensive use of computational resources. Due to the presence of narrow tidal creeks, variations of salt marsh topography can be significant over spatial length scales on the order of a meter. With growing availability of high-resolution bathymetry measurements, like LiDAR-derived DEM data, it is increasingly desirable to run a high-resolution model in a large domain and for a long period of time to get trends of sedimentation patterns, morphological change and marsh evolution. However, high spatial-resolution poses a big challenge in both computational time and memory storage, when simulating a salt marsh with dimensions of up to O(100 km^2) with a small time step. In this study, we have developed a so-called Pre-storage, Sub-grid Model (PSM, Wu et al., 2015) for simulating flooding and draining processes in salt marshes. The simulation of Brokenbridge salt marsh, Delaware, shows that, with the combination of the sub-grid model and the pre-storage method, over 2 orders of magnitude computational speed-up can be achieved with minimal loss of model accuracy. We recently extended PSM to include a sediment transport component and models for biomass growth and sedimentation in the sub-grid model framework. The sediment transport model is formulated based on a newly derived sub-grid sediment concentration equation following Defina's (2000) area-averaging procedure. Suspended sediment transport is modeled by the advection-diffusion equation in the coarse grid level, but the local erosion and sedimentation rates are integrated over the sub-grid level. The morphological model is based on the existing morphological model in NearCoM (Shi et al., 2013), extended to include organic production from the biomass model. The vegetation biomass is predicted by a simple logistic equation model proposed by Marani et al. (2010). The biomass component is loosely coupled with hydrodynamic and

  3. Ecology of Great Salt Pond, Block Island

    EPA Science Inventory

    Great Salt Pond is an island of estuarine water on Block Island, which sits in the middle of the Northwest Atlantic Continental Shelf. When the last continental glaciers retreated, they left a high spot on a terminal moraine. The rising sea from melting glaciers formed two island...

  4. Two planets: Earth and Mars - One salt model: The Hydrothermal SCRIW-Model

    NASA Astrophysics Data System (ADS)

    Hovland, M. T.; Rueslaatten, H.; Johnsen, H. K.; Indreiten, T.

    2011-12-01

    One of the common characteristics of planets Earth and Mars is that both host water (H2O) and large accumulations of salt. Whereas Earth's surface-environment can be regarded as 'water-friendly' and 'salt hostile', the reverse can be said for the surface of Mars. This is because liquid water is stable on Earth, and the atmosphere transports humidity around the globe, whereas on planet Mars, liquid water is unstable, rendering the atmosphere dry and, therefore, 'salt-friendly'. The riddle as to how the salt accumulated in various locations on those two planets is one of long-lasting and great debate. The salt accumulations on Earth are traditionally termed 'evaporites', meaning that they formed by the evaporation of large masses of seawater. How the accumulations on Mars formed is much harder to explain, with a similar model, as surface water, representing a large ocean only existed briefly. Although water molecules and OH-groups may exist in abundance in bound form (crystal water, adsorbed water, etc.), the only place where free water is expected to be stable on Mars is within underground faults, fractures, and crevices. Here it likely occurs as brine or in the form of ice. Based on these conditions, a key to understanding the accumulation of large deposits of salt on both planets is linked to how brines behave in the subsurface when pressurized and heated beyond their supercritical point. At depths greater than about 3 km (i.e., a pressure, P>300 bars) water will no longer boil in a steam phase. Rather, it becomes supercritical and will form a supercritical water 'vapor' (SCRIW) with a specific gravity of typically 0.3 g/cm3. An important characteristic of SCRIW is its inability to dissolve the common sea salts. The salt dissolved in the brines will therefore precipitate as solid particles when brines (seawater on the Earth) move into the supercritical P&T-domain (above 400 C and 300 bars). Numerical modeling of a hydrothermal system in the Atlantis II Deep of the

  5. Size-resolved characterization of the polysaccharidic and proteinaceous components of sea spray aerosol

    NASA Astrophysics Data System (ADS)

    Aller, Josephine Y.; Radway, JoAnn C.; Kilthau, Wendy P.; Bothe, Dylan W.; Wilson, Theodore W.; Vaillancourt, Robert D.; Quinn, Patricia K.; Coffman, Derek J.; Murray, Benjamin J.; Knopf, Daniel A.

    2017-04-01

    Dissolved organic polymers released by phytoplankton and bacteria abiologically self-assemble in surface ocean waters into nano-to micro-sized gels containing polysaccharides, proteins, lipids and other components. These gels concentrate in the sea surface microlayer (SML), where they can potentially contribute to sea spray aerosol (SSA). Sea spray is a major source of atmospheric aerosol mass over much of the earth's surface, and knowledge of its properties (including the amount and nature of the organic content), size distributions and fluxes are fundamental for determining its role in atmospheric chemistry and climate. Using a cascade impactor, we collected size-fractionated aerosol particles from ambient air and from freshly generated Sea Sweep SSA in the western North Atlantic Ocean together with biological and chemical characterization of subsurface and SML waters. Spectrophotometric methods were applied to quantify the polysaccharide-containing transparent exopolymer (TEP) and protein-containing Coomassie stainable material (CSM) in these particles and waters. This study demonstrates that both TEP and CSM in surface ocean waters are aerosolized with sea spray with the greatest total TEP associated with particles <180 nm in diameter and >5 000 nm. The higher concentrations of TEP and CSM in particles >5 000 nm most likely reflects collection of microorganism cells and/or fragments. The greater concentration of CSM in larger size particles may also reflect greater stability of proteinaceous gels compared to polysaccharide-rich gels in surface waters and the SML. Both TEP and CSM were measured in the ambient marine air sample with concentrations of 2.1 ± 0.16 μg xanthan gum equivalents (XG eq.) m-3 and 14 ± 1.0 μg bovine serum albumin equivalents (BSA eq.) m-3. TEP in Sea Sweep SSA averaged 4.7 ± 3.1 μg XG eq. m-3 and CSM 8.6 ± 7.3 μg BSA eq. m-3. This work shows the transport of marine biogenic material across the air-sea interface through primary

  6. Electrolytic orthoborate salts for lithium batteries

    DOEpatents

    Angell, Charles Austen [Mesa, AZ; Xu, Wu [Tempe, AZ

    2008-01-01

    Orthoborate salts suitable for use as electrolytes in lithium batteries and methods for making the electrolyte salts are provided. The electrolytic salts have one of the formulae (I). In this formula anionic orthoborate groups are capped with two bidentate chelating groups, Y1 and Y2. Certain preferred chelating groups are dibasic acid residues, most preferably oxalyl, malonyl and succinyl, disulfonic acid residues, sulfoacetic acid residues and halo-substituted alkylenes. The salts are soluble in non-aqueous solvents and polymeric gels and are useful components of lithium batteries in electrochemical devices.

  7. Electrolytic orthoborate salts for lithium batteries

    DOEpatents

    Angell, Charles Austen [Mesa, AZ; Xu, Wu [Tempe, AZ

    2009-05-05

    Orthoborate salts suitable for use as electrolytes in lithium batteries and methods for making the electrolyte salts are provided. The electrolytic salts have one of the formulae (I). In this formula anionic orthoborate groups are capped with two bidentate chelating groups, Y1 and Y2. Certain preferred chelating groups are dibasic acid residues, most preferably oxalyl, malonyl and succinyl, disulfonic acid residues, sulfoacetic acid residues and halo-substituted alkylenes. The salts are soluble in non-aqueous solvents and polymeric gels and are useful components of lithium batteries in electrochemical devices.

  8. Sea salt emission, transport and influence on size-segregated nitrate simulation: a case study in northwestern Europe by WRF-Chem

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Cheng, Yafang; Ma, Nan; Wolke, Ralf; Nordmann, Stephan; Schüttauf, Stephanie; Ran, Liang; Wehner, Birgit; Birmili, Wolfram; Denier van der Gon, Hugo A. C.; Mu, Qing; Barthel, Stefan; Spindler, Gerald; Stieger, Bastian; Müller, Konrad; Zheng, Guang-Jie; Pöschl, Ulrich; Su, Hang; Wiedensohler, Alfred

    2016-09-01

    Sea salt aerosol (SSA) is one of the major components of primary aerosols and has significant impact on the formation of secondary inorganic particles mass on a global scale. In this study, the fully online coupled WRF-Chem model was utilized to evaluate the SSA emission scheme and its influence on the nitrate simulation in a case study in Europe during 10-20 September 2013. Meteorological conditions near the surface, wind pattern and thermal stratification structure were well reproduced by the model. Nonetheless, the coarse-mode (PM1 - 10) particle mass concentration was substantially overestimated due to the overestimation of SSA and nitrate. Compared to filter measurements at four EMEP stations (coastal stations: Bilthoven, Kollumerwaard and Vredepeel; inland station: Melpitz), the model overestimated SSA concentrations by a factor of 8-20. We found that this overestimation was mainly caused by overestimated SSA emissions over the North Sea during 16-20 September. Over the coastal regions, SSA was injected into the continental free troposphere through an "aloft bridge" (about 500 to 1000 m above the ground), a result of the different thermodynamic properties and planetary boundary layer (PBL) structure between continental and marine regions. The injected SSA was further transported inland and mixed downward to the surface through downdraft and PBL turbulence. This process extended the influence of SSA to a larger downwind region, leading, for example, to an overestimation of SSA at Melpitz, Germany, by a factor of ˜ 20. As a result, the nitrate partitioning fraction (ratio between particulate nitrate and the summation of particulate nitrate and gas-phase nitric acid) increased by about 20 % for the coarse-mode nitrate due to the overestimation of SSA at Melpitz. However, no significant difference in the partitioning fraction for the fine-mode nitrate was found. About 140 % overestimation of the coarse-mode nitrate resulted from the influence of SSA at Melpitz

  9. Top-down and bottom-up controls on southern New England salt marsh crab populations

    EPA Science Inventory

    Southern New England salt marsh vegetation and habitats are changing rapidly in response to sea-level rise. At the same time, fiddler crab (Uca spp.) distributions have expanded and purple marsh crab (Sesarma reticulatum) grazing on creekbank vegetation has increased. Sea-level r...

  10. Systematic Evaluation of Salt Cavern Well Integrity

    NASA Astrophysics Data System (ADS)

    Roberts, B. L.; Lord, D. L.; Lord, A. S.; Bettin, G.; Sobolik, S. R.; Park, B. Y.

    2017-12-01

    The U.S. Strategic Petroleum Reserve (SPR) holds a reserve of crude oil ( 700 million barrels) to help ease any interruptions in oil import to the United States. The oil is stored in a set of 63 underground caverns distributed across four sites along the U.S. Gulf Coast. The caverns were solution mined into salt domes at each of the four sites. The plastic nature of the salt is beneficial for the storage of crude oil as it heals any fractures that may occur in the salt. The SPR is responsible for operating and maintaining the nearly 120 wells used to access the storage caverns over operational lifetimes spanning decades. Salt creep can induce deformation of the well casing which must be remediated to insure cavern and well integrity. This is particularly true at the interface between the plastic salt and the rigid caprock. The Department of Energy, the SPR Management and Operations contractor, and Sandia National Laboratories has developed a multidimensional well-grading system for the salt cavern access wells. This system is designed to assign numeric grades to each well indicating its risk of losing integrity and remediation priority. The system consists of several main components which themselves may consist of sub-components. The main components consider such things as salt cavern pressure history, results from geomechanical simulations modeling salt deformation, and measurements of well casing deformation due to salt creep. In addition, the geology of the salt domes and their overlying caprock is also included in the grading. These multiple factors are combined into summary values giving the monitoring and remediation priority for each well. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  11. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2

    EPA Pesticide Factsheets

    The uploaded data consists of the BRACE Na aerosol observations paired with CMAQ model output, the updated model's parameterization of sea salt aerosol emission size distribution, and the model's parameterization of the sea salt emission factor as a function of sea surface temperature. This dataset is associated with the following publication:Gantt , B., J. Kelly , and J. Bash. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2. Geoscientific Model Development. Copernicus Publications, Katlenburg-Lindau, GERMANY, 8: 3733-3746, (2015).

  12. Factors influencing capture of invasive sea lamprey in traps baited with a synthesized sex pheromone component

    USGS Publications Warehouse

    Johnson, Nicholas; Siefkes, Michael J.; Wagner, C. Michael; Bravener, Gale; Steeves, Todd; Twohey, Michael; Li, Weiming

    2015-01-01

    The sea lamprey, Petromyzon marinus, is emerging as a model organism for understanding how pheromones can be used for manipulating vertebrate behavior in an integrated pest management program. In a previous study, a synthetic sex pheromone component 7α,12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3kPZS) was applied to sea lamprey traps in eight streams at a final in-stream concentration of 10−12 M. Application of 3kPZS increased sea lamprey catch, but where and when 3kPZS had the greatest impact was not determined. Here, by applying 3kPZS to additional streams, we determined that overall increases in yearly exploitation rate (proportion of sea lampreys that were marked, released, and subsequently recaptured) were highest (20–40 %) in wide streams (~40 m) with low adult sea lamprey abundance (<1000). Wide streams with low adult abundance may be representative of low-attraction systems for adult sea lamprey and, in the absence of other attractants (larval odor, sex pheromone), sea lamprey may have been more responsive to a partial sex pheromone blend emitted from traps. Furthermore, we found that the largest and most consistent responses to 3kPZS were during nights early in the trapping season, when water temperatures were increasing. This may have occurred because, during periods of increasing water temperatures, sea lamprey become more active and males at large may not have begun to release sex pheromone. In general, our results are consistent with those for pheromones of invertebrates, which are most effective when pest density is low and when pheromone competition is low.

  13. Draft Genome of Scalindua rubra, Obtained from the Interface Above the Discovery Deep Brine in the Red Sea, Sheds Light on Potential Salt Adaptation Strategies in Anammox Bacteria.

    PubMed

    Speth, Daan R; Lagkouvardos, Ilias; Wang, Yong; Qian, Pei-Yuan; Dutilh, Bas E; Jetten, Mike S M

    2017-07-01

    Several recent studies have indicated that members of the phylum Planctomycetes are abundantly present at the brine-seawater interface (BSI) above multiple brine pools in the Red Sea. Planctomycetes include bacteria capable of anaerobic ammonium oxidation (anammox). Here, we investigated the possibility of anammox at BSI sites using metagenomic shotgun sequencing of DNA obtained from the BSI above the Discovery Deep brine pool. Analysis of sequencing reads matching the 16S rRNA and hzsA genes confirmed presence of anammox bacteria of the genus Scalindua. Phylogenetic analysis of the 16S rRNA gene indicated that this Scalindua sp. belongs to a distinct group, separate from the anammox bacteria in the seawater column, that contains mostly sequences retrieved from high-salt environments. Using coverage- and composition-based binning, we extracted and assembled the draft genome of the dominant anammox bacterium. Comparative genomic analysis indicated that this Scalindua species uses compatible solutes for osmoadaptation, in contrast to other marine anammox bacteria that likely use a salt-in strategy. We propose the name Candidatus Scalindua rubra for this novel species, alluding to its discovery in the Red Sea.

  14. Aral Sea in Uzbekastan seen from STS-59

    NASA Image and Video Library

    1994-04-14

    STS059-L22-140 (9-20 April 1994) --- View northeastward across Uzbekastan to the partly-ice-covered Aral Sea and Kazakhstan. The irrigated fan-delta of the Amu Darya extends from the right side of the photograph to end in extensive salt flats at the south end of the sea. The Aral was the fourth-largest inland sea or lake in the world, until diversion and over-use of the river water for irrigation led, in this arid climate, to the sea's decline. Linhof camera.

  15. Space Radar Image of Weddell Sea, Antarctica

    NASA Image and Video Library

    1999-05-01

    This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths

  16. Satellite Observations of Tropospheric BrO over Salt Lakes and Northern High Latitudes from EOS/OMI and SNPP/OMPS

    NASA Astrophysics Data System (ADS)

    Kurosu, T. P.; Stutz, J.; Brockway, N.; Saiz-Lopez, A.; Suleiman, R. M.; Natraj, V.; Jaross, G.; Seftor, C. J.

    2017-12-01

    We present observations of tropospheric bromine monoxide (BrO) derived from two satellite instruments: the Ozone Monitoring Instrument (OMI) on EOS-Aura, and the Nadir Mapper component of the Ozone Mapping and Profiler Suite (OMPS) on Suomi/NPP. BrO observations from OMPS constitute a new and experimental measurement that we first report on here and compare with the standard BrO data product from OMI. BrO is a halogen oxide present mostly in the lower stratosphere, where it catalytically destroys ozone with about 25 times the efficiency of ClO. BrO also has a tropospheric component, where it is released from sea surfaces, at the interface of ocean water and sea ice in the polar spring, in volcanic plumes, and in the vicinity of salt lakes. Tropospheric BrO has been linked to mercury (Hg) deposition through BrO-induced conversion of gaseous Hg to reactive Hg, which is then deposited on the surface and enters the food chain, ultimately affecting human health. As part of NASA's Aura Science Team, we are developing an OMI Tropospheric BrO data product that provides a unique global data set on BrO spatial and vertical distribution in the troposphere and stratosphere. Information of this kind is currently unavailable from any of the past and present bromine-monitoring instruments. In this presentation, we focus on multi-year time series of BrO released from a range of salt lakes - the Rann of Kutch, Salar de Uyuni, the Aral Sea, and others. We quantify the amount of bromine released from the lakes and investigate the possibility of lake desiccation monitoring based on independent BrO observations. The quality and limits of OMI and OMPS tropospheric BrO observations is investigated by comparison with ground-based MAX-DOAS observations over central Greenland.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  18. Measurements of Hygroscopicity- and Size-Resolved Sea Spray Aerosol

    NASA Astrophysics Data System (ADS)

    Phillips, B.; Dawson, K. W.; Royalty, T. M.; Reed, R. E.; Petters, M.; Meskhidze, N.

    2015-12-01

    Atmospheric aerosols play a central role in many environmental processes by influencing the Earth's radiative balance, tropospheric chemistry, clouds, biogeochemical cycles, and visibility as well as adversely impacting human health. Based on their origin, atmospheric aerosols can be defined as anthropogenic or natural. Recent studies have shown that a large fraction of uncertainty in the radiative effects of anthropogenic aerosols is related to uncertainty in natural—background—aerosols. Marine aerosols are of particular interest due to the abundance of oceans covering the Earth's surface. Despite their importance, limited information is currently available for size- and composition-resolved marine aerosol emission fluxes. Our group has designed and built an instrument for measuring the size- and hygroscopicity-resolved sea spray aerosol fluxes. The instrument was first deployed during spring 2015 at the end of the 560 m pier of the US Army Corps of Engineers' Field Research Facility in Duck, NC. Measurements include 200 nm-sized diameter growth factor (hygroscopicity) distributions, sea spray particle flux measurements, and total sub-micron sized aerosol concentration. Ancillary ocean data includes salinity, pH, sea surface temperature, dissolved oxygen content, and relative fluorescence (proxy for [Chl-a]). Hygroscopicity distribution measurements show two broad peaks, one indicative of organics and sulfates and another suggestive of sea salt. The fraction of 200 nm-sized salt particles having hygroscopicity similar to that of sea-spray aerosol contributes up to ~24% of the distribution on days with high-speed onshore winds and up to ~3% on calm days with winds blowing from the continent. However, the total concentration of sea-spray-like particles originating from offshore versus onshore winds was relatively similar. Changes in the relative contribution of sea-salt to number concentration were caused by a concomitant changes in total aerosol concentration

  19. Salt-Bridge Energetics in Halophilic Proteins

    PubMed Central

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are −3.0 kcal mol−1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of −5.0 kcal mol−1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (−10 kcal mol−1) exceeds than that of bridge term (−7 kcal mol−1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic

  20. Salt-bridge energetics in halophilic proteins.

    PubMed

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1) exceeds than that of bridge term (-7 kcal mol-1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its

  1. Non-sea-salt sulfate and methanesulfonate at American Samoa

    NASA Technical Reports Server (NTRS)

    Savoie, Dennis L.; Prospero, Joseph M.; Arimoto, Richard; Duce, Robert

    1994-01-01

    High-volume bulk aerosol samples have been collected at American Samoa (14.25 deg S, 170.58 deg W) on a semicontinuous basis since the system was erected as part of the Sea/Air Exchange Program (SEAREX) in March 1983. In this report we consider those samples collected through May 6, 1992. For most of this period the sample filters were changed once a week. However, during November 1989 and from May 10 to June 10, 1990, in conjunction with the aircraft missions of the NASA Global Backscatter Experiment (GLOBE), the filters were changed daily. All of the samples were analyzed for nonsea-salt (nss) SO4(2-) and NO3(-). Analyses for methanesulfonate (MSA) include all of the 53 daily samples, 22 weekly samples from March 19, 1983, through April 12, 1984, and 96 weekly samples from January 3, 1990, through May 6, 1992. The mean concentrations (in micrograms per cubic meter) were 0.37 for nss SO4(2-), 0.0229 for MSA, 0.114 for NO3(-), and 5.1 for Na(+). Nss SO4(2-) and MSA are strongly linearly correlated in these 171 samples (r(exp 2) = 0.66) and the regression intercept does not differ significantly from zero. The geometric mean (GM) nss SO4(2-)/MSA ratio, 18.1 +/- 0.9 (where +/- indicates the 95% confidence interval of the GM) is about 7% higher than had previously been reported for this station. The ratio exhibits no significant seasonal variation. Although the ratio appeared to be significantly lower in the May - June 1990 daily samples (GM = 15.3 +/- 1.2), a further examination of the results indicated that the variance of the measured ratios from 18.1 (the GM for the whole data set) was attributable almost exclusively to the typical random errors in the analyses as determined from the 1 sigma analytical uncertainties of 5% for MSA and SO4(2-) and 2% for Na(+).

  2. Will fluctuations in salt marsh–mangrove dominance alter vulnerability of a subtropical wetland to sea‐level rise?

    USGS Publications Warehouse

    Mckee, Karen L.; Vervaeke, William

    2018-01-01

    To avoid submergence during sea-level rise, coastal wetlands build soil surfaces vertically through accumulation of inorganic sediment and organic matter. At climatic boundaries where mangroves are expanding and replacing salt marsh, wetland capacity to respond to sea-level rise may change. To compare how well mangroves and salt marshes accommodate sea-level rise, we conducted a manipulative field experiment in a subtropical plant community in the subsiding Mississippi River Delta. Experimental plots were established in spatially equivalent positions along creek banks in monospecific stands of Spartina alterniflora (smooth cordgrass) or Avicennia germinans (black mangrove) and in mixed stands containing both species. To examine the effect of disturbance on elevation dynamics, vegetation in half of the plots was subjected to freezing (mangrove) or wrack burial (salt marsh), which caused shoot mortality. Vertical soil development was monitored for 6 years with the surface elevation table-marker horizon system. Comparison of land movement with relative sea-level rise showed that this plant community was experiencing an elevation deficit (i.e., sea level was rising faster than the wetland was building vertically) and was relying on elevation capital (i.e., relative position in the tidal frame) to survive. Although Avicennia plots had more elevation capital, suggesting longer survival, than Spartina or mixed plots, vegetation type had no effect on rates of accretion, vertical movement in root and sub-root zones, or net elevation change. Thus, these salt marsh and mangrove assemblages were accreting sediment and building vertically at equivalent rates. Small-scale disturbance of the plant canopy also had no effect on elevation trajectories—contrary to work in peat-forming wetlands showing elevation responses to changes in plant productivity. The findings indicate that in this deltaic setting with strong physical influences controlling elevation (sediment

  3. Retrieve sea surface salinity using principal component regression model based on SMOS satellite data

    NASA Astrophysics Data System (ADS)

    Zhao, Hong; Li, Changjun; Li, Hongping; Lv, Kebo; Zhao, Qinghui

    2016-06-01

    The sea surface salinity (SSS) is a key parameter in monitoring ocean states. Observing SSS can promote the understanding of global water cycle. This paper provides a new approach for retrieving sea surface salinity from Soil Moisture and Ocean Salinity (SMOS) satellite data. Based on the principal component regression (PCR) model, SSS can also be retrieved from the brightness temperature data of SMOS L2 measurements and Auxiliary data. 26 pair matchup data is used in model validation for the South China Sea (in the area of 4°-25°N, 105°-125°E). The RMSE value of PCR model retrieved SSS reaches 0.37 psu (practical salinity units) and the RMSE of SMOS SSS1 is 1.65 psu when compared with in-situ SSS. The corresponding Argo daily salinity data during April to June 2013 is also used in our validation with RMSE value 0.46 psu compared to 1.82 psu for daily averaged SMOS L2 products. This indicates that the PCR model is valid and may provide us with a good approach for retrieving SSS from SMOS satellite data.

  4. SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line

    NASA Astrophysics Data System (ADS)

    Modzelewska, J.; Czerny, B.; Hryniewicz, K.; Bilicki, M.; Krupa, M.; Świȩtoń, A.; Pych, W.; Udalski, A.; Adhikari, T. P.; Petrogalli, F.

    2014-10-01

    Context. Quasars can be used as a complementary tool to SN Ia to probe the distribution of dark energy in the Universe by measuring the time delay of the emission line with respect to the continuum. The understanding of the Mg II emission line structure is important for cosmological application and for the black hole mass measurements of intermediate redshift quasars. Aims: Knowing the shape of Mg II line and its variability allows for identifying which part of the line should be used to measure the time delay and the black hole mass. We thus aim at determining the structure and the variability of the Mg II line, as well as the underlying Fe II pseudo-continuum. Methods: We performed five spectroscopic observations of a quasar CTS C30.10 (z = 0.9000) with the SALT telescope between December 2012 and March 2014, and we studied the variations in the spectral shape in the 2700 Å-2900 Å rest frame. Results: We show that the Mg II line in this source consists of two kinematic components, which makes the source representative of type B quasars. Both components were modeled well with a Lorentzian shape, and they vary in a similar way. The Fe II contribution seems to be related only to the first (blue) Mg II component. Broad band spectral fitting instead favor the use of the whole line profile. The contribution of the narrow line region to Mg II is very low, below 2%. The Mg II variability is lower than the variability of the continuum, which is consistent with the simple reprocessing scenario. The variability level of CTS C30.10 and the measurement accuracy of the line and continuum is high enough to expect that further monitoring will allow the time delay between the Mg II line and continuum to be measured. Based on observations made with the Southern African Large Telescope (SALT) under program 2012-2-POL-003 and 2013-1-POL-RSA-002 (PI: B. Czerny).Spectra shown in Figs. 3 and 4 are only available in electronic form at the CDS via anonymous ftp to http

  5. Aerial observation of nitrogen compounds over the East China Sea in 2009 and 2010

    NASA Astrophysics Data System (ADS)

    Fujiwara, Hiroshi; Sadanaga, Yasuhiro; Urata, Junki; Masui, Yoshihiko; Bandow, Hiroshi; Ikeda, Keisuke; Hanaoka, Sayuri; Watanabe, Izumi; Arakaki, Takemitsu; Kato, Shungo; Kajii, Yoshizumi; Zhang, Daizhou; Hara, Kazutaka; Fujimoto, Toshiyuki; Seto, Takafumi; Okuyama, Kikuo; Ogi, Takashi; Takami, Akinori; Shimizu, Atsushi; Hatakeyama, Shiro

    2014-11-01

    Aerial observations of atmospheric pollutants were made over the East China Sea to analyze the transport of air pollutants, especially nitrogen oxides, from East Asia. Three flights each were conducted in October 2009 (autumn) and December 2010 (winter). Onboard measurements of gaseous total odd nitrogen species, gaseous nitric acid (HNO3(g)), O3, SO2, CO and black carbon were made and particles were collected on filters for ionic and metal component analyses. The NO3-(p)/T.NO3 (T.NO3 = HNO3(g) + NO3-(p); NO3-(p) indicates particulate nitrate) ratios were less than 0.5 in most cases. Exceptions were 17 October and 11 December, when high concentrations of dust particles (Kosa) were transported. The average T.NO3/NOy (NOy indicates total odd nitrogen species) ratio in winter was 0.59, and that in autumn was 0.71. In addition, positive and negative correlations between NOy - T.NO3 and ozone were observed in autumn and winter, respectively. These results indicate that the main components of NOy - T.NO3 are NOx and its descendant photochemical products, such as peroxyacyl nitrates and alkyl nitrates, in winter and autumn, respectively. Ratios of Na+ to Cl- + NO3- in particles were close to the seawater ratio for observations in both autumn and winter, save for the Kosa events. The main NO3-(p) formation process was the reaction of HNO3(g) with sea salt aerosols during autumn and winter. On the other hand, NO3-(p) was generated by the reaction of HNO3(g) with dust particles and sea salt during the Kosa events. The fraction of NH4NO3 in NO3-(p) was very small.

  6. OMI observations of bromine monoxide emissions from salt lakes

    NASA Astrophysics Data System (ADS)

    Suleiman, R. M.; Chance, K.; Liu, X.; Gonzalez Abad, G.; Kurosu, T. P.

    2015-12-01

    In this study, we analyze bromine monoxide (BrO) data from the Ozone Monitoring Instrument (OMI) over various salt lakes. We used OMI data from 2005 to 2014 to investigate BrO signatures from salt lakes. The salt lakes regions we cover include Dead Sea; Salt Lake City, US; Salar de Uyuni, Bolivia; and Namtso, Tibet. Elevated signatures of BrO was found in July and August BrO monthly averages over the Dead Sea. Similar results were found in the BrO monthly averages for August 2006 for the Bolivian Salt Flats. We present a detailed description of the retrieval algorithm for the OMI operational bromine monoxide (BrO) product. The algorithm is based on direct fitting of radiances from 319.0-347.5 nm, within the UV-2 channel of OMI. Radiances are modeled from the solar irradiance, attenuated by contributions from the target gas and interfering gases, rotational Raman scattering, additive and multiplicative closure polynomials and a common mode spectrum. The common mode spectra (one per cross-track position, computed on-line) are the average of several hundred fitting residuals. They include any instrument effects that are unrelated to molecular scattering and absorption cross sections. The BrO retrieval uses albedo- and wavelength-dependent air mass factors (AMFs), which have been pre-computed using climatological BrO profiles. The wavelength-dependent AMF is applied pre-fit to the BrO cross-sections so that vertical column densities are retrieved directly. We validate OMI BrO with ground-based measurements from three stations (Harestua, Lauder, and Barrow) and with chemical transport model simulations. We analyze the global distribution and seasonal variation of BrO and investigate BrO emissions from volcanoes and salt lakes.

  7. An innovative spraying setup to obtain uniform salt(s) mixture deposition to investigate hot corrosion

    NASA Astrophysics Data System (ADS)

    Mannava, Venkateswararao; Swaminathan, A. Vignesh; Kamaraj, M.; Kottada, Ravi Sankar

    2016-02-01

    A hot corrosion study via molten salt deposition and its interaction with creep/fatigue play a critical role in predicting the life of gas turbine engine components. To do systematic hot corrosion studies, deposition of molten salts on specimens should be uniform with good adherence. Thus, the present study describes an in-house developed spraying setup that produces uniform and reliable molten salt deposition in a repeatable fashion. The efficacy of the present method was illustrated by depositing 90 wt. % Na2SO4 + 5 wt. % NaCl + 5 wt. % NaV O3 salt mixture on hot corrosion coupons and on creep specimens, and also by comparing with other deposition methods.

  8. Deep Biosphere Secrets of the Mediterranean Salt Giant

    NASA Astrophysics Data System (ADS)

    Aloisi, Giovanni; Lugli, Stefano; McGenity, Terry; Kuroda, Junichiro; Takai, Ken; Treude, Tina; Camerlenghi, Angelo

    2015-04-01

    One component of the IODP multi-platform drilling proposal called DREAM (Deep-Sea Record of Mediterranean Messisnian Events), plans to investigate the deep biosphere associated to the Messinian Salinity Crisis (MSC) Salt Giant. We propose that the MSC Salt Giant, because of the variety of chemical environments it produces, has the potential to harbour an unprecedented diversity of microbial life with exceptional metabolic activity. Gypsum and anhydrite deposits provide a virtually unlimited source of sulphate at depths where oxidants are a rarity in other sedimentary environments. When reduced organic carbon comes into contact with these minerals there is the potential for a dynamic deep biosphere community of sulphate reducers to develop, with implications for sedimentary biogeochemical cycles and the souring of cruide oil. But the thickness of the Messinian evaporites and the range of chemical environments it harbours poses fundamental questions: will the interaction of several extreme conditions of temperature, salinity, pressure and chemical composition limit the ability of microbes to take advantage of such favourable thermodynamic conditions? And has such a diverse set of physical and chemical environments fostered microbal diversity, rather than phylogenetic specialization, as recent research into deep Mediterranean brine systems seems to indicate ? Over three kilometres in thickness, approaching the known temperature limits of life and with fluids precipitating carbonate, sulphate, halite and potash salts, microbes living within and around the MSC Salt Giant will be subject to the most exotic combinations of extremes, and have likely evolved yet unknown adaptations. Gypsum and Halite crystals contain fluid inclusions that are a micro-habitat in which microbes survive for tens of thousands, to possibly millions, of years, posing the fundamental question of cells devoting nearly all of their energy flow to somatic maintenance needs, rather than growth and

  9. Aircraft Monitoring of Sea-Spray and Changes in Hurricane Intensity

    NASA Astrophysics Data System (ADS)

    Lawrence, J. R.

    2010-12-01

    Sea spray above the ocean surface in hurricanes enhances the transfer of sensible heat to the atmospheric boundary layer. Sea spray becomes of greater significance as the intensity and thereby the wind speed of the hurricane increases. A fuller knowledge of the distribution of sea spray over the ocean may help in understanding changes in intensity of the most dangerous hurricanes. An instrument to measure the salt content of rain has been developed and installed on one of NOAA’s P3 hurricane research aircraft. The instrument detects changes in the conductivity of a thin film of water on the surface of the instrument. Calibration of the instrument has been completed at the University of Texas A&M wind tunnel facility. An earlier version of the sensor was flown into Hurricane Paloma (2008) at an elevation of 4 km. Changes in salt concentration were detected. A sturdier version of the instrument was flown into winter storms off the coast of Newfoundland in February of 2010. For the most part, the instrument did not function because the precipitation was a solid. But the one time the on-board meteorologist noted there was liquid precipitation, the instrument did function. Rain samples collected at ground level from eleven land falling hurricanes ranged from 5 ppm to 50 ppm (Lawrence et al, 2006 Fall AGU abstract, session A33). Hurricane Katrina showed the highest concentration of salt at 50 ppm. Sea salt measurements in rain from Hurricane Earl were underway starting on August 28 with continued plans through September 3. Salinity measurements by the instrument will be compared to wind velocities measured by the on-board radar. Because sea spray increases heat-transfer from the ocean to the hurricane atmosphere, especially in category 3 to 5 hurricanes, these studies may help improve models that predict changes in hurricane intensity.

  10. The geophysical importance of bubbles in the sea

    NASA Technical Reports Server (NTRS)

    Cirpriano, R. J.

    1982-01-01

    Present knowledge of the mechanisms for production and enrichment and film drops by bursting bubbles is summarized, with particular emphasis on the unsolved problems. Sea salt is by far the major constituent cycled through the Earth's atmosphere each year. Bursting bubbles in the oceans appear to be primarily responsible. These salt particles play a role in the formation of maritime clouds, which in turn affect the Earth's radiation budget. Along with the salt are carried various chemical pollutants and potentially pathogenic microorganisms, often in highly enriched form.

  11. The origin of brines and salts in Chilean salars: a hydrochemical review

    NASA Astrophysics Data System (ADS)

    Risacher, François; Alonso, Hugo; Salazar, Carlos

    2003-11-01

    Northern Chile is characterized by a succession of north-south-trending ranges and basins occupied by numerous saline lakes and salt crusts, collectively called salars. Fossil salt crusts are found to the west in the extremely arid Central Valley, while active salars receiving permanent inflows fill many intravolcanic basins to the east in the semiarid Cordillera. Sea salts and desert dust are blown eastward over the Cordillera, where they constitute an appreciable fraction of the solute load of very dilute waters (salt content<0.1 g/l). The weathering of volcanic rocks contributes most components to inflow waters with salt content ranging from 0.1 to 0.6 g/l. However, the average salt content of all inflows is much higher: about 3.2 g/l. Chemical composition, Cl/Br ratio, and 18O- 2H isotope contents point to the mixing of very dilute meteoric waters with present lake brines for the origin of saline inflows. Ancient gypsum in deep sedimentary formations seems to be the only evaporitic mineral recycled in present salars. Saline lakes and subsurface brines are under steady-state regime. The average residence time of conservative components ranges from a few years to some thousands years, which indicates a permanent leakage of the brines through bottom sediments. The infiltrating brines are recycled in the hydrologic system where they mix with dilute meteoric waters. High heat flow is the likely driving force that moves the deep waters in this magmatic arc region. Active Chilean salars cannot be considered as terminal lakes nor, strictly speaking, as closed basin lakes. Almost all incoming salts leave the basin and are transported elsewhere. Moreover, the dissolution of fossil salt crusts in some active salars also carries away important fluxes of components in percolating brines. Evaporative concentration of inflow waters leads to sulfate-rich or calcium-rich, near-neutral brines. Alkaline brines are almost completely lacking. The alkalinity/calcium ratio of inflow

  12. Pressure adaptation is linked to thermal adaptation in salt-saturated marine habitats.

    PubMed

    Alcaide, María; Stogios, Peter J; Lafraya, Álvaro; Tchigvintsev, Anatoli; Flick, Robert; Bargiela, Rafael; Chernikova, Tatyana N; Reva, Oleg N; Hai, Tran; Leggewie, Christian C; Katzke, Nadine; La Cono, Violetta; Matesanz, Ruth; Jebbar, Mohamed; Jaeger, Karl-Erich; Yakimov, Michail M; Yakunin, Alexander F; Golyshin, Peter N; Golyshina, Olga V; Savchenko, Alexei; Ferrer, Manuel

    2015-02-01

    The present study provides a deeper view of protein functionality as a function of temperature, salt and pressure in deep-sea habitats. A set of eight different enzymes from five distinct deep-sea (3040-4908 m depth), moderately warm (14.0-16.5°C) biotopes, characterized by a wide range of salinities (39-348 practical salinity units), were investigated for this purpose. An enzyme from a 'superficial' marine hydrothermal habitat (65°C) was isolated and characterized for comparative purposes. We report here the first experimental evidence suggesting that in salt-saturated deep-sea habitats, the adaptation to high pressure is linked to high thermal resistance (P value = 0.0036). Salinity might therefore increase the temperature window for enzyme activity, and possibly microbial growth, in deep-sea habitats. As an example, Lake Medee, the largest hypersaline deep-sea anoxic lake of the Eastern Mediterranean Sea, where the water temperature is never higher than 16°C, was shown to contain halopiezophilic-like enzymes that are most active at 70°C and with denaturing temperatures of 71.4°C. The determination of the crystal structures of five proteins revealed unknown molecular mechanisms involved in protein adaptation to poly-extremes as well as distinct active site architectures and substrate preferences relative to other structurally characterized enzymes. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Salt precipitation and dissolution in the late Quaternary Dead Sea: Evidence from chemical and δ37Cl composition of pore fluids and halites

    NASA Astrophysics Data System (ADS)

    Levy, Elan J.; Yechieli, Yoseph; Gavrieli, Ittai; Lazar, Boaz; Kiro, Yael; Stein, Mordechai; Sivan, Orit

    2018-04-01

    The chemical composition and δ37Cl of pore fluids from the ICDP core drilled in the deepest floor of the terminal and hypersaline Dead Sea, and halites from the adjacent Mount Sedom salt diapir, are used to establish the dynamics of halite precipitation and dissolution during the last interglacial and glacial periods. Between ∼132 and 116 thousand years ago (ka) halites precipitated in the lake resulting in the expulsion of Na+ and Cl- from the residual solution. Over 50% of the Cl- reservoir was removed, resulting in a decrease in the Na/Cl ratio from 0.57 to 0.19. This process was accompanied by a decrease in δ37Cl values in the precipitating halites and the associated residual Cl- in the lake. The observed decrease fits a Rayleigh distillation curve with a fractionation factor of Δ(NaCl-Dead Sea solution) = +0.32‰ (±0.12) determined in the present study. This behavior implies negligible contribution of external sources of Cl- to the lake during the main peak of the last interglacial, MIS5e. Subsequently, during the last glacial (ca. 117 to 17 ka) dissolution of halite took place, the Na+ and Cl- inventory were replenished, accompanied by an increase in Na/Cl from 0.21 to 0.55 and in the δ37Cl values from -0.46‰ to -0.12‰. While the lake underwent significant dilution during that time, the decrease in salinity was somewhat suppressed by the dissolution of the halite which was mostly derived from Mount Sedom salt diapir.

  14. Reactive uptake of HOCl to laboratory generated sea salt particles and nascent sea-spray aerosol

    NASA Astrophysics Data System (ADS)

    Campbell, N. R.; Ryder, O. S.; Bertram, T. H.

    2013-12-01

    Field observations suggest that the reactive uptake of HOCl on marine aerosol particles is an important source of chlorine radicals, particularly under low NOx conditions. However to date, laboratory measurements disagree on the magnitude of the reactive uptake coefficient for HOCl by a factor of 5 (γ(HOCl) ranges between 0.0004 and 0.0018), and there are no measurements of γ(HOCl) on nascent sea-spray aerosol. Here, we present measurements of the reactive uptake of HOCl to laboratory generated sodium chloride and sea-spray aerosol particles generated in a novel Marine Aerosol Reference Tank (MART), coupled to an entrained aerosol flow reactor and Chemical Ionization Mass Spectrometer (CIMS). Measurements of γ(HOCl) retrieved here are compared against those in the literature, and the role of organic coatings on nascent sea-spray aerosol is explored.

  15. Imaging Shallow Salt With 3D Refraction Migration

    NASA Astrophysics Data System (ADS)

    Vanschuyver, C. J.; Hilterman, F. J.

    2005-05-01

    In offshore West Africa, numerous salt walls are within 200 m of sea level. Because of the shallowness of these salt walls, reflections from the salt top can be difficult to map, making it impossible to build an accurate velocity model for subsequent pre-stack depth migration. An accurate definition of salt boundaries is critical to any depth model where salt is present. Unfortunately, when a salt body is very shallow, the reflection from the upper interface can be obscured due to large offsets between the source and near receivers and also due to the interference from multiples and other near-surface noise events. A new method is described using 3D migration of the refraction waveforms which is simplified because of several constraints in the model definition. The azimuth and dip of the refractor is found by imaging with Kirchhoff theory. A Kirchhoff migration is performed where the traveltime values are adjusted to use the CMP refraction traveltime equation. I assume the sediment and salt velocities to be known such that once the image time is specified, then the dip and azimuth of the refraction path can be found. The resulting 3D refraction migrations are in excellent depth agreement with available well control. In addition, the refraction migration time picks of deeper salt events are in agreement with time picks of the same events on the reflection migration.

  16. Occurrence of organohalogens at the Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Tubbesing, Christoph; Kotte, Karsten; Keppler, Frank; Krause, Torsten; Bahlmann, Enno; Schöler, Heinfried

    2013-04-01

    Most arid and semi-arid regions are characterized by evaporites, which are assured sources for volatile organohalogens (VOX) [1]. These compounds play an important role in tropospheric and stratospheric chemistry. The Dead Sea between Israel and Jordan is the world's most famous and biggest all-season water covered salt lake. In both countries chemical plants like the Dead Sea Works and the Arab Potash Company are located at the southern part of the Dead Sea and mine various elements such as bromine and magnesium. Conveying sea water through constructed evaporation pans multifarious salts are enriched and precipitated. In contrast, the Northern basin and main part of the Dead Sea has remained almost untouched by industrial salt production. Its fresh water supply from the Jordan River is constantly decreasing, leading to further increased salinity. During a HALOPROC campaign (Natural Halogenation Processes in the Environment) we collected various samples including air, soils, sediments, halophytic plants, ground- and seawater from the Northern and Southern basin of the Israeli side of the Dead Sea. These samples were investigated for the occurrence of halocarbons using different analytical techniques. Most samples were analyzed for volatile organohalogens such as haloalkanes using gas chromatography- mass spectrometry (GC-MS). Interestingly, there is a strong enrichment of trihalomethanes (THM), especially all chlorinated and brominated ones and also the iodinated compound dichloroiodomethane were found in the Southern basin. In addition, volatile organic carbons (VOC) such as ethene and some other alkenes were analyzed by a gas chromatography-flame ionisation detector (GC-FID) to obtain further information about potential precursors of halogenated compounds. Halophytic plants were investigated for their potential to release chloromethane and bromomethane but also for their stable carbon and hydrogen isotope composition. For this purpose, a plant chamber was

  17. Wetland loss patterns and inundation-productivity relationships prognosticate widespread salt marsh loss for southern New England

    EPA Science Inventory

    Tidal salt marsh is a key defense against, yet is especially vulnerable to, the effects of accelerated sea level rise. To determine whether salt marshes in southern New England will be stable given increasing inundation over the coming decades, we examined current loss patterns, ...

  18. Wetland Loss Patterns and Inundation-Productivity Relationships Prognosticate Widespread Salt Marsh Loss for Southern New England

    EPA Science Inventory

    Tidal salt marsh is a key defense against, yet is especially vulnerable to, the effects of accelerated sea level rise. To determine whether salt marshes in southern New England will be stable given increasing inundation over the coming decades, we examined current loss patterns, ...

  19. A sea lamprey (Petromyzon marinus) sex pheromone mixture increases trap catch relative to a single synthesized component in specific environments

    USGS Publications Warehouse

    Johnson, Nicholas S.; Tix, John A.; Hlina, Benjamin L.; Wagner, C. Michael; Siefkes, Michael J.; Wang, Huiyong; Li, Weiming

    2015-01-01

    Spermiating male sea lamprey (Petromyzon marinus) release a sex pheromone, of which a component, 7α, 12α, 24-trihydoxy-3-one-5α-cholan-24-sulfate (3kPZS), has been identified and shown to induce long distance preference responses in ovulated females. However, other pheromone components exist, and when 3kPZS alone was used to control invasive sea lamprey populations in the Laurentian Great Lakes, trap catch increase was significant, but gains were generally marginal. We hypothesized that free-ranging sea lamprey populations discriminate between a partial and complete pheromone while migrating to spawning grounds and searching for mates at spawning grounds. As a means to test our hypothesis, and to test two possible uses of sex pheromones for sea lamprey control, we asked whether the full sex pheromone mixture released by males (spermiating male washings; SMW) is more effective than 3kPZS in capturing animals in traditional traps (1) en route to spawning grounds and (2) at spawning grounds. At locations where traps target sea lampreys en route to spawning grounds, SMW-baited traps captured significantly more sea lampreys than paired 3kPZS-baited traps (~10 % increase). At spawning grounds, no difference in trap catch was observed between 3kPZS and SMW-baited traps. The lack of an observed difference at spawning grounds may be attributed to increased pheromone competition and possible involvement of other sensory modalities to locate mates. Because fishes often rely on multiple and sometimes redundant sensory modalities for critical life history events, the addition of sex pheromones to traditionally used traps is not likely to work in all circumstances. In the case of the sea lamprey, sex pheromone application may increase catch when applied to specifically designed traps deployed in streams with low adult density and limited spawning habitat.

  20. Sea level reconstructions and non-marine sedimentation at the Triassic-Jurassic boundary: southwestern margin of the Neotethys in the Salt Range, Pakistan

    NASA Astrophysics Data System (ADS)

    Iqbal, Shahid; Wagreich, Michael

    2016-04-01

    The environmental changes during the Triassic-Jurassic boundary interval and the associated mass extinction event are still strongly debated. Sea-level reconstruction records during this interval reveal an end-Triassic global regression event. Erosion and karstification at the top of Triassic sediments, and Lower Jurassic fluvial channels with reworked Triassic clasts indicate widespread regression in the European basins. Laterite at the top of the Triassic, and quartzose conglomerates/sandstones at the base of the Jurassic indicate a fluvial/terrestrial onset in Iran and Afghanistan. Abrupt emergence, erosion and facies dislocation, from the Triassic dolomites (Kingriali Formation) to Lower Jurassic fluvial/continental quartzose conglomerates/pebbly sandstones (Datta Formation) occur in the Tethyan Salt Range of Pakistan. Sedimentological analyses indicate marine regression and emergence under tropical-subtropical conditions (Greenhouse conditions) and negates the possibility of glacial influence in this region. Field evidences indicate the presence of an undulatory surface at the base of the Jurassic and a high (Sargodha High) is present south of the Salt Range Thrust, the southern boundary of the basin. Furthermore, geophysical data (mostly seismic sections) in different parts of the basin display normal faults in the basement. These features are interpreted as horst and graben structures at the Triassic-Jurassic boundary in the Kohat-Potwar Plateau. The Lower Jurassic Datta Formation appears to have been deposited in an overall graben fill settings. Similar normal faults and graben fill geometries are observed on seismic sections in Tanzania, Mozambique, Madagascar and other regions of the southeastern margin of the African Plate and are related to the Karoo rift system. To summarize, the basement normal faults and the graben fill features at the Triassic-Jurassic boundary in the Kohat-Potwar Plateau can be correlated to similar features common in the Karoo

  1. Salt-responsive lytic polysaccharide monooxygenases from the mangrove fungus Pestalotiopsis sp. NCi6.

    PubMed

    Patel, Ilabahen; Kracher, Daniel; Ma, Su; Garajova, Sona; Haon, Mireille; Faulds, Craig B; Berrin, Jean-Guy; Ludwig, Roland; Record, Eric

    2016-01-01

    Lytic polysaccharide monooxygenases (LPMOs) belong to the "auxiliary activities (AA)" enzyme class of the CAZy database. They are known to strongly improve the saccharification process and boost soluble sugar yields from lignocellulosic biomass, which is a key step in the efficient production of sustainable economic biofuels. To date, most LPMOs have been characterized from terrestrial fungi, but novel fungal LPMOs isolated from more extreme environments such as an estuary mangrove ecosystem could offer enzymes with unique properties in terms of salt tolerance and higher stability under harsh condition. Two LPMOs secreted by the mangrove-associated fungus Pestalotiopsis sp. NCi6 (PsLPMOA and PsLPMOB) were expressed in the yeast Pichia pastoris and produced in a bioreactor with >85 mg L(-1) for PsLPMOA and >260 mg L(-1) for PsLPMOB. Structure-guided homology modeling of the PsLPMOs showed a high abundance of negative surface charges, enabling enhanced protein stability and activity in the presence of sea salt. Both PsLPMOs were activated by a cellobiose dehydrogenase (CDH) from Neurospora crassa, with an apparent optimum of interaction at pH 5.5. Investigation into their regioselective mode of action revealed that PsLPMOA released C1- and C4-oxidized cello-oligosaccharide products, while PsLPMOB released only C4-oxidized products. PsLPMOA was found to cleave polymeric cellulose in the presence of up to 6 % sea salt, which emphasizes the use of sea water in the industrial saccharification process with improved ecological footprints. Two new LPMOs from the mangrove fungus Pestalotiopsis sp. NCi6 were found to be fully reactive against cellulose. The combined hydrolytic activities of these salt-responsive LPMOs could therefore facilitate the saccharification process using sea water as a reaction medium for large-scale biorefineries.

  2. Major components of seawater and hydrothermal plumes in the Okinawa Trough, East China Sea, and Yellow Sea

    NASA Astrophysics Data System (ADS)

    Zeng, Z.; Rong, K.; Chen, C. T. A.; Wang, X.; Qi, H.

    2017-12-01

    Analyses of the major components of seawater and hydrothermal plumes in hydrothermal fields are essential for an improved understanding of ocean carbonate system, element solubility and redox reactions (e.g., iron and copper). The composition of major components in seawater and hydrothermal plume samples from 118 stations have been investigated in the Okinawa Trough (OT), East China Sea (ECS), and Yellow Sea (YS). At least seven water masses take part in the mixing processes: the Kuroshio water, OT water, ECS water, YS water, Taiwan Strait water, vent fluid and hydrothermal plume water. About 6 - 16 % of the plume water comes from the Kuroshio deep water, 50 - 64% of the hydrothermal plume water comes from the vent fluid in the wet and dry season. In addition, the calculated SHVF (36 and 36.8) and SHPW (35 and 35.8) values are higher than the measured salinity values (34.4) of hydrothermal plumes in the OT. Major elements exhibit linear correlation in seawater (e.g., B3+ and Sr2+) of the OT, the ECS, and the YS. Element ratios (e.g., Sr/Ca, Ca/Cl) in OT water column are similar to that in average seawater, indicating that Sr/Ca and Ca/Cl ratios might be a useful proxy for chemical properties of seawater. Furthermore, from the southern and middle OT to the northern OT, ECS, and YS, the salinity, potential density, Cl/salinity ratio of seawater tend to decrease. The positive correlations between major components (e.g., SO42-, Cl-), physical properties (e.g., salinity, temperature, potential density) and current (velocity) in the seawater column suggests that the physical and chemical properties of seawater in the OT are affected by input of the Kuroshio current. In the Iheya North knoll, Clam, Yonaguni Knoll IV, and Tangyin hydrothermal fields of the OT, anomalous layers of seawater in the water column have higher Ca/SO42-, Mn/Mg ratios and higher optical anomalies than other layers, suggesting that the chemical variations of hydrothermal plumes result in the

  3. A search for scale in sea-level studies

    USGS Publications Warehouse

    Larsen, C.E.; Clark, I.

    2006-01-01

    Many researchers assume a proportional relationship among the atmospheric CO2 concentration, temperature, and sea level. Thus, the rate of sea-level rise should increase in concert with the documented exponential increase in CO2. Although sea surface temperature has increased in places over the past century and short-term sea level rose abruptly during the 1990s, it is difficult to demonstrate a proportional relationship using existing geologic or historic records. Tide gauge records in the United States cover too short a time interval to verify acceleration in the rate of sea-level rise, although multicentury tide gauge and staff records from the Netherlands and Sweden suggest a mid-19th-century acceleration in sea-level rise. Reconstructions of sea-level changes for the past 1000 years derived using benthic foraminifer data from salt marshes along the East Coast of the United States suggest an increased rate of relative sea-level rise beginning in the 1600s. Geologic records of relative sea-level rise for the past 6000 years are available for several sites along the US East Coast from 14C-dated basal peat below salt marshes and estuarine sediments. When these three scales of sea-level variation are integrated, adjusted for postglacial isostatic movement, and replotted, the range of variation in sea level suggested by basal peat ages is within ??1 meter of the long-term trend. The reconstruction from Long Island Sound data shows a linear rise in sea level beginning in the mid-1600s at a rate consistent with the historic record of mean high water. Long-term tide gauge records from Europe and North America show similar trends since the mid-19th century. There is no clear proportional exponential increase in the rate of sea-level rise. If proportionality exists among sea level, atmospheric CO2, and temperature, there may be a significant time lag before an anthropogenic increase in the rate of sea-level rise occurs.

  4. An atlas of monthly mean distributions of GEOSAT sea surface height, SSMI surface wind speed, AVHRR/2 sea surface temperature, and ECMWF surface wind components during 1988

    NASA Technical Reports Server (NTRS)

    Halpern, D.; Zlotnicki, V.; Newman, J.; Brown, O.; Wentz, F.

    1991-01-01

    Monthly mean global distributions for 1988 are presented with a common color scale and geographical map. Distributions are included for sea surface height variation estimated from GEOSAT; surface wind speed estimated from the Special Sensor Microwave Imager on the Defense Meteorological Satellite Program spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer on NOAA spacecrafts; and the Cartesian components of the 10m height wind vector computed by the European Center for Medium Range Weather Forecasting. Charts of monthly mean value, sampling distribution, and standard deviation value are displayed. Annual mean distributions are displayed.

  5. Salt Marsh Sustainability in New England: Progress and Remaining Challenges

    EPA Science Inventory

    Natural resource managers, conservationists, and scientists described marsh loss and degradation in many New England coastal systems at the 2014 “Effects of Sea Level Rise on Rhode Island’s Salt Marshes” workshop, organized by the Narragansett Bay National Estua...

  6. A multi-proxy study of sedimentary humic substances in the salt marsh of the Changjiang Estuary, China

    NASA Astrophysics Data System (ADS)

    Zhang, Yaoling; Du, Jinzhou; Zhao, Xin; Wu, Wangsuo; Peng, Bo; Zhang, Jing

    2014-12-01

    To better understand the origin, composition, and reactivity of sedimentary humic substances (HSs) in salt marshes in the Changjiang Estuary, HS samples were isolated from a sediment core that was collected from the Eastern Chongming salt marsh. Chemical and spectroscopic methods were used to analyze the features of these HSs. The results indicate that the studied HSs in the salt marsh sediments are mainly terrestrial-derived and that the sedimentary organic matter (SOM) in the top layer may contain more organic matter from marine sources and/or autochthonous materials due to the dramatic decreasing of the sediment supply as a result of damming. The degradation of labile carbohydrates and proteins and the preservation of refractory lignin components dominate the early diagenetic reactions of SOM in the salt marsh area. The average contents of the carboxylic groups in FAs and HAs are 11.64 ± 1.08 and 7.13 ± 0.16 meq/gC, and those of phenolic groups are 1.95 ± 0.13 and 2.40 ± 0.44 meq/gC, respectively. The content of carboxylic groups increased with increasing depth, while there were no obvious changes in the content of phenolic groups. The average concentration of total proton-binding sites is approximately 12.5 μmol/g sediment for the studied HSs. These values may provide insight into the migration and fate of HS-bound contaminants in sediments and the overlying sea water in the salt marsh areas of the Changjiang Estuary.

  7. Formation of zinc protoporphyrin IX in Parma-like ham without nitrate or nitrite.

    PubMed

    Wakamatsu, Jun-ichi; Uemura, Juichi; Odagiri, Hiroko; Okui, Jun; Hayashi, Nobutaka; Hioki, Shoji; Nishimura, Takanori; Hattori, Akihito

    2009-04-01

    Zinc protoporphyrin IX (ZPP) is a characteristic red pigment in meat products that are manufactured without the addition of a curing agent such as nitrate or nitrite. To examine the effects of impurities such as mineral components in sea salt on the formation of ZPP, we manufactured Parmatype dry-cured hams that were salted with refined salt or sea salt and examined the involvement of oxidation-reduction potential (ORP) in the formation of ZPP. The content of ZPP was increased drastically after 40 weeks. Microscopic observation showed strong fluorescence caused by ZPP muscle fiber after 40 weeks. Conversely, heme content varied considerably during processing. ORP increased during processing. However, there was no obvious difference between ham salted with refined salt and that salted with sea salt. Therefore, it was concluded that impurities in sea salt were not involved in the formation of ZPP.

  8. Ethanol modulates the VR-1 variant amiloride-insensitive salt taste receptor. II. Effect on chorda tympani salt responses.

    PubMed

    Lyall, Vijay; Heck, Gerard L; Phan, Tam-Hao T; Mummalaneni, Shobha; Malik, Shahbaz A; Vinnikova, Anna K; Desimone, John A

    2005-06-01

    The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by direct measurement of intracellular Na(+) activity ([Na(+)](i)) using fluorescence imaging in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) taste nerve recordings. CT responses to KCl and NaCl were recorded in Sprague-Dawley rats, and in wild-type (WT) and vanilloid receptor-1 (VR-1) knockout mice (KO). CT responses were monitored in the presence of Bz, a specific blocker of the epithelial Na(+) channel (ENaC). CT responses were also recorded in the presence of agonists (resiniferatoxin and elevated temperature) and antagonists (capsazepine and SB-366791) of VR-1 that similarly modulate the Bz-insensitive VR-1 variant salt taste receptor. In the absence of mineral salts, ethanol induced a transient decrease in TRC volume and elicited only transient phasic CT responses. In the presence of mineral salts, ethanol increased the apical cation flux in TRCs without a change in volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a phasic component and a sustained tonic component. At concentrations <50%, ethanol enhanced responses to KCl and NaCl, while at ethanol concentrations >50%, those CT responses were inhibited. Resiniferatoxin and elevated temperature increased the sensitivity of the CT response to ethanol in salt-containing media, and SB-366791 inhibited the effect of ethanol, resiniferatoxin, and elevated temperature on the CT responses to mineral salts. VR-1 KO mice demonstrated no Bz-insensitive CT response to NaCl and no sensitivity to ethanol. We conclude that ethanol increases salt taste sensitivity by its direct action on the Bz-insensitive VR-1 variant salt taste receptor.

  9. Sea salt sodium record from Talos Dome (East Antarctica) as a potential proxy of the Antarctic past sea ice extent.

    PubMed

    Severi, M; Becagli, S; Caiazzo, L; Ciardini, V; Colizza, E; Giardi, F; Mezgec, K; Scarchilli, C; Stenni, B; Thomas, E R; Traversi, R; Udisti, R

    2017-06-01

    Antarctic sea ice has shown an increasing trend in recent decades, but with strong regional differences from one sector to another of the Southern Ocean. The Ross Sea and the Indian sectors have seen an increase in sea ice during the satellite era (1979 onwards). Here we present a record of ssNa + flux in the Talos Dome region during a 25-year period spanning from 1979 to 2003, showing that this marker could be used as a potential proxy for reconstructing the sea ice extent in the Ross Sea and Western Pacific Ocean at least for recent decades. After finding a positive relationship between the maxima in sea ice extent for a 25-year period, we used this relationship in the TALDICE record in order to reconstruct the sea ice conditions over the 20th century. Our tentative reconstruction highlighted a decline in the sea ice extent (SIE) starting in the 1950s and pointed out a higher variability of SIE starting from the 1960s and that the largest sea ice extents of the last century occurred during the 1990s. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Salt Marsh Sustainability in New England: Progress and Remaining Challenges

    EPA Science Inventory

    Natural resource managers, conservationists, and scientists described marsh loss and degradation in many New England coastal systems at the 2014 “Effects of Sea Level Rise on Rhode Island’s Salt Marshes” workshop, organized by the Narragansett Bay National Estuarine Research Rese...

  11. Sensitization of salt appetite is associated with increased "wanting" but not "liking" of a salt reward in the sodium-deplete rat.

    PubMed

    Clark, Jeremy J; Bernstein, Ilene L

    2006-02-01

    To examine the role of incentive sensitization in the potentiation of salt appetite by prior depletions, the authors assessed the motivation to obtain salt ("wanting") and the palatability of salt ("liking") independently in salt-sensitized rats. Breakpoint on a progressive ratio reinforcement schedule was used to measure salt wanting and taste reactivity was used to measure salt liking in rats with and without a history of Na+ depletion. Salt-sensitized rats displayed higher breakpoints relative to controls. However, a history of Na+ depletion was not associated with a greater positive shift in taste reactivity measures. The data suggest that these components of reward are separable in this model and support the general proposition that sensitization may alter wanting but not liking.

  12. On the brine drainage and algal uptake controls of the nutrient supply to the sea ice interior

    NASA Astrophysics Data System (ADS)

    Vancoppenolle, M.; Goosse, H.; de Montety, A.; Fichefet, T.; Tison, J.-L.

    2009-04-01

    Sea ice ecosystems are important components of the biogeochemical cycles (including carbon) and hence have a potential impact on climate. They are characterized by large stocks of micro-algae. Those algae (mostly diatoms) live in liquid inclusions of saline brine, which are encased within the solid ice matrix and require sustained nutrient supply to grow. In this study, we investigate the interactions between nutrients, brine motion and algal growth, using a one-dimensional (1D) sea ice model. The model includes (i) a classical formulation for snow and ice thermodynamics with explicit, reformulated brine physics and (ii) an idealized sea ice biological component, characterized by one single nutrient, namely dissolved silica (DSi), which stocks are reduced by a prescribed primary production. DSi is considered as a passive tracer dissolved within brine following fluid motion. The brine flow regime (advective, diffusive or turbulent) is computed as a function of environmental ice conditions. In winter, a Rayleigh number proposed by Notz and Worster (2008) is used to differentiate diffusion and convection. Ice salinity and DSi concentrations within the ice are solutions of 1D advection-diffusion equations over the variable volume brine network domain. The model is configured for a typical year of seasonal Weddell Sea ice. The simulated vertical salinity and tracer profiles as well as ice-ocean salt fluxes realistically agree with observations. Complex bio-physical interactions are simulated by the model. Analysis highlights the role of convection in the lowermost 5-10 cm of ice (gravity drainage), mixing highly saline, nutrient-depleted brine with comparatively fresh, nutrient-rich seawater. Hence, gravity drainage rejects salt to the ocean and provides nutrients to the ice interior. In turn, primary production and brine convection act synergetically to form a nutrient pump, which enhances the net ocean-to-ice DSi flux by 20-115%, compared to an abiotic situation. The

  13. Innovative methods to reduce salt water intrusion in harbours

    NASA Astrophysics Data System (ADS)

    Groenenboom, J.; Uittenbogaard, R.; Hulsen, L.; van der Kaaij, T.; Kielen, N.

    2017-12-01

    The availability of fresh water in densely populated estuarine environments will in the future more often be threatened due to both human (e.g. channel deepening) and natural (sea-level rise, storm surges, extremely low river discharges) causes. Here, the salt water intrusion into the New Waterway, the main navigation channel of the port of Rotterdam, is used as a case study to elaborate on two innovative ways to mitigate the effects of salt water intrusion. The first method is based on the concept that vertical mixing of a salt wedge reduces its intrusion length. The idea is to equip a vessel with cranes that hold perforated tubes close to the bed alongside the vessel. By connecting compressors to the perforated tubes, a bubble screen with an adjustable vertical location can be created. Since the horizontal location of the bubble screens is not fixed, the vessel can sail in the vicinity of the moving salt wedge therewith increasing the effectiveness of the method. Another advantage of this intervention is that it can be deployed temporarily when the urgency for the prevention of salt water intrusion is high. The second method originates from the Port of Rotterdam Authority and is inspired by a small bypass that is present between two parallel channels (New Waterway and Caland Canal) connecting the North Sea to the Port of Rotterdam. Due to the different hydrodynamic characteristics of the hinterland of both channels, a difference in salinity and water level is present between both ends of the bypass. As a result, a lateral inflow of water into the New Waterway occurs at the same moment that the flood velocities transport saline water landwards. The lateral inflow of water into this channel has no momentum in the landward direction and therefore decreases the landward flow velocity and therewith the salt water intrusion. In addition, the inflow drives a vertical circulation that mixes the water column close to the bypass. Similar to the bubble screens mentioned

  14. Origin of salt giants in abyssal serpentinite systems

    NASA Astrophysics Data System (ADS)

    Scribano, Vittorio; Carbone, Serafina; Manuella, Fabio C.; Hovland, Martin; Rueslåtten, Håkon; Johnsen, Hans-K.

    2017-10-01

    Worldwide marine salt deposits ranging over the entire geological record are generally considered climate-related evaporites, derived from the precipitation of salts (mainly chlorides and sulfates) from saturated solutions driven by solar evaporation of seawater. This explanation may be realistic for a salt thickness ≤100 m, being therefore inadequate for thicker (>1 km) deposits. Moreover, sub-seafloor salt deposits in deep marine basins are difficult to reconcile with a surface evaporation model. Marine geology reports on abyssal serpentinite systems provide an alternative explanation for some salt deposits. Seawater-driven serpentinization consumes water and increases the salinity of the associated aqueous brines. Brines can be trapped in fractures and cavities in serpentinites and the surrounding `country' rocks. Successive thermal dehydration of buried serpentinites can mobilize and accumulate the brines, forming highly saline hydrothermal solutions. These can migrate upwards and erupt onto the seafloor as saline geysers, which may form salt-saturated water pools, as are currently observed in numerous deeps in the Red Sea and elsewhere. The drainage of deep-seated saline brines to seafloor may be a long-lasting, effective process, mainly occurring in areas characterized by strong tectonic stresses and/or igneous intrusions. Alternatively, brines could be slowly expelled from fractured serpentinites by buoyancy gradients and, hence, separated salts/brines could intrude vertically into surrounding rocks, forming salt diapirs. Serpentinization is an ubiquitous, exothermic, long-lasting process which can modify large volumes of oceanic lithosphere over geological times. Therefore, buried salt deposits in many areas of the world can be reasonably related to serpentinites.

  15. Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

    2011-01-01

    Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

  16. The Story of the Oceans and Salt. What We Take from Our Environment. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Science Education Center.

    This module provides information on: (1) the origin of the oceans; (2) sources of minerals and salt found in the sea; and (3) the role and uses of salt in various cultures (stating, for example, that the expression "salt of the earth" describes a person who is considered one of the best). (JN)

  17. Marshes on the Move: Testing effects of seawater intrusion on vegetation communities of the salt marsh-upland ecotone

    EPA Science Inventory

    The Northeastern United States is a hotspot for sea level rise (SLR), subjecting coastal salt marshes to erosive loss, shifts in vegetation communities, and altered biogeochemistry due to seawater intrusion. Salt marsh plant community zonation is driven by tradeoffs in stress to...

  18. Ecological effects of climate change on salt marsh wildlife: a case study from a highly urbanized estuary

    USGS Publications Warehouse

    Thorne, Karen M.; Takekawa, John Y.; Elliott-Fisk, Deborah L.

    2012-01-01

    Coastal areas are high-risk zones subject to the impacts of global climate change, with significant increases in the frequencies of extreme weather and storm events, and sea-level rise forecast by 2100. These physical processes are expected to alter estuaries, resulting in loss of intertidal wetlands and their component wildlife species. In particular, impacts to salt marshes and their wildlife will vary both temporally and spatially and may be irreversible and severe. Synergistic effects caused by combining stressors with anthropogenic land-use patterns could create areas of significant biodiversity loss and extinction, especially in urbanized estuaries that are already heavily degraded. In this paper, we discuss current ideas, challenges, and concerns regarding the maintenance of salt marshes and their resident wildlife in light of future climate conditions. We suggest that many salt marsh habitats are already impaired and are located where upslope transgression is restricted, resulting in reduction and loss of these habitats in the future. In addition, we conclude that increased inundation frequency and water depth will have negative impacts on the demography of small or isolated wildlife meta-populations as well as their community interactions. We illustrate our points with a case study on the Pacific Coast of North America at San Pablo Bay National Wildlife Refuge in California, an area that supports endangered wildlife species reliant on salt marshes for all aspects of their life histories.

  19. High-Albedo Salt Crusts on the Tropical Ocean of Snowball Earth: Measurements and Modeling

    NASA Astrophysics Data System (ADS)

    Carns, R.; Light, B.; Warren, S. G.

    2014-12-01

    During a Snowball Earth event, almost all of the ocean surface first freezes as sea ice. As in modern sea ice, trapped inclusions of liquid brine permeate the ice cover. As the ice grows and cools, salt crystals precipitate within the inclusions. At -23C, the most abundant salt in seawater, sodium chloride, begins to precipitate as the dihydrate mineral hydrohalite (NaCl·2H2O). Crystals of hydrohalite within the sea ice scatter light. Measurements of cold, natural sea ice show a broadband albedo increase of 10-20% when salt precipitates. Such snow-free natural sea ice with a surface temperature below -23C is rare on modern Earth, but would have been common in tropical regions of a Snowball Earth where evaporation exceeded precipitation. The persistent cold and lack of summer melt on the Snowball ocean surface, combined with net evaporation, is hypothesized to yield lag deposits of hydrohalite crystals on the ice surface. To investigate this process, we prepared laboratory-grown sea ice in a 1000 liter tank in a walk-in freezer laboratory. The ice was cooled below -23 C and the surface sprayed with a 23% NaCl solution to create a layer of hydrohalite-enriched ice, a proxy for lag deposits that would have formed over long periods of surface sublimation. We have developed a novel technique for measuring the spectral albedo of ice surfaces in the laboratory; this technique was used to monitor the evolution of the surface albedo of our salt crust as the ice matrix sublimated away leaving a layer of fine-grained hydrohalite crystals. Measurements of this hydrohalite surface crust show a very high albedo, comparable to fresh snow at visible wavelengths and significantly larger than fresh snow at near infrared wavelengths. Broadband albedos are 0.55 for bare artificial sea ice at -30C, 0.75 for ice containing 25% hydrohalite by volume, 0.84 after five days of desiccation and 0.93 after 47 days of desiccation. Using our laboratory measurements, along with estimates of

  20. Early Stages of Sea-Level Rise Lead To Decreased Salt Marsh Plant Diversity through Stronger Competition in Mediterranean-Climate Marshes.

    PubMed

    Noto, Akana E; Shurin, Jonathan B

    2017-01-01

    Climate change shuffles species ranges and creates novel interactions that may either buffer communities against climate change or exacerbate its effect. For instance, facilitation can become more prevalent in salt marshes under stressful conditions while competition is stronger in benign environments. Sea-level rise (SLR) is a consequence of climate change that affects the distribution of stress from inundation and salinity. To determine how interactions early in SLR are affected by changes in these two stressors in Mediterranean-climate marshes, we transplanted marsh turfs to lower elevations to simulate SLR and manipulated cover of the dominant plant species, Salicornia pacifica (formerly Salicornia virginica). We found that both S. pacifica and the subordinate species were affected by inundation treatments, and that subordinate species cover and diversity were lower at low elevations in the presence of S. pacifica than when it was removed. These results suggest that the competitive effect of S. pacifica on other plants is stronger at lower tidal elevations where we also found that salinity is reduced. As sea levels rise, stronger competition by the dominant plant will likely reduce diversity and cover of subordinate species, suggesting that stronger species interactions will exacerbate the effects of climate change on the plant community.

  1. Sea-level variability over the Common Era

    NASA Astrophysics Data System (ADS)

    Kopp, Robert; Horton, Benjamin; Kemp, Andrew; Engelhart, Simon; Little, Chris

    2017-04-01

    The Common Era (CE) sea-level response to climate forcing, and its relationship to centennial-timescale climate variability such as the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), is fragmentary relative to other proxy-derived climate records (e.g. atmospheric surface temperature). However, the Atlantic coast of North America provides a rich sedimentary record of CE relative sea level with sufficient spatial and temporal resolution to inform mechanisms underlying regional and global sea level variability and their relationship to other climate proxies. This coast has a small tidal range, improving the precision of sea-level reconstructions. Coastal subsidence (from glacial isostatic adjustment, GIA) creates accommodation space that is filled by salt-marsh peat and preserves accurate and precise sea-level indicators and abundant material for radiocarbon dating. In addition to longer term GIA induced land-level change from ongoing collapse of the Laurentide forebulge, these records are ideally situated to capture climate-driven sea level changes. The western North Atlantic Ocean sea level is sensitive to static equilibrium effects from melting of the Greenland Ice Sheet, as well as large-scale changes in ocean circulation and winds. Our reconstructions reveal two distinct patterns in sea-level during the CE along the United States Atlantic coast: (1) South of Cape Hatteras, North Carolina, to Florida sea-level rise is essentially flat, with the record dominated by long-term geological processes until the onset of historic rates of rise in the late 19th century; (2) North of Cape Hatteras to Connecticut, sea level rise to maximum around 1000CE, a sea-level minimum around 1500 CE, and a long-term sea-level rise through the second half of the second millennium. The northern-intensified sea-level fall beginning 1000 is coincident with shifts toward persistent positive NAO-like atmospheric states inferred from other proxy records and is consistent with

  2. Salt-Stress Response Mechanisms Using de Novo Transcriptome Sequencing of Salt-Tolerant and Sensitive Corchorus spp. Genotypes

    PubMed Central

    Yang, Zemao; Lu, Ruike; Dai, Zhigang; Yan, An; Tang, Qing; Cheng, Chaohua; Xu, Ying; Yang, Wenting; Su, Jianguang

    2017-01-01

    High salinity is a major environmental stressor for crops. To understand the regulatory mechanisms underlying salt tolerance, we conducted a comparative transcriptome analysis between salt-tolerant and salt-sensitive jute (Corchorus spp.) genotypes in leaf and root tissues under salt stress and control conditions. In total, 68,961 unigenes were identified. Additionally, 11,100 unigenes (including 385 transcription factors (TFs)) exhibited significant differential expression in salt-tolerant or salt-sensitive genotypes. Numerous common and unique differentially expressed unigenes (DEGs) between the two genotypes were discovered. Fewer DEGs were observed in salt-tolerant jute genotypes whether in root or leaf tissues. These DEGs were involved in various pathways, such as ABA signaling, amino acid metabolism, etc. Among the enriched pathways, plant hormone signal transduction (ko04075) and cysteine/methionine metabolism (ko00270) were the most notable. Eight common DEGs across both tissues and genotypes with similar expression profiles were part of the PYL-ABA-PP2C (pyrabactin resistant-like/regulatory components of ABA receptors-abscisic acid-protein phosphatase 2C). The methionine metabolism pathway was only enriched in salt-tolerant jute root tissue. Twenty-three DEGs were involved in methionine metabolism. Overall, numerous common and unique salt-stress response DEGs and pathways between salt-tolerant and salt-sensitive jute have been discovered, which will provide valuable information regarding salt-stress response mechanisms and help improve salt-resistance molecular breeding in jute. PMID:28927022

  3. The Tiberias Basin salt deposits and their effects on lake salinity

    NASA Astrophysics Data System (ADS)

    Inbar, Nimrod; Rosenthal, Eliahu; Möller, Peter; Yellin-Dror, Annat; Guttman, Josef; Siebert, Christian; Magri, Fabien

    2015-04-01

    Lake Tiberias is situated in one of the pull-apart basins comprising the Dead Sea transform. The Tiberias basin extends along the northern boundary of the Lower Jordan Rift Valley (LJRV) which is known for its massive salt deposits, mostly at its southern end, at the Dead Sea basin. Nevertheless, prior to the drilling of Zemah-1 wildcat, drilled close to the southern shores of Lake Tiberias, the Tiberias Basin was considered rather shallow and free of salt deposits (Starinsky, 1974). In 1983, Zemah-1 wildcat penetrated 2.8 km thick sequence of sedimentary and magmatic rocks of which 980m are salt deposits (Marcus et al., 1984). Recent studies, including the presented geophysical investigations, lay out the mechanisms of salt deposition in the Tiberias basin and estimate its abundance. Supported by seismic data, our interpreted cross-sections display relatively thick salt deposits distributed over the entire basin. Since early days of hydrological research in the area, saline springs are known to exist at Lake Tiberias' surroundings. Water temperatures in some of the springs indicate their origin to be at depths of 2-3 km (Simon and Mero, 1992). In the last decade, several studies suggested that the salinity of springs may be attributed, at least partially, to the Zemah-1 salt deposits. Chemical justification was attributed to post-halite minerals which were thought to be present among those deposits. This hypothesis was never verified. Moreover, Möller et al. (2011) presented a calculation contradicting this theory. In addition to the geophysical investigations, numerical models of thermally driven flow, examine the possible fluid dynamics developing near salt deposits below the lake and their interactions with springs along the lakeshore (Magri et al., 2015). It is shown that leached halite is too heavy to reach the surface. However, salt diffusing from shallow salt crest may locally reach the western side of the lakeshore. References Magri, F., N. Inbar

  4. Examining effects of sea level rise and marsh crabs on Spartina patens using mesocosms

    EPA Science Inventory

    Coastal salt marshes provide essential ecosystem services but face increasing threats from habitat loss, eutrophication, changing precipitation patterns, and accelerating rates of sea level rise (SLR). Recent studies have suggested that herbivory and burrowing by native salt mars...

  5. Synoptic conditions of fine-particle transport to the last interglacial Red Sea-Dead Sea from Nd-Sr compositions of sediment cores

    NASA Astrophysics Data System (ADS)

    Palchan, Daniel; Stein, Mordechai; Goldstein, Steven L.; Almogi-Labin, Ahuva; Tirosh, Ofir; Erel, Yigal

    2018-01-01

    The sediments deposited at the depocenter of the Dead Sea comprise high-resolution archive of hydrological changes in the lake's watershed and record the desert dust transport to the region. This paper reconstructs the dust transport to the region during the termination of glacial Marine Isotope Stage 6 (MIS 6; ∼135-129 ka) and the last interglacial peak period (MIS5e, ∼129-116 ka). We use chemical and Nd and Sr isotope compositions of fine detritus material recovered from sediment core drilled at the deepest floor of the Dead Sea. The data is integrated with data achieved from cores drilled at the floor of the Red Sea, thus, forming a Red Sea-Dead Sea transect extending from the desert belt to the Mediterranean climate zone. The Dead Sea accumulated flood sediments derived from three regional surface cover types: settled desert dust, mountain loess-soils and loess-soils filling valleys in the Dead Sea watershed termed here "Valley Loess". The Valley Loess shows a distinct 87Sr/86Sr ratio of 0.7081 ± 1, inherited from dissolved detrital calcites that originate from dried waterbodies in the Sahara and are transported with the dust to the entire transect. Our hydro-climate and synoptic conditions reconstruction illustrates the following history: During glacial period MIS6, Mediterranean cyclones governed the transport of Saharan dust and rains to the Dead Sea watershed, driving the development of both mountain soils and Valley Loess. Then, at Heinrich event 11, dry western winds blew Saharan dust over the entire Red Sea - Dead Sea transect marking latitudinal expansion of the desert belt. Later, when global sea-level rose, the Dead Sea watershed went through extreme aridity, the lake retreated, depositing salt and accumulating fine detritus of the Valley Loess. During peak interglacial MIS 5e, enhanced flooding activity flushed the mountain soils and fine detritus from all around the Dead Sea and Red Sea, marking a significant "contraction" of the desert belt

  6. Future sea-level rise in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2014-05-01

    Secular sea level variations in the Mediterranean Sea are the result of a number of processes characterized by distinct time scales and spatial patterns. Here we predict the future sea level variations in the Mediterranean Sea to year 2050 combining the contributions from terrestrial ice melt (TIM), glacial isostatic adjustment (GIA), and the ocean response (OR) that includes the thermal expansion and the ocean circulation contributions. The three contributions are characterized by comparable magnitudes but distinctly different sea-level fingerprints across the Mediterranean basin. The TIM component of future sea-level rise is taken from Spada et al. (2013) and it is mainly driven by the melt of small glaciers and ice caps and by the dynamic ice loss from Antarctica. The sea-level fingerprint associated with GIA is studied using two distinct models available from the literature: ICE-5G(VM2) (Peltier, 2004) and the ice model progressively developed at the Research School of Earth Sciences (RSES) of the National Australian University (KL05) (see Fleming and Lambeck, 2004 and references therein). Both the GIA and the TIM sea-level predictions have been obtained with the aid of the SELEN program (Spada and Stocchi, 2007). The spatially-averaged OR component, which includes thermosteric and halosteric sea-level variations, recently obtained using a regional coupled ocean-atmosphere model (Carillo et al., 2012), vary between 2 and 7 cm according to scenarios adopted (EA1B and EA1B2, see Meehl at al., 2007). Since the sea-level variations associated with TIM mainly result from the gravitational interactions between the cryosphere components, the oceans and the solid Earth, and long-wavelength rotational variations, they are characterized by a very smooth global pattern and by a marked zonal symmetry reflecting the dipole geometry of the ice sources. Since the Mediterranean Sea is located in the intermediate far-field of major ice sources, TIM sea-level changes have sub

  7. Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water

    NASA Technical Reports Server (NTRS)

    Ortiz, R. M.; Worthy, G. A.; Byers, F. M.

    1999-01-01

    The ability of West Indian manatees (Trichechus manatus) to move between fresh and salt water raises the question of whether manatees drink salt water. Water turnover rates were estimated in captive West Indian manatees using the deuterium oxide dilution technique. Rates were quantified in animals using four experimental treatments: (1) held in fresh water and fed lettuce (N=4), (2) held in salt water and fed lettuce (N=2), (3) acutely exposed to salt water and fed lettuce (N=4), and (4) chronically exposed to salt water with limited access to fresh water and fed sea grass (N=5). Animals held in fresh water had the highest turnover rates (145+/-12 ml kg-1 day-1) (mean +/- s.e.m.). Animals acutely exposed to salt water decreased their turnover rate significantly when moved into salt water (from 124+/-15 to 65+/-15 ml kg-1 day-1) and subsequently increased their turnover rate upon re-entry to fresh water (146+/-19 ml kg-1 day-1). Manatees chronically exposed to salt water had significantly lower turnover rates (21+/-3 ml kg-1 day-1) compared with animals held in salt water and fed lettuce (45+/-3 ml kg-1 day-1). Manatees chronically exposed to salt water and fed sea grass had very low turnover rates compared with manatees held in salt water and fed lettuce, which is consistent with a lack of mariposia. Manatees in fresh water drank large volumes of water, which may make them susceptible to hyponatremia if access to a source of Na+ is not provided.

  8. Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water.

    PubMed

    Ortiz, R M; Worthy, G A; Byers, F M

    1999-01-01

    The ability of West Indian manatees (Trichechus manatus) to move between fresh and salt water raises the question of whether manatees drink salt water. Water turnover rates were estimated in captive West Indian manatees using the deuterium oxide dilution technique. Rates were quantified in animals using four experimental treatments: (1) held in fresh water and fed lettuce (N=4), (2) held in salt water and fed lettuce (N=2), (3) acutely exposed to salt water and fed lettuce (N=4), and (4) chronically exposed to salt water with limited access to fresh water and fed sea grass (N=5). Animals held in fresh water had the highest turnover rates (145+/-12 ml kg-1 day-1) (mean +/- s.e.m.). Animals acutely exposed to salt water decreased their turnover rate significantly when moved into salt water (from 124+/-15 to 65+/-15 ml kg-1 day-1) and subsequently increased their turnover rate upon re-entry to fresh water (146+/-19 ml kg-1 day-1). Manatees chronically exposed to salt water had significantly lower turnover rates (21+/-3 ml kg-1 day-1) compared with animals held in salt water and fed lettuce (45+/-3 ml kg-1 day-1). Manatees chronically exposed to salt water and fed sea grass had very low turnover rates compared with manatees held in salt water and fed lettuce, which is consistent with a lack of mariposia. Manatees in fresh water drank large volumes of water, which may make them susceptible to hyponatremia if access to a source of Na+ is not provided.

  9. Salt Attack on Rocks and Expansion of Soils on Mars

    NASA Astrophysics Data System (ADS)

    Vaniman, D. T.; Bish, D. L.; Chipera, S. J.; Carey, J. W.

    2004-12-01

    Salt-rich sediments observed by the MER rover Opportunity at Meridiani Planum show that brines have been present on Mars in the past, but a role for groundwater in widespread rock weathering and soil formation is uncertain. Experiments by several groups suggest instead the action of acid fog over long time spans, with episodic input of volcanic gases, as a more significant agent of Mars weathering. Salt minerals formed in these acid weathering experiments consistently include gypsum and alunogen, with epsomite or hexahydrite forming where olivine provides a source of Mg. Analogous to the martian acid fog scenario are terrestrial acid rain or acid fog attacks on building and monument stone by chemical action and mechanical wedging through growth of gypsum, anhydrite, epsomite, hexahydrite, kieserite, and other sulfate minerals. Physical effects can be aggressive, operating by both primary salt growth and hydration of anhydrous or less-hydrous primary salts. In contrast, soils evolve to states where chemical attack is lessened and salt mineral growth leads to expansion with cementation; in this situation the process becomes constructive rather than destructive. We have made synthetic salt-cemented soils (duricrusts) from clays, zeolites, palagonites and other media mixed with ultrapure Mg-sulfate solutions. Although near-neutral in pH, these solutions still exchange or leach Ca from the solids to form cements containing gypsum as well as hexahydrite. At low total P (1 torr) and low RH (<1%) hexahydrite becomes amorphous but gypsum does not. If allowed to rehydrate from vapor at higher RH, the Mg-sulfate component of the duricrust expands by formation of a complex mixture of Mg-sulfate phases with various hydration states. The expanded form is retained even if the duricrust is again dehydrated, suggesting that soil porosity thus formed is difficult to destroy. These processes can be considered in the context of Viking, Pathfinder, and MER evidence for differing salt

  10. Bamboo salt attenuates CCl4-induced hepatic damage in Sprague-Dawley rats

    PubMed Central

    Zhao, Xin; Song, Jia-Le; Kil, Jeung-Ha

    2013-01-01

    Bamboo salt, a Korean folk medicine, is prepared with solar salt (sea salt) and baked several times at high temperatures in a bamboo case. In this study, we compared the preventive effects of bamboo salt and purified and solar salts on hepatic damage induced by carbon tetrachloride in Sprague-Dawley rats. Compared with purified and solar salts, bamboo salts prevented hepatic damage in rats, as evidenced by significantly reduced serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase (P < 0.05). Bamboo salt (baked 9×) triggered the greatest reduction in these enzyme levels. In addition, it also reduced the levels of the proinflammatory cytokines interleukin (IL)-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Histopathological sections of liver tissue demonstrated the protective effect of bamboo salt, whereas sections from animals treated with the other salt groups showed a greater degree of necrosis. We also performed reverse transcription-polymerase chain reaction and western blot analyses of the inflammation-related genes iNOS, COX-2, TNF-α, and IL-1β in rat liver tissues. Bamboo salt induced a significant decrease (~80%) in mRNA and protein expression levels of COX-2, iNOS, TNF-α, and IL-1β, compared with the other salts. Thus, we found that baked bamboo salt preparations could prevent CCl4-induced hepatic damage in vivo. PMID:23964314

  11. Molecular response of canola to salt stress: insights on tolerance mechanisms.

    PubMed

    Shokri-Gharelo, Reza; Noparvar, Pouya Motie

    2018-01-01

    Canola ( Brassica napus L. ) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as 'salt-tolerant', plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests what researchers should focus on in future studies.

  12. Effects assessment of 10 functioning years on the main components of the molten salt PCS experimental facility of ENEA

    NASA Astrophysics Data System (ADS)

    Gaggioli, Walter; Di Ascenzi, Primo; Rinaldi, Luca; Tarquini, Pietro; Fabrizi, Fabrizio

    2016-05-01

    In the frame of the Solar Thermodynamic Laboratory, ENEA has improved CSP Parabolic Trough technologies by adopting new advanced solutions for linear tube receivers and by implementing a binary mixture of molten salt (60% NaNO3 and 40% KNO3) [1] as both heat transfer fluid and heat storage medium in solar field and in storage tanks, thus allowing the solar plants to operate at high temperatures up to 550°C. Further improvements have regarded parabolic mirror collectors, piping and process instrumentation. All the innovative components developed by ENEA, together with other standard parts of the plant, have been tested and qualified under actual solar operating conditions on the PCS experimental facility at the ENEA Casaccia Research Center in Rome (Italy). The PCS (Prova Collettori Solari, i.e. Test of Solar Collectors) facility is the main testing loop built by ENEA and it is unique in the world for what concerns the high operating temperature and the fluid used (mixture of molten salt). It consists in one line of parabolic trough collectors (test section of 100 m long life-size solar collectors) using, as heat transfer fluid, the aforesaid binary mixture of molten salt up to 10 bar, at high temperature in the range 270° and 550°C and a flow rate up to 6.5 kg/s. It has been working since early 2004 [2] till now; it consists in a unique closed loop, and it is totally instrumented. In this paper the effects of over ten years qualification tests on the pressurized tank will be presented, together with the characterization of the thermal losses of the piping of the molten salt circuit, and some observations performed on the PCS facility during its first ten years of operation.

  13. Vulnerability of Rhode Island Salt Marshes to Sea Level Rise and Poor Water Quality

    EPA Science Inventory

    Across the northeastern Unites States, salt marshes are losing ground. Edges are eroding, tidal channel networks are expanding, and new ponds are forming and expanding within salt marshes. This leaves shorelines - and in some cases houses - more vulnerable to nor'easters and tr...

  14. Reconsolidated Salt as a Geotechnical Barrier

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

    Hansen, Francis D.; Gadbury, Casey

    Salt as a geologic medium has several attributes favorable to long-term isolation of waste placed in mined openings. Salt formations are largely impermeable and induced fractures heal as stress returns to equilibrium. Permanent isolation also depends upon the ability to construct geotechnical barriers that achieve nearly the same high-performance characteristics attributed to the native salt formation. Salt repository seal concepts often include elements of reconstituted granular salt. As a specific case in point, the Waste Isolation Pilot Plant recently received regulatory approval to change the disposal panel closure design from an engineered barrier constructed of a salt-based concrete to onemore » that employs simple run-of-mine salt and temporary bulkheads for isolation from ventilation. The Waste Isolation Pilot Plant is a radioactive waste disposal repository for defense-related transuranic elements mined from the Permian evaporite salt beds in southeast New Mexico. Its approved shaft seal design incorporates barrier components comprising salt-based concrete, bentonite, and substantial depths of crushed salt compacted to enhance reconsolidation. This paper will focus on crushed salt behavior when applied as drift closures to isolate disposal rooms during operations. Scientific aspects of salt reconsolidation have been studied extensively. The technical basis for geotechnical barrier performance has been strengthened by recent experimental findings and analogue comparisons. The panel closure change was accompanied by recognition that granular salt will return to a physical state similar to the halite surrounding it. Use of run-of-mine salt ensures physical and chemical compatibility with the repository environment and simplifies ongoing disposal operations. Our current knowledge and expected outcome of research can be assimilated with lessons learned to put forward designs and operational concepts for the next generation of salt repositories. Mined salt

  15. Salt Tolerance and Polyphyly in the Cyanobacterium Chroococcidiopsis (Pleurocapsales)1

    NASA Technical Reports Server (NTRS)

    Cumbers, John Robert; Rothschild, Lynn J.

    2014-01-01

    Chroococcidiopsis Geitler (Geitler 1933) is a genus of cyanobacteria containing desiccation and radiation resistant species. Members of the genus live in habitats ranging from hot and cold deserts to fresh and saltwater environments. Morphology and cell division pattern have historically been used to define the genus. To better understand the genetic and phenotypic diversity of the genus, 15 species were selected that had been previously isolated from different locations, including salt and freshwater environments. Four markers were sequenced from these 15 species, the 16S rRNA, rbcL, desC1 and gltX genes. Phylogenetic trees were generated which identified two distinct clades, a salt-tolerant clade and a freshwater clade. This study demonstrates that the genus is polyphyletic based on saltwater and freshwater phenotypes. To understand the resistance to salt in more details, species were grown on a range of sea salt concentrations which demonstrated that the freshwater species were salt-intolerant whilst the saltwater species required salt for growth. This study shows an increased resolution of the phylogeny of Chroococcidiopsis and provides further evidence that the genus is polyphyletic and should be reclassified to improve clarity in the literature.

  16. Multiple stressors and the potential for synergistic loss of New England salt marshes

    PubMed Central

    Angelini, Christine; Bertness, Mark D.

    2017-01-01

    Climate change and other anthropogenic stressors are converging on coastal ecosystems worldwide. Understanding how these stressors interact to affect ecosystem structure and function has immediate implications for coastal planning, however few studies quantify stressor interactions. We examined past and potential future interactions between two leading stressors on New England salt marshes: sea-level rise and marsh crab (Sesarma reticulatum) grazing driven low marsh die-off. Geospatial analyses reveal that crab-driven die-off has led to an order of magnitude more marsh loss than sea-level rise between 2005 and 2013. However, field transplant experimental results suggest that sea-level rise will facilitate crab expansion into higher elevation marsh platforms by inundating and gradually softening now-tough high marsh peat, exposing large areas to crab-driven die-off. Taking interactive effects of marsh softening and concomitant overgrazing into account, we estimate that even modest levels of sea-level rise will lead to levels of salt marsh habitat loss that are 3x greater than the additive effects of sea-level rise and crab-driven die-off would predict. These findings highlight the importance of multiple stressor studies in enhancing mechanistic understanding of ecosystem vulnerabilities to future stress scenarios and encourage managers to focus on ameliorating local stressors to break detrimental synergisms, reduce future ecosystem loss, and enhance ecosystem resilience to global change. PMID:28859097

  17. Multiple stressors and the potential for synergistic loss of New England salt marshes.

    PubMed

    Crotty, Sinead M; Angelini, Christine; Bertness, Mark D

    2017-01-01

    Climate change and other anthropogenic stressors are converging on coastal ecosystems worldwide. Understanding how these stressors interact to affect ecosystem structure and function has immediate implications for coastal planning, however few studies quantify stressor interactions. We examined past and potential future interactions between two leading stressors on New England salt marshes: sea-level rise and marsh crab (Sesarma reticulatum) grazing driven low marsh die-off. Geospatial analyses reveal that crab-driven die-off has led to an order of magnitude more marsh loss than sea-level rise between 2005 and 2013. However, field transplant experimental results suggest that sea-level rise will facilitate crab expansion into higher elevation marsh platforms by inundating and gradually softening now-tough high marsh peat, exposing large areas to crab-driven die-off. Taking interactive effects of marsh softening and concomitant overgrazing into account, we estimate that even modest levels of sea-level rise will lead to levels of salt marsh habitat loss that are 3x greater than the additive effects of sea-level rise and crab-driven die-off would predict. These findings highlight the importance of multiple stressor studies in enhancing mechanistic understanding of ecosystem vulnerabilities to future stress scenarios and encourage managers to focus on ameliorating local stressors to break detrimental synergisms, reduce future ecosystem loss, and enhance ecosystem resilience to global change.

  18. Crystal structures of seven molecular salts derived from benzylamine and organic acidic components

    NASA Astrophysics Data System (ADS)

    Wen, Xianhong; Jin, Xiunan; Lv, Chengcai; Jin, Shouwen; Zheng, Xiuqing; Liu, Bin; Wang, Daqi; Guo, Ming; Xu, Weiqiang

    2017-07-01

    Cocrystallization of the commonly available organic amine, benzylamine, with a series of organic acids gave a total of seven molecular salts with the compositions: (benzylamine): (p-toluenesulfonic acid) (1) [(HL)+ · (tsa-)], (benzylamine): (o-nitrobenzoic acid) (2) [(HL+) · (onba)-], (benzylamine): (3,4-methylenedioxybenzoic acid) (3) [(HL+) · (mdba-)], (benzylamine): (mandelic acid) (4) [(HL+) · (mda-)], (benzylamine): (5-bromosalicylic acid)2(5) [(HL+) · (bsac-) · (Hbsac)], (benzylamine): (m-phthalic acid) (6) [(HL+) · (Hmpta-)], and (benzylamine)2: (trimesic acid) (7) [(HL+)2 · (Htma2-)]. The seven salts have been characterised by X-ray diffraction technique, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the seven investigated crystals the NH2 groups in the benzylamine moieties are protonated when the organic acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted Nsbnd H⋯O hydrogen bond formation between the ammonium and the deprotonated acidic groups. Except the Nsbnd H⋯O hydrogen bond, the Osbnd H⋯O hydrogen bonds (charge assisted or neutral) were also found at the salts 4-7. Further analysis of the crystal packing of the salts indicated that a different family of additional CHsbnd O/CH2sbnd O, CHsbnd π/CH2sbnd π, Osbnd O, and Osbnd Cπ associations contribute to the stabilization and expansion of the total high-dimensional (2D-3D) framework structures. For the coexistence of the various weak nonbonding interactions these structures adopted homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R42(8), R43(10) and R44(12), usually observed in organic solids of organic acids with amine, were again shown to be involved in constructing most of these hydrogen bonding networks.

  19. Soil Respiration and Belowground Carbon Stores Among Salt Marshes Subjected to Increasing Watershed Nitrogen Loadings in Southern New England

    EPA Science Inventory

    Coastal salt marshes are ecosystems located between the uplands and sea, and because of their location are subject to increasing watershed nutrient loadings and rising sea levels. Residential development along the coast is intense, and there is a significant relationship between...

  20. Scavenging processes of marine aerosols by sea fog over the northern North Pacific

    NASA Astrophysics Data System (ADS)

    Narita, Y.; Iwamoto, Y.; Yoshida, K.; Kondo, M.; Uematsu, M.

    2007-12-01

    Sea fog appears frequently over the subarctic North Pacific in summertime. Typical advection fog over this region may affect the distribution of natural and anthropogenic substances from lands as well as marine biogenic substances. To clarify the variation of chemical composition in fog water, size distribution of fog droplets and fog scavenging processes, investigation was conducted over the northern North Pacific, where sea fog appears frequently in summer, during the KH-04-3 cruise of R/V Hakuho-maru in 2004. The sea salt composition is governed 65% of total concentration of inorganic ions and the non-sea-salt (nss-) sulfate occupied 10 % in the 90 sea fog water samples. The average size distribution of liquid water content (LWC) of sea fog showed a bimodal pattern with peaks of 7.0 and 27.5 μm in diameter, while its distribution on land fog commonly showed a monomodal pattern. LWC, number concentrations of fog droplets and concentrations of sea salt composition were high at the edge of the fog area, and decreased toward the center of the fog area. The peak of LWC size distribution was shifted from 17.0 μm at the edge to 36.5 μm in the center area. Based on the relationship of chemical compositions between aerosols and fog droplets, nss-SO42- and NH 4 + in sea fog water consisted of 85 % of the coarse mode aerosol and 15 % of the fine mode by ion basis. The fog droplets are expected to deposit with growing of its droplet size with coagulation and adsorbing reactive gases as a function of the distance from the edge of the sea fog area. These results suggest that sea fog over the subarctic North Pacific is an important as a scavenger of natural and anthropogenic substances transported from the Asian continent and its nitrogen flux to the marine environment may stimulate phytoplankton growth.

  1. Seismic evidence of Messinian salt in opposite margins of West Mediterranean

    NASA Astrophysics Data System (ADS)

    Mocnik, Arianna; Camerlenghi, Angelo; Del Ben, Anna; Geletti, Riccardo; Wardell, Nigel; Zgur, Fabrizio

    2015-04-01

    sedimentary cover. During the MSC the margins of the West Mediterranean Sea seem to be involved in some tectonic events probably connected to reactivation of normal faults and to the fast variation of the water load related to sea level fluctuations. The absence of calibrating boreholes in the deep Mediterranean basins and the hard penetration of seismic energy below the evaporitic layers, represent a limit for the knowledge of the geological evolution of the basins; the interpretation of the presented datasets could be a contribution to the comprehension of the evaporitic deposition and early-stage salt deformation during the MSC in the Mediterranean sea.

  2. Metabolite Profiling of Triterpene Glycosides of the Far Eastern Sea Cucumber Eupentacta fraudatrix and Their Distribution in Various Body Components Using LC-ESI QTOF-MS.

    PubMed

    Popov, Roman S; Ivanchina, Natalia V; Silchenko, Alexandra S; Avilov, Sergey A; Kalinin, Vladimir I; Dolmatov, Igor Yu; Stonik, Valentin A; Dmitrenok, Pavel S

    2017-10-02

    The Far Eastern sea cucumber Eupentacta fraudatrix is an inhabitant of shallow waters of the south part of the Sea of Japan. This animal is an interesting and rich source of triterpene glycosides with unique chemical structures and various biological activities. The objective of this study was to investigate composition and distribution in various body components of triterpene glycosides of the sea cucumber E. fraudatrix . We applied LC-ESI MS (liquid chromatography-electrospray mass spectrometry) of whole body extract and extracts of various body components for metabolic profiling and structure elucidation of triterpene glycosides from the E. fraudatrix . Totally, 54 compounds, including 26 sulfated, 18 non-sulfated and 10 disulfated glycosides were detected and described. Triterpene glycosides from the body walls, gonads, aquapharyngeal bulbs, guts and respiratory trees were extracted separately and the distributions of the detected compounds in various body components were analyzed. Series of new glycosides with unusual structural features were described in E. fraudatrix , which allow clarifying the biosynthesis of these compounds. Comparison of the triterpene glycosides contents from the five different body components revealed that the profiles of triterpene glycosides were qualitatively similar, and only some quantitative variabilities for minor compounds were observed.

  3. The significance of salt reconstruction for basin modeling results

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

    Johansen, H.; Blomvik, V.; Bonnell, L.

    1996-12-31

    Salt structures can play a major role in the temperature history as well as in the formation of hydrocarbon traps. Salt movement through time is therefore an important process to incorporate into basin models. Based on this need, a new model for geologic reconstruction of salt geometries was incorporated into the BMT{trademark} basin modeling system. The reconstruction model is based on two basic mechanisms: (1) The ability to change lithology for a polygon (a sub-domain in the cross section) at a given time (litho-switching) and (2) the ability to inflate/deflate mass in polygons. Litho-switching is used where salt diapirs penetratemore » overlaying strata. Inflation/deflation is used to change the shape of a salt polygon. By inflating/deflating parts of polygons, it is possible to restore the salt layer step by step back to original form. The advantage of this approach is its applicability to geological problems that cannot be addressed by many basin modeling systems. To test the approach, we have reconstructed a cross-section from the Central Graben of the North Sea using two different geological models. One model assumes that synforms developed on the surface during Triassic deposition. These synforms were later preserved as sediment {open_quotes}pods{close_quotes}. The other geological model assumes that the salt movement was passively related to eastward basin subsidence, with salt upwelling between rafted Triassic blocks. The test indicate that the approach is versatile and can be used to evaluate the thermal consequences of a number of geologic models of salt movement.« less

  4. The significance of salt reconstruction for basin modeling results

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

    Johansen, H.; Blomvik, V.; Bonnell, L.

    1996-01-01

    Salt structures can play a major role in the temperature history as well as in the formation of hydrocarbon traps. Salt movement through time is therefore an important process to incorporate into basin models. Based on this need, a new model for geologic reconstruction of salt geometries was incorporated into the BMT[trademark] basin modeling system. The reconstruction model is based on two basic mechanisms: (1) The ability to change lithology for a polygon (a sub-domain in the cross section) at a given time (litho-switching) and (2) the ability to inflate/deflate mass in polygons. Litho-switching is used where salt diapirs penetratemore » overlaying strata. Inflation/deflation is used to change the shape of a salt polygon. By inflating/deflating parts of polygons, it is possible to restore the salt layer step by step back to original form. The advantage of this approach is its applicability to geological problems that cannot be addressed by many basin modeling systems. To test the approach, we have reconstructed a cross-section from the Central Graben of the North Sea using two different geological models. One model assumes that synforms developed on the surface during Triassic deposition. These synforms were later preserved as sediment [open quotes]pods[close quotes]. The other geological model assumes that the salt movement was passively related to eastward basin subsidence, with salt upwelling between rafted Triassic blocks. The test indicate that the approach is versatile and can be used to evaluate the thermal consequences of a number of geologic models of salt movement.« less

  5. Multivariate analyses of salt stress and metabolite sensing in auto- and heterotroph Chenopodium cell suspensions.

    PubMed

    Wongchai, C; Chaidee, A; Pfeiffer, W

    2012-01-01

    Global warming increases plant salt stress via evaporation after irrigation, but how plant cells sense salt stress remains unknown. Here, we searched for correlation-based targets of salt stress sensing in Chenopodium rubrum cell suspension cultures. We proposed a linkage between the sensing of salt stress and the sensing of distinct metabolites. Consequently, we analysed various extracellular pH signals in autotroph and heterotroph cell suspensions. Our search included signals after 52 treatments: salt and osmotic stress, ion channel inhibitors (amiloride, quinidine), salt-sensing modulators (proline), amino acids, carboxylic acids and regulators (salicylic acid, 2,4-dichlorphenoxyacetic acid). Multivariate analyses revealed hirarchical clusters of signals and five principal components of extracellular proton flux. The principal component correlated with salt stress was an antagonism of γ-aminobutyric and salicylic acid, confirming involvement of acid-sensing ion channels (ASICs) in salt stress sensing. Proline, short non-substituted mono-carboxylic acids (C2-C6), lactic acid and amiloride characterised the four uncorrelated principal components of proton flux. The proline-associated principal component included an antagonism of 2,4-dichlorphenoxyacetic acid and a set of amino acids (hydrophobic, polar, acidic, basic). The five principal components captured 100% of variance of extracellular proton flux. Thus, a bias-free, functional high-throughput screening was established to extract new clusters of response elements and potential signalling pathways, and to serve as a core for quantitative meta-analysis in plant biology. The eigenvectors reorient research, associating proline with development instead of salt stress, and the proof of existence of multiple components of proton flux can help to resolve controversy about the acid growth theory. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Does vegetation prevent wave erosion of salt marsh edges?

    PubMed

    Feagin, R A; Lozada-Bernard, S M; Ravens, T M; Möller, I; Yeager, K M; Baird, A H

    2009-06-23

    This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do not significantly mitigate the total amount of erosion along a wetland edge. We found that the soil type is the primary variable that influences the lateral erosion rate and although plants do not directly reduce wetland edge erosion, they may do so indirectly via modification of soil parameters. We conclude that coastal vegetation is best-suited to modify and control sedimentary dynamics in response to gradual phenomena like sea-level rise or tidal forces, but is less well-suited to resist punctuated disturbances at the seaward margin of salt marshes, specifically breaking waves.

  7. Quantifying the impact of sub-grid surface wind variability on sea salt and dust emissions in CAM5

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Zhao, Chun; Wan, Hui; Qian, Yun; Easter, Richard C.; Ghan, Steven J.; Sakaguchi, Koichi; Liu, Xiaohong

    2016-02-01

    This paper evaluates the impact of sub-grid variability of surface wind on sea salt and dust emissions in the Community Atmosphere Model version 5 (CAM5). The basic strategy is to calculate emission fluxes multiple times, using different wind speed samples of a Weibull probability distribution derived from model-predicted grid-box mean quantities. In order to derive the Weibull distribution, the sub-grid standard deviation of surface wind speed is estimated by taking into account four mechanisms: turbulence under neutral and stable conditions, dry convective eddies, moist convective eddies over the ocean, and air motions induced by mesoscale systems and fine-scale topography over land. The contributions of turbulence and dry convective eddy are parameterized using schemes from the literature. Wind variabilities caused by moist convective eddies and fine-scale topography are estimated using empirical relationships derived from an operational weather analysis data set at 15 km resolution. The estimated sub-grid standard deviations of surface wind speed agree well with reference results derived from 1 year of global weather analysis at 15 km resolution and from two regional model simulations with 3 km grid spacing.The wind-distribution-based emission calculations are implemented in CAM5. In terms of computational cost, the increase in total simulation time turns out to be less than 3 %. Simulations at 2° resolution indicate that sub-grid wind variability has relatively small impacts (about 7 % increase) on the global annual mean emission of sea salt aerosols, but considerable influence on the emission of dust. Among the considered mechanisms, dry convective eddies and mesoscale flows associated with topography are major causes of dust emission enhancement. With all the four mechanisms included and without additional adjustment of uncertain parameters in the model, the simulated global and annual mean dust emission increase by about 50 % compared to the default model

  8. Quantifying the impact of sub-grid surface wind variability on sea salt and dust emissions in CAM5

    DOE PAGES

    Zhang, Kai; Zhao, Chun; Wan, Hui; ...

    2016-02-12

    This paper evaluates the impact of sub-grid variability of surface wind on sea salt and dust emissions in the Community Atmosphere Model version 5 (CAM5). The basic strategy is to calculate emission fluxes multiple times, using different wind speed samples of a Weibull probability distribution derived from model-predicted grid-box mean quantities. In order to derive the Weibull distribution, the sub-grid standard deviation of surface wind speed is estimated by taking into account four mechanisms: turbulence under neutral and stable conditions, dry convective eddies, moist convective eddies over the ocean, and air motions induced by mesoscale systems and fine-scale topography overmore » land. The contributions of turbulence and dry convective eddy are parameterized using schemes from the literature. Wind variabilities caused by moist convective eddies and fine-scale topography are estimated using empirical relationships derived from an operational weather analysis data set at 15 km resolution. The estimated sub-grid standard deviations of surface wind speed agree well with reference results derived from 1 year of global weather analysis at 15 km resolution and from two regional model simulations with 3 km grid spacing.The wind-distribution-based emission calculations are implemented in CAM5. In terms of computational cost, the increase in total simulation time turns out to be less than 3 %. Simulations at 2° resolution indicate that sub-grid wind variability has relatively small impacts (about 7 % increase) on the global annual mean emission of sea salt aerosols, but considerable influence on the emission of dust. Among the considered mechanisms, dry convective eddies and mesoscale flows associated with topography are major causes of dust emission enhancement. With all the four mechanisms included and without additional adjustment of uncertain parameters in the model, the simulated global and annual mean dust emission increase by about 50 % compared to the

  9. Quantifying the impact of sub-grid surface wind variability on sea salt and dust emissions in CAM5

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

    Zhang, Kai; Zhao, Chun; Wan, Hui

    This paper evaluates the impact of sub-grid variability of surface wind on sea salt and dust emissions in the Community Atmosphere Model version 5 (CAM5). The basic strategy is to calculate emission fluxes multiple times, using different wind speed samples of a Weibull probability distribution derived from model-predicted grid-box mean quantities. In order to derive the Weibull distribution, the sub-grid standard deviation of surface wind speed is estimated by taking into account four mechanisms: turbulence under neutral and stable conditions, dry convective eddies, moist convective eddies over the ocean, and air motions induced by mesoscale systems and fine-scale topography overmore » land. The contributions of turbulence and dry convective eddy are parameterized using schemes from the literature. Wind variabilities caused by moist convective eddies and fine-scale topography are estimated using empirical relationships derived from an operational weather analysis data set at 15 km resolution. The estimated sub-grid standard deviations of surface wind speed agree well with reference results derived from 1 year of global weather analysis at 15 km resolution and from two regional model simulations with 3 km grid spacing.The wind-distribution-based emission calculations are implemented in CAM5. In terms of computational cost, the increase in total simulation time turns out to be less than 3 %. Simulations at 2° resolution indicate that sub-grid wind variability has relatively small impacts (about 7 % increase) on the global annual mean emission of sea salt aerosols, but considerable influence on the emission of dust. Among the considered mechanisms, dry convective eddies and mesoscale flows associated with topography are major causes of dust emission enhancement. With all the four mechanisms included and without additional adjustment of uncertain parameters in the model, the simulated global and annual mean dust emission increase by about 50 % compared to the

  10. Effect of iron and salt on prodigiosin synthesis in Serratia marcescens.

    NASA Technical Reports Server (NTRS)

    Silverman, M. P.; Munoz, E. F.

    1973-01-01

    Iron requirements of Serratia marcescens for growth and prodigiosin synthesis are investigated. Sodium chloride of sea salt is shown to be responsible for inhibition of prodigiosin synthesis in the microorganism. The role of sodium chloride in the terminal biosynthetic pathway of the pigment is discussed.

  11. Mechanistic controls on diverse fates of terrestrial organic components in the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhu, Chun; Wagner, Thomas; Talbot, Helen M.; Weijers, Johan W. H.; Pan, Jian-Ming; Pancost, Richard D.

    2013-09-01

    Terrestrial carbon transferred from the land to sea is a critical component of the global carbon cycle. A range of geochemical proxies has been developed to fingerprint the fate of terrestrial organic matter (TOM) in marine sediments. However, discrepancies among different proxies limit our ability to quantify and interpret the terrestrial signals in marine sediments, with consequences for the investigation of both the modern carbon cycle and past environmental change. To mechanistically understand these discrepancies, we examined the distributions of a range of terrestrial proxies and their aquatic counterparts (i.e. marine proxies) in the Yangtze river-East China Sea (YR-ECS) shelf system, where TOM experiences extensive modification during transport and burial. TOM proxies in the YR-ECS system collectively fit a power-law model but with distinct attenuation rates (the a∗ values) for individual molecular proxy groups. Among a range of TOM proxies, the modeled a∗ values decrease in the order: soil-marker BHPs > triterpenols > lignin > HMW n-alkanols > branched GDGTs > HMW n-alkanes for biomarkers; and Rsoil > BIT > %TOMiso for proxies tracing %TOM. Rapid loss of TOM components through dissociation in the narrow estuary, followed by oxidation over the wide open shelf, are best described by power curves. Inherent chemical reactivity (i.e. the number of functional groups), responses to hydraulic sorting, and in situ production regulate the individual attenuation rates. Of them, chemical reactivity plays the most important role on proxy behavior, supported by a strong correlation between a∗ values and standard molal Gibbs energies. Both, physical protection and chemical reactivity fundamentally control the overall behavior of TOM components, with the relative importance being setting-dependant: The former is relatively important in the estuary, whereas the later is the primary control over the open shelf. Moreover, regional variation of different marine

  12. Vertical Mixing in the Dead Sea

    NASA Astrophysics Data System (ADS)

    Gertman, Isaac; Ozer, Tal; Katsenelson, Boris; Lensky, Nadav

    2015-04-01

    For hundreds of years, the Dead Sea was characterized by a stable haline stratification, supported by runoff. The penetration of the winter convection was limited to an upper mixed layer (UML) of about 30-50 m. Below the UML, a stable halocline prevented the mixing. As a result of the runoff reduction, the UML salinity increased and the gravitational stability diminished. During the winter of 1978-1979, the sea water overturned, ending the long-term stable hydrological regime. Since 1979, the haline stratification structure reoccurred twice after extremely rainy winters, in 1980-82 and 1992-1995. In other years, the sea was entirely mixed by winter thermal convection ( which occurs from November to March ) and had a seasonal pycnocline beneath the UML during summer. Profiles of temperature and quasi-salinity (density anomaly from 1000 kg/m3 for the chosen reference temperature of 32° C) during the last 19 years, show the formation of summer ``overturning halocline'' beneath the UML, and the thermocline that supports the stable stratification. Another warm and saline layer is formed also during the summer period near the bottom. This layer spreads from the southern part of the sea, where end-brine is discharged to the sea from the Israeli and Jordanian salt plants' evaporation ponds. The end-brine has extremely high salinity (˜ 350 g/kg) and, in spite of the high temperatures ( ˜ 45° C), high density (1350 kg/m^3), it therefore spreads as a gravitational current in the Dead Sea deep basin. Estimation of the density ratio (Rρ) for the Dead Sea water (where measurements of water salinity is quite difficult) was done using quasi-salinity (σ32) and potential temperature (θ): Rρ= [α(partialθ/partial z)]/[β(partial σ32/partial z)], where α and β are temperature expansion and quasi-salinity contraction coefficients respectively. The values of α and β for the Dead Sea water were defined from water samples collected during 2008. The Rρ values confirm that

  13. Mean dynamic topography over Peninsular Malaysian seas using multimission satellite altimetry

    NASA Astrophysics Data System (ADS)

    Abazu, Isaac Chidi; Din, Ami Hassan Md; Omar, Kamaludin Mohd

    2017-04-01

    The development of satellite altimeters (SALTs) has brought huge benefits, among which is the ability to more adequately sense ocean-surface topography. The radar altimeter database system was used to capture and process ENVISAT, CRYOSAT-2, SARAL, JASON-1, and JASON-2 SALT data of 5 years between 2011 and 2015. The time series of monthly multimission SALT data showed an estimated sea level trend of 1.0, 2.4, 2.4, 3.6, and 12.0 mm/year at Gelang, Port Kelang, Kukup, Cendering, and Keling. The correlation analysis for the selected tide gauge stations produced satisfying results of R-squared with 0.86, 0.89, 0.91, and 0.97 for Cendering, Sedili, Gelang, and Geting, respectively. The ITG-Grace2010s geoid model was used to compute the mean dynamic topography (MDT) and plot to a grid of 0.25 deg for the Malacca Strait and South China Sea of Peninsular Malaysia, with Keling, Port Kelang, Geting, Sedili, and Johor Bahru tide gauge stations having values determined by interpolation to be 1.14, 1.19, 1.26, 1.88, and 2.91 m, respectively. MDT is computed from the SALT with respect to Port Kelang, the north-south sea slope ranges between -0.64 and 0.29 m/50 km and -0.01 and 0.52 m/50 km along the east and west coasts of Peninsular Malaysia, respectively.

  14. A High Resolution Tampa Bay Hydrodynamic Model and its Application to Residence Time Estimation and Salt Balance Diagnosis

    NASA Astrophysics Data System (ADS)

    Zheng, L.; Weisberg, R. H.

    2016-02-01

    A 3D, numerical circulation model, with high resolution (20 m) at important mass conveyances (inlets and rivers etc.), is developed to estimate the bulk residence time and diagnose the salt balances and salt fluxes for Tampa Bay estuary. These analyses are justified via quantitative comparisons between the simulation and observations of sea level, velocity and salinity. The non-tidal circulation is the primary agent for the flushing of Tampa Bay. Tides alone have a minor effect. Exceptions pertain to within a tidal excursion from the bay mouth and regions with multiple inlets where different tide phases aid in flushing. The fully 3D salt flux divergences (SFD) and fluxes vary spatially throughout the estuary. On experimental duration (three month) average, the total advective SFD is balanced primarily by the vertical diffusive SFD, except near the bottom of the channel where the horizontal diffusive SFD is also important. Instantaneously, the local rate of salinity change is controlled primarily by the advective SFD, with a secondary contribution by the vertical diffusive SFD everywhere and the horizontal diffusive SFD near the channel bottom. After decomposing the advective salt fluxes and their divergences into mean quantity and tidal pumping, the horizontal and vertical advective SFDs by the mean quantities are large and counterbalance, with their sum being a small but significant residual. The horizontal and vertical advective SFDs by tidal pumping are relatively small (when compared with the mean quantities) and counterbalance; but, when summed, their residual is comparable in magnitude to that by the mean quantities. So whereas the salt fluxes by tidal pumping are secondary importance to the salt fluxes by the mean quantities, their total flux divergences are of comparable importance. The salt flux 3D components vary along the Tampa Bay axis, and these findings may be typical of coastal plain estuaries given their geometrical complexities.

  15. Investigation of indigenous water, salt and soil for solar ponds

    NASA Astrophysics Data System (ADS)

    Marsh, H. E.

    The existence of salt-gradient solar ponds in nature is a strong indication that the successful exploitation of this phenomenon must account adequately for the influences of the local setting. Sun, weather and other general factors are treated elsewhere. This paper deals with water, salt, and soil. A general methodology for evaluating and, where feasible, adjusting the effects of these elements is under development. Eight essential solar pond characteristics have been identified, along with a variety of their dependencies upon properties of water, salt and soil. The comprehensive methodology, when fully developed, will include laboratory investigation in such diverse areas as brine physical chemistry, light transmission, water treatment, brine-soil interactions, sealants, and others. With the Salton Sea solar pond investigation as an example, some methods under development will be described.

  16. Investigation of indigenous water, salt and soil for solar ponds

    NASA Technical Reports Server (NTRS)

    Marsh, H. E.

    1983-01-01

    The existence of salt-gradient solar ponds in nature is a strong indication that the successful exploitation of this phenomenon must account adequately for the influences of the local setting. Sun, weather and other general factors are treated elsewhere. This paper deals with water, salt, and soil. A general methodology for evaluating and, where feasible, adjusting the effects of these elements is under development. Eight essential solar pond characteristics have been identified, along with a variety of their dependencies upon properties of water, salt and soil. The comprehensive methodology, when fully developed, will include laboratory investigation in such diverse areas as brine physical chemistry, light transmission, water treatment, brine-soil interactions, sealants, and others. With the Salton Sea solar pond investigation as an example, some methods under development will be described.

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

    PubMed

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

    2018-01-25

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

  18. Synoptic conditions of fine-particle transport to the last interglacial Red Sea -Dead Sea from Nd-Sr compositions of sediment cores

    NASA Astrophysics Data System (ADS)

    Stein, M.; Palchan, D.; Goldstein, S. L.; Almogi-Labin, A.; Tirosh, O.; Erel, Y.

    2017-12-01

    The last interglacial peak, Marine Isotope Stage 5e (MIS 5e), was associated with stronger northern hemisphere insolation, higher global sea levels and higher average global temperatures compared to the Holocene, and is considered as an analogue for a future warming world. In this perspective the present-day areas of the Sahara - Arabia deserts (the "desert belt") are of special interest since their margins are densely inhabited and global climate models predict enhanced aridity in these regions due to future warming. The Red Sea situated at the midst of the desert belt and the Dead Sea at the northern fringe of the desert belt comprise sensitive monitors for past hydroclimate changes in the Red Sea-Levant regions as global climate shifted from glacial to interglacial conditions. Here, we reconstruct the synoptic conditions that controlled desert dust transport to the Red Sea and the Dead Sea during MIS5e. The reconstruction is based on Nd-Sr isotopes and chemical composition of carbonate-free detritus recovered from sediment cores drilled at the deep floors of these water-bodies combined with data of contemporaneous dust storms transporting dust to the lake and sea floors. During Termination 2 ( 134-130 ka) the Sahara, Nile River desiccated and the Dead Sea watershed were under extreme dry conditions manifested by lake level drop, deposition of salt and enhanced transport of Sahara dusts to the entire studied transect. At the peak of the interglacial MIS 5e ( 130-120 ka), enhanced flooding activity mobilized local fine detritus from the surroundings of the Red Sea and the Dead Sea watershed into the water-bodies. This interval coincided with the Sapropel event S5 in the Mediterranean that responded to enhanced monsoon rains at the heads of the Blue Nile River. At the end of MIS 5e ( 120-116 ka) the effect of the regional floods faded and the Dead Sea and Red Sea areas re-entered sever arid conditions with salt deposition at the Dead Sea. Overall, the desert

  19. Does the invasive plant Elymus athericus modify fish diet in tidal salt marshes?

    NASA Astrophysics Data System (ADS)

    Laffaille, P.; Pétillon, J.; Parlier, E.; Valéry, L.; Ysnel, F.; Radureau, A.; Feunteun, E.; Lefeuvre, J.-C.

    2005-12-01

    The invasion of Mont-Saint-Michel Bay salt marshes (France) by a grass species ( Elymus athericus) has led to important changes in vegetation cover, which is likely to modify the habitat for many invertebrates. Some of them constitute the main food items for several fish species, such as young sea bass ( Dicentrarchus labrax) and sand goby ( Pomatoschistus minutus), that feed in salt marsh creeks during high tides. As a result, fish nursery functions of salt marshes could be modified by the E. athericus invasion. In order to test this hypothesis, gut contents of the two most abundant fish species (sea bass and sand goby) were compared before and after E. athericus invasion in the same salt marsh creek and using the same methodology. The accessibility and availability of the main food item, the semi-terrestrial amphipod Orchestia gammarella, were estimated and compared between invaded (dominated by E. athericus) and original areas (dominated by Atriplex portulacoides). Gut content analysis showed a significantly greater percentage of fish leaving with empty guts from E. athericus areas than from A. portulacoides areas. The sea bass diet composition study showed a major shift in the relative importance of the main food items: before E. athericus invasion, diets were dominated by the semi-terrestrial species O. gammarella, whereas after the E. athericus invasion they were dominated by a marine mysid Neomysis integer. The same trend was found for sand gobies, with a shift of the main food item from O. gammarella before invasion to the polychaete Hediste diversicolor after invasion. These trophic changes may be explained by the lower accessibility and availability of O. gammarella in invaded communities than in natural ones. The E. athericus invasion, observed throughout northern Europe, is thus likely to disturb trophic function of natural salt marshes for fish. This preliminary study of the E. athericus invasion is also an illustration that invasive species are an

  20. Aerosol Optical Properties over Northwestern European Seas

    NASA Astrophysics Data System (ADS)

    Avgousta Floutsi, Athina; Korras Carraca, Marios Bruno; Matsoukas, Christos; Riva, Riccardo; Biskos, George

    2017-04-01

    Atmospheric aerosols, both natural and anthropogenic, can affect the regional and global climate through their direct, indirect, and semi-direct effects on the radiative energy budget of the Earth-atmosphere system. In order to quantify these effects it is necessary to determine the aerosol load. An effective way to do this is by measuring the aerosol optical depth (AOD). Besides AOD, the Fine mode Fraction (AOD of particles smaller than 1 μm / total AOD, FF) is a useful parameter for the characterization of the aerosol and provides a good proxy for particle size. In this study, we investigate the spatial and temporal variability of the AOD and FF over the Western and Northwestern European Seas (43° N - 67° N, 10° W - 31° E), where significant sources of both natural and anthropogenic particles are located. Anthropogenic particles (mostly fine mode) originate from ship activity, or from urban-industrial and biomass-burning processes in the European countries. The natural, coarse mode particles are primarily sea salt. The study is performed using Collection 006 Level-3 mean daily aerosol data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on board Aqua satellite, available in 1° × 1° resolution (ca. 100 km × 100 km) over the period 2002- 2014. Our results indicate significant spatial variability of the aerosol load over the study region. The highest AOD values (up to 0.32 on annual level) are observed over the English Channel and the coasts of the Netherlands and Germany. In these regions the highest FF values are also observed (up to 0.77), indicating a relatively large contribution of anthropogenic particles to the aerosol load. Offshore, both AOD and FF are lower compared to coastal regions, indicating the predominance of maritime aerosols (sea salt). The data also show a clear seasonal cycle, with larger aerosol load during spring and summer (AOD up to 0.60), and lower during autumn and winter (AOD up to 0.30). A similar

  1. Seasonality of Red Sea Mixed-Layer Depth and Density Budget

    NASA Astrophysics Data System (ADS)

    Kartadikaria, A. R.; Cerovecki, I.; Krokos, G.; Hoteit, I.

    2016-02-01

    The Red Sea is an active area of water mass formation. Dense water initially formed in the northern Red Sea, in the Gulf of Aqaba and the Gulf of Suez, spreads southward and finally flows to the open ocean through the Gulf of Aden via the narrow strait of Bab Al Mandeb. The signature of this outflow can be traced until the southern Indian Ocean, and is characterized by potential density of σθ ≈ 27.4. This water mass is important because it represents a significant source of heat and salt for the Indian Ocean. Using a high-resolution 1km regional MITgcm ocean model for the period 1992-2001 configured for the Red Sea, we examine the spatio-temporal characteristics of water mass formation inside the basin by analyzing closed and complete temperature and salinity budgets. The deepest mixed-layers (MLD) always develop in the northern part of the basin where surface ocean buoyancy loss leads to the Red Sea Intermediate and Deep Water formation. As this water is advected south, it is strongly modified by diapycnal mixing of heat and salt.

  2. Pectin methylesterase31 positively regulates salt stress tolerance in Arabidopsis.

    PubMed

    Yan, Jingwei; He, Huan; Fang, Lin; Zhang, Aying

    2018-02-05

    The alteration of cell wall component and structure is an important adaption to saline environment. Pectins, a major cell wall component, are often present in a highly methylesterified form. The level of methyl esterification determined by pectin methylesterases (PMEs) influences many important wall properties that are believed to relate to the adaption to saline stress. However, little is known about the function of PMEs in response to salt stress. Here, we established a link between pectin methylesterase31 (PME31) and salt stress tolerance. Salt stress significantly increases PME31 expression. PME31 is located in the plasma membrane and the expression level of PME31 was high in dry seeds. Knock-down mutants in PME31 conferred hypersensitive phenotypes to salt stress in seed germination and post-germination growth. Real-time PCR analysis revealed that the transcript levels of several stress genes (DREB2A, RD29A and RD29B) are lower in pme31-2 mutant than that in the wild type in response to salt stress. These results suggested that PME31 could positively modulate salt stress tolerance. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Assessing the Potential for Inland Migration of a Northeastern Salt Marsh

    NASA Astrophysics Data System (ADS)

    Farron, S.; FitzGerald, D.; Hughes, Z. J.

    2017-12-01

    It is often assumed that as sea level rises, salt marshes will expand inland. If the slope of the upland is relatively flat and sufficient sediment is available, marshes should be able to spread horizontally and grow vertically in order to maintain their areal extent. However, in cases where marshes are backed by steeper slopes, or sediment supply is limited, rising sea level will produce minimal gains along the landward edge insufficient to offset potential losses along the seaward edge. This study uses future sea level rise scenarios to project areal losses for the Great Marsh in Massachusetts, the largest continuous salt marsh in New England. Land area covered by salt marsh is defined by surface elevation. Annual sediment input to the system is estimated based on the areal extent of high and low marsh, historical accretion rates for each, and known organic/inorganic ratios. Unlike other studies, sediment availability is considered to be finite, and future accretion rates are limited based on the assumption that the system is presently receiving the maximum sediment input available. The Great Marsh is dominated by high marsh; as sea level rises, it will convert to low marsh, vastly altering the ecological and sedimentological dynamics of the system. If it is assumed that former high marsh areas will build vertically at the increased rate associated with low marsh, then much of the total marsh area will be maintained. However, this may be an unrealistic assumption due to the low levels of suspended sediment within the Great Marsh system. Modeling the evolution of the Great Marsh by assuming that the current accretion rate is the maximum possible for this system reveals much greater losses than models assuming an unlimited sediment supply would predict (17% less marsh by 2115). In addition, uplands surrounding the Great Marsh have been shaped by glaciation, leaving numerous drumlins and other glacial landforms. Compared to the flat backbarrier, the surrounding

  4. The role of surface and subsurface processes in keeping pace with sea level rise in intertidal wetlands of Moreton Bay, Queensland, Australia

    USGS Publications Warehouse

    Lovelock, Catherine E.; Bennion, Vicki; Grinham, Alistair; Cahoon, Donald R.

    2011-01-01

    Increases in the elevation of the soil surfaces of mangroves and salt marshes are key to the maintenance of these habitats with accelerating sea level rise. Understanding the processes that give rise to increases in soil surface elevation provides science for management of landscapes for sustainable coastal wetlands. Here, we tested whether the soil surface elevation of mangroves and salt marshes in Moreton Bay is keeping up with local rates of sea level rise (2.358 mm y-1) and whether accretion on the soil surface was the most important process for keeping up with sea level rise. We found variability in surface elevation gains, with sandy areas in the eastern bay having the highest surface elevation gains in both mangrove and salt marsh (5.9 and 1.9 mm y-1) whereas in the muddier western bay rates of surface elevation gain were lower (1.4 and -0.3 mm y-1 in mangrove and salt marsh, respectively). Both sides of the bay had similar rates of surface accretion (~7–9 mm y-1 in the mangrove and 1–3 mm y-1 in the salt marsh), but mangrove soils in the western bay were subsiding at a rate of approximately 8 mm y-1, possibly due to compaction of organic sediments. Over the study surface elevation increments were sensitive to position in the intertidal zone (higher when lower in the intertidal) and also to variation in mean sea level (higher at high sea level). Although surface accretion was the most important process for keeping up with sea level rise in the eastern bay, subsidence largely negated gains made through surface accretion in the western bay indicating a high vulnerability to sea level rise in these forests.

  5. In-tube extraction and GC-MS analysis of volatile components from wild and cultivated sea buckthorn (Hippophae rhamnoides L. ssp. Carpatica) berry varieties and juice.

    PubMed

    Socaci, Sonia A; Socaciu, Carmen; Tofană, Maria; Raţi, Ioan V; Pintea, Adela

    2013-01-01

    The health benefits of sea buckthorn (Hippophae rhamnoides L.) are well documented due to its rich content in bioactive phytochemicals (pigments, phenolics and vitamins) as well as volatiles responsible for specific flavours and bacteriostatic action. The volatile compounds are good biomarkers of berry freshness, quality and authenticity. To develop a fast and efficient GC-MS method including a minimal sample preparation technique (in-tube extraction, ITEX) for the discrimination of sea buckthorn varieties based on their chromatographic volatile fingerprint. Twelve sea buckthorn varieties (wild and cultivated) were collected from forestry departments and experimental fields, respectively. The extraction of volatile compounds was performed using the ITEX technique whereas separation and identification was performed using a GC-MS QP-2010. Principal component analysis (PCA) was applied to discriminate the differences among sample composition. Using GC-MS analysis, from the headspace of sea buckthorn samples, 46 volatile compounds were separated with 43 being identified. The most abundant derivatives were ethyl esters of 2-methylbutanoic acid, 3-methylbutanoic acid, hexanoic acid, octanoic acid and butanoic acid, as well as 3-methylbutyl 3-methylbutanoate, 3-methylbutyl 2-methylbutanoate and benzoic acid ethyl ester (over 80% of all volatile compounds). Principal component analysis showed that the first two components explain 79% of data variance, demonstrating a good discrimination between samples. A reliable, fast and eco-friendly ITEX/GC-MS method was applied to fingerprint the volatile profile and to discriminate between wild and cultivated sea buckthorn berries originating from the Carpathians, with relevance to food science and technology. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Does vegetation prevent wave erosion of salt marsh edges?

    PubMed Central

    Feagin, R. A.; Lozada-Bernard, S. M.; Ravens, T. M.; Möller, I.; Yeager, K. M.; Baird, A. H.

    2009-01-01

    This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do not significantly mitigate the total amount of erosion along a wetland edge. We found that the soil type is the primary variable that influences the lateral erosion rate and although plants do not directly reduce wetland edge erosion, they may do so indirectly via modification of soil parameters. We conclude that coastal vegetation is best-suited to modify and control sedimentary dynamics in response to gradual phenomena like sea-level rise or tidal forces, but is less well-suited to resist punctuated disturbances at the seaward margin of salt marshes, specifically breaking waves. PMID:19509340

  7. A review of sea ice proxy information from polar ice cores

    NASA Astrophysics Data System (ADS)

    Abram, Nerilie J.; Wolff, Eric W.; Curran, Mark A. J.

    2013-11-01

    Sea ice plays an important role in Earth's climate system. The lack of direct indications of past sea ice coverage, however, means that there is limited knowledge of the sensitivity and rate at which sea ice dynamics are involved in amplifying climate changes. As such, there is a need to develop new proxy records for reconstructing past sea ice conditions. Here we review the advances that have been made in using chemical tracers preserved in ice cores to determine past changes in sea ice cover around Antarctica. Ice core records of sea salt concentration show promise for revealing patterns of sea ice extent particularly over glacial-interglacial time scales. In the coldest climates, however, the sea salt signal appears to lose sensitivity and further work is required to determine how this proxy can be developed into a quantitative sea ice indicator. Methane sulphonic acid (MSA) in near-coastal ice cores has been used to reconstruct quantified changes and interannual variability in sea ice extent over shorter time scales spanning the last ˜160 years, and has potential to be extended to produce records of Antarctic sea ice changes throughout the Holocene. However the MSA ice core proxy also requires careful site assessment and interpretation alongside other palaeoclimate indicators to ensure reconstructions are not biased by non-sea ice factors, and we summarise some recommended strategies for the further development of sea ice histories from ice core MSA. For both proxies the limited information about the production and transfer of chemical markers from the sea ice zone to the Antarctic ice sheets remains an issue that requires further multidisciplinary study. Despite some exploratory and statistical work, the application of either proxy as an indicator of sea ice change in the Arctic also remains largely unknown. As information about these new ice core proxies builds, so too does the potential to develop a more comprehensive understanding of past changes in sea

  8. Mediterranean salt giants beyond the evaporite model: The Sicily perspective

    NASA Astrophysics Data System (ADS)

    Carmelo Manuella, Fabio; Scribano, Vittorio; Carbone, Serafina; Hovland, Martin; Johnsen, Hans-Konrad; Rueslåtten, Håkon

    2017-04-01

    Mediterranean salt giants, occurring both in sub-seafloor and in onshore settings (the "Gessoso Solfifera Group"), are traditionally explained by repeated cycles of desiccation and replenishment of the entire basin. However, such hypotheses are strongly biased by mass balance calculations and geodynamic considerations. In addition, any hypothesis without full desiccation, still based on the evaporite model, should consider that seawater brines start to precipitate halite when 2/3 of the seawater has evaporated, and hence the level of the basin cannot be the same as the adjacent ocean. On the other hand, hydrothermal venting of hot saline brines onto the seafloor can precipitate salt in a deep marine basin if a layer of heavy brine exists along the seafloor. This process, likely related to sub-surface boiling or supercritical out-salting (Hovland et al., 2006), is consistent with geological evidence in the Red Sea "Deeps" (Hovland et al., 2015). Although supercritical out-salting and phase separation can sufficiently explain the formation of several marine salt deposits, even in deep marine settings, the Mediterranean salt giant formations can also be explained by the serpentinization model (Scribano et al., 2016). Serpentinization of abyssal peridotites does not involve seawater salts, and large quantities of saline brines accumulate in pores and fractures of the sub-seafloor serpentinites. If these rocks undergo thermal dehydration, for example, due to igneous intrusions, brines and salt slurries can migrate upwards as hydrothermal plumes, eventually venting at the seafloor, giving rise to giant salt deposits over time. These hydrothermal processes can take place in a temporal sequence, as it occurred in the "Caltanissetta Basin" (Sicily). There, salt accumulation associated with serpentinization started during Triassic times (and even earlier), and venting of heavy brines onto the seafloor eventually occurred in the Messinian via the hydrothermal plume mechanism

  9. Distribution and migration of 239+240Pu in abiotic components of the Black Sea ecosystems during the post-Chernobyl period.

    PubMed

    Tereshchenko, N N; Gulin, S B; Proskurnin, V Yu

    2018-08-01

    Distribution of 239,240 Pu in abiotic components (water and bottom sediment) of the Black Sea ecosystems was studied during the post-Chernobyl period at different offshore and near-shore locations. The trends of these radionuclides accumulation by sediments were analyzed. The spatial-temporal changes in the 239,240 Pu distribution as well as effective half-life for these radionuclides in the Black Sea surface water in deep-sea area are presented. The estimations of the average annual removal fluxes of the 239,240 Pu into the bottom sediments were obtained. The Black Sea sediments were characterized by a higher 239,240 Pu concentration factor (C f  ≈ n·10 4 -n·10 6 ) and radiocapacity factor (F( 239,240 Pu) was about 99.9% on the shelf, 94.5-99.1% on deep-sea basin for silty and 94.6-98.9% on the shelf for sandy bottom sediments) as compared with C f and F for 137 Cs and 90 Sr. Silty bottom sediments play the role of 239,240 Pu main depot in the Black Sea ecosystem. The studied radioecological characteristics of Pu allowed us to define the type of plutonium biogeochemical behavior in the Black Sea as a pedotropic one. The results of this complex radioecological monitoring of 239+240 Pu contamination in the Black Sea and their analysis makes it possible to understand the plutonium redistribution pathways which will enable to carry out the tracing of its migration within the ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Experimental salt marsh islands: A model system for novel metacommunity experiments

    NASA Astrophysics Data System (ADS)

    Balke, Thorsten; Lõhmus, Kertu; Hillebrand, Helmut; Zielinski, Oliver; Haynert, Kristin; Meier, Daniela; Hodapp, Dorothee; Minden, Vanessa; Kleyer, Michael

    2017-11-01

    Shallow tidal coasts are characterised by shifting tidal flats and emerging or eroding islands above the high tide line. Salt marsh vegetation colonising new habitats distant from existing marshes are an ideal model to investigate metacommunity theory. We installed a set of 12 experimental salt marsh islands made from metal cages on a tidal flat in the German Wadden Sea to study the assembly of salt marsh communities in a metacommunity context. Experimental plots at the same elevation were established within the adjacent salt marsh on the island of Spiekeroog. For both, experimental islands and salt marsh enclosed plots, the same three elevational levels were realised while creating bare patches open for colonisation and vegetated patches with a defined transplanted community. One year into the experiment, the bare islands were colonised by plant species with high fecundity although with a lower frequency compared to the salt marsh enclosed bare plots. Initial plant community variations due to species sorting along the inundation gradient were evident in the transplanted vegetation. Competitive exclusion was not observed and is only expected to unfold in the coming years. Our study highlights that spatially and temporally explicit metacommunity dynamics should be considered in salt marsh plant community assembly and disassembly.

  11. Carbon stocks in mangroves, salt marshes, and salt barrens in Tampa Bay, Florida, USA: Vegetative and soil characteristics.

    NASA Astrophysics Data System (ADS)

    Moyer, R. P.; Radabaugh, K.; Chappel, A. R.; Powell, C.; Bociu, I.; Smoak, J. M.

    2017-12-01

    carbon stocks in mangroves and salt marshes, likely due to Tampa Bay's location near the northern limit of mangrove habitat, recent habitat conversion from salt marshes to mangroves, young age of the restored wetlands, and proximity to intense coastal development. Vulnerability of these blue carbon habitats to climate change and sea-level rise will also be discussed.

  12. Northeastern Salt Marshes: Elevation Capital and Resilience to Sea Level Rise

    EPA Science Inventory

    Stable tidal salt marshes exist at an elevation that is supra-optimal relative to peak biomass production, which for Spartina alterniflora, and other marsh macrophytes, follows a parabolic distribution as a function of elevation, as a surrogate for inundation frequency. In order...

  13. Technological and sensory characteristics of reduced/low-fat, low-salt frankfurters as affected by the addition of konjac and seaweed.

    PubMed

    Jiménez-Colmenero, F; Cofrades, S; López-López, I; Ruiz-Capillas, C; Pintado, T; Solas, M T

    2010-03-01

    This paper reports the effect of an edible seaweed, Sea Spaghetti (Himanthalia elongata), on the physicochemical (emulsion stability, cooking loss, colour, texture, residual nitrite and microstructure) and sensory characteristics of reduced- and low-fat, low-salt (NaCl) frankfurters prepared with konjac gel as a fat substitute. The effects on emulsion stability of substituting konjac gel for pork backfat were conditioned by the proportion of the substitution. Incorporation of a combination of Sea Spaghetti/konjac gel (accompanied by reduction in salt) increased (P<0.05) cooking loss and reduced (P<0.05) emulsion stability in the gel/emulsion systems. Incorporation of Sea Spaghetti/konjac gel produced a decrease (P<0.05) of lightness (L*) and redness (a*) values and an increase (P<0.05) of yellowness (b*) as compared to the other samples. The effect of adding seaweed on the texture parameters of low-salt frankfurters varied depending on the proportion of konjac gel used in the formulation. Morphological differences in frankfurter microstructure were observed as fat content was reduced and konjac gel increased. Incorporation of a combination of Sea Spaghetti/konjac gel caused the formation of a more heterogeneous structure, in which the seaweed was integrated in the meat protein matrix. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Understanding the Spatio-Temporal Dynamics of Denitrification in an Oregon Salt Marsh

    EPA Science Inventory

    Salt marshes are highly susceptible to a range of climate change effects (e.g., sea-level rise, salinity changes, storm severity, shifts in vegetation across watershed). It is unclear how these effects will alter the spatial and temporal dynamics of denitrification, a potential p...

  15. Salt additions increase soil nitrate leaching: Implications for near-coastal watershed biogeochemistry

    EPA Science Inventory

    Deposition of sea salt aerosols is often elevated along the coast relative to inland areas, yet little is known about the effects of this deposition on terrestrial ecosystem biogeochemistry. Spatial patterns of stream chemistry in the Oregon Coast Range led us to hypothesize tha...

  16. Helminth component community of the loggerhead sea turtle, Caretta caretta, from Madeira Archipelago, Portugal.

    PubMed

    Valente, Ana Luisa; Delgado, Cláudia; Moreira, Cláudia; Ferreira, Sandra; Dellinger, Thomas; Pinheiro de Carvalho, Miguel A A; Costa, Graça

    2009-02-01

    The helminth fauna of pelagic-stage loggerhead sea turtles, Caretta caretta, is still poorly known. Here, we describe the helminth-component community of healthy, free-ranging juvenile loggerhead sea turtles captured in the waters around Madeira Island, Portugal. Fifty-seven were used in this study. The esophagus, stomach, intestine, liver, gallbladder, spleen, kidneys, trachea, bronchi, urinary bladder, heart, left and right aortas, and coelomic cavity were macroscopically inspected; organs and tissues were removed and washed through a sieve. A search for parasites was made using a stereoscopic microscope; recovered parasites were fixed and stored in 70% alcohol until staining and identification. Prevalence, mean intensity, and mean abundance values were recorded. In total, 156 parasite specimens belonging to 9 species were found: nematodes included Anisakis simplex s.l. (larvae) and an unidentified species; digenetic trematodes present were Enodiotrema megachondrus, Rhytidodes gelatinosus, Pyelosomum renicapite, and Calycodes anthos; acanthocephalans included Bolbosoma vasculosum and Rhadinorhynchus pristis; a single cestode, Nybelinia sp., was present. Parasite infections were found to have both low prevalences and intensities. Possible reasons for this include the oligotrophic conditions of the pelagic habitat around Madeira; a 'dilution effect' because of the vastness of the area; and the small size, and thus ingestion rate, of the turtles. Results are discussed in terms of the various turtle populations that may use the waters surrounding Madeira. This work provides valuable information on the parasite fauna of a poorly known stage in the life of loggerhead sea turtles, thereby filling a fundamental gap with regard to features of the parasite fauna in this species.

  17. Deconjugated Bile Salts Produced by Extracellular Bile-Salt Hydrolase-Like Activities from the Probiotic Lactobacillus johnsonii La1 Inhibit Giardia duodenalis In vitro Growth.

    PubMed

    Travers, Marie-Agnès; Sow, Cissé; Zirah, Séverine; Deregnaucourt, Christiane; Chaouch, Soraya; Queiroz, Rayner M L; Charneau, Sébastien; Allain, Thibault; Florent, Isabelle; Grellier, Philippe

    2016-01-01

    Giardiasis, currently considered a neglected disease, is caused by the intestinal protozoan parasite Giardia duodenalis and is widely spread in human as well as domestic and wild animals. The lack of appropriate medications and the spread of resistant parasite strains urgently call for the development of novel therapeutic strategies. Host microbiota or certain probiotic strains have the capacity to provide some protection against giardiasis. By combining biological and biochemical approaches, we have been able to decipher a molecular mechanism used by the probiotic strain Lactobacillus johnsonii La1 to prevent Giardia growth in vitro . We provide evidence that the supernatant of this strain contains active principle(s) not directly toxic to Giardia but able to convert non-toxic components of bile into components highly toxic to Giardia . By using bile acid profiling, these components were identified as deconjugated bile-salts. A bacterial bile-salt-hydrolase of commercial origin was able to mimic the properties of the supernatant. Mass spectrometric analysis of the bacterial supernatant identified two of the three bile-salt-hydrolases encoded in the genome of this probiotic strain. These observations document a possible mechanism by which L. johnsonii La1, by secreting, or releasing BSH-like activity(ies) in the vicinity of replicating Giardia in an environment where bile is present and abundant, can fight this parasite. This discovery has both fundamental and applied outcomes to fight giardiasis, based on local delivery of deconjugated bile salts, enzyme deconjugation of bile components, or natural or recombinant probiotic strains that secrete or release such deconjugating activities in a compartment where both bile salts and Giardia are present.

  18. Deconjugated Bile Salts Produced by Extracellular Bile-Salt Hydrolase-Like Activities from the Probiotic Lactobacillus johnsonii La1 Inhibit Giardia duodenalis In vitro Growth

    PubMed Central

    Travers, Marie-Agnès; Sow, Cissé; Zirah, Séverine; Deregnaucourt, Christiane; Chaouch, Soraya; Queiroz, Rayner M. L.; Charneau, Sébastien; Allain, Thibault; Florent, Isabelle; Grellier, Philippe

    2016-01-01

    Giardiasis, currently considered a neglected disease, is caused by the intestinal protozoan parasite Giardia duodenalis and is widely spread in human as well as domestic and wild animals. The lack of appropriate medications and the spread of resistant parasite strains urgently call for the development of novel therapeutic strategies. Host microbiota or certain probiotic strains have the capacity to provide some protection against giardiasis. By combining biological and biochemical approaches, we have been able to decipher a molecular mechanism used by the probiotic strain Lactobacillus johnsonii La1 to prevent Giardia growth in vitro. We provide evidence that the supernatant of this strain contains active principle(s) not directly toxic to Giardia but able to convert non-toxic components of bile into components highly toxic to Giardia. By using bile acid profiling, these components were identified as deconjugated bile-salts. A bacterial bile-salt-hydrolase of commercial origin was able to mimic the properties of the supernatant. Mass spectrometric analysis of the bacterial supernatant identified two of the three bile-salt-hydrolases encoded in the genome of this probiotic strain. These observations document a possible mechanism by which L. johnsonii La1, by secreting, or releasing BSH-like activity(ies) in the vicinity of replicating Giardia in an environment where bile is present and abundant, can fight this parasite. This discovery has both fundamental and applied outcomes to fight giardiasis, based on local delivery of deconjugated bile salts, enzyme deconjugation of bile components, or natural or recombinant probiotic strains that secrete or release such deconjugating activities in a compartment where both bile salts and Giardia are present. PMID:27729900

  19. Ten metre global sea-level change associated with South Atlantic Aptian salt deposition

    NASA Technical Reports Server (NTRS)

    Burke, Kevin; Sengor, A. M. Celal

    1988-01-01

    Catastrophic filling of the kind of subsea-level depression commonly formed during ocean opening and ocean closing is the only mechanism, other than glacial eustacy, capable of rapidly lowering sea level. Aptian evaporites overlying oceanic crust on both sides of the South Atlantic between the Walvis Ridge and the Niger Delta were deposited in such a basin by repeated spilling of ocean water. The final flooding of the South Atlantic north of the Walvis Ridge extracted about 14 x 10 to the 8th cu km of sea water from the world ocean and effected about 10 m of sea-level lowering. It is speculated that the middle Aptian unconformity, which is one of the more prominent world-wide unconformities, is associated with this sea-level drop of about 10 m. A corollary of this interpretation is that if the catastrophic sea-level lowerings during the Mesozoic era had amplitudes substantially greater than 10 m, then a glacial mechanism to explain them would seem inescapable although the stratigraphic record has not yet yielded any evidence of such glaciation.

  20. Effects of livestock species and stocking density on accretion rates in grazed salt marshes

    NASA Astrophysics Data System (ADS)

    Nolte, Stefanie; Esselink, Peter; Bakker, Jan P.; Smit, Christian

    2015-01-01

    Coastal ecosystems, such as salt marshes, are threatened by accelerated sea-level rise (SLR). Salt marshes deliver valuable ecosystem services such as coastal protection and the provision of habitat for a unique flora and fauna. Whether salt marshes in the Wadden Sea area are able to survive accelerated SLR depends on sufficient deposition of sediments which add to vertical marsh accretion. Accretion rate is influenced by a number of factors, and livestock grazing was recently included. Livestock grazing is assumed to reduce accretion rates in two ways: (a) directly by increasing soil compaction through trampling, and (b) indirectly by affecting the vegetation structure, which may lower the sediment deposition. For four years, we studied the impact of two livestock species (horse and cattle) at two stocking densities (0.5 and 1.0 animal ha-1) on accretion in a large-scale grazing experiment using sedimentation plates. We found lower cumulative accretion rates in high stocking densities, probably because more animals cause more compaction and create a lower canopy. Furthermore, a trend towards lower accretion rates in horse-compared to cattle-grazed treatments was found, most likely because (1) horses are more active and thus cause more compaction, and (2) herbage intake by horses is higher than by cattle, which causes a higher biomass removal and shorter canopy. During summer periods, negative accretion rates were found. When the grazing and non-grazing seasons were separated, the impact of grazing differed among years. In summer, we only found an effect of different treatments if soil moisture (precipitation) was relatively low. In winter, a sufficiently high inundation frequency was necessary to create differences between grazing treatments. We conclude that stocking densities, and to a certain extent also livestock species, affect accretion rates in salt marshes. Both stocking densities and livestock species should thus be taken into account in management

  1. Sea ice concentration temporal variability over the Weddell Sea and its relationship with tropical sea surface temperature

    USGS Publications Warehouse

    Barreira, S.; Compagnucci, R.

    2007-01-01

    Principal Components Analysis (PCA) in S-Mode (correlation between temporal series) was performed on sea ice monthly anomalies, in order to investigate which are the main temporal patterns, where are the homogenous areas located and how are they related to the sea surface temperature (SST). This analysis provides 9 patterns (4 in the Amundsen and Bellingshausen Seas and 5 in the Weddell Sea) that represent the most important temporal features that dominated sea ice concentration anomalies (SICA) variability in the Weddell, Amundsen and Bellingshausen Seas over the 1979-2000 period. Monthly Polar Gridded Sea Ice Concentrations data set derived from satellite information generated by NASA Team algorithm and acquired from the National Snow and Ice Data Center (NSIDC) were used. Monthly means SST are provided by the National Center for Environmental Prediction reanalysis. The first temporal pattern series obtained by PCA has its homogeneous area located at the external region of the Weddell and Bellingshausen Seas and Drake Passage, mostly north of 60°S. The second region is centered in 30°W and located at the southeast of the Weddell. The third area is localized east of 30°W and north of 60°S. South of the first area, the fourth PC series has its homogenous region, between 30° and 60°W. The last area is centered at 0° W and south of 60°S. Correlation charts between the five Principal Components series and SST were performed. Positive correlations over the Tropical Pacific Ocean were found for the five PCs when SST series preceded SICA PC series. The sign of the correlation could relate the occurrence of an El Niño/Southern Oscillation (ENSO) warm (cold) event with posterior positive (negative) anomalies of sea ice concentration over the Weddell Sea.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  3. Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation.

    PubMed

    Roman-Lopez, J; Piña López, Y I; Cruz-Zaragoza, E; Marcazzó, J

    2018-08-01

    In this work, the continuous wave - optically stimulated luminescence (CW-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The CW-OSL dose response of natural salt showed a linear range between 0.5Gy and 10Gy of gamma radiation of 60 Co. Samples exposed at 3Gy exhibited good repeatability with a variation coefficient of 4.6%. The CW-OSL response as function of the preheating temperature (50-250°C) was analyzed. An increase of 15% of the CW-OSL response was observed in NaCl samples during storage period of 336h. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Micromechanical processes in consolidated granular salt

    DOE PAGES

    Mills, Melissa Marie; Stormont, John C.; Bauer, Stephen J.

    2018-03-27

    Here, granular salt is likely to be used as backfill material and a seal system component within geologic salt formations serving as a repository for long-term isolation of nuclear waste. Pressure from closure of the surrounding salt formation will promote consolidation of granular salt, eventually resulting in properties comparable to native salt. Understanding dependence of consolidation processes on stress state, moisture availability, temperature, and time is important for demonstrating sealing functions and long-term repository performance. This study characterizes laboratory-consolidated granular salt by means of microstructural observations. Granular salt material from mining operations was obtained from the bedded Salado Formation hostingmore » the Waste Isolation Pilot Plant and the Avery Island salt dome. Laboratory test conditions included hydrostatic consolidation of jacketed granular salt with varying conditions of confining isochoric stress to 38 MPa, temperature to 250 °C, moisture additions of 1% by weight, time duration, and vented and non-vented states. Resultant porosities ranged between 1% and 22%. Optical and scanning electron microscopic techniques were used to ascertain consolidation mechanisms. From these investigations, samples with 1% added moisture or unvented during consolidation, exhibit clear pressure solution processes with tightly cohered grain boundaries and occluded fluid pores. Samples with only natural moisture content consolidated by a combination of brittle, cataclastic, and crystal plastic deformation. Recrystallization at 250 °C irrespective of moisture conditions was also observed. The range and variability of conditions applied in this study, combined with the techniques used to display microstructural features, are unique, and provide insight into an important area of governing deformation mechanism(s) occurring within salt repository applications.« less

  5. Micromechanical processes in consolidated granular salt

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

    Mills, Melissa Marie; Stormont, John C.; Bauer, Stephen J.

    Here, granular salt is likely to be used as backfill material and a seal system component within geologic salt formations serving as a repository for long-term isolation of nuclear waste. Pressure from closure of the surrounding salt formation will promote consolidation of granular salt, eventually resulting in properties comparable to native salt. Understanding dependence of consolidation processes on stress state, moisture availability, temperature, and time is important for demonstrating sealing functions and long-term repository performance. This study characterizes laboratory-consolidated granular salt by means of microstructural observations. Granular salt material from mining operations was obtained from the bedded Salado Formation hostingmore » the Waste Isolation Pilot Plant and the Avery Island salt dome. Laboratory test conditions included hydrostatic consolidation of jacketed granular salt with varying conditions of confining isochoric stress to 38 MPa, temperature to 250 °C, moisture additions of 1% by weight, time duration, and vented and non-vented states. Resultant porosities ranged between 1% and 22%. Optical and scanning electron microscopic techniques were used to ascertain consolidation mechanisms. From these investigations, samples with 1% added moisture or unvented during consolidation, exhibit clear pressure solution processes with tightly cohered grain boundaries and occluded fluid pores. Samples with only natural moisture content consolidated by a combination of brittle, cataclastic, and crystal plastic deformation. Recrystallization at 250 °C irrespective of moisture conditions was also observed. The range and variability of conditions applied in this study, combined with the techniques used to display microstructural features, are unique, and provide insight into an important area of governing deformation mechanism(s) occurring within salt repository applications.« less

  6. Comparison of Bottomless Lift Nets and Breder Traps for Sampling Salt-Marsh Nekton

    EPA Science Inventory

    Vegetated salt-marsh surfaces provide refuge, forage, and spawning habitat for estuarine nekton, yet are threatened by accelerating rates of sea-level rise in southern New England and elsewhere. Nekton responses to ongoing marsh surface changes need to be evaluated with effective...

  7. Study of erosion processes in the Tinto salt-marshes with remote sensing images.

    DOT National Transportation Integrated Search

    2016-01-01

    Both climatic factors and the sea wave energy are two important factors to study the tidal wetlands. One of the most important wetlands in the Southwest of the Iberian Peninsula is the Tinto salt-marshes, the third largest wetland in Andalusia after ...

  8. Salt

    USGS Publications Warehouse

    Franson, J.C.; Friend, M.

    1999-01-01

    Animals become victims of salt poisoning or toxicosis when toxic levels of sodium and chloride accumulate in the blood after they ingest large amounts of salt or, in some species, are deprived of water. For birds, salt sources may include saline water and road salt.Normally, the salt glands of birds (Fig. 47.1) excrete sodium and chloride to maintain the proper physiologic chemical balance. However, when there has been insufficient time for acclimation of the salt gland to the saline environment, or when salt gland function is compromised by exposure to certain pesticides or oil, the electrolyte balance of the blood may be upset by the excess sodium and chloride, resulting in toxicosis. Salt accumulation on the outside of the body, or salt encrustation, is a greater problem for waterbirds that use very saline waters than is salt toxicosis. Salt encrustation can lead to exertion, acute muscle degeneration, and eventual drowning during the struggle to escape entrapment.

  9. Is It Possible to Distinguish Between Dust and Salt Aerosol Over Waters with Unknown Chlorophyll Concentrations Using Spectral Remote Sensing?

    NASA Technical Reports Server (NTRS)

    Levy, R. C.; Kaufman, Y. J.

    1999-01-01

    Atmospheric aerosol has uncertain impacts on the global climate system, as well as on atmospheric and bio-geo-chemical processes of regional and local scales. EOS-MODIS is one example of a satellite sensor designed to improve understanding of the aerosols' type, size and distribution at all temporal and spatial scales. Ocean scientists also plan to use data from EOS-MODIS to assess the temporal and spatial coverage of in-water chlorophyll. MODIS is the first sensor planned to observe the combined ocean-atmosphere system with a wide spectral range (from 410 to 2200 nm). Dust aerosol and salt aerosol have similar spectral signals for wavelengths longer than 550 nm, but because dust selectively absorbs blue light, they have divergent signals in the blue wavelength regions (412 to 490 nm). Chlorophyll also selectively absorbs blue radiation, so that varying chlorophyll concentrations produces a highly varying signal in the blue regions, but less variability in the green, and almost no signal in the red to mid-infrared regions. Thus, theoretically, it may be difficult to differentiate dust and salt in the presence of unknown chlorophyll in the ocean. This study attempts to address the cases in which aerosol and chlorophyll signals can and cannot be separated. For the aerosol spectra, we use the aerosol lookup table from the operational MODIS aerosol-over-ocean algorithm, and for chlorophyll spectra, we use the SeaBAM data set (created for SeaWiFS). We compare the signals using Principal Component Analysis and attempt to retrieve both chlorophyll and aerosol properties using a variant of the operational MODIS aerosol-over-ocean algorithm. Results show that for small optical depths, less than 0.5, it is not possible to differentiate between dust and salt and to determine the chlorophyll concentration at the same time. For larger aerosol optical depths, the chlorophyll signals are comparatively insignificant, and we can hope to distinguish between dust and salt.

  10. Tudor-SN, a component of stress granules, regulates growth under salt stress by modulating GA20ox3 mRNA levels in Arabidopsis

    PubMed Central

    Yan, Chunxia; Yan, Zongyun; Wang, Yizheng; Yan, Xiaoyuan; Han, Yuzhen

    2014-01-01

    The Tudor-SN protein (TSN) is universally expressed and highly conserved in eukaryotes. In Arabidopsis, TSN is reportedly involved in stress adaptation, but the mechanism involved in this adaptation is not understood. Here, we provide evidence that TSN regulates the mRNA levels of GA20ox3, a key enzyme for gibberellin (GA) biosynthesis. The levels of GA20ox3 transcripts decreased in TSN1/TSN2 RNA interference (RNAi) transgenic lines and increased in TSN1 over-expression (OE) transgenic lines. The TSN1 OE lines displayed phenotypes that may be attributed to the overproduction of GA. No obvious defects were observed in the RNAi transgenic lines under normal conditions, but under salt stress conditions these lines displayed slower growth than wild-type (WT) plants. Two mutants of GA20ox3, ga20ox3-1 and -2, also showed slower growth under stress than WT plants. Moreover, a higher accumulation of GA20ox3 transcripts was observed under salt stress. The results of a western blot analysis indicated that higher levels of TSN1 accumulated after salt treatment than under normal conditions. Subcellular localization studies showed that TSN1 was uniformly distributed in the cytoplasm under normal conditions but accumulated in small granules and co-localized with RBP47, a marker protein for stress granules (SGs), in response to salt stress. The results of RNA immunoprecipitation experiments indicated that TSN1 bound GA20ox3 mRNA in vivo. On the basis of these findings, we conclude that TSN is a novel component of plant SGs that regulates growth under salt stress by modulating levels of GA20ox3 mRNA. PMID:25205572

  11. Discrimination of first year sea ice thickness classes from a quad-Pol SAR image.

    NASA Astrophysics Data System (ADS)

    Hudier, E. J. J.

    2016-12-01

    Several methods have been developed to relate the average scattering represented by a T3 matrix into a dominant physical mechanism. These decomposition theorems rewrite the coherency matrix as the sum of physical components. Data extracted through these methods can then be used to classify ice areas according to a similarity in the statistics regarding those components. As the ice sheet is still thin enough to rupture under compressive forces, wind and current drag forces erect ridges at the periphery of un-deformed ice plates while opening up leads in which a an ice cover quickly develops. Freeze up under colder temperatures cause the ice to retain more salt in its upper layers therefore altering radar scattering compared to older ice areas. The statistics presented in the result section were computed implementing an eigenvalue/eigenvector decomposition method coupled with a whishart classifier on RadarSat II images of a late spring sea ice. It first shows a good resolution of the different ice environments characterized as a) linear ridges, b) rubble fields, c) old un-deformed ice and, d) young (thus thinner) un-deformed ice. The alpha angle parameter is coherent with a dominant surface scattering mechanism all over the scene which is consistent with a late spring sea ice and leads us to anticipate a classification mostly linked to surface roughness and ice surface orientation (in ridges). It is thus interesting to note than un-deformed ice areas result in two separate classes. We observe that areas of ice formed later during the winter season are well identified and their limits clearly delineated. Whereas, other ice areas display a certain diversity in term of scattering mechanisms, this type of ice turned out to be an almost perfect forward scatterer. While the main factor allowing to separate this type of ice from the rest of the sea ice may be the salt content of the surface layer, it gives an indirect way to discriminate sea ice areas of different

  12. Polarimetric Signatures of Sea Ice. Part 1; Theoretical Model

    NASA Technical Reports Server (NTRS)

    Nghiem, S. V.; Kwok, R.; Yueh, S. H.; Drinkwater, M. R.

    1995-01-01

    Physical, structural, and electromagnetic properties and interrelating processes in sea ice are used to develop a composite model for polarimetric backscattering signatures of sea ice. Physical properties of sea ice constituents such as ice, brine, air, and salt are presented in terms of their effects on electromagnetic wave interactions. Sea ice structure and geometry of scatterers are related to wave propagation, attenuation, and scattering. Temperature and salinity, which are determining factors for the thermodynamic phase distribution in sea ice, are consistently used to derive both effective permittivities and polarimetric scattering coefficients. Polarimetric signatures of sea ice depend on crystal sizes and brine volumes, which are affected by ice growth rates. Desalination by brine expulsion, drainage, or other mechanisms modifies wave penetration and scattering. Sea ice signatures are further complicated by surface conditions such as rough interfaces, hummocks, snow cover, brine skim, or slush layer. Based on the same set of geophysical parameters characterizing sea ice, a composite model is developed to calculate effective permittivities and backscattering covariance matrices at microwave frequencies for interpretation of sea ice polarimetric signatures.

  13. Synthesizing long-term sea level rise projections - the MAGICC sea level model v2.0

    NASA Astrophysics Data System (ADS)

    Nauels, Alexander; Meinshausen, Malte; Mengel, Matthias; Lorbacher, Katja; Wigley, Tom M. L.

    2017-06-01

    Sea level rise (SLR) is one of the major impacts of global warming; it will threaten coastal populations, infrastructure, and ecosystems around the globe in coming centuries. Well-constrained sea level projections are needed to estimate future losses from SLR and benefits of climate protection and adaptation. Process-based models that are designed to resolve the underlying physics of individual sea level drivers form the basis for state-of-the-art sea level projections. However, associated computational costs allow for only a small number of simulations based on selected scenarios that often vary for different sea level components. This approach does not sufficiently support sea level impact science and climate policy analysis, which require a sea level projection methodology that is flexible with regard to the climate scenario yet comprehensive and bound by the physical constraints provided by process-based models. To fill this gap, we present a sea level model that emulates global-mean long-term process-based model projections for all major sea level components. Thermal expansion estimates are calculated with the hemispheric upwelling-diffusion ocean component of the simple carbon-cycle climate model MAGICC, which has been updated and calibrated against CMIP5 ocean temperature profiles and thermal expansion data. Global glacier contributions are estimated based on a parameterization constrained by transient and equilibrium process-based projections. Sea level contribution estimates for Greenland and Antarctic ice sheets are derived from surface mass balance and solid ice discharge parameterizations reproducing current output from ice-sheet models. The land water storage component replicates recent hydrological modeling results. For 2100, we project 0.35 to 0.56 m (66 % range) total SLR based on the RCP2.6 scenario, 0.45 to 0.67 m for RCP4.5, 0.46 to 0.71 m for RCP6.0, and 0.65 to 0.97 m for RCP8.5. These projections lie within the range of the latest IPCC SLR

  14. Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

    PubMed

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-08-02

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  15. Deep-Sea Biodiversity in the Mediterranean Sea: The Known, the Unknown, and the Unknowable

    PubMed Central

    Danovaro, Roberto; Company, Joan Batista; Corinaldesi, Cinzia; D'Onghia, Gianfranco; Galil, Bella; Gambi, Cristina; Gooday, Andrew J.; Lampadariou, Nikolaos; Luna, Gian Marco; Morigi, Caterina; Olu, Karine; Polymenakou, Paraskevi; Ramirez-Llodra, Eva; Sabbatini, Anna; Sardà, Francesc; Sibuet, Myriam; Tselepides, Anastasios

    2010-01-01

    Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna) in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth), including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes) reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components investigated

  16. Atmospheric components of the surface energy budget over young sea ice: Results from the N-ICE2015 campaign

    NASA Astrophysics Data System (ADS)

    Walden, Von P.; Hudson, Stephen R.; Cohen, Lana; Murphy, Sarah Y.; Granskog, Mats A.

    2017-08-01

    The Norwegian young sea ice campaign obtained the first measurements of the surface energy budget over young, thin Arctic sea ice through the seasonal transition from winter to summer. This campaign was the first of its kind in the North Atlantic sector of the Arctic. This study describes the atmospheric and surface conditions and the radiative and turbulent heat fluxes over young, thin sea ice. The shortwave albedo of the snow surface ranged from about 0.85 in winter to 0.72-0.80 in early summer. The near-surface atmosphere was typically stable in winter, unstable in spring, and near neutral in summer once the surface skin temperature reached 0°C. The daily average radiative and turbulent heat fluxes typically sum to negative values (-40 to 0 W m-2) in winter but then transition toward positive values of up to nearly +60 W m-2 as solar radiation contributes significantly to the surface energy budget. The sensible heat flux typically ranges from +20-30 W m-2 in winter (into the surface) to negative values between 0 and -20 W m-2 in spring and summer. A winter case study highlights the significant effect of synoptic storms and demonstrates the complex interplay of wind, clouds, and heat and moisture advection on the surface energy components over sea ice in winter. A spring case study contrasts a rare period of 24 h of clear-sky conditions with typical overcast conditions and highlights the impact of clouds on the surface radiation and energy budgets over young, thin sea ice.

  17. Salt enrichment of municipal sewage: New prevention approaches in Israel

    NASA Astrophysics Data System (ADS)

    Weber, Baruch; Avnimelech, Yoram; Juanico, Marcelo

    1996-07-01

    Wastewater irrigation is an environmentally sound wastewater disposal practice, but sewage is more saline than the supplied fresh water and the salts are recycled together with the water. Salts have negative environmental effects on crops, soils, and groundwater. There are no inexpensive ways to remove the salts once they enter sewage, and the prevention of sewage salt enrichment is the most immediately available solution. The body of initiatives presently structured by the Ministry of the Environment of Israel are herein described, with the aim to contribute to the search for a long-term solution of salinity problems in arid countries. The new initiatives are based on: (1) search for new technologies to reduce salt consumption and discharge into sewage; (2) different technologies to cope with different situations; (3) raising the awareness of the public and industry on the environmental implications of salinity pollution; and (4) an elastic legal approach expressed through new state-of-the-art regulations. The main contributor to the salinity of sewage in Israel is the watersoftening process followed by the meat koshering process. Some of the adopted technical solutions are: the discharge of the brine into the sea, the substitution of sodium by potassium salts in the ion-exchangers, the construction of centralized systems for the supply of soft water in industrial areas, the precipitation of Ca and Mg in the effluents from ion-exchangers and recycling of the NaCI solution, a reduction of the discharge of salts by the meat koshering process, and new membrane technology for salt recovery.

  18. Seasonal Variability of Salt Marsh Foraminifera at the Narrow River, Rhode Island, USA

    NASA Astrophysics Data System (ADS)

    Amelse, C. M.; Engelhart, S. E.; Halavik, B.; Kemp, A.

    2016-12-01

    Salt-marsh foraminifera are commonly used as proxies for producing high-resolution relative sea-level reconstructions over the Holocene. These reconstructions are based on the analogy between modern and fossil assemblages of foraminifera, in which modern assemblages were characterized using surface sediment samples collected on a single day. This approach implicitly assumes that instantaneous sampling of modern salt-marsh foraminifera is adequate to characterize the relationship between foraminiferal assemblages and tidal elevation. However, foraminiferal populations may vary during a year in response to seasonal changes, which may affect the reliability of relative sea-level reconstructions. The effect of seasonality on salt marsh foraminiferal populations has been studied in the United Kingdom as well as on the Pacific coast of the USA, but is absent on the Atlantic coast of the USA. To address this, we investigated the role of seasonality on foraminiferal distributions from a salt marsh environment at the Narrow River (Rhode Island, USA). We analyzed living and dead foraminiferal species from 48 samples through a full year during all four seasons. Common species included Trochammina inflata, Jadammina macrescens, Tiphotrocha comprimata, Miliammina fusca, Reophax spp., and Haplophragmoides spp. Other species included Siphotrochammina lobata, Arenoparella mexicana, Textularia spp., Ammobaculites spp., and Eggerella advena. Low marsh samples were dominated by Miliammina fusca and Reophax spp., while high marsh samples are identified by high abundances of Haplophragmoides spp. Statistical analyses of these samples enables us to identify the influence of seasonality on modern foraminiferal distributions.

  19. Sea Level Rise in Santa Clara County

    NASA Technical Reports Server (NTRS)

    Milesi, Cristina

    2005-01-01

    Presentation by Cristina Milesi, First Author, NASA Ames Research Center, Moffett Field, CA at the "Meeting the Challenge of Sea Level Rise in Santa Clara County" on June 19, 2005 Santa Clara County, bordering with the southern portion of the San Francisco Bay, is highly vulnerable to flooding and to sea level rise (SLR). In this presentation, the latest sea level rise projections for the San Francisco Bay will be discussed in the context of extreme water height frequency and extent of flooding vulnerability. I will also present preliminary estimations of levee requirements and possible mitigation through tidal restoration of existing salt ponds. The examples will draw mainly from the work done by the NASA Climate Adaptation Science Investigators at NASA Ames.

  20. Rheology of Dead Sea shampoo containing the antidandruff climbazole.

    PubMed

    Abu-Jdayil, B; Mohameed, H A

    2004-12-01

    In this study, the effect of the antidandruff climbazole on the rheology of hair shampoo containing Dead Sea (DS) salt was investigated. The presence of either DS salt or the climbazole led to increase in the shampoo viscosity. An optimum concentration was found where the viscosity of shampoo was maximum. In the absence of DS salt, the viscosity of hair shampoo increased with increasing the climbazole concentration to reach a maximum value at 1.0 wt%. Further addition of climbazole decreased the viscosity of shampoo. Adjusting the pH of the shampoo at 5.5 and 5.0 shifted the optimum climbazole concentration (corresponds to maximum viscosity) to 0.8 wt% and led to increase in the viscosity of shampoo. On the other hand, the addition of climbazole to the shampoo containing DS salt resulted in a decrease in shampoo viscosity. This decrease of shampoo viscosity became more pronounced with increasing the climbazole and/or DS salt concentrations. By controlling the pH of shampoo, an optimum formula of shampoo comprising both climbazole and DS salt and having maximum viscosity was obtained.

  1. Is Our Food Future in the Sea? A Marine Education Infusion Unit on Aquaculture and Sea Farming. Revised Edition.

    ERIC Educational Resources Information Center

    Butzow, John W.; And Others

    Designed to introduce middle and junior high school teachers and students to aquaculture and sea farming, the information and lessons in this unit focus on the biology, economics, and gastronomics of these fresh and salt water activities. An extensive section containing teacher background information describes how to farm shellfish and finfish,…

  2. Understanding the Spatio-Temporal Dynamics of Denitrification in an Oregon Salt Marsh

    NASA Astrophysics Data System (ADS)

    Moon, J. B.; Stecher, H. A.; DeWitt, T.; Nahlik, A.; Fennessy, M. S.; Michael, L.; Regutti, R.; Mckane, R.; Marois, D.; Naithani, K. J.

    2016-12-01

    Salt marshes are highly susceptible to a range of climate change effects (e.g., sea-level rise, salinity changes, storm severity, shifts in vegetation across watershed). It is unclear how these effects will alter the spatial and temporal dynamics of denitrification, a potential pathway of nitrogen interception and removal from adjacent estuaries. Our overall objective is to determine whether salt marshes in the Pacific Northwest act as sources or sinks of nitrogen to estuaries, and to be able to predict changes in these dynamics under future climate scenarios. We have built a probabilistic denitrification model based on observations from a salt marsh in the Yaquina Estuary (Newport, Oregon). We observed a non-linear relationship between denitrification rates and distance to the marsh-upland interface and soil nitrate concentrations, which are indicators of nitrate delivery flow paths from upslope red alder. We also modeled spatial variability in oxygen availability as a function of elevation, which affects inundation period, and distance to channel, which affects the saturation period through the dewatering rate. Simulations suggest denitrification "hot spots" occur in mid-marsh locations, where both nitrate availability and inundation periods are maximized. Once marsh accretion is outpaced, sea level rise will likely reduce salt marsh area due to steep adjacent uplands that limit marsh retreat, and increase inundation duration near the marsh-upland interface. Expansion of red alder cover is concurrently expected to increase nitrate availability to downslope ecosystems. Taking these effects together, our future scenario simulations suggest a movement of "hot-spots" towards the marsh-upland boundary.

  3. Coastal vertebrate exposure to predicted habitat changes due to sea level rise

    USGS Publications Warehouse

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel; Moore, Clinton; Cooper, Robert J.

    2015-01-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species’ fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species’ foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  4. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise.

    PubMed

    Hunter, Elizabeth A; Nibbelink, Nathan P; Alexander, Clark R; Barrett, Kyle; Mengak, Lara F; Guy, Rachel K; Moore, Clinton T; Cooper, Robert J

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  5. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel K.; Moore, Clinton T.; Cooper, Robert J.

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species ( n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  6. Salt movements and faulting of the overburden - can numerical modeling predict the fault patterns above salt structures?

    NASA Astrophysics Data System (ADS)

    Clausen, O. R.; Egholm, D. L.; Wesenberg, R.

    2012-04-01

    Salt deformation has been the topic of numerous studies through the 20th century and up until present because of the close relation between commercial hydrocarbons and salt structure provinces of the world (Hudec & Jackson, 2007). The fault distribution in sediments above salt structures influences among other things the productivity due to the segmentation of the reservoir (Stewart 2006). 3D seismic data above salt structures can map such fault patterns in great detail and studies have shown that a variety of fault patterns exists. Yet, most patterns fall between two end members: concentric and radiating fault patterns. Here we use a modified version of the numerical spring-slider model introduced by Malthe-Sørenssen et al.(1998a) for simulating the emergence of small scale faults and fractures above a rising salt structure. The three-dimensional spring-slider model enables us to control the rheology of the deforming overburden, the mechanical coupling between the overburden and the underlying salt, as well as the kinematics of the moving salt structure. In this presentation, we demonstrate how the horizontal component on the salt motion influences the fracture patterns within the overburden. The modeling shows that purely vertical movement of the salt introduces a mesh of concentric normal faults in the overburden, and that the frequency of radiating faults increases with the amount of lateral movements across the salt-overburden interface. The two end-member fault patterns (concentric vs. radiating) can thus be linked to two different styles of salt movement: i) the vertical rising of a salt indenter and ii) the inflation of a 'salt-balloon' beneath the deformed strata. The results are in accordance with published analogue and theoretical models, as well as natural systems, and the model may - when used appropriately - provide new insight into how the internal dynamics of the salt in a structure controls the generation of fault patterns above the structure. The

  7. [Composition and source of atmosphere aerosol water soluble ions over the East China Sea in winter].

    PubMed

    He, Yu-Hui; Yang, Gui-Peng; Zhang, Hong-Hai

    2011-08-01

    With the ion chromatographic method, the water-soluble ion concentrations of Cl(-), NO3(-), SO4(2-) , CH3SO3(-) (MSA), Na+, K+, NH4+, Mg2+ and Ca2+ in the atmospheric aerosol over the East China Sea in winter 2009 was determined and the sources of these ions was investigated through correlation analysis by SPSS (statistical package for social sciences) software. The results indicated that the concentrations of secondary ions in aerosol were the highest (non-sea-salt sulfates nss-SO4(2-), NO3(-), NH4+), accounting for 78.4% of total determining ions. The calculation results of equivalent concentration of anions and cations showed that the acid ions of aerosol were neutralized inadequately. The stoichiometry of NH4+ in different compounds showed that NH4HSO4 was the main binding form of NH4+ and SO4(2-) in the aerosol. The concentration of methanesulfonic acid (MSA) was low, and the average value was (0.0088 +/- 0.0037) microg x m(-3). According to calculation, the contribution of sea-salt sulfates was 4.5% to total sulfates, and that of biogenous sulfates was 1.4% to non-sea-salt sulfate (nss-SO4(2-)), showing that human input was the main source of sulfates in aerosol over the East China Sea. In addition, nss-SO4(2-)/NO3(-) in the aerosol was 1.08, reflecting that China's energy structure adjustment played an important role in recent years.

  8. Trends and interannual variability of mass and steric sea level in the Tropical Asian Seas

    NASA Astrophysics Data System (ADS)

    Kleinherenbrink, Marcel; Riva, Riccardo; Frederikse, Thomas; Merrifield, Mark; Wada, Yoshihide

    2017-08-01

    The mass and steric components of sea level changes have been separated in the Tropical Asian Seas (TAS) using a statistically optimal combination of Jason satellite altimetry, GRACE satellite gravimetry, and ocean reanalyses. Using observational uncertainties, statistically optimally weighted time series for both components have been obtained in four regions within the TAS over the period January 2005 to December 2012. The mass and steric sea level variability is regressed with the first two principal components (PC1&2) of Pacific equatorial wind stress and the Dipole Mode Index (DMI). Sea level in the South China Sea is not affected by any of the indices. Steric variability in the TAS is largest in the deep Banda and Celebes seas and is affected by both PCs and the DMI. Mass variability is largest on the continental shelves, which is primarily controlled by PC1. We argue that a water flux from the Western Tropical Pacific Ocean is the cause for mass variability in the TAS. The steric trends are about 2 mm yr-1 larger than the mass trends in the TAS. A significant part of the mass trend can be explained by the aforementioned indices and the nodal cycle. Trends obtained from fingerprints of mass redistribution are statistically equal to mass trends after subtracting the nodal cycle and the indices. Ultimately, the effect of omitting the TAS in global sea level budgets is estimated to be 0.3 mm yr-1.

  9. Modelling the baroclinic circulation with tidal components in the Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Guarnieri, A.; Pinardi, N.; Oddo, P.; Bortoluzzi, G.; Ravaioli, M.

    2012-04-01

    The impact of tides in the circulation of the Adriatic sea has been investigated by means of a nested baroclinic numerical ocean model. Tides have been introduced using a modified Flather boundary condition at the open side of the domain. The results show that tidal amplitudes and phases are reproduced correctly by the baroclinic model and the tidal harmonic constants errors are comparable with those resulting from the most consolidated barotropic models. Numerical experiments were conducted to estimate and assess the impact of (i) the modified Flather lateral boundary condition, (ii) the tides on temperature, salinity and stratification structures in the basin, and (iii) the tides on mixing and circulation in general. Tides induce a different momentum advective component in the basin which in turn produces a different distribution of water masses in the basin. Tides impact on mixing and stratification in the Po river region (north-western Adriatic) and induce fluctuations of salinity and temperature on semidiurnal frequencies in all seasons for the first and only winter for the second.

  10. Source apportionment of particulate pollutants in the atmosphere over the Northern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Wang, L.; Qi, J. H.; Shi, J. H.; Chen, X. J.; Gao, H. W.

    2013-05-01

    Atmospheric aerosol samples were collected over the Northern Yellow Sea of China during the years of 2006 and 2007, in which the Total Carbon (TC), Cu, Pb, Cd, V, Zn, Fe, Al, Na+, Ca2+, Mg2+, NH4+, NO3-, SO42-, Cl-, and K+ were measured. The principle components analysis (PCA) and positive matrix factorization (PMF) receptor models were used to identify the sources of particulate matter. The results indicated that seven factors contributed to the atmospheric particles over the Northern Yellow Sea, i.e., two secondary aerosols (sulfate and nitrate), soil dust, biomass burning, oil combustion, sea salt, and metal smelting. When the whole database was considered, secondary aerosol formation contributed the most to the atmospheric particle content, followed by soil dust. Secondary aerosols and soil dust consisted of 65.65% of the total mass of particulate matter. The results also suggested that the aerosols over the North Yellow Sea were heavily influenced by ship emission over the local sea area and by continental agricultural activities in the northern China, indicating by high loading of V in oil combustion and high loading of K+ in biomass burning. However, the contribution of each factor varied greatly over the different seasons. In spring and autumn, soil dust and biomass burning were the dominant factors. In summer, heavy oil combustion contributed the most among these factors. In winter, secondary aerosols were major sources. Backward trajectories analysis indicated the 66% of air mass in summer was from the ocean, while the air mass is mainly from the continent in other seasons.

  11. Optimization for Reduced-Fat / Low-NaCl Meat Emulsion Systems with Sea Mustard (Undaria pinnatifida) and Phosphate

    PubMed Central

    Kim, Cheon-Jei; Hwang, Ko-Eun; Song, Dong-Heon; Jeong, Tae-Jun; Kim, Hyun-Wook

    2015-01-01

    The effects of reducing fat levels from 30% to 20% and salt concentrations from 1.5% to 1.0% by partially substituting incorporated phosphate and sea mustard were investigated based on physicochemical properties of reduced-fat / low-NaCl meat emulsion systems. Cooking loss and emulsion stability, hardness, springiness, and cohesiveness for reduced-fat / low-NaCl meat emulsion systems with 20% pork back fat and 1.2% sodium chloride samples with incorporation of phosphate and sea mustard were similar to the control with 30% pork back fat and 1.5% sodium chloride. Results showed that reduced-fat / low-NaCl meat emulsion system samples containing phosphate and sea mustard had higher apparent viscosity. The results of this study show that the incorporation of phosphate and sea mustard in the formulation will successfully reduce fat and salt in the final meat products. PMID:26761874

  12. Tritium in the western Mediterranean Sea during 1981 Phycemed cruise

    NASA Astrophysics Data System (ADS)

    Andrie, Chantal; Merlivat, Liliane

    1988-02-01

    We report on simultaneous hydrological and tritium data taken in the western Mediterranean Sea during April 1981 and which implement our knowledge of the spatial and temporal variability of the convection process occurring in the Northern Basin (Gulf of Lion, Ligurian Sea). The renewal time of the deep waters in the Medoc area is calculated to be 11 ± 2 years using a box-model assymption. An important local phenomenon of "cascading" off the Ebro River near the Spanish coast is, noticeable by the use of tritium data. In the Sardinia Straits area tritium data indicate very active mixing between 100 and 500 m depth. The tritium subsurface maxima in Sardinia Straits suggests the influence of not only the Levantine Intermediate Water (LIW) but also an important shallower component. In waters deeper than 500m, an active mixing occurs between the deep water and the LIW via an intermediate water mass from the Tyrrhenian Sea by "salt-fingering". Assuming a two end-member mixing. We determine the deep tritium content in the Sardinia Channel to be 1.8 TU. For comparison, the deep tritium content of the Northern Basin is equal to 1.3 TU. Tritium data relative to the Alboran Sea show that a layer of high tritium content persists all along its path from Sardifia to Gibraltar on a density surface shallower than the intermediate water. The homogeneity of the deep tritium concentrations between 1200 m depth and the bottom corroborate the upward "pumping" and westward circulation of deep waters along the continental slope of the North African Shelf. From the data measured in the Sardinia Straits and in the Alboran Sea, and upper limit of the deep advection rate of the order of 0.5 cm s-1 is estimated.

  13. Assessing the Effects of Sea Level Rise on Plum Island Estuary Marshes Using a Hydrodynamic-marsh Modeling Tool

    NASA Astrophysics Data System (ADS)

    Demissie, H. K.; Bilskie, M. V.; Hagen, S. C.; Morris, J. T.; Alizad, K.

    2015-12-01

    Sea level rise (SLR) can significantly impact both human and ecological habitats in coastal and inland regions. Studies show that coastal estuaries and marsh systems are at the risk of losing their productivity under increasing rates of SLR (Donnelly and Bertness, 2001; Warren and Niering, 1993). The integrated hydrodynamic-marsh model (Hagen et al., 2013 & Alizad et al., 2015) uses a set of parameters and conditions to simulate tidal flow through the salt marsh of Plum Island Estuary, Massachusetts. The hydrodynamic model computes mean high water (MHW) and mean low water (MLW) and is coupled to the zero-dimensional Marsh Equilibrium Model (Morris et al. 2002) to estimate changes in biomass productivity and accretion. The coupled hydrodynamic-marsh model was used to examine the effects of different scenarios of SLR (Parris et al., 2012) on salt marsh productivity for the year 2100 in the Plum Island Estuary. In this particular study, responses of salt marsh production for different scenarios of SLR were compared. The study shows higher productivity of salt marsh under a low SLR scenario and lower productivity under the higher SLR. The study also demonstrates the migration of salt marshes under higher SLR scenarios. References: Alizad, K., S. C. Hagen, Morris, J.T., Bacopoulos, P., Bilskie, M.V., and John, F.W. 2015. A coupled, two-dimensional hydrodynamic-marsh model with biological feedback. Limnology and Oceanography, In review. Donnelly, J.P., and M.D. Bertness. 2001. Rapid shoreward encroachment of salt marsh cordgrass in response to accelerated sea-level rise. Proceedings of the National Academy of Sciences 98: 14218-14223.Hagen, S.C., J.T. Morris, P. Bacopoulos, and J. Weishampel. 2013. Sea-Level Rise Impact on a Salt Marsh System of the Lower St. Johns River. ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 139, No. 2, March/April 2013, pp. 118-125.Morris, J.T., P.V. Sundareshwar, C.T. Nietch, B. Kjerfve, and D.R. Cahoon. 2002. Responses

  14. Climate related sea-level variations over the past two millennia

    PubMed Central

    Kemp, Andrew C.; Horton, Benjamin P.; Donnelly, Jeffrey P.; Mann, Michael E.; Vermeer, Martin; Rahmstorf, Stefan

    2011-01-01

    We present new sea-level reconstructions for the past 2100 y based on salt-marsh sedimentary sequences from the US Atlantic coast. The data from North Carolina reveal four phases of persistent sea-level change after correction for glacial isostatic adjustment. Sea level was stable from at least BC 100 until AD 950. Sea level then increased for 400 y at a rate of 0.6 mm/y, followed by a further period of stable, or slightly falling, sea level that persisted until the late 19th century. Since then, sea level has risen at an average rate of 2.1 mm/y, representing the steepest century-scale increase of the past two millennia. This rate was initiated between AD 1865 and 1892. Using an extended semiempirical modeling approach, we show that these sea-level changes are consistent with global temperature for at least the past millennium. PMID:21690367

  15. Potential Evaporite Biomarkers from the Dead Sea

    NASA Technical Reports Server (NTRS)

    Morris, Penny A.; Wentworth, Susan J.; Thomas-Keprta, Kathie; Allen, Carlton C.; McKay, David S.

    2001-01-01

    The Dead Sea is located on the northern branch of the African-Levant Rift systems. The rift system, according to one model, was formed by a series of strike slip faults, initially forming approximately two million years ago. The Dead Sea is an evaporite basin that receives freshwater from springs and from the Jordan River. The Dead Sea is different from other evaporite basins, such as the Great Salt Lake, in that it possesses high concentrations of magnesium and has an average pH of 6.1. The dominant cation in the Great Salt Lake is sodium, and the pH is 7.7. Calcium concentrations are also higher in the Dead Sea than in the Great Salt Lake. Both basins are similar in that the dominant anion is chlorine and the salinity levels are approximately 20 %. Other common cations that have been identified from the waters of the Dead Sea and the Great Salt Lake include sodium and potassium. A variety of Archea, Bacteria, and a single genus of a green algal, Dunaliella, has been described from the Dead Sea. Earlier studies concentrated on microbial identification and analysis of their unique physiology that allows them to survive in this type of extreme environment. Potential microbial fossilization processes, microbial fossils, and the metallic ions associated with fossilization have not been studied thoroughly. The present study is restricted to identifying probable microbial morphologies and associated metallic ions. XRD (X Ray Diffraction) analysis indicates the presence of halite, quartz, and orthoclase feldspar. In addition to these minerals, other workers have reported potassium chloride, magnesium bromide, magnesium chloride, calcium chloride, and calcium sulfate. Halite, calcium sulfate, and orthoclase were examined in this report for the presence of microbes, microbially induced deposits or microbial alteration. Neither the gypsum nor the orthoclase surfaces possesses any obvious indications of microbial life or fossilization. The sand-sized orthoclase particles are

  16. Deliquescence Measurements of Potassium Salts

    NASA Astrophysics Data System (ADS)

    Freney, E. J.; Martin, S. T.; Buseck, P. R.

    2007-12-01

    Potassium compounds such as KCl, K2SO4, and KNO3 are salts resulting from biomass burning. With time the number of aerosol particles containing KCl decreases, and the number of particles containing KNO3 and K2SO4 increases. The transformation of KCl to K2SO4 and KNO3 with aging of the smoke could lead to changes in the hygroscopic properties of the smoke particles and thus their cloud-nucleating potential. Similar reaction mechanisms are likely to be involved in the conversion of KCl in smoke particles as occur for NaCl in sea salt. Little experimental work has been published on the hygroscopic properties of potassium salts because of their high DRH values. Instruments that are commonly used to measure hygroscopic properties such as differential mobility analyzers or electrodynamic balances do not operate accurately at RH > 90%. Here we present data describing the hygroscopic properties of several fresh potassium salts, as well as laboratory generated mixed salts, using transmission and scanning electron microscopes (TEM and SEM). Both microscopes have environmental chambers that enable study of the interaction of water with single particles. DRH values for KCl, KNO3 and K2SO4 were found to be 86%, 92%, and 97%, respectively. KNO3 particles formed by atomization appear rounded and undergo continuous hygroscopic growth without a distinct deliquescence point. Similar results have been published for NaNO3. In contrast, when KNO3 powder is ground in a mortar and pestle and placed in the SEM, the grains appear euhedral and have a DRH at 92%, in agreement with literature values. It appears that KNO3 particles formed by atomization will readily take up water at RH values below their DRH. Our results indicate that the hygroscopic properties of KNO3 particles are influenced by their histories. Water associated with aged or mixed particles at RH's less than their DRH will affect how these particles uptake and react with gases.

  17. The regional structure of the Red Sea Rift revised

    NASA Astrophysics Data System (ADS)

    Augustin, Nico; van der Zwan, Froukje M.; Devey, Colin W.; Brandsdóttir, Bryndís

    2017-04-01

    The Red Sea Rift has, for decades, been considered a text book example of how young ocean basins form and mature. Nevertheless, most studies of submarine processes in the Red Sea were previously based on sparse data (mostly obtained between the late 1960's and 1980's) collected at very low resolution. This low resolution, combined with large gaps between individual datasets, required large interpolations when developing geological models. Thus, these models generally considered the Red Sea Rift a special case of young ocean basement formation, dividing it from North to South into three zones: a continental thinning zone, a "transition zone" and a fully developed spreading zone. All these zones are imagined, in most of the models, to be separated by large transform faults, potentially starting and ending on the African and Arabian continental shields. However, no consensus between models e.g. about the locations (or even the existence) of major faults, the nature of the transition zone or the extent of oceanic crust in the Red Sea Rift has been reached. Recently, high resolution bathymetry revealed detailed seafloor morphology as never seen before from the Red Sea, very comparable to other (ultra)slow spreading mid-ocean ridges such as the Gakkel Ridge, the Mid-Atlantic Ridge and SW-Indian Ridge, changing the overall picture of the Red Sea significantly. New discoveries about the extent, movement and physical properties of submarine salt deposits led to the Red Sea Rift being linked to the young Aptian-age South Atlantic. Extensive crosscutting transform faults are not evident in the modern bathymetry data, neither in teleseismic nor vertical gravity gradient data and comparisons to Gakkel Ridge and the SW-Indian Ridge suggest that the Red Sea is much simpler in terms of structural geology than was previously thought. Complicated tectonic models do not appear necessary and there appears to be large areas of oceanic crust under the Red Sea salt blankets. Based on

  18. Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea

    NASA Astrophysics Data System (ADS)

    Pemberton, Per; Löptien, Ulrike; Hordoir, Robinson; Höglund, Anders; Schimanke, Semjon; Axell, Lars; Haapala, Jari

    2017-08-01

    The Baltic Sea is a seasonally ice-covered marginal sea in northern Europe with intense wintertime ship traffic and a sensitive ecosystem. Understanding and modeling the evolution of the sea-ice pack is important for climate effect studies and forecasting purposes. Here we present and evaluate the sea-ice component of a new NEMO-LIM3.6-based ocean-sea-ice setup for the North Sea and Baltic Sea region (NEMO-Nordic). The setup includes a new depth-based fast-ice parametrization for the Baltic Sea. The evaluation focuses on long-term statistics, from a 45-year long hindcast, although short-term daily performance is also briefly evaluated. We show that NEMO-Nordic is well suited for simulating the mean sea-ice extent, concentration, and thickness as compared to the best available observational data set. The variability of the annual maximum Baltic Sea ice extent is well in line with the observations, but the 1961-2006 trend is underestimated. Capturing the correct ice thickness distribution is more challenging. Based on the simulated ice thickness distribution we estimate the undeformed and deformed ice thickness and concentration in the Baltic Sea, which compares reasonably well with observations.

  19. Technical Feasibility Study of an Effective Low-Toxicity Obscurant Material

    DTIC Science & Technology

    2012-08-01

    2. REPORT TYPE FINAL 3. DATES COVERED (From - To) 04/2011 – 07/2012 4 . TITLE AND SUBTITLE 5a. CONTRACT NUMBER W912HQ-11-C-0034 Technical...6 4 Work Package 3 – Laboratory-scale tests...chemistry to sea-salt aerosol. 4 The major component of sea-salt is sodium chloride. Sodium chloride can be very simply generated by the combustion

  20. Accelerated life assessment of coating on the radar structure components in coastal environment.

    PubMed

    Liu, Zhe; Ming, ZhiMao

    2016-07-04

    This paper aimed to build an accelerated life test scheme and carry out quantitative analysis between accelerated life test in the laboratory and actual service for the coating composed of epoxy primer and polyurethane paint on structure components of some kind of radar served in the coastal environment of South China Sea. The accelerated life test scheme was built based on the service environment and failure analysis of the coating. The quantitative analysis between accelerated life test and actual service was conducted by comparing the gloss loss, discoloration, chalking, blistering, cracking and electrochemical impedance spectroscopy of the coating. The main factors leading to the coating failure were ultraviolet radiation, temperature, moisture, salt fog and loads, the accelerated life test included ultraviolet radiation, damp heat, thermal shock, fatigue and salt spray. The quantitative relationship was that one cycle of the accelerated life test was equal to actual service for one year. It was established that one cycle of the accelerated life test was equal to actual service for one year. It provided a precise way to predict actual service life of newly developed coatings for the manufacturer.

  1. Higher salt preference in heart failure patients.

    PubMed

    de Souza, Juli Thomaz; Matsubara, Luiz S; Menani, José Vanderlei; Matsubara, Beatriz B; Johnson, Alan Kim; De Gobbi, Juliana Irani Fratucci

    2012-02-01

    Heart failure (HF) is a complex syndrome that involves changes in behavioral, neural and endocrine regulatory systems. Dietary salt restriction along with pharmacotherapy is considered an essential component in the effective management of symptomatic HF patients. However, it is well recognized that HF patients typically have great difficulty in restricting sodium intake. We hypothesized that under HF altered activity in systems that normally function to regulate body fluid and cardiovascular homeostasis could produce an increased preference for the taste of salt. Therefore, this study was conducted to evaluate the perceived palatability (defined as salt preference) of food with different concentrations of added salt in compensated chronically medicated HF patients and comparable control subjects. Healthy volunteers (n=25) and medicated, clinically stable HF patients (n=38, NYHA functional class II or III) were interviewed and given an evaluation to assess their preferences for different amounts of saltiness. Three salt concentrations (0.58, 0.82, and 1.16 g/100 g) of bean soup were presented to the subjects. Salt preference for each concentration was quantified using an adjective scale (unpleasant, fair or delicious). Healthy volunteers preferred the soup with medium salt concentration (p=0.042), HF patients disliked the low concentration (p<0.001) and preferred the high concentration of salted bean soup (p<0.001). When compared to healthy volunteers, HF patients demonstrated a significantly greater preference for the soup with a high salt concentration (p=0.038). It is concluded that medicated, compensated patients under chronic treatment for HF have an increased preference for salt. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Contrasting Decadal-Scale Changes in Elevation and Vegetation in Two Long Island Sound Salt Marshes

    EPA Science Inventory

    Northeastern US salt marshes face multiple co-stressors, including accelerating rates of relative sea level rise (RSLR), elevated nutrient inputs, and low sediment supplies. In order to evaluate how marsh surface elevations respond to such factors, we used surface elevation table...

  3. Effects of enhanced hydrological connectivity on Mediterranean salt marsh fish assemblages with emphasis on the endangered Spanish toothcarp (Aphanius iberus).

    PubMed

    Prado, Patricia; Alcaraz, Carles; Jornet, Lluis; Caiola, Nuno; Ibáñez, Carles

    2017-01-01

    The hydrological connectivity between the salt marsh and the sea was partially restored in a Mediterranean wetland containing isolated ponds resulting from former salt extraction and aquaculture activities. A preliminary assessment provided evidence that ponds farther from the sea hosted very large numbers of the endangered Spanish toothcarp, Aphanius iberus , suggesting that individuals had been trapped and consequently reach unnaturally high densities. In order to achieve both habitat rehabilitation and toothcarp conservation, efforts were made to create a gradient of hydrologically connected areas, including isolated fish reservoirs, semi-isolated, and connected salt marsh-sea areas that could allow migratory movements of fish and provide some protection for A. iberus . The fish community was monitored prior to, and for three years after rehabilitation. Results showed an increase in the number of fish species within semi-isolated areas (Zone A), whereas areas adjacent to the sea (Zone B) increased the number of marine species and decreased that of estuarine species (ES). Yet overall differences in fish assemblages were much higher between zones than among study years. Generalized linear models (GLMs) evidenced that distance to the sea was the most important variable explaining the local diversity of the fish community after restoration, with occasional influence of other factors such as temperature, and depth. The abundance of A. iberus was consistently higher in semi-isolated areas at greater distances from the sea, but a decline occurred in both zones and in isolated reservoir ponds after restoration efforts, which may be attributable to interannual differences in recruitment success and, to a lesser extent, to dispersal into adjacent habitats. A negative effect of restoration works on fish population cannot be excluded, but the final outcome of the intervention likely needs a longer period.

  4. Seasonal Variability of Salt Transports in the Northern Indian Ocean

    NASA Astrophysics Data System (ADS)

    D'Addezio, J. M.; Bulusu, S.

    2016-02-01

    Due to limited observational data in the Indian Ocean compared to other regions of the global ocean, past work on the Northern Indian Ocean (NIO) has relied heavily upon model analysis to study the variability of regional salinity advection caused by the monsoon seasons. With the launch of the Soil Moisture and Ocean Salinity (SMOS) satellite in 2009 and the Aquarius SAC-D mission in 2011 (ended on June 7, 2011), remotely sensed, synoptic scale sea surface salinity (SSS) data is now readily available to study this dynamic region. The new observational data has allowed us to revisit the region to analyze seasonal variability of salinity advection in the NIO using several modeled products, the Aquarius and SMOS satellites, and Argo floats data. The model simulations include the Consortium for Estimating the Circulation and Climate of the Ocean (ECCO2), European Centre for Medium-Range Weather Forecasts - Ocean Reanalysis System 4 (ECMWF-ORSA4), Simple Ocean Data Assimilation (SODA) Reanalysis, and HYbrid Coordinate Ocean Model (HYCOM). Our analyses of salinity at the surface and at depths up to 200 m, surface salt transport in the top 5 m layer, and depth-integrated salt transports revealed different salinity processes in the NIO that are dominantly related to the semi-annual monsoons. Aquarius and SMOS prove useful tools for observing this dynamic region, and reveal some aspects of SSS that Argo cannot resolve. Meridional depth-integrated salt transports using the modeled products along 6°N revealed dominant advective processes from the surface towards near-bottom depths. Finally, a difference in subsurface salinity stratification causes many of the modeled products to incorrectly estimate the magnitude and seasonality of NIO barrier layer thickness (BLT) when compared to the Argo solution. This problem is also evident in model output from the Seychelles-Chagos Thermocline Ridge (SCTR), a region with strong air-sea teleconnections with the Arabian Sea.

  5. Salt tectonics and shallow subseafloor fluid convection: Models of coupled fluid-heat-salt transport

    USGS Publications Warehouse

    Wilson, A.; Ruppel, C.

    2007-01-01

    Thermohaline convection associated with salt domes has the potential to drive significant fluid flow and mass and heat transport in continental margins, but previous studies of fluid flow associated with salt structures have focused on continental settings or deep flow systems of importance to petroleum exploration. Motivated by recent geophysical and geochemical observations that suggest a convective pattern to near-seafloor pore fluid flow in the northern Gulf of Mexico (GoMex), we devise numerical models that fully couple thermal and chemical processes to quantify the effects of salt geometry and seafloor relief on fluid flow beneath the seafloor. Steady-state models that ignore halite dissolution demonstrate that seafloor relief plays an important role in the evolution of shallow geothermal convection cells and that salt at depth can contribute a thermal component to this convection. The inclusion of faults causes significant, but highly localized, increases in flow rates at seafloor discharge zones. Transient models that include halite dissolution show the evolution of flow during brine formation from early salt-driven convection to later geothermal convection, characteristics of which are controlled by the interplay of seafloor relief and salt geometry. Predicted flow rates are on the order of a few millimeters per year or less for homogeneous sediments with a permeability of 10−15 m2, comparable to compaction-driven flow rates. Sediment permeabilities likely fall below 10−15 m2 at depth in the GoMex basin, but such thermohaline convection can drive pervasive mass transport across the seafloor, affecting sediment diagenesis in shallow sediments. In more permeable settings, such flow could affect methane hydrate stability, seafloor chemosynthetic communities, and the longevity of fluid seeps.

  6. Regulation of salt marsh mosquito populations by the 18.6-yr lunar-nodal cycle.

    PubMed

    Rochlin, Ilia; Morris, James T

    2017-08-01

    The 18.6-yr lunar-nodal cycle drives changes in tidal amplitude globally, affecting coastal habitat formation, species and communities inhabiting rocky shores, and salt marsh vegetation. However, the cycle's influence on salt marsh fauna lacked sufficient long-term data for testing its effect. We circumvented this problem by using salt marsh mosquito records obtained over a period of over four decades in two estuaries in the northeastern USA. Salt marsh mosquito habitat is near the highest tide level where the impact of the nodal cycle on flood frequency is greatest. Wavelet spectral and cross-correlation analyses revealed periodicity in salt marsh mosquito abundance that was negatively correlated with tidal amplitude. Tidal amplitude was a significant predictor of salt marsh mosquito abundance with the cycle maxima coinciding with lower mosquito populations, possibly due to access by predatory fish. However, these effects were detected only at the location with extensive salt marsh habitat and astronomical tides and were weakened or lacked significance at the location with small microtidal salt marshes and wind-driven tides. Mosquitoes can serve as proxy indicators for numerous invertebrate species on the salt marsh. These predictable cycles and their effects need to be taken into consideration when investigating, restoring, or managing intertidal communities that are also facing sea-level rise. © 2017 by the Ecological Society of America.

  7. Fluoride metabolism when added to salt.

    PubMed

    Whitford, Gary M

    2005-01-01

    The purpose of this review is to present the general characteristics of the metabolism of fluoride particularly as it occurs when ingested with fluoridated salt. Following the absorption of salt-borne fluoride from the stomach and intestines, its metabolism is identical to that of water-borne fluoride or other vehicles containing ionized fluoride. Because fluoridated salt is almost always ingested with food, however, absorption from the gastrointestinal tract may be delayed or reduced. Reports dealing with this subject have shown that fluoride absorption is delayed and, therefore, peak plasma concentrations are lower than when fluoride is ingested with water. The amount of ingested fluoride that is finally absorbed, however, is not appreciably affected unless the meal is composed mainly of components with high calcium concentrations. In this case, the extent of absorption can be reduced by as much as 50%. Fluoridated salt is also ingested less frequently than fluoridated water. Data are presented to show that the dose size and frequency of ingestion have only minor effects on fluoride retention in the body and on the concentrations in plasma, bone and enamel. Finally, calculations are presented to show that the risk of acute toxicity from fluoridated salt is virtually non-existent.

  8. Using Nitrogen Stable Isotope Tracers to Track Climate Change Impacts on Coastal Salt Marshes

    EPA Science Inventory

    Climate change impacts on coastal salt marshes are predicted to be complex and multi-faceted. In addition to rising sea level and warmer water temperatures, regional precipitation patterns are also expected to change. At least in the Northeast and Mid-Atlantic U.S., more severe s...

  9. Microwave heat treating of manufactured components

    DOEpatents

    Ripley, Edward B.

    2007-01-09

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

  10. Multiplex CARS spectroscopy of Rochelle salt crystal

    NASA Astrophysics Data System (ADS)

    Hadjichristov, G. B.; Kircheva, P. P.; Kirov, N.

    1996-08-01

    An optical four-wave mixing (FWM) described by the nonlinear susceptibility x(3) ( ωas = 2 ωp - ωs) is studied in a single crystal of Rochelle salt (NaKC 4H 4O 6·H 2O). In addition to the coherent anti-Stokes Raman Scattering (CARS) structure, the FWM spectra consist of nonvibrational (background) components. After analysis of the FWM spectra in the range from 1100 to 1450 cm -1, the nonresonant (electronic) susceptibility elements xelzzzz and xelxxxx of Rochelle salt single crystal are estimated.

  11. A Numerical Study of Tropical Sea-Air Interactions Using a Cloud Resolving Model Coupled with an Ocean Mixed-Layer Model

    NASA Technical Reports Server (NTRS)

    Shie, Chung-Lin; Tao, Wei-Kuo; Johnson, Dan; Simpson, Joanne; Li, Xiaofan; Sui, Chung-Hsiung; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Coupling a cloud resolving model (CRM) with an ocean mixed layer (OML) model can provide a powerful tool for better understanding impacts of atmospheric precipitation on sea surface temperature (SST) and salinity. The objective of this study is twofold. First, by using the three dimensional (3-D) CRM-simulated (the Goddard Cumulus Ensemble model, GCE) diabatic source terms, radiation (longwave and shortwave), surface fluxes (sensible and latent heat, and wind stress), and precipitation as input for the OML model, the respective impact of individual component on upper ocean heat and salt budgets are investigated. Secondly, a two-way air-sea interaction between tropical atmospheric climates (involving atmospheric radiative-convective processes) and upper ocean boundary layer is also examined using a coupled two dimensional (2-D) GCE and OML model. Results presented here, however, only involve the first aspect. Complete results will be presented at the conference.

  12. Effect of inorganic salts on bacterial omega-3 PUFA production.

    PubMed

    Abd Elrazak, Ahmed; Ward, Alan C; Glassey, Jarka

    2017-03-16

    The increasing demand of omega-3 in the market and the challenges facing its conventional supplies led to an increasing interest to microbial omega-3 sources. This research concentrates on the statistical role of some metal ions on the biosynthesis and productivity of eicosapentaenoic acid (essential omega-3 element) in bacterial isolate, Shewanella 717. A Plackett-Burman design was applied to screen the main effect of all metal salts entrenched in the artificial sea water medium components. Four salts, in particular, in addition to the interaction among them were highlighted as having a statistically significant effect upon the growth and/or eicosapentaenoic acid production. A subsequent central composite design was performed to determine the exact optimum concentration of each of the chosen variables which was found to be 2.5, 1.8, 1.2, and 23 g/l, for Na 2 HPO 4 , MgSO 4 , KCl, and NaCl, respectively. All the experiments were performed with the minimal amount of carbon and nitrogen to eliminate any potential masking effect. A bioreactor batch run was operated and the ion uptake was monitored, using EDAX® electron microscopy, concluding that the process of microbial omega-3 production could be a phosphate-limited process. Optimizing the concentration of the tested metal ions led to a remarkable increase in the omega-3 productivity resulted in a 30, 9, and 10 times increase in yield, concentration, and percentage to the total fatty acids, respectively, even though the carbon and nitrogen were kept constant all over the research work.

  13. Onset and localisation of convection during transient growth of mushy sea ice

    NASA Astrophysics Data System (ADS)

    Wells, Andrew; Hitchen, Joe

    2017-11-01

    More than 20 million square kilometres of the polar oceans freeze over each year to form sea ice. Sea ice is a mushy layer: a reactive, porous, multiphase material consisting of ice crystals bathed in liquid brine. Atmospheric cooling generates a density gradient in the interstitial brine, which can drive convection and rejection of brine from the sea ice to force ocean circulation and mixing. We use linear stability analysis and nonlinear numerical simulations to consider the convection in a transiently growing mushy layer. An initial salt water layer is cooled from above via a linearised thermal exchange with the atmosphere, and generates a growing mushy layer with the porosity varying in space and time. We determine how the critical porous-medium Rayleigh number for the onset of convection varies with the surface cooling rate, and the initial temperature and salinity of the solidifying salt water. Differences in the cooling conditions modify the structure of the ice and the resulting convection cells. Weak cooling leads to full-depth convection through ice with slowly varying porosity, whilst stronger cooling leads to localised convection confined to a highly permeable basal layer. These results provide insight into the onset of convective brine drainage from growing sea ice.

  14. Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi

    PubMed Central

    Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2016-01-01

    The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids. PMID:27187362

  15. Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi.

    PubMed

    Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2016-05-12

    The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids.

  16. S.E.A.

    ERIC Educational Resources Information Center

    Hawkins, Richard H.

    1976-01-01

    Sea Semester combines a six-week apprenticeship on a sailing ship with an intensive shore preparation component. Through Boston University, students learn marine and nautical sciences before putting some of this information to practice. Students, having completed the shore and sailing components, can enroll in more advanced shore component…

  17. Liking, salt taste perception and use of table salt when consuming reduced-salt chicken stews in light of South Africa's new salt regulations.

    PubMed

    De Kock, H L; Zandstra, E H; Sayed, N; Wentzel-Viljoen, E

    2016-01-01

    This study investigated the impact of salt reduction on liking, salt taste perception, and use of table salt when consuming chicken stew in light of South Africa's new salt recommendations. In total, 432 South-African consumers (aged 35.2 ± 12.3 years) consumed a full portion of a chicken stew meal once at a central location. Four stock cube powders varying in salt content were used to prepare chicken stews: 1) no reduction - 2013 Na level; regular salt level as currently available on the South African market (24473 mg Na/100 g), 2) salt reduction smaller than 2016 level, i.e. 10%-reduced (22025 mg Na/100 g), 3) 2016 salt level, as per regulatory prescriptions (18000 mg Na/100 g), 4) 2019 salt level, as per regulatory prescriptions (13000 mg Na/100 g). Consumers were randomly allocated to consume one of the four meals. Liking, salt taste perception, and use of table salt and pepper were measured. Chicken stews prepared with reduced-salt stock powders were equally well-liked as chicken stews with the current salt level. Moreover, a gradual reduction of the salt in the chicken stews resulted in a reduced salt intake, up to an average of 19% for the total group compared to the benchmark 2013 Na level stew. However, 19% of consumers compensated by adding salt back to full compensation in some cases. More salt was added with increased reductions of salt in the meals, even to the point of full compensation. Further investigation into the impacts of nutrition communication and education about salt reduction on salt taste perception and use is needed. This research provides new consumer insights on salt use and emphasises the need for consumer-focused behaviour change approaches, in addition to reformulation of products. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Role of Rayleigh numbers on characteristics of double diffusive salt fingers

    NASA Astrophysics Data System (ADS)

    Rehman, F.; Singh, O. P.

    2018-05-01

    Double diffusion convection, driven by two constituents of the fluid with different molecular diffusivity, is widely applied in oceanography and large number of other fields like astrophysics, geology, chemistry and metallurgy. In case of ocean, heat (T) and salinity (S) are the two components with varying diffusivity, where heat diffuses hundred times faster than salt. Component (T) stabilizes the system whereas components (S) destabilizes the system with overall density remains stable and forms the rising and sinking fingers known as salt fingers. Recent observations suggest that salt finger characteristics such as growth rates, wavenumber, and fluxes are strongly depending on the Rayleigh numbers as major driving force. In this paper, we corroborate this observation with the help of experiments, numerical simulations and linear theory. An eigenvalue expression for growth rate is derived from the linearized governing equations with explicit dependence on Rayleigh numbers, density stability ratio, Prandtl number and diffusivity ratio. Expressions for fastest growing fingers are also derived as a function various non-dimensional parameter. The predicted results corroborate well with the data reported from the field measurements, experiments and numerical simulations.

  19. Timescales of Equatorward Transport through the Solomon Sea from Glider and Altimetry

    NASA Astrophysics Data System (ADS)

    Hristova, H. G.; Kessler, W. S.; Davis, R.

    2016-12-01

    Passage through the semi-enclosed Solomon Sea is the last hurdle in the equatorward journey of the South Pacific western boundary currents before reaching the equator where they contribute to the mass, heat and salt budgets of the equatorial Pacific. We use satellite sea surface height (SSH) and in-situ data from 10 years of glider observations in the Solomon Sea to relate surface geostrophic currents to equatorward transport variability estimated from the gliders. The interior Solomon Sea has enhanced SSH variability compared to the surrounding ocean — its magnitude is largest on ENSO timescales, but also includes significant contributions from the annual and intraseasonal (<120 days) frequencies. Intraseasonal surface variability is dominated by basin-scale, westward propagating disturbances with 60-90 day period, consistent with basin resonance. Because the period of these disturbances is comparable to the time it takes a glider to complete a section across the Sea, the energetic intraseasonal variability is aliased in the glider data and results in section to section spikes in the glider transport estimates. Lower frequency (interannual and annual) SSH correlates well with dynamic height relative to 500m from the glider. Thus, a good lower frequency transport time-series can be obtained from SSH alone. However, the glider provides in addition a vertical structure for the mass transport, as well as estimates of heat and salt transport through the Sea. Two major El Nino events (2009/2010 and 2015/2016) occurred during the glider observation period, both of which show a distinct signature in the mass and heat transport anomalies.

  20. Rapid response of tidal channel networks to sea-level variations (Venice Lagoon, Italy)

    NASA Astrophysics Data System (ADS)

    Rizzetto, Federica; Tosi, Luigi

    2012-07-01

    The aim of the present paper is to examine the effects of long- and short-term sea-level fluctuations (i.e. relative sea-level rise and tides) on the geomorphologic evolution of modern tidal channels through the joint interpretation of channel modifications, the 1938-2010 yearly time series of relative sea-level rise, and the variations of strength and frequency of high tides which occurred in the same period. We analyzed a salt marsh area not particularly modified by human interventions, located in the northern Venice Lagoon, Italy. The availability of a long historical record of high-resolution aerial photographs provided us the opportunity to reconstruct in detail the evolution of the drainage patterns from 1938 to the present. Results from our analyses gave us information about the degree of control of long- and short-term sea-level fluctuations on planimetric development of tidal channels and provided demonstration of the rapid response of the drainage network to these oscillations. We found that both relative sea-level rise and high tide frequency greatly influenced salt marsh margin shift and meander evolution of tidal channels in the long term, but short-term sinuosity changes of creeks were often also closely related to tide variations. Channels nearer the marsh margin were more exposed to the action of the increasing tides.

  1. Salt Marsh Formation in the Lower Hudson River Estuary

    NASA Technical Reports Server (NTRS)

    Merley, Michael; Peteet, Dorothy; Hansen, James E. (Technical Monitor)

    2001-01-01

    Salt marshes are constant depositional environments and as a result contain accurate indicators of past relative sea level rise and salinity. The Hudson River marshes are at least twice as deep when compared to coastal marshes on either side of the mouth of the Hudson. The reason for this difference in sedimentation is unclear. This study uses macrofossil data as well as sediment stratigraphy in order to understand the formation and evolution of these marshes. The composition of seeds, roots, shoots and foraminifera, are used to indicate past sea levels. The four sites involved in this study are, from south to north, the Arthur Kill Marsh in Staten Island (40 36 N, 74 77W), Piermont marsh (N 4100; 73 55W) Croton Point (41 14 N; 73 50W) and Iona Island (41 18N, 73 58W). These are all tidally influenced but with increasing distances from the New York Bight, which gives a good spectrum of tidal influence. AMS-C14 dates on basal macrofossils will document the time of each marsh formation. Basal material from Arthur Kill (8 m) includes freshwater seeds such as Viola, Potomageton and Alnus along with Salix buds. Basal material from Croton Point (10 m) includes fibrous woody material, foraminifera and Zanichellia seeds and other brackish vegetational components. The basal material from Piermont (13.77 m) is lacking any identifiable macrofossils between 150 and 500 microns. The basal material from Iona Island (10 m) has vegetation such as Scirpus and Cyperus seeds, probably implying a brackish environment. The freshwater origin of the Arthur Kill marsh in Staten Island is significant because it predates either sea level rise or the western channel incision. Additional implications for this study include evidence for changes in river channel geomorphology. Reasons for the relatively deeper river marshes include possible basal clay compaction, high production due to river and marine nutrients as well as tectonic activity. This study provides the groundwork for more high

  2. A Late Pleistocene sea level stack

    NASA Astrophysics Data System (ADS)

    Spratt, R. M.; Lisiecki, L. E.

    2015-08-01

    Late Pleistocene sea level has been reconstructed from ocean sediment core data using a wide variety of proxies and models. However, the accuracy of individual reconstructions is limited by measurement error, local variations in salinity and temperature, and assumptions particular to each technique. Here we present a sea level stack (average) which increases the signal-to-noise ratio of individual reconstructions. Specifically, we perform principal component analysis (PCA) on seven records from 0-430 ka and five records from 0-798 ka. The first principal component, which we use as the stack, describes ~80 % of the variance in the data and is similar using either five or seven records. After scaling the stack based on Holocene and Last Glacial Maximum (LGM) sea level estimates, the stack agrees to within 5 m with isostatically adjusted coral sea level estimates for Marine Isotope Stages 5e and 11 (125 and 400 ka, respectively). When we compare the sea level stack with the δ18O of benthic foraminifera, we find that sea level change accounts for about ~40 % of the total orbital-band variance in benthic δ18O, compared to a 65 % contribution during the LGM-to-Holocene transition. Additionally, the second and third principal components of our analyses reflect differences between proxy records associated with spatial variations in the δ18O of seawater.

  3. Temporal variability in SeaWiFS derived apparent optical properties in European seas

    NASA Astrophysics Data System (ADS)

    Vantrepotte, V.; Mélin, F.

    2010-02-01

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

  4. 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

  5. Cloud Condensation Nuclei and Chemical Composition of size-resolved particles in a Brazilian megacity: Effect of NPF event, biomass burning and sea salt from remote regions on the CCN properties

    NASA Astrophysics Data System (ADS)

    Souto-Oliveira, Carlos; de Fátima Andrade, Maria; Kumar, Prashant; Lopes, Fabio; Babinski, Marly; Landulfo, Eduado; Vara-Vela, Angel

    2016-04-01

    Atmospheric aerosol particles are an important source of cloud condensation nuclei (CCN). Their microphysics and chemical composition can directly affect development of clouds and precipitation process1,2. Only a few studies in Latin American have reported the impact of urban aerosol on the formation of CCN and their contribution to global climate change3. In this study, we simultaneously measured size distributed particle number concentration (PNC), CCN, black carbon (BC) and elemental concentrations (EC) in aerosol samples from São Paulo city. The PNC was measured by DMPS (model 3936) operated with a DMA (model 3080) and CPC (TSI, model 3010). The CCN was measuredby a single-column continuous-flow stream-wise thermal gradient CCN chamber (DMT CCNC-100). The BC and EC were determined in polycarbonate filter collected by Cascade Impactor (MOUDI-MSP), using a smoke stain reflectometer and an ED-XRF (EDX 700; Shimadzu), respectively. During the study period, which was August to September 2014, four events of new particle formation (NPF), characterizing secondary process of aerosol formation were noted. The total PNC varied between 1106 and 29168 cm-3, while CCN presented concentrations of 206 to 12761 cm-3for SS=1.0%. The PNC showed different concentrations during diurnal and nocturnal periods with average of 16392±7811 cm-3 and 6874±3444cm-3, respectively. The activated ratio (CCN/CN) presented diurnal and nocturnal values of 0.19±0.10 and 0.41±0.18, while apparent activation diameter (Dact,a) was estimated to be 110±29 and 71±28 nm (SS=0.6%), respectively. Combining EC and BC results with air mass trajectory analysis (Lidar aerosol profiles and Hysplit air trajectories), apportionment events were identified for sea salt and biomass burning from coastal and continental regions, respectively. The nocturnal AR and Dact,apresented values of 0.46±0.11 and 49±15 nm (SS=0.6%) for sea salt events as opposed to 0.33±0.14 and 64±30 nm (SS=0.6%) during biomass

  6. Scale-free distribution of Dead Sea sinkholes: Observations and modeling

    NASA Astrophysics Data System (ADS)

    Yizhaq, H.; Ish-Shalom, C.; Raz, E.; Ashkenazy, Y.

    2017-05-01

    There are currently more than 5500 sinkholes along the Dead Sea in Israel. These were formed due to the dissolution of subsurface salt layers as a result of the replacement of hypersaline groundwater by fresh brackish groundwater. This process has been associated with a sharp decline in the Dead Sea water level, currently more than 1 m/yr, resulting in a lower water table that has allowed the intrusion of fresher brackish water. We studied the distribution of the sinkhole sizes and found that it is scale free with a power law exponent close to 2. We constructed a stochastic cellular automata model to understand the observed scale-free behavior and the growth of the sinkhole area in time. The model consists of a lower salt layer and an upper soil layer in which cavities that develop in the lower layer lead to collapses in the upper layer. The model reproduces the observed power law distribution without involving the threshold behavior commonly associated with criticality.

  7. A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes

    PubMed Central

    Leonardi, Nicoletta; Ganju, Neil K.; Fagherazzi, Sergio

    2016-01-01

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans. PMID:26699461

  8. A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes

    USGS Publications Warehouse

    Leonardi, Nicoletta; Ganju, Neil K.; Fagherazzi, Sergio

    2016-01-01

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  9. A linear relationship between wave power and erosion determines salt-marsh resilience to violent storms and hurricanes.

    PubMed

    Leonardi, Nicoletta; Ganju, Neil K; Fagherazzi, Sergio

    2016-01-05

    Salt marsh losses have been documented worldwide because of land use change, wave erosion, and sea-level rise. It is still unclear how resistant salt marshes are to extreme storms and whether they can survive multiple events without collapsing. Based on a large dataset of salt marsh lateral erosion rates collected around the world, here, we determine the general response of salt marsh boundaries to wave action under normal and extreme weather conditions. As wave energy increases, salt marsh response to wind waves remains linear, and there is not a critical threshold in wave energy above which salt marsh erosion drastically accelerates. We apply our general formulation for salt marsh erosion to historical wave climates at eight salt marsh locations affected by hurricanes in the United States. Based on the analysis of two decades of data, we find that violent storms and hurricanes contribute less than 1% to long-term salt marsh erosion rates. In contrast, moderate storms with a return period of 2.5 mo are those causing the most salt marsh deterioration. Therefore, salt marshes seem more susceptible to variations in mean wave energy rather than changes in the extremes. The intrinsic resistance of salt marshes to violent storms and their predictable erosion rates during moderate events should be taken into account by coastal managers in restoration projects and risk management plans.

  10. Mangrove expansion and salt marsh decline at mangrove poleward limits.

    PubMed

    Saintilan, Neil; Wilson, Nicholas C; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W

    2014-01-01

    Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the USA Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province, China. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the poleward extension of temperature thresholds coincident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation. © 2013 John Wiley & Sons Ltd.

  11. Possible Sea Ice Impacts on Oceanic Deep Convection

    NASA Technical Reports Server (NTRS)

    Parkinson, C. L.

    1984-01-01

    Many regions of the world ocean known or suspected to have deep convection are sea-ice covered for at least a portion of the annual cycle. As this suggests that sea ice might have some impact on generating or maintaining this phenomenon, several mechanisms by which sea ice could exert an influence are presented in the following paragraphs. Sea ice formation could be a direct causal factor in deep convection by providing the surface density increase necessary to initiate the convective overturning. As sea ice forms, either by ice accretion or by in situ ice formation in open water or in lead areas between ice floes, salt is rejected to the underlying water. This increases the water salinity, thereby increasing water density in the mixed layer under the ice. A sufficient increase in density will lead to mixing with deeper waters, and perhaps to deep convection or even bottom water formation. Observations are needed to establish whether this process is actually occurring; it is most likely in regions with extensive ice formation and a relatively unstable oceanic density structure.

  12. Sea salt irradiation experiments relevant to the surface conditions of ocean worlds such as Europa and Enceladus

    NASA Astrophysics Data System (ADS)

    Hand, Kevin P.; Carlson, Robert W.

    2015-11-01

    We have conducted a set of laboratory experiments to measure changes in NaCl, KCl, MgCl2, and mixtures of these salts, as a function of exposure to the temperature, pressure, and radiation conditions relevant to ice covered ocean worlds in our solar system. Reagent grade salts were placed onto a diffuse aluminum target at the end of a cryostat coldfinger and loaded into an ultra-high vacuum chamber. The samples were then cooled to 100 K and the chamber pumped down to ~10-8 Torr, achieving conditions comparable to the surface of several moons of the outer solar system. Samples were subsequently irradiated with 10 keV electrons at an average current of 1 µA.We examined a range of conditions for NaCl including pure salts grains (~300 µm diameter), salt grains with water ice deposited on top, and evaporites. For the evaporites saturated salt water was loaded onto the cryostat target, the chamber closed, and then slowly pumped down to remove the water, leaving behind a salt evaporate for irradiation.The electron bombardment resulted in the trapping of electrons in halogen vacancies, yielding the the F- and M- color centers. After irraditiation we observed yellow-brown discoloration in NaCl. KCl was observed to turn a distinct violet. In NaCl these centers have strong absorptions at 450 nm and 720 nm, respectively, providing a highly diagnostic signature of otherwise transparent alkali halides, making it possible to remotely characterize and quantify the composition and salinity of ocean worlds.

  13. Temperature-dependent formation of NaCl dihydrate in levitated NaCl and sea salt aerosol particles.

    PubMed

    Peckhaus, Andreas; Kiselev, Alexei; Wagner, Robert; Duft, Denis; Leisner, Thomas

    2016-12-28

    Recent laboratory studies indicate that the hydrated form of crystalline NaCl is potentially important for atmospheric processes involving depositional ice nucleation on NaCl dihydrate particles under cirrus cloud conditions. However, recent experimental studies reported a strong discrepancy between the temperature intervals where the efflorescence of NaCl dihydrate has been observed. Here we report the measurements of the volume specific nucleation rate of crystalline NaCl in the aqueous solution droplets of pure NaCl suspended in an electrodynamic balance at constant temperature and humidity in the range from 250 K to 241 K. Based on these measurements, we derive the interfacial energy of crystalline NaCl dihydrate in a supersaturated NaCl solution and determined its temperature dependence. Taking into account both temperature and concentration dependence of nucleation rate coefficients, we explain the difference in the observed fractions of NaCl dihydrate reported in the previous studies. Applying the heterogeneous classical nucleation theory model, we have been able to reproduce the 5 K shift of the NaCl dihydrate efflorescence curve observed for the sea salt aerosol particles, assuming the presence of super-micron solid inclusions (hypothetically gypsum or hemihydrate of CaSO 4 ). These results support the notion that the phase transitions in microscopic droplets of supersaturated solution should be interpreted by accounting for the stochastic nature of homogeneous and heterogeneous nucleation and cannot be understood on the ground of bulk phase diagrams alone.

  14. Temperature-dependent formation of NaCl dihydrate in levitated NaCl and sea salt aerosol particles

    NASA Astrophysics Data System (ADS)

    Peckhaus, Andreas; Kiselev, Alexei; Wagner, Robert; Duft, Denis; Leisner, Thomas

    2016-12-01

    Recent laboratory studies indicate that the hydrated form of crystalline NaCl is potentially important for atmospheric processes involving depositional ice nucleation on NaCl dihydrate particles under cirrus cloud conditions. However, recent experimental studies reported a strong discrepancy between the temperature intervals where the efflorescence of NaCl dihydrate has been observed. Here we report the measurements of the volume specific nucleation rate of crystalline NaCl in the aqueous solution droplets of pure NaCl suspended in an electrodynamic balance at constant temperature and humidity in the range from 250 K to 241 K. Based on these measurements, we derive the interfacial energy of crystalline NaCl dihydrate in a supersaturated NaCl solution and determined its temperature dependence. Taking into account both temperature and concentration dependence of nucleation rate coefficients, we explain the difference in the observed fractions of NaCl dihydrate reported in the previous studies. Applying the heterogeneous classical nucleation theory model, we have been able to reproduce the 5 K shift of the NaCl dihydrate efflorescence curve observed for the sea salt aerosol particles, assuming the presence of super-micron solid inclusions (hypothetically gypsum or hemihydrate of CaSO4). These results support the notion that the phase transitions in microscopic droplets of supersaturated solution should be interpreted by accounting for the stochastic nature of homogeneous and heterogeneous nucleation and cannot be understood on the ground of bulk phase diagrams alone.

  15. SeaDataNet : Pan-European infrastructure for marine and ocean data management - Project objectives, structure and components

    NASA Astrophysics Data System (ADS)

    Maudire, G.; Maillard, C.; Fichaut, M.; Manzella, G.; Schaap, D. M. A.

    2009-04-01

    SeaDataNet : Pan-European infrastructure for marine and ocean data management Project objectives, structure and components G. Maudire (1), C. Maillard (1), G. Manzella (2), M. Fichaut (1), D.M.A. Schaap (3), E. Iona (4) and the SeaDataNet consortium. (1) IFREMER, Brest, France (Gilbert.Maudire@ifremer.fr), (2) ENEA, La Spezia, Italy, (3) Mariene Informatie Service 'MARIS', Voorburg, The Netherlands, (4) Hellenic Centre for Marine Research-HCMR, Anavyssos, Greece. Since a large part of the earth population lives near the oceans or carries on activities directly or indirectly linked to the seas (fishery and aquaculture, exploitation of sea bottom resources, international shipping, tourism), knowledge of oceans is of primary importance for security and economy. However, observation and monitoring of the oceans remains difficult and expensive even if real improvements have been achieved using research vessels and submersibles, satellites and automatic observatories like buoys, floats and seafloor observatories transmitting directly to the shore using global transmission systems. More than 600 governmental or private organizations are active in observation of seas bordering Europe, but European oceanographic data are fragmented, not always validated and not always easily accessible. That highlights the need of international collaboration to tend toward a comprehensive view of ocean mechanisms, resources and changes. SeaDataNet is an Integrated research Infrastructure Initiative (I3) in European Union Framework Program 6 (2006 - 2011) to provide the data management system adapted both to the fragmented observation systems and to the users need for an integrated access to data, meta-data, products and services. Its major objectives are to: - encourage long-term archiving at national level to secure ocean data taking into account that all the observations made in the variable oceanic environment can never be remade if they are lost; - promote best practices for data

  16. Temporal and Spatial Variability in Relative Sea Level from Narragansett Bay, Rhode Island (USA)

    NASA Astrophysics Data System (ADS)

    Halavik, B. T.; Engelhart, S. E.

    2017-12-01

    Geological reconstructions of past relative sea level (RSL) provide observations to compare to instrumental measurements of land-level changes (e.g., GPS) and to provide constraints on Glacial Isostatic Adjustment (GIA) models. Given the importance of the east coast of the United States to our understanding of GIA (due to its proximity and orientation to the collapsing forebulge of the Laurentide ice sheet), we set out to reconstruct the first compaction-free late Holocene RSL record for Rhode Island, USA. We sought to quantify and compare RSL changes at multiple sites within Rhode Island's Narragansett Bay. Previous work suggests Narragansett Bay may span a gradient in GIA. The small tidal range (0.9-1.4m) in Narragansett Bay permits the development of high-resolution sea-level index points that have the potential to identify small differences in RSL between sites. To address our research goals we collected a south to north transect of salt marsh basal peats from four Rhode Island salt marshes at Fox Hill, Nag Creek, Touisset, and Osamequin. We reconstructed paleomarsh elevations utilizing a multi-proxy approach using salt-marsh foraminifera and bulk sediment δ13C. Sample age was determined using accelerated mass spectrometry (AMS) radiocarbon of identifiable in-situ plant macrofossils. Basal peats in Rhode Island typically form within the tidal frame as indicated by foraminifera within close proximity (<5cm) to the underlying glacial deposits. Our current database of RSL consists of 30 new sea-level index points that document changes in RSL since 3200 cal yrs BP. At our southerly Fox Hill site, 12 sea-level index points demonstrate that RSL rose from -3.87 ± 0.24 m at 3,140 ± 69 cal yrs BP. Conversely, at the northerly Touisset site, six sea-level index points demonstrate that salt marshes developed later in this region with RSL rising from -1.65 ± 0.22 m at 1,246 ± 56 cal yrs BP. An additional 12 sea-level index points have been reconstructed from Osamequin

  17. Restoring Ecological Function to a Submerged Salt Marsh

    USGS Publications Warehouse

    Stagg, C.L.; Mendelssohn, I.A.

    2010-01-01

    Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase marsh surface elevation, thus ameliorating effects of excessive inundation. Although this technique is growing in popularity, the restoration of ecological function after sediment addition has received little attention. To determine if sediment subsidized salt marshes are functionally equivalent to natural marshes, we examined above- and belowground primary production in replicated restored marshes receiving four levels of sediment addition (29-42 cm North American Vertical Datum of 1988 [NAVD 88]) and in degraded and natural ambient marshes (4-22 cm NAVD 88). Moderate intensities of sediment-slurry addition, resulting in elevations at the mid to high intertidal zone (29-36 cm NAVD 88), restored ecological function to degraded salt marshes. Sediment additions significantly decreased flood duration and frequency and increased bulk density, resulting in greater soil drainage and redox potential and significantly lower phytotoxic sulfide concentrations. However, ecological function in the restored salt marsh showed a sediment addition threshold that was characterized by a decline in primary productivity in areas of excessive sediment addition and high elevation (>36 cm NAVD 88). Hence, the addition of intermediate levels of sediment to submerging salt marshes increased marsh surface elevation, ameliorated impacts of prolonged inundation, and increased primary productivity. However, too much sediment resulted in diminished ecological function that was equivalent to the submerged or degraded system. ?? 2010 Society for Ecological Restoration International.

  18. Coatal salt marshes and mangrove swamps in China

    NASA Astrophysics Data System (ADS)

    Yang, Shi-Lun; Chen, Ji-Yu

    1995-12-01

    Based on plant specimen data, sediment samples, photos, and sketches from 45 coastal crosssections, and materials from two recent countrywide comprehensive investigations on Chinese coasts and islands, this paper deals with China’s vegetative tidal-flats: salt marshes and mangrove swamps. There are now 141700 acres of salt marshes and 51000 acres of mangrove swamps which together cover about 30% of the mud-coast area of the country and distribute between 18°N (Southern Hainan Island) and 41 °N (Liaodong Bay). Over the past 45 years, about 1750000 acres of salt marshes and 49400 acres of mangrove swamps have been reclaimed. The 2.0×109 tons of fine sediments input by rivers into the Chinese seas form extensive tidal flats, the soil basis of coastal helophytes. Different climates result in the diversity of vegetation. The 3˜8 m tidal range favors intertidal zone development. Of over 20 plant species in the salt marshes, native Suaeda salsa, Phragmites australis, Aeluropus littoralis, Zoysia maerostachys, Imperata cylindrica and introduced Spartina anglica are the most extensive in distribution. Of the 41 mangrove swamps species, Kandelia candel, Bruguiera gymnorrhiza, Excoecaria agallocha and Avicennia marina are much wider in latitudinal distribution than the others. Developing stages of marshes originally relevant to the evolution of tidal flats are given out. The roles of pioneer plants in decreasing flood water energy and increasing accretion rate in the Changjiang River delta are discussed.

  19. Artisanal salt production in Aveiro/Portugal - an ecofriendly process.

    PubMed

    Rodrigues, Carolina M; Bio, Ana; Amat, Francisco; Vieira, Natividade

    2011-11-04

    Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend.It is, however, possible to generate revenue from salinas at several levels, not merely in terms of good quality salt production, but also by obtaining other products that can be commercialized, or by exploring their potential for tourism, and as research facilities, among others. Furthermore, with an adequate management, biodiversity can be restored to abandoned salinas, which constitute important feeding and breeding grounds for resident and migratory aquatic birds, many of which are protected by European Community Directives.The aims of this manuscript are to present a brief overview on the current state of sea salt exploitation in Portugal and to stress the importance of recovering these salinas for the conservation of this particular environment, for the regional economy, the scientific community and the general public. The Aveiro salina complex is presented in detail, to exemplify salina structure and functioning, as well as current problems and potential solutions for artisanal salinas.

  20. Artisanal salt production in Aveiro/Portugal - an ecofriendly process

    PubMed Central

    2011-01-01

    Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend. It is, however, possible to generate revenue from salinas at several levels, not merely in terms of good quality salt production, but also by obtaining other products that can be commercialized, or by exploring their potential for tourism, and as research facilities, among others. Furthermore, with an adequate management, biodiversity can be restored to abandoned salinas, which constitute important feeding and breeding grounds for resident and migratory aquatic birds, many of which are protected by European Community Directives. The aims of this manuscript are to present a brief overview on the current state of sea salt exploitation in Portugal and to stress the importance of recovering these salinas for the conservation of this particular environment, for the regional economy, the scientific community and the general public. The Aveiro salina complex is presented in detail, to exemplify salina structure and functioning, as well as current problems and potential solutions for artisanal salinas. PMID:22053788

  1. Interaction between crustal tectonics and salt deformation in the Eastern Sardinian margin, Western Tyrrhenian Sea: seismic data and analogue modelling

    NASA Astrophysics Data System (ADS)

    Vendeville, Bruno; Lymer, Gael; Gaullier, Virginie; Chanier, Frank; Maillard, Agnes; Sage, Françoise; Lofi, Johanna; Thinon, Isabelle

    2014-05-01

    The Tyrrhenian Basin opened by eastward migration of the Apennine subduction system. Rifting along the Eastern Sardinian margin started during the middle to late Miocene times and hence this timing partly overlapped the Messinian Salinity Crisis. The two "METYSS" cruises were conducted to use the deformation of the Messinian salt and its Plio-Quaternary overburden as a proxy for better delineating the tectonic history of the sub-salt basement. Many parts of the study area contain two of the most typical Messinian series of the Western Mediterranean: the Mobile Unit (MU; salt, mainly halite), overlain by the more competent Upper Unit (UU: alternating dolomitic marls and anhydrite). The brittle Plio-Quaternary cover overlies the UU. Usually, the presence of mobile salt is viewed as a nuisance for understanding crustal tectonics because salt's ability to act as a structural buffer between the basement and the cover. However, we illustrate, using examples from the Cornaglia Terrace, how we can use thin-skinned salt tectonics as indicators of vertical movements in the sub-salt, pre-Messinian basement. There, slip along N-S-trending crustal normal faults bounding basement troughs has been recorded by salt and overburden in two different manners: - First, post-salt basement faulting (typically after deposition of the Upper Unit and the early Pliocene), and some crustal-scale southward tilting, triggered along-strike (southward) thin-skinned, gliding of salt and overburden recorded by upslope extension and downslope shortening. - Second, and less obvious at first glance, there was some crustal activity along another basement trough, located East of the Baronie Ridge after deposition of the Messinian salt. This trough is narrow, trends N-S and is bounded by crustal faults. The narrow width of the trough allowed for only minor across-strike (E-W) gliding. The resulting geometry would suggest that nothing happened after Messinian times, but some structural features (confirmed

  2. Modeling of Dense Water Production and Salt Transport from Alaskan Coastal Polynyas

    NASA Technical Reports Server (NTRS)

    Signorini, Sergio R.; Cavalieri, Donald J.

    2000-01-01

    The main significance of this paper is that a realistic, three-dimensional, high-resolution primitive equation model has been developed to study the effects of dense water formation in Arctic coastal polynyas. The model includes realistic ambient stratification, realistic bottom topography, and is forced by time-variant surface heat flux, surface salt flux, and time-dependent coastal flow. The salt and heat fluxes, and the surface ice drift, are derived from satellite observations (SSM/I and NSCAT sensors). The model is used to study the stratification, salt transport, and circulation in the vicinity of Barrow Canyon during the 1996/97 winter season. The coastal flow (Alaska coastal current), which is an extension of the Bering Sea throughflow, is formulated in the model using the wind-transport regression. The results show that for the 1996/97 winter the northeastward coastal current exports 13% to 26% of the salt produced by coastal polynyas upstream of Barrow Canyon in 20 to 30 days. The salt export occurs more rapidly during less persistent polynyas. The inclusion of ice-water stress in the model makes the coastal current slightly weaker and much wider due to the combined effects of surface drag and offshore Ekman transport.

  3. Fault and fracture patterns around a strike-slip influenced salt wall

    NASA Astrophysics Data System (ADS)

    Alsop, G. I.; Weinberger, R.; Marco, S.; Levi, T.

    2018-01-01

    The trends of faults and fractures in overburden next to a salt diapir are generally considered to be either parallel to the salt margin to form concentric patterns, or at right angles to the salt contact to create an overall radial distribution around the diapir. However, these simple diapir-related patterns may become more complex if regional tectonics influences the siting and growth of a diapir. Using the Sedom salt wall in the Dead Sea Fault system as our case study, we examine the influence of regional strike-slip faulting on fracture patterns around a salt diapir. This type of influence is important in general as the distribution and orientation of fractures on all scales may influence permeability and hence control fluid and hydrocarbon flow. Fractures adjacent to the N-S trending salt wall contain fibrous gypsum veins and injected clastic dykes, attesting to high fluid pressures adjacent to the diapir. Next to the western flank of the salt wall, broad (∼1000 m) zones of upturn or 'drape folds' are associated with NW-SE striking conjugate extensional fractures within the overburden. Within 300 m of the salt contact, fracture patterns in map view display a progressive ∼30°-35° clockwise rotation with more NNW-SSE strikes immediately adjacent to the salt wall. While some extensional faults display growth geometries, indicating that they were syn-depositional and initiated prior to tilting of beds associated with drape folding, other fractures display increasing dips towards the salt, suggesting that they have formed during upturn of bedding near the diapir. These observations collectively suggest that many fractures developed to accommodate rotation of beds during drape folding. Extensional fractures in the overburden define a mean strike that is ∼45° anticlockwise (counter-clockwise) of the N-S trending salt wall, and are therefore consistent with sinistral transtension along the N-S trending Sedom Fault that underlies the salt wall. Our outcrop

  4. The Aral Sea Disaster

    NASA Astrophysics Data System (ADS)

    Micklin, Philip

    2007-05-01

    The Aral Sea is a huge terminal lake located among the deserts of Central Asia. Over the past 10 millennia, it has repeatedly filled and dried, owing both to natural and human forces. The most recent desiccation started in the early 1960s and owes overwhelmingly to the expansion of irrigation that has drained its two tributary rivers. Lake level has fallen 23 m, area shrunk 74%, volume decreased 90%, and salinity grew from 10 to more than 100g/l, causing negative ecological changes, including decimation of native fish species, initiation of dust/salt storms, degradation of deltaic biotic communities, and climate change around the former shoreline. The population residing around the lake has also been negatively impacted. There is little hope in the foreseeable future to fully restore the Aral Sea, but measures to preserve/rehabilitate parts of the water body and the deltas are feasible.

  5. Geochemical interpretation of distribution of aromatic hydrocarbons in components of geologic environment of Pechora, Barents and Kara seas.

    NASA Astrophysics Data System (ADS)

    Kursheva, Anna; Petrova, Vera; Litvinenko, Ivan; Morgunova, Inna

    2017-04-01

    Information about the hydrocarbons content (including aromatic ones) in components of geologic environment allows to define common factors in distribution and correlation both nature and technogenic component, and also to reveal the sources of contamination. At that, it should be noted, that hydrocarbons are widely spread in lithosphere and create steady geochemical background, variations are caused here by specifics of initial organic matter, conditions of its accumulation and transformation. The basis of the study are the samples of sea water and deep sea sediments (more than 600 stations), collected in western sector of Arctic region (Pechora, Barents and Kara seas) during the scientific-research expeditions of FSBI "VNIIOkeangeologia" for the period 2000-2010. Total content of aromatic hydrocarbons was defined by spectrofluorometric method using analyzer «FLUORAT-Panorama-02». Certification of data was performed on representative samples based on contents and molecule structure of polycyclic aromatic hydrocarbons using GC-MS (Agilent 5973/6850 GC-MS System). Results of spectrofluorometric analysis of lipid fraction of organic matter of bottom sediments allowed to define specific parameters, which characterize various lithofacies groups of sediments. Thus, sandy residues are characterized by low level of aromatic hydrocarbons (ca. 4.3 μg/g) with prevalence of bi- and tri-aromatic compounds (λmax 270-310 nm). This correlates with low sorption capacity of coarse-grained sediments and absence of organic-mineral component, containing the breakdown products of initial organic matter. Tetra- and penta- aromatic structures prevail in clay sediments (ca. 13.0 μg/g), which are typical components of lipid fraction of organic matter of post sedimentation and early diagenetic stages of transformation. At that, changes of spectral characteristic of sediments in stratigraphic sequence completely reflect processes of diagenetic transformation of organic matter, including

  6. Nitrogen retention in salt marsh systems across nutrient-enrichment, elevation, and precipitation regimes: a multiple stressor experiment

    EPA Science Inventory

    In the Northeastern U.S., multiple anthropogenic stressors, including changing nutrient loads, accelerated sea-level rise, and altered climactic patterns are co-occurring, and are likely to influence salt marsh nitrogen (N) dynamics. We conducted a multiple stressor mesocosm expe...

  7. Salton Sea Project, Phase 1. [solar pond power plant

    NASA Technical Reports Server (NTRS)

    Peelgren, M. L.

    1982-01-01

    A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.

  8. Physical processes in the transition zone between North Sea and Baltic Sea. Numerical simulations and observations

    NASA Astrophysics Data System (ADS)

    Stanev, Emil V.; Lu, Xi; Grashorn, Sebastian

    2015-09-01

    The dynamics in the transition zone between the North Sea and Baltic Sea are analyzed here using data from a 22-year-long climatic simulation with a focus on the periods 1992-1994 and 2001-2003 when two recent major inflow events occurred. Observations from gauges and in situ measurements are used to validate the model. Parameters, which cannot be easily measured, such as water and salt transports through straits, have been compared against similar previous estimates. The good performance of simulations is attributed to the finer resolution of the model compared to earlier set ups. The outflow in the Kattegat, which is an analogue of the tidal outflows, tends to propagate to the North over the shallows without showing a substantial deflection to the right due to the Earth's rotation. The inflow follows the topography. The different inflow and outflow pathways are explained as a consequence of the specific combination of bathymetry, axial and lateral processes. The circulation in Kattegat is persistently clockwise with an eastern intensification during inflow and a western one during outflow regimes. The tidal wave there propagates as Kelvin wave, keeping the coast on its right. The flows in the two main straits reveal very different responses to tides, which are also highly asymmetric during inflow and outflow conditions. The circulation has a typical two-layer structure, the correlation between salinity and velocity tends to increase the salt transport in the salinity conveyor belt. The transversal circulation in the entrance of the Sound enhances the vertical mixing of the saltier North Sea water. The long-term averaged ratio of the water transports through the Great Belt and the Sound is ∼2.6-2.7 but this number changes reaching lower values during the major inflow in 1993. The transports in the straits are asymmetric. During inflow events the repartition of water penetrating the Baltic Sea is strongly in favor of the pathway through the Sound, which provides

  9. Inorganic and carbonaceous components in indoor/outdoor particulate matter in two residential houses in Oslo, Norway.

    PubMed

    Lazaridis, Mihalis; Aleksandropoulou, Victoria; Hanssen, Jan Erik; Dye, Christian; Eleftheriadis, Kostantinos; Katsivela, Eleftheria

    2008-03-01

    A detailed analysis of indoor/outdoor physicochemical aerosol properties has been performed. Aerosol measurements were taken at two dwellings, one in the city center and the other in the suburbs of the Oslo metropolitan area, during summer/fall and winter/spring periods of 2002-2003. In this paper, emphasis is placed on the chemical characteristics (water-soluble ions and carbonaceous components) of fine (PM2.5) and coarse (PM2.5-10) particles and their indoor/outdoor relationship. Results demonstrate that the carbonaceous species were dominant in all fractions of the PM10 particles (cut off size: 0.09-11.31 microm) during all measurement periods, except winter 2003, when increased concentrations of water-soluble inorganic ions were predominant because of sea salt transport. The concentration of organic carbon was higher in the fine and coarse PM10 fractions indoors, whereas elemental carbon was higher indoors only in the coarse fraction. In regards to the carbonaceous species, local traffic and secondary organic aerosol formation were, probably, the main sources outdoors, whereas indoors combustion activities such as preparation of food, burning of candles, and cigarette smoking were the main sources. In contrast, the concentrations of water-soluble inorganic ions were higher outdoors than indoors. The variability of water-soluble inorganic ion concentrations outdoors was related to changes in emissions from local anthropogenic sources, long-range transport of particles, sea salt emissions, and resuspension of roadside and soil dusts. In the indoor environment the infiltration of the outdoor air indoors was the major source of inorganic ions.

  10. Materials Testing for an Accelerator-Driven Subcritical Molten Salt Fission System: A look at the Materials Science of Molten Salt Corrosion

    NASA Astrophysics Data System (ADS)

    Sooby, Elizabeth; Balachandran, Shreyas; Foley, David; Hartwig, Karl; McIntyre, Peter; Phongikaroon, Supathorn; Pogue, Nathaniel; Simpson, Michael; Tripathy, Prabhat

    2011-10-01

    For an accelerator-driven subcritical molten salt fission core to survive its 50+ year fuel life, the primary vessel, heat exchanger, and various internal components must be made of materials that resist corrosion and radiation damage in a high-temperature environment, (500-800 C). An experimental study of the corrosion behavior of candidate metals in contact with molten salt is being conducted at the Center for Advanced Energy Studies. Initial experiments have been run on Nb, Ta, Ni, two zirconium alloys, Hastelloy-N, and a series of steel alloys to form a base line for corrosion in both chloride and bromide salt. Metal coupons were immersed in LiCl-KCl or LiBr-KBr at 700 C in an inert-atmosphere. Salt samples were extracted on a time schedule over a 24-hr period. The samples were analyzed using inductively coupled plasma-mass spectrometry to determine concentrations of metals from corrosion. Preliminary results will be presented.

  11. Fish in Vitro Digestion: Influence of Fish Salting on the Extent of Lipolysis, Oxidation, and Other Reactions.

    PubMed

    Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Manzanos, María J; Guillén, María D

    2017-02-01

    A study of the various chemical reactions which take place during fish in vitro digestion and the potential effect of fish salting on their extent is addressed for the first time. Farmed European sea bass fillets, raw, brine-salted or dry-salted, were digested using a gastrointestinal in vitro model. Fish lipid extracts before and after digestion were analyzed by 1 H NMR, and the headspace composition of the digestates was investigated by SPME-GC/MS. During digestion, not only lipolysis, but also fish lipid oxidation took place. This latter was evidenced by the generation of conjugated dienes supported on chains having also hydroperoxy- and hydroxy-groups (primary oxidation compounds), by the increase of volatile secondary oxidation products, and by the decrease of the antioxidant 2,6-di-tert-butyl-hydroxytoluene (BHT). Likewise, esterification and Maillard-type reactions also occurred. Salting, and especially dry-salting, enhanced all these reactions, except for lipolysis, during digestion.

  12. Development of the Inland Sea and its evaporites in the Jordan-Dead Sea Transform based on hydrogeochemical considerations and the geological consequences

    NASA Astrophysics Data System (ADS)

    Möller, Peter; Rosenthal, E.; Inbar, N.; Siebert, C.

    2018-04-01

    Differences in the distribution of Na/Cl, Br/Cl and Mg/Ca equivalent values suggest a morphotectonic barrier at Marma Feiyad dividing the Tertiary Inland Sea into two basins covering the region of the Jordan Valley, Middle East. Depending on the Tethys sea level, three phases of evaporation are distinguishable that are related to three sections of the drilling log of Zemah 1. In phase 1 and 3 only the northern basin was flooded. During phase 2 both basins were inundated, but halite mainly precipitated in the southern one. The halite deposition in one or the other basin by evaporation is estimated by applying a two-box model. The results are constrained by the average subduction rate of 700-875 m/Ma and characteristic Na/Cl values of 0.52 and 0.12 in the northern and southern basin, respectively. In different scenarios the sedimentation rates of halite and non-halite components are varied due to assumed halokinesis, reshuffling of salt and erosion of non-halite sediments. These simulations suggest that periods of 450-600 and 100-170 ka in the southern and northern basin were needed, until the Na/Cl values of 0.12 and 0.52 were, respectively, attained. The Inland Sea most probably existed for 2.2 ± 0.3 Ma between 8.5 and 6.3 Ma ago (Tortonian). It was terminated at the beginning of the Messinian crisis. In all simulations the drainage flux into the southern basin exceeded that into the northern basin, suggesting that the proto-Jordan River either did not exist at that time or did not discharge into the northern basin.

  13. Effects of Sea-Surface Waves and Ocean Spray on Air-Sea Momentum Fluxes

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Song, Jinbao

    2018-04-01

    The effects of sea-surface waves and ocean spray on the marine atmospheric boundary layer (MABL) at different wind speeds and wave ages were investigated. An MABL model was developed that introduces a wave-induced component and spray force to the total surface stress. The theoretical model solution was determined assuming the eddy viscosity coefficient varied linearly with height above the sea surface. The wave-induced component was evaluated using a directional wave spectrum and growth rate. Spray force was described using interactions between ocean-spray droplets and wind-velocity shear. Wind profiles and sea-surface drag coefficients were calculated for low to high wind speeds for wind-generated sea at different wave ages to examine surface-wave and ocean-spray effects on MABL momentum distribution. The theoretical solutions were compared with model solutions neglecting wave-induced stress and/or spray stress. Surface waves strongly affected near-surface wind profiles and sea-surface drag coefficients at low to moderate wind speeds. Drag coefficients and near-surface wind speeds were lower for young than for old waves. At high wind speeds, ocean-spray droplets produced by wind-tearing breaking-wave crests affected the MABL strongly in comparison with surface waves, implying that wave age affects the MABL only negligibly. Low drag coefficients at high wind caused by ocean-spray production increased turbulent stress in the sea-spray generation layer, accelerating near-sea-surface wind. Comparing the analytical drag coefficient values with laboratory measurements and field observations indicated that surface waves and ocean spray significantly affect the MABL at different wind speeds and wave ages.

  14. Sea ice and polar climate in the NCAR CSM

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

    Weatherly, J.W.; Briegleb, B.P.; Large, W.G.

    The Climate System Model (CSM) consists of atmosphere, ocean, land, and sea-ice components linked by a flux coupler, which computes fluxes of energy and momentum between components. The sea-ice component consists of a thermodynamic formulation for ice, snow, and leads within the ice pack, and ice dynamics using the cavitating-fluid ice rheology, which allows for the compressive strength of ice but ignores shear viscosity. The results of a 300-yr climate simulation are presented, with the focus on sea ice and the atmospheric forcing over sea ice in the polar regions. The atmospheric model results are compared to analyses from themore » European Centre for Medium-Range Weather Forecasts and other observational sources. The sea-ice concentrations and velocities are compared to satellite observational data. The atmospheric sea level pressure (SLP) in CSM exhibits a high in the central Arctic displaced poleward from the observed Beaufort high. The Southern Hemisphere SLP over sea ice is generally 5 mb lower than observed. Air temperatures over sea ice in both hemispheres exhibit cold biases of 2--4 K. The precipitation-minus-evaporation fields in both hemispheres are greatly improved over those from earlier versions of the atmospheric GCM.« less

  15. Alterations in nanoparticle protein corona by biological surfactants: impact of bile salts on β-lactoglobulin-coated gold nanoparticles.

    PubMed

    Winuprasith, Thunnalin; Chantarak, Sirinya; Suphantharika, Manop; He, Lili; McClements, David Julian

    2014-07-15

    The impact of biological surfactants (bile salts) on the protein (β-lactoglobulin) corona surrounding gold nanoparticles (200 nm) was studied using a variety of analytical techniques at pH 7: dynamic light scattering (DLS); particle electrophoresis (ζ-potential); UV-visible (UV) spectroscopy; transmission electron microscopy (TEM); and surface-enhanced Raman scattering (SERS). The bile salts adsorbed to the protein-coated nanoparticle surfaces and altered their interfacial composition, charge, and structure. SERS spectra of protein-coated nanoparticles after bile salt addition contained bands from both protein and bile salts, indicating that the protein was not fully displaced by the bile salts. UV, DLS and TEM techniques also indicated that the protein coating was not fully displaced from the nanoparticle surfaces. The impact of bile salts could be described by an orogenic mechanism: mixed interfaces were formed that consisted of islands of aggregated proteins surrounded by a sea of bile salts. This knowledge is useful for understanding the interactions of bile salts with protein-coated colloidal particles, which may be important for controlling the fate of colloidal delivery systems in the human gastrointestinal tract, or the gastrointestinal fate of ingested inorganic nanoparticles. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Nuclear Hybrid Energy System: Molten Salt Energy Storage (Summer Report 2013)

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

    Sabharwall, Piyush; mckellar, Michael George; Yoon, Su-Jong

    2013-11-01

    Effective energy use is a main focus and concern in the world today because of the growing demand for energy. The nuclear hybrid energy system (NHES) is a valuable technical concept that can potentially diversify and leverage existing energy technologies. This report considers a particular NHES design that combines multiple energy systems including a nuclear reactor, energy storage system (ESS), variable renewable generator (VRG), and additional process heat applications. Energy storage is an essential component of this particular NHES because its design allows the system to produce peak power while the nuclear reactor operates at constant power output. Many energymore » storage options are available, but this study mainly focuses on a molten salt ESS. The primary purpose of the molten salt ESS is to enable the nuclear reactor to be a purely constant heat source by acting as a heat storage component for the reactor during times of low demand, and providing additional capacity for thermo-electric power generation during times of peak electricity demand. This report will describe the rationale behind using a molten salt ESS and identify an efficient molten salt ESS configuration that may be used in load following power applications. Several criteria are considered for effective energy storage and are used to identify the most effective ESS within the NHES. Different types of energy storage are briefly described with their advantages and disadvantages. The general analysis to determine the most efficient molten salt ESS involves two parts: thermodynamic, in which energetic and exergetic efficiencies are considered; and economic. Within the molten salt ESS, the two-part analysis covers three major system elements: molten salt ESS designs (two tank direct and thermocline), the molten salt choice, and the different power cycles coupled with the molten salt ESS. Analysis models are formulated and analyzed to determine the most effective ESS. The results show that the

  17. Sea sand disruption method (SSDM) as a valuable tool for isolating essential oil components from conifers.

    PubMed

    Dawidowicz, Andrzej L; Czapczyńska, Natalia B

    2011-11-01

    Essential oils are one of nature's most precious gifts with surprisingly potent and outstanding properties. Coniferous oils, for instance, are nowadays being used extensively to treat or prevent many types of infections, modify immune responses, soothe inflammations, stabilize moods, and to help ease all forms of non-acute pain. Given the broad spectrum of usage of coniferous essential oils, a fast, safe, simple, and efficient sample-preparation method is needed in the estimation procedure of essential oil components in fresh plant material. Generally, the time- and energy-consuming steam distillation (SD) is applied for this purpose. This paper will compare SD, pressurized liquid extraction (PLE), matrix solid-phase dispersion (MSPD), and the sea sand disruption method (SSDM) as isolation techniques to obtain aroma components from Scots pine (Pinus sylvestris), spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii). According to the obtained data, SSDM is the most efficient sample preparation method in determining the essential oil composition of conifers. Moreover, SSDM requires small organic solvent amounts and a short extraction time, which makes it an advantageous alternative procedure for the routine analysis of coniferous oils. The superiority of SSDM over MSPD efficiency is ascertained, as there are no chemical interactions between the plant cell components and the sand. This fact confirms the reliability and efficacy of SSDM for the analysis of volatile oil components. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  18. Hydrodynamic Restoration to Vulnerable Marsh Ecosystems to Improve Response to Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Orescanin, M. M.; Hamilton, R. P., Jr.

    2016-12-01

    Rising sea levels pose imminent threats to low-lying marsh ecosystems owing to delicate balances between water levels, salinity, and sediment transport. Further complications arise from human modifications to these low-lying coastal areas that modify topography, thus altering tidal exchanges. The Milford Neck Conservation Area, near Milford, DE, is a salt marsh system on Delaware Bay that has undergone morphological modifications owing to both human activity and natural processes resulting in damage to the surrounding marsh habitats. A century-old abandoned canal acted as a physical barrier to any tidal exchange for upland marsh for decades, allowing land at low elevations to be dry and used for agricultural activities. However, a breach to the system in the 1980s created a link to Delaware Bay that flooded salt hay fields, creating a large area of open water. Owing to tidal restrictions in the system, it has been difficult to transport sufficient sediment and water into the system to promote natural marsh growth. At the same time, the eroding barrier beach increases vulnerability to sea level rise and storms of increasing severity and frequency, and places upland forest at risk of episodic salt intrusion. To increase the effectiveness of this area as a barrier to sea level rise, it is necessary to increase marsh resiliency. Hydrodynamic measurements collected during fall 2015 and spring/summer 2016 show tidal choking in the system that limits exchange of salt water from Delaware Bay and prevents drainage from storm runoff. Numerical model results using the hydrodynamic model, CMS-flow, confirm tidal choking in this system and suggest localized areas are responsible for the most significant reduction in tidal exchange between the marsh and Delaware Bay. Analysis of hypsometry of the area combined with potential for improving tidal flushing suggest the possibility of restoring close to 400 acres of open water and damaged marsh.

  19. Middle to Late Holocene Fluctuations of C3 and C4 Vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine

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

    Johnson, B J; Moore, K A; Lehmann, C

    2006-05-26

    A 3.1 meter sediment core was analyzed for stable carbon isotope composition of organic matter and higher plant leaf wax (HPLW) lipid biomarkers to determine Holocene shifts in C{sub 3} (higher high marsh) and C{sub 4} (low and/or high marsh) plant deposition at the Sprague River Salt Marsh, Phippsburg, Maine. The carbon isotope composition of the bulk sediment and the HPLW parallel each other throughout most of the core, suggesting that terrestrial plants are an important source of organic matter to the sediments, and diagenetic alteration of the bulk sediments is minimal. The current salt marsh began to form 2500more » cal yr BP. Low and/or high C{sub 4} marsh plants dominated deposition at 2000 cal yr BP, 700 cal yr BP, and for the last 200 cal yr BP. Expansion of higher high marsh C{sub 3} plants occurred at 1300 and 600 cal yr BP. These major vegetation shifts result from a combination of changes in relative sea-level rise and sediment accumulation rates. Average annual carbon sequestration rates for the last 2500 years approximate 40 g C yr{sup -1} m{sup -2}, and are in strong agreement with other values published for the Gulf of Maine. Given that Maine salt marshes cover an area of {approx}79 km{sup 2}, they represent an important component of the terrestrial carbon sink. More detailed isotopic and age records from a network of sediment cores at Sprague Marsh are needed to truly evaluate the long term changes in salt marsh plant communities and the impact of more recent human activity, including global warming, on salt marsh vegetation.« less

  20. Long Term Analysis of Deformations in Salt Mines: Kłodawa Salt Mine Case Study, Central Poland

    NASA Astrophysics Data System (ADS)

    Cała, Marek; Tajduś, Antoni; Andrusikiewicz, Wacław; Kowalski, Michał; Kolano, Malwina; Stopkowicz, Agnieszka; Cyran, Katarzyna; Jakóbczyk, Joanna

    2017-09-01

    Located in central Poland, the Kłodawa salt dome is 26 km long and about 2 km wide. Exploitation of the dome started in 1956, currently rock salt extraction is carried out in 7 mining fields and the 12 mining levels at the depth from 322 to 625 meters below sea level (m.b.s.l.). It is planned to maintain the mining activity till 2052 and extend rock salt extraction to deeper levels. The dome is characterised by complex geological structure resulted from halokinetic and tectonic processes. Projection of the 3D numerical analysis took into account the following factors: mine working distribution within the Kłodawa mine (about 1000 rooms, 350 km of galleries), complex geological structure of the salt dome, complicated structure and geometry of mine workings and distinction in rocks mechanical properties e.g. rock salt and anhydrite. Analysis of past mine workings deformation and prediction of future rock mass behaviour was divided into four stages: building of the 3D model (state of mine workings in year 2014), model extension of the future mine workings planned for extraction in years 2015-2052, the 3D model calibration and stability analysis of all mine workings. The 3D numerical model of Kłodawa salt mine included extracted and planned mine workings in 7 mining fields and 14 mining levels (about 2000 mine workings). The dimensions of the model were 4200 m × 4700 m × 1200 m what was simulated by 33 million elements. The 3D model was calibrated on the grounds of convergence measurements and laboratory tests. Stability assessment of mine workings was based on analysis of the strength/stress ratio and vertical stress. The strength/stress ratio analysis enabled to indicate endangered area in mine workings and can be defined as the factor of safety. Mine workings in state close to collapse are indicated by the strength/stress ratio equals 1. Analysis of the vertical stress in mine workings produced the estimation of current state of stress in comparison to initial

  1. SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component

    NASA Astrophysics Data System (ADS)

    Hryniewicz, K.; Czerny, B.; Pych, W.; Udalski, A.; Krupa, M.; Świȩtoń, A.; Kaluzny, J.

    2014-02-01

    Context. The Mg II line is of extreme importance in intermediate redshift quasars since it allows us to measure the black hole mass in these sources and to use these sources as probes of the distribution of dark energy in the Universe, as a complementary tool to SN Ia. Aims: Reliable use of Mg II requires a good understanding of all the systematic effects involved in the measurement of the line properties, including the contamination by Fe II UV emission. Methods: We performed three spectroscopic observations of a quasar LBQS 2113-4538 (z = 0.956) with the SALT telescope, separated in time by several months and we analyze in detail the mean spectrum and the variability in the spectral shape. Results: We show that even in our good-quality spectra the Mg II doublet is well fit by a single Lorentzian shape. We tested several models of the Fe II pseudo-continuum and showed that one of them well represents all the data. The amplitudes of both components vary in time, but the shapes do not change significantly. The measured line width of LBQS 2113-4538 identifies this object as a class A quasar. The upper limit of 3% for the contribution of the narrow line region (NLR) to Mg II may suggest that the separation of the broad line region and NLR disappears in this class of objects. Based on observations made with the Southern African Large Telescope (SALT) under program 2012-1-POL-008 (PI: Czerny).Fe II template shown in Fig. 8 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/562/A34

  2. Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: molecular dynamics simulations of oil alkanes and dispersants in atmospheric air/salt water interfaces.

    PubMed

    Liyana-Arachchi, Thilanga P; Zhang, Zenghui; Ehrenhauser, Franz S; Avij, Paria; Valsaraj, Kalliat T; Hung, Francisco R

    2014-01-01

    Potential of mean force (PMF) calculations and molecular dynamics (MD) simulations were performed to investigate the properties of oil n-alkanes [i.e., n-pentadecane (C15), n-icosane (C20) and n-triacontane (C30)], as well as several surfactant species [i.e., the standard anionic surfactant sodium dodecyl sulfate (SDS), and three model dispersants similar to the Tween and Span species present in Corexit 9500A] at air/salt water interfaces. This study was motivated by the 2010 Deepwater Horizon (DWH) oil spill, and our simulation results show that, from the thermodynamic point of view, the n-alkanes and the model dispersants have a strong preference to remain at the air/salt water interface, as indicated by the presence of deep free energy minima at these interfaces. The free energy minimum of these n-alkanes becomes deeper as their chain length increases, and as the concentration of surfactant species at the interface increases. The n-alkanes tend to adopt a flat orientation and form aggregates at the bare air/salt water interface. When this interface is coated with surfactants, the n-alkanes tend to adopt more tilted orientations with respect to the vector normal to the interface. These simulation results are consistent with the experimental findings reported in the accompanying paper [Ehrenhauser et al., Environ. Sci.: Processes Impacts 2013, in press, (DOI: 10.1039/c3em00390f)]. The fact that these long-chain n-alkanes show a strong thermodynamic preference to remain at the air/salt water interfaces, especially if these interfaces are coated with surfactants, makes these species very likely to adsorb at the surface of bubbles or droplets and be ejected to the atmosphere by sea surface processes such as whitecaps (breaking waves) and bubble bursting. Finally, the experimental finding that more oil hydrocarbons are ejected when Corexit 9500A is present in the system is consistent with the deeper free energy minima observed for the n-alkanes at the air/salt water

  3. 21 CFR 100.155 - Salt and iodized salt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Salt and iodized salt. 100.155 Section 100.155 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION GENERAL Specific Administrative Rulings and Decisions § 100.155 Salt and iodized salt. (a) For the purposes of this section, the...

  4. The Nordkapp Basin, Norway: Development of salt and sediment interplays for hydrocarbon exploration

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

    Lerche, I.; Toerudbakken, B.O.

    1996-12-31

    Investigation of a particular salt diapir in the Nordkapp Basin, Barents Sea has revealed the following sequence of events: (1) salt started to rise when approximately 1.5 {+-} 0.3 km of sedimentary cover was present (Carboniferous/Permian time); (2) salt reached the sediment surface when about 3.5 {+-} 0.7 km of sediment had been deposited (Triassic time); (3) the mushroom cap on the salt stock top developed over a period of about 75--100 Ma (i.e. during the time when about another km of sediment had been deposited) (Triassic through Base Cretaceous time); (4) the mushroom cap started to dip down significantlymore » ({approximately}1 km) into the sediments around Cretaceous to Tertiary erosion time; (5) oil generation started in the deep sediments of the Carboniferous around the time that salt reached the surface (Triassic time) and continues to the present day at sedimentary depths between about 4 to 7 km (currently Triassic and deeper sediments); (6)gas generation started around mushroom cap development time and continues to the present day at sedimentary depths greater than about 6--7 km (Permian/Carboniferous); (7) the salt stock is currently 3--4 km wide, considerably less than the mushroom cap which is 9 km wide and 1 km thick. The relative timing of mushroom cap development, bed upturning, and hydrocarbon generation makes the salt diapir an attractive exploration target, with suggested reservoir trapping under the downturned mushroom cap on the deep basin side of the salt. In addition, rough estimates of rim syncline fill suggest the basin had an original salt thickness of 2.4--3.3 km, depending upon the amount of salt removed at the Tertiary erosion event.« less

  5. Sea level budget in the Arctic during the satellite altimetry era

    NASA Astrophysics Data System (ADS)

    Carret, Alice; Cazenave, Anny; Meyssignac, Benoît; Prandi, Pierre; Ablain, Michael; Andersen, Ole; Blazquez, Alejandro

    2016-04-01

    Studying sea level variations in the Arctic region is challenging because of data scarcity. Here we present results of the sea level budget in the Arctic (up to 82°N) during the altimetry era. We first investigate closure of the sea level budget since 2002 using altimetry data from Envisat and Cryosat for estimating sea level, temperature and salinity data from the ORAP5 reanalysis and GRACE space gravimetry to estimate the steric and mass components. Two altimetry sea level data sets are considered (from DTU and CLS), based on Envisat waveforms retracking. Regional sea level trends seen in the altimetric map, in particular over the Beaufort Gyre and along the eastern coast of Greenland are of steric origin. However, in terms of regional average, the steric component contributes very little to the observed sea level trend, suggesting a dominant mass contribution in the Arctic region. This is confirmed by GRACE-based ocean mass time series that agree very well with the altimetry-based sea level time series. Direct estimate of the mass component is not possible prior to GRACE. Thus we estimated the mass contribution over the whole altimetry era from the difference between altimetry-based sea level and the ORAP5 steric component. Finally we compared altimetry-based coastal sea level with tide gauge records available along Norwegian, Greenland and Siberian coastlines and investigated whether the Arctic Oscillation that was the main driver of coastal sea level in the Arctic during the past decades still plays a dominant role or if other factors (e.g., of anthropogenic origin) become detectable.

  6. Diclofenac salts. III. Alkaline and earth alkaline salts.

    PubMed

    Fini, Adamo; Fazio, Giuseppe; Rosetti, Francesca; Angeles Holgado, M; Iruín, Ana; Alvarez-Fuentes, Josefa

    2005-11-01

    Diclofenac salts containing the alkaline and two earth alkaline cations have been prepared and characterized by scanning electron microscopy (SEM) and EDAX spectroscopy; and by thermal and thermogravimetric analysis (TGA): all of them crystallize as hydrate when precipitated from water. The salts dehydrate at room temperature and more easily on heating, but recovery the hydration, when placed in a humid environment. X-ray diffraction spectra suggest that on dehydration new peaks appear on diffractograms and the lattice of the salts partially looses crystallinity. This phenomenon is readily visible in the case of the calcium and magnesium salts, whose thermograms display a crystallization exotherm, before melting or decomposing at temperatures near or above 200 degrees C; these last salts appear to form solvates, when prepared from methanol. The thermogram of each salt shows a complex endotherm of dehydration about 100 degrees C; the calcium salt displays two endotherms, well separated at about 120 and 160 degrees C, which disappear after prolonged heating. Decomposition exotherms, before or soon after the melting, appear below 300 degrees C. The ammonium salt is thermally unstable and, when heated to start dehydration, dissociates and leaves acidic diclofenac.

  7. Inorganic salts interact with oxalic acid in submicron particles to form material with low hygroscopicity and volatility

    NASA Astrophysics Data System (ADS)

    Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.

    2014-05-01

    Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. While the hygroscopicities of pure salts, di-carboxylic acids (DCA), and DCA salts are known, the hygroscopicity of internal mixtures of these components, as they are typically found in the atmosphere, has not been fully characterized. Here we show that inorganic-organic component interactions typically not considered in atmospheric models can lead to very strongly bound metal-organic complexes and greatly affect aerosol volatility and hygroscopicity; in particular, the bi-dentate binding of DCA to soluble inorganic ions. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the cloud condensation nuclei (CCN) activation diameter for particles with di-valent salts (e.g., CaCl2) and relatively small particle volume fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O : C ratios are capable of forming low-volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low-particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles without the need for a phase transition.

  8. A Late Pleistocene sea level stack

    NASA Astrophysics Data System (ADS)

    Spratt, Rachel M.; Lisiecki, Lorraine E.

    2016-04-01

    Late Pleistocene sea level has been reconstructed from ocean sediment core data using a wide variety of proxies and models. However, the accuracy of individual reconstructions is limited by measurement error, local variations in salinity and temperature, and assumptions particular to each technique. Here we present a sea level stack (average) which increases the signal-to-noise ratio of individual reconstructions. Specifically, we perform principal component analysis (PCA) on seven records from 0 to 430 ka and five records from 0 to 798 ka. The first principal component, which we use as the stack, describes ˜ 80 % of the variance in the data and is similar using either five or seven records. After scaling the stack based on Holocene and Last Glacial Maximum (LGM) sea level estimates, the stack agrees to within 5 m with isostatically adjusted coral sea level estimates for Marine Isotope Stages 5e and 11 (125 and 400 ka, respectively). Bootstrapping and random sampling yield mean uncertainty estimates of 9-12 m (1σ) for the scaled stack. Sea level change accounts for about 45 % of the total orbital-band variance in benthic δ18O, compared to a 65 % contribution during the LGM-to-Holocene transition. Additionally, the second and third principal components of our analyses reflect differences between proxy records associated with spatial variations in the δ18O of seawater.

  9. Modeling brine and nutrient dynamics in Antarctic sea ice: the case of dissolved silica

    NASA Astrophysics Data System (ADS)

    Vancoppenolle, M.; Goosse, H.; de Montety, A.; Fichefet, T.; Tremblay, B.; Tison, J.

    2009-12-01

    Sea ice ecosystems are characterized by micro-algae living in brine inclusions. The growth rate of ice algae depends on light and nutrient supply. Here, the interactions between nutrients and brine dynamics under the influence of algae are investigated using a one-dimensional model. The model includes snow and ice thermodynamics with brine physics and an idealized sea ice biological component, characterized by one nutrient, namely dissolved silica (DSi). In the model, DSi follows brine motion and is consumed by ice algae. Depending on physical ice characteristics, the brine flow is either advective, diffusive or turbulent. The vertical profiles of ice salinity and DSi concentration are solutions of advection-diffusion equations. The model is configured to simulate the typical thermodynamic regimes of first-year Antarctic pack ice. The simulated vertical profiles of salinity and DSi qualitatively reproduce observations. Analysis of results highlights the role of convection in the lowermost 5-10 cm of ice. Convection mixes saline, nutrient-poor brine with comparatively fresh, nutrient-rich seawater. This implies a rejection of salt to the ocean and a flux of DSi to the ice. In presence of growing algae, the simulated ocean-to-ice DSi flux increases by 0-115% compared to an abiotic situation. In turn, primary production and brine convection act in synergy to form a nutrient pump. The other important processes are the flooding of the surface by seawater and the percolation of meltwater. The former refills nutrients near the ice surface in spring. The latter, if present, tends to expell nutrients from the ice in summer. Sketch of salt (left) and nutrient (right) exchanges at the ice-ocean interface proposed in this paper.

  10. 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.

  11. Salt tolerant green crop species for sodium management in space agriculture

    NASA Astrophysics Data System (ADS)

    Yamashita, Masamichi; Hashimoto, Hirofumi; Tomita-Yokotani, Kaori; Shimoda, Toshifumi; Nose, Akihiro; Space Agriculture Task Force, J.

    Ecological system and materials recycling loop of space agriculture are quite tight compared to natural ecological system on Earth. Sodium management will be a keen issue for space agricul-ture. Human nutritional requirements include sodium salt. Since sodium at high concentration is toxic for most of plant growth, excreted sodium of human waste should be removed from compost fertilizer. Use of marine algae is promising for harvesting potassium and other min-erals required for plant growth and returning remained sodium to satisfy human need of its intake. Farming salt tolerant green crop species is another approach to manage sodium problem in both space and terrestrial agriculture. We chose ice plant and New Zealand spinach. These two plant species are widely accepted green vegetable with many recipe. Ice plant can grow at the salinity level of sea water, and contain sodium salt up to 30% of its dry mass. Sodium distributes mainly in its bladder cells. New Zealand spinach is a plant species found in the front zone of sea shore, and tolerant against high salinity as well. Plant body size of both species at harvest is quite large, and easy to farm. Capability of bio-remediation of high saline soil is examined with ice plant and New Zealand spinach. Incubation medium was chosen to contain high concentration of sodium and potassium at the Na/K ratio of human excreta. In case Na/K ratio of plant body grown by this medium is greatly higher than that of incubation medium or soil, these halophytes are effective to remediate soil for farming less tolerant plant crop. Experimental results was less positive in this context.

  12. Solid tags for identifying failed reactor components

    DOEpatents

    Bunch, Wilbur L.; Schenter, Robert E.

    1987-01-01

    A solid tag material which generates stable detectable, identifiable, and measurable isotopic gases on exposure to a neutron flux to be placed in a nuclear reactor component, particularly a fuel element, in order to identify the reactor component in event of its failure. Several tag materials consisting of salts which generate a multiplicity of gaseous isotopes in predetermined ratios are used to identify different reactor components.

  13. Exopolymer alteration of physical properties of sea ice and implications for ice habitability and biogeochemistry in a warmer Arctic

    PubMed Central

    Krembs, Christopher; Eicken, Hajo; Deming, Jody W.

    2011-01-01

    The physical properties of Arctic sea ice determine its habitability. Whether ice-dwelling organisms can change those properties has rarely been addressed. Following discovery that sea ice contains an abundance of gelatinous extracellular polymeric substances (EPS), we examined the effects of algal EPS on the microstructure and salt retention of ice grown from saline solutions containing EPS from a culture of the sea-ice diatom, Melosira arctica. We also experimented with xanthan gum and with EPS from a culture of the cold-adapted bacterium Colwellia psychrerythraea strain 34H. Quantitative microscopic analyses of the artificial ice containing Melosira EPS revealed convoluted ice-pore morphologies of high fractal dimension, mimicking features found in EPS-rich coastal sea ice, whereas EPS-free (control) ice featured much simpler pore geometries. A heat-sensitive glycoprotein fraction of Melosira EPS accounted for complex pore morphologies. Although all tested forms of EPS increased bulk ice salinity (by 11–59%) above the controls, ice containing native Melosira EPS retained the most salt. EPS effects on ice and pore microstructure improve sea ice habitability, survivability, and potential for increased primary productivity, even as they may alter the persistence and biogeochemical imprint of sea ice on the surface ocean in a warming climate. PMID:21368216

  14. Exopolymer alteration of physical properties of sea ice and implications for ice habitability and biogeochemistry in a warmer Arctic.

    PubMed

    Krembs, Christopher; Eicken, Hajo; Deming, Jody W

    2011-03-01

    The physical properties of Arctic sea ice determine its habitability. Whether ice-dwelling organisms can change those properties has rarely been addressed. Following discovery that sea ice contains an abundance of gelatinous extracellular polymeric substances (EPS), we examined the effects of algal EPS on the microstructure and salt retention of ice grown from saline solutions containing EPS from a culture of the sea-ice diatom, Melosira arctica. We also experimented with xanthan gum and with EPS from a culture of the cold-adapted bacterium Colwellia psychrerythraea strain 34H. Quantitative microscopic analyses of the artificial ice containing Melosira EPS revealed convoluted ice-pore morphologies of high fractal dimension, mimicking features found in EPS-rich coastal sea ice, whereas EPS-free (control) ice featured much simpler pore geometries. A heat-sensitive glycoprotein fraction of Melosira EPS accounted for complex pore morphologies. Although all tested forms of EPS increased bulk ice salinity (by 11-59%) above the controls, ice containing native Melosira EPS retained the most salt. EPS effects on ice and pore microstructure improve sea ice habitability, survivability, and potential for increased primary productivity, even as they may alter the persistence and biogeochemical imprint of sea ice on the surface ocean in a warming climate.

  15. Precipitation of sparingly soluble salts in packed sandbeds

    NASA Astrophysics Data System (ADS)

    Pavlakou, Efstathia I.; Sygouni, Varvara; Paraskeva, Christakis A.

    2015-04-01

    One of the main problems encountered by the oil extraction industry, is the reduction of the local permeability of the rock formation near the extraction wells because of salt deposition in the pores of the rocks during the injection of brine water to displace the trapped oil ganglia within the oil formations. This phenomenon makes the oil recovery less efficient and under extreme cases the well is abandoned with a large amount of oil entrapped. Several detailed studies have been conducted in the past concerning sand bed consolidation using sparingly soluble salts for varying conditions (e.g. temperature, grain size, sand type, salt concentrations etc) and various salts [1]. Nevertheless, salt precipitation in the rock formation pores under the presence of other miscible or immiscible substances with water has not been investigated in details yet. In the present study, salt (CaCO3) precipitation experiments were performed in small beds packed with sea sand mixed with a low amount of CaCO3 seed grains. The experiments were performed using pure solutions (NaHCO3, CaCl2.2H2O) and solutions mixed with Ethylene Glycol in sand beds. Additionally, precipitation experiments were performed using pure solutions in sand beds saturated with oil phase (n-dodecane) for a wide range of solution supersaturation. During the experiments the ionic strength was kept constant. pH and concentration values of calcium ion of the effluent were measured and the precipitated salt crystals were identified using X-ray Diffraction (XRD) method. At the end of each experiment Scanning Electron Microscope (SEM) was conducted using a sample of the precipitated sand to identify the morphology of the precipitated crystals and their cohesion with sand grains. Acknowledgments This research was partially funded by the European Union (European Social Fund-ESF) and Greek National Funds through the Operational program "Education and Lifelong Learning" under the action Aristeia II (Code No 4420). References

  16. Thermal-hydraulics of internally heated molten salts and application to the Molten Salt Fast Reactor

    NASA Astrophysics Data System (ADS)

    Fiorina, Carlo; Cammi, Antonio; Luzzi, Lelio; Mikityuk, Konstantin; Ninokata, Hisashi; Ricotti, Marco E.

    2014-04-01

    The Molten Salt Reactors (MSR) are an innovative kind of nuclear reactors and are presently considered in the framework of the Generation IV International Forum (GIF-IV) for their promising performances in terms of low resource utilization, waste minimization and enhanced safety. A unique feature of MSRs is that molten fluoride salts play the distinctive role of both fuel (heat source) and coolant. The presence of an internal heat generation perturbs the temperature field and consequences are to be expected on the heat transfer characteristics of the molten salts. In this paper, the problem of heat transfer for internally heated fluids in a straight circular channel is first faced on a theoretical ground. The effect of internal heat generation is demonstrated to be described by a corrective factor applied to traditional correlations for the Nusselt number. It is shown that the corrective factor can be fully characterized by making explicit the dependency on Reynolds and Prandtl numbers. On this basis, a preliminary correlation is proposed for the case of molten fluoride salts by interpolating the results provided by an analytic approach previously developed at the Politecnico di Milano. The experimental facility and the related measuring procedure for testing the proposed correlation are then presented. Finally, the developed correlation is used to carry out a parametric investigation on the effect of internal heat generation on the main out-of-core components of the Molten Salt Fast Reactor (MSFR), the reference circulating-fuel MSR design in the GIF-IV. The volumetric power determines higher temperatures at the channel wall, but the effect is significant only in case of large diameters and/or low velocities.

  17. Hygroscopic behavior of atmospheric aerosols containing nitrate salts and water-soluble organic acids

    NASA Astrophysics Data System (ADS)

    Jing, Bo; Wang, Zhen; Tan, Fang; Guo, Yucong; Tong, Shengrui; Wang, Weigang; Zhang, Yunhong; Ge, Maofa

    2018-04-01

    While nitrate salts have critical impacts on environmental effects of atmospheric aerosols, the effects of coexisting species on hygroscopicity of nitrate salts remain uncertain. The hygroscopic behaviors of nitrate salt aerosols (NH4NO3, NaNO3, Ca(NO3)2) and their internal mixtures with water-soluble organic acids were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA). The nitrate salt / organic acid mixed aerosols exhibit varying phase behavior and hygroscopic growth depending upon the type of components in the particles. Whereas pure nitrate salt particles show continuous water uptake with increasing relative humidity (RH), the deliquescence transition is still observed for ammonium nitrate particles internally mixed with organic acids such as oxalic acid and succinic acid with a high deliquescence point. The hygroscopicity of submicron aerosols containing sodium nitrate and an organic acid is also characterized by continuous growth, indicating that sodium nitrate tends to exist in a liquid-like state under dry conditions. It is observed that in contrast to the pure components, the water uptake is hindered at low and moderate RH for calcium nitrate particles containing malonic acid or phthalic acid, suggesting the potential effects of mass transfer limitation in highly viscous mixed systems. Our findings improve fundamental understanding of the phase behavior and water uptake of nitrate-salt-containing aerosols in the atmospheric environment.

  18. Chemical composition of aerosol, sea fog, and rainwater in the marine boundary layer of the northwestern North Pacific and its marginal seas

    NASA Astrophysics Data System (ADS)

    Sasakawa, Motoki; Uematsu, Mitsuo

    2002-12-01

    Samples of aerosol, sea fog, and rainwater were collected during a research cruise in the northwestern North Pacific, the Sea of Okhotsk, and the Sea of Japan in the summer of 1998. High concentrations of NO3-, nss-SO42- and NH4+ in aerosol over the Sea of Japan suggest that anthropogenic substances were transported to this region. Although the Sea of Okhotsk was covered with a clean marine air mass, the concentration of nss-SO42- was comparatively high in the aerosol samples. This nss-SO42- is probably of marine biogenic origin. The pH values of fogwater samples were measured to be <3.0 over the Sea of Okhotsk and the Sea of Japan. The concentrations of NO3- and NH4+ in the fogwater collected over the Sea of Japan were higher than those in the other regions, suggesting that the sea fog scavenged anthropogenic substances. The concentration of nss-SO42- in fogwater over the Sea of Okhotsk was equivalent to that over the Sea of Japan, probably because nss-SO42- and SO2 of marine biogenic origin were scavenged by the sea fog over the Sea of Okhotsk. The pH values of rainwater samples ranged from 6.1 to 7.2 during the cruise, and acidification of the rain was not significant. The concentrations of nss-Ca2+ in the rainwater were higher than those of the fogwater. This suggests that the rain-scavenged continental CaCO3 may have existed above the lower marine boundary layer, where sea fog appeared. Comparisons of the composition of aerosol and fogwater indicated that coarse particles, such as sea salts predominantly act as condensation nuclei of sea fog droplets rather than fine particles such as (NH4)2SO4.

  19. The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

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

    Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.

    Covering 71% of the Earth’s surface, oceans represent a significant global source of atmospheric aerosols. The size and composition of sea spray aerosols (SSA) affect their ability to serve as cloud seeds and thus understanding the factors controlling their composition is critical to predicting their impact on clouds and climate. SSA particles have been shown to be an external mixture of particles with different compositions. Film and jet drop production mechanisms ultimately determine the individual particle compositions which are comprised of an array of salt/organic mixtures ranging from pure sea salt to nearly pure organic particles. It is often assumedmore » that the majority of submicron SSA are formed by film drops produced from bursting hydrophobic organic-rich bubble film caps at the sea surface, and in contrast, jet drops are postulated to produce larger supermicron particles from underlying seawater comprised largely of salts and water soluble organic species. However, here we show that jet drops produced by bursting sub-100 m bubbles account for up to 40 % of all submicron particles. They have distinct chemical compositions, organic volume fractions and ice nucleating activities from submicron film drops. Thus a substantial fraction of submicron particles will not necessarily be controlled by the composition of the sea surface microlayer as has been assumed in many studies. This finding has significant ramifications for the size-resolved mixing states of SSA particles which must be taken into consideration when accessing SSA impacts on clouds.« less

  20. The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

    DOE PAGES

    Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.; ...

    2017-06-19

    Covering 71% of the Earth’s surface, oceans represent a significant global source of atmospheric aerosols. The size and composition of sea spray aerosols (SSA) affect their ability to serve as cloud seeds and thus understanding the factors controlling their composition is critical to predicting their impact on clouds and climate. SSA particles have been shown to be an external mixture of particles with different compositions. Film and jet drop production mechanisms ultimately determine the individual particle compositions which are comprised of an array of salt/organic mixtures ranging from pure sea salt to nearly pure organic particles. It is often assumedmore » that the majority of submicron SSA are formed by film drops produced from bursting hydrophobic organic-rich bubble film caps at the sea surface, and in contrast, jet drops are postulated to produce larger supermicron particles from underlying seawater comprised largely of salts and water soluble organic species. However, here we show that jet drops produced by bursting sub-100 m bubbles account for up to 40 % of all submicron particles. They have distinct chemical compositions, organic volume fractions and ice nucleating activities from submicron film drops. Thus a substantial fraction of submicron particles will not necessarily be controlled by the composition of the sea surface microlayer as has been assumed in many studies. This finding has significant ramifications for the size-resolved mixing states of SSA particles which must be taken into consideration when accessing SSA impacts on clouds.« less

  1. Improving crop salt tolerance.

    PubMed

    Flowers, T J

    2004-02-01

    Salinity is an ever-present threat to crop yields, especially in countries where irrigation is an essential aid to agriculture. Although the tolerance of saline conditions by plants is variable, crop species are generally intolerant of one-third of the concentration of salts found in seawater. Attempts to improve the salt tolerance of crops through conventional breeding programmes have met with very limited success, due to the complexity of the trait: salt tolerance is complex genetically and physiologically. Tolerance often shows the characteristics of a multigenic trait, with quantitative trait loci (QTLs) associated with tolerance identified in barley, citrus, rice, and tomato and with ion transport under saline conditions in barley, citrus and rice. Physiologically salt tolerance is also complex, with halophytes and less tolerant plants showing a wide range of adaptations. Attempts to enhance tolerance have involved conventional breeding programmes, the use of in vitro selection, pooling physiological traits, interspecific hybridization, using halophytes as alternative crops, the use of marker-aided selection, and the use of transgenic plants. It is surprising that, in spite of the complexity of salt tolerance, there are commonly claims in the literature that the transfer of a single or a few genes can increase the tolerance of plants to saline conditions. Evaluation of such claims reveals that, of the 68 papers produced between 1993 and early 2003, only 19 report quantitative estimates of plant growth. Of these, four papers contain quantitative data on the response of transformants and wild-type of six species without and with salinity applied in an appropriate manner. About half of all the papers report data on experiments conducted under conditions where there is little or no transpiration: such experiments may provide insights into components of tolerance, but are not grounds for claims of enhanced tolerance at the whole plant level. Whether enhanced

  2. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use Physical Oceanography Component: Soundscapes Under Sea Ice: Can We Listen for Open Water?

    DTIC Science & Technology

    2013-09-30

    Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use Physical Oceanography Component: Soundscapes Under Sea Ice: Can we listen for... Soundscapes Under Sea Ice: Can we listen for open water? 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...the source. These different sounds can be described as “ soundscapes ”, and graphically represented by comparing two or more features of the sound

  3. Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    The economic growth and population increase in recent A